@article{Quaisser1994, author = {Quaisser, Erhard}, title = {Zw{\"o}lf Punkte auf einer Kugel}, year = {1994}, language = {de} } @masterthesis{Engelhardt2021, type = {Bachelor Thesis}, author = {Engelhardt, Max Angel Ronan}, title = {Zwischen Simulation und Beweis - eine mathematische Analyse des Bienaym{\´e}-Galton-Watson-Prozesses und sein Einsatz innerhalb des Mathematikunterrichts}, doi = {10.25932/publishup-52447}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-524474}, school = {Universit{\"a}t Potsdam}, pages = {117}, year = {2021}, abstract = {Die Bienaym{\´e}-Galton-Watson Prozesse k{\"o}nnen f{\"u}r die Untersuchung von speziellen und sich entwickelnden Populationen verwendet werden. Die Populationen umfassen Individuen, welche sich identisch, zuf{\"a}llig, selbstst{\"a}ndig und unabh{\"a}ngig voneinander fortpflanzen und die jeweils nur eine Generation existieren. Die n-te Generation ergibt sich als zuf{\"a}llige Summe der Individuen der (n-1)-ten Generation. Die Relevanz dieser Prozesse begr{\"u}ndet sich innerhalb der Historie und der inner- und außermathematischen Bedeutung. Die Geschichte der Bienaym{\´e}-Galton-Watson-Prozesse wird anhand der Entwicklung des Konzeptes bis heute dargestellt. Dabei werden die Wissenschaftler:innen verschiedener Disziplinen angef{\"u}hrt, die Erkenntnisse zu dem Themengebiet beigetragen und das Konzept in ihren Fachbereichen angef{\"u}hrt haben. Somit ergibt sich die außermathematische Signifikanz. Des Weiteren erh{\"a}lt man die innermathematische Bedeutsamkeit mittels des Konzeptes der Verzweigungsprozesse, welches auf die Bienaym{\´e}-Galton-Watson Prozesse zur{\"u}ckzuf{\"u}hren ist. Die Verzweigungsprozesse stellen eines der aussagekr{\"a}ftigsten Modelle f{\"u}r die Beschreibung des Populationswachstums dar. Dar{\"u}ber hinaus besteht die derzeitige Wichtigkeit durch die Anwendungsm{\"o}glichkeit der Verzweigungsprozesse und der Bienaym{\´e}-Galton-Watson Prozesse innerhalb der Epidemiologie. Es werden die Ebola- und die Corona-Pandemie als Anwendungsfelder angef{\"u}hrt. Die Prozesse dienen als Entscheidungsst{\"u}tze f{\"u}r die Politik und erm{\"o}glichen Aussagen {\"u}ber die Auswirkungen von Maßnahmen bez{\"u}glich der Pandemien. Neben den Prozessen werden ebenfalls der bedingte Erwartungswert bez{\"u}glich diskreter Zufallsvariablen, die wahrscheinlichkeitserzeugende Funktion und die zuf{\"a}llige Summe eingef{\"u}hrt. Die Konzepte vereinfachen die Beschreibung der Prozesse und bilden somit die Grundlage der Betrachtungen. Außerdem werden die ben{\"o}tigten und weiterf{\"u}hrenden Eigenschaften der grundlegenden Themengebiete und der Prozesse aufgef{\"u}hrt und bewiesen. Das Kapitel erreicht seinen H{\"o}hepunkt bei dem Beweis des Kritikalit{\"a}tstheorems, wodurch eine Aussage {\"u}ber das Aussterben des Prozesses in verschiedenen F{\"a}llen und somit {\"u}ber die Aussterbewahrscheinlichkeit get{\"a}tigt werden kann. Die F{\"a}lle werden anhand der zu erwartenden Anzahl an Nachkommen eines Individuums unterschieden. Es zeigt sich, dass ein Prozess bei einer zu erwartenden Anzahl kleiner gleich Eins mit Sicherheit ausstirbt und bei einer Anzahl gr{\"o}ßer als Eins, die Population nicht in jedem Fall aussterben muss. Danach werden einzelne Beispiele, wie der linear fractional case, die Population von Fibroblasten (Bindegewebszellen) von M{\"a}usen und die Entstehungsfragestellung der Prozesse, angef{\"u}hrt. Diese werden mithilfe der erlangten Ergebnisse untersucht und einige ausgew{\"a}hlte zuf{\"a}llige Dynamiken werden im nachfolgenden Kapitel simuliert. Die Simulationen erfolgen durch ein in Python erstelltes Programm und werden mithilfe der Inversionsmethode realisiert. Die Simulationen stellen beispielhaft die Entwicklungen in den verschiedenen Kritikalit{\"a}tsf{\"a}llen der Prozesse dar. Zudem werden die H{\"a}ufigkeiten der einzelnen Populationsgr{\"o}ßen in Form von Histogrammen angebracht. Dabei l{\"a}sst sich der Unterschied zwischen den einzelnen F{\"a}llen best{\"a}tigen und es wird die Anwendungsm{\"o}glichkeit der Bienaym{\´e}-Galton-Watson Prozesse bei komplexeren Problemen deutlich. Histogramme bekr{\"a}ftigen, dass die einzelnen Populationsgr{\"o}ßen nur endlich oft vorkommen. Diese Aussage wurde von Galton aufgeworfen und in der Extinktions-Explosions-Dichotomie verwendet. Die dargestellten Erkenntnisse {\"u}ber das Themengebiet und die Betrachtung des Konzeptes werden mit einer didaktischen Analyse abgeschlossen. Die Untersuchung beinhaltet die Ber{\"u}cksichtigung der Fundamentalen Ideen, der Fundamentalen Ideen der Stochastik und der Leitidee „Daten und Zufall". Dabei ergibt sich, dass in Abh{\"a}ngigkeit der gew{\"a}hlten Perspektive die Anwendung der Bienaym{\´e}-Galton-Watson Prozesse innerhalb der Schule plausibel ist und von Vorteil f{\"u}r die Sch{\"u}ler:innen sein kann. F{\"u}r die Behandlung wird exemplarisch der Rahmenlehrplan f{\"u}r Berlin und Brandenburg analysiert und mit dem Kernlehrplan Nordrhein-Westfalens verglichen. Die Konzeption des Lehrplans aus Berlin und Brandenburg l{\"a}sst nicht den Schluss zu, dass die Bienaym{\´e}-Galton-Watson Prozesse angewendet werden sollten. Es l{\"a}sst sich feststellen, dass die zugrunde liegende Leitidee nicht vollumf{\"a}nglich mit manchen Fundamentalen Ideen der Stochastik vereinbar ist. Somit w{\"u}rde eine Modifikation hinsichtlich einer st{\"a}rkeren Orientierung des Lehrplans an den Fundamentalen Ideen die Anwendung der Prozesse erm{\"o}glichen. Die Aussage wird durch die Betrachtung und {\"U}bertragung eines nordrhein-westf{\"a}lischen Unterrichtsentwurfes f{\"u}r stochastische Prozesse auf die Bienaym{\´e}-Galton-Watson Prozesse unterst{\"u}tzt. Dar{\"u}ber hinaus werden eine Concept Map und ein Vernetzungspentagraph nach von der Bank konzipiert um diesen Aspekt hervorzuheben.}, language = {de} } @article{Westphal1996, author = {Westphal, Anke}, title = {Zur Wertorientierung in der instrumentalen Leistungsmotivation : glechtsspezifische Aspkte ; eine Studie an Brandenburger Musikschulen}, year = {1996}, language = {de} } @book{MatthesNawrotzki1996, author = {Matthes, Klaus and Nawrotzki, Kurt}, title = {Zur Struktur von Verzweigungsprozessen}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik}, volume = {1996, 02}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik}, publisher = {Univ.}, address = {Potsdam}, pages = {40 S.}, year = {1996}, language = {de} } @article{Jahnke1998, author = {Jahnke, Thomas}, title = {Zur Kritik und Bedeutung der Stoffdidaktik}, year = {1998}, language = {de} } @article{Jahnke2006, author = {Jahnke, Thomas}, title = {Zur Ideologie von PISA und Co}, isbn = {978-388120-428-6}, year = {2006}, language = {de} } @article{Jahnke1995, author = {Jahnke, Thomas}, title = {Zur Erinnerung an Mathematikerinnen und Mathematiker, die im Nationalsozialismus verfolgt wurden}, isbn = {3-88120-264-1}, year = {1995}, language = {de} } @article{Jahnke1995, author = {Jahnke, Thomas}, title = {Zur Bedeutung "des Computers" f{\"u}r den Mathematikunterricht}, year = {1995}, language = {de} } @book{Koehler1996, author = {K{\"o}hler, Torsten}, title = {Zur Antennensteuerung bei der Hyperthermie-Behandlung}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik}, volume = {1996, 12}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik}, publisher = {Univ.}, address = {Potsdam}, year = {1996}, language = {de} } @article{SchmidtBaierBleyeretal.1994, author = {Schmidt, Hans-J{\"u}rgen and Baier, Frank W. and Bleyer, Ulrich and Hubrig, Swetlana and Meister, Claudia-Veronika and Schilbach, Elena and Tiersch, Heinz}, title = {Zum Wissenschaftler-Integrationsprogramm}, year = {1994}, language = {de} } @unpublished{KytmanovMyslivetsTarkhanov2004, author = {Kytmanov, Aleksandr and Myslivets, Simona and Tarkhanov, Nikolai Nikolaevich}, title = {Zeta-function of a nonlinear system}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26795}, year = {2004}, abstract = {Given a system of entire functions in Cn with at most countable set of common zeros, we introduce the concept of zeta-function associated with the system. Under reasonable assumptions on the system, the zeta-function is well defined for all s ∈ Zn with sufficiently large components. Using residue theory we get an integral representation for the zeta-function which allows us to construct an analytic extension of the zeta-function to an infinite cone in Cn.}, language = {en} } @article{FigariTeta2020, author = {Figari, Rodolfo and Teta, Alessandro}, title = {Zero-range hamiltonians for three quantum particles}, series = {Lectures in pure and applied mathematics}, journal = {Lectures in pure and applied mathematics}, number = {6}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-485-2}, issn = {2199-4951}, doi = {10.25932/publishup-47218}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472189}, pages = {175 -- 184}, year = {2020}, language = {en} } @article{Hermann2014, author = {Hermann, Andreas}, title = {Zero sets of eigenspinors for generic metrics}, series = {Communications in analysis and geometry}, volume = {22}, journal = {Communications in analysis and geometry}, number = {2}, publisher = {International Press of Boston}, address = {Somerville}, issn = {1019-8385}, pages = {177 -- 218}, year = {2014}, abstract = {Let M be a closed connected spin manifold of dimension 2 or 3 with a fixed orientation and a fixed spin structure. We prove that for a generic Riemannian metric on M the non-harmonic eigenspinors of the Dirac operator are nowhere zero. The proof is based on a transversality theorem and the unique continuation property of the Dirac operator.}, language = {en} } @misc{Quaisser1992, author = {Quaisser, Erhard}, title = {Zeitler, H., Mathematische Semesterberichte, 39 (1992), S. 163 - 183}, year = {1992}, language = {de} } @misc{Dahl2023, type = {Master Thesis}, author = {Dahl, Dorothee Sophie}, title = {Zahlen in den Fingern}, doi = {10.25932/publishup-60762}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-607629}, school = {Universit{\"a}t Potsdam}, pages = {118}, year = {2023}, abstract = {Die Debatte {\"u}ber den Einsatz von digitalen Werkzeugen in der mathematischen Fr{\"u}hf{\"o}rderung ist hoch aktuell. Lernspiele werden konstruiert, mit dem Ziel, mathematisches, informelles Wissen aufzubauen und so einen besseren Schulstart zu erm{\"o}glichen. Doch allein die digitale und spielerische Aufarbeitung f{\"u}hrt nicht zwingend zu einem Lernerfolg. Daher ist es umso wichtiger, die konkrete Implementation der theoretischen Konstrukte und Interaktionsm{\"o}glichkeiten mit den Werkzeugen zu analysieren und passend aufzubereiten. In dieser Masterarbeit wird dazu exemplarisch ein mathematisches Lernspiel namens „Fingu" f{\"u}r den Einsatz im vorschulischen Bereich theoretisch und empirisch im Rahmen der Artifact-Centric Activity Theory (ACAT) untersucht. Dazu werden zun{\"a}chst die theoretischen Hintergr{\"u}nde zum Zahlensinn, Zahlbegriffserwerb, Teil-Ganze-Verst{\"a}ndnis, der Anzahlwahrnehmung und -bestimmung, den Anzahlvergleichen und der Anzahldarstellung mithilfe von Fingern gem{\"a}ß der Embodied Cognition sowie der Verwendung von digitalen Werkzeugen und Multi-Touch-Ger{\"a}ten umfassend beschrieben. Anschließend wird die App Fingu erkl{\"a}rt und dann theoretisch entlang des ACAT-Review-Guides analysiert. Zuletzt wird die selbstst{\"a}ndig durchgef{\"u}hrte Studie mit zehn Vorschulkindern erl{\"a}utert und darauf aufbauend Verbesserungs- und Entwicklungsm{\"o}glichkeiten der App auf wissenschaftlicher Grundlage beigetragen. F{\"u}r Fingu l{\"a}sst sich abschließend festhalten, dass viele Prozesse wie die (Quasi-)Simultanerfassung oder das Z{\"a}hlen gef{\"o}rdert werden k{\"o}nnen, f{\"u}r andere wie das Teil-Ganze-Verst{\"a}ndnis aber noch Anpassungen und/oder die Begleitung durch Erwachsene n{\"o}tig ist.}, language = {de} } @article{DzhunushalievSchmidt2000, author = {Dzhunushaliev, Vladimir and Schmidt, Hans-J{\"u}rgen}, title = {Wormholes and Flux Tubes in the 7D Gravity on the Principal Bundle with SU(2) Gauge Group as the Extra Dimensions}, year = {2000}, language = {en} } @misc{Quaisser1992, author = {Quaisser, Erhard}, title = {Woodall, D., Geombinatorics, 1 (1992), 4, S. 18 - 20}, year = {1992}, language = {de} } @article{Schrohe1997, author = {Schrohe, Elmar}, title = {Wodzicki{\"i}s noncommutative residue and trace for operator algebras on manifolds with conical singularities}, year = {1997}, language = {en} } @article{Jahnke1996, author = {Jahnke, Thomas}, title = {Wo bleibt das Subversive? : ist die Fachdidaktik ein harmloses Metier?}, year = {1996}, language = {de} } @article{Jahnke1997, author = {Jahnke, Thomas}, title = {Wo bleibt das Subversive?}, isbn = {3-88120-284-6}, year = {1997}, language = {de} } @book{Jahnke1999, author = {Jahnke, Thomas}, title = {Wo bleibt das Subversive?}, year = {1999}, language = {de} } @misc{Schrohe1998, author = {Schrohe, Elmar}, title = {Wloka, J. T. [u.a.], Boundary value problems for eliptic systems}, year = {1998}, language = {en} } @article{YenvonSpechtLinetal.2022, author = {Yen, Ming-Hsuan and von Specht, Sebastian and Lin, Yen-Yu and Cotton, Fabrice and Ma, Kuo-Fong}, title = {Within- and between-event variabilities of strong-velocity pulses of moderate earthquakes within dense seismic arrays}, series = {Bulletin of the Seismological Society of America}, volume = {112}, journal = {Bulletin of the Seismological Society of America}, number = {1}, publisher = {Seismological Society of America}, address = {El Cerito, Calif.}, issn = {0037-1106}, doi = {10.1785/0120200376}, pages = {361 -- 380}, year = {2022}, abstract = {Ground motion with strong-velocity pulses can cause significant damage to buildings and structures at certain periods; hence, knowing the period and velocity amplitude of such pulses is critical for earthquake structural engineering. However, the physical factors relating the scaling of pulse periods with magnitude are poorly understood. In this study, we investigate moderate but damaging earthquakes (M-w 6-7) and characterize ground- motion pulses using the method of Shahi and Baker (2014) while considering the potential static-offset effects. We confirm that the within-event variability of the pulses is large. The identified pulses in this study are mostly from strike-slip-like earthquakes. We further perform simulations using the freq uency-wavenumber algorithm to investigate the causes of the variability of the pulse periods within and between events for moderate strike-slip earthquakes. We test the effect of fault dips, and the impact of the asperity locations and sizes. The simulations reveal that the asperity properties have a high impact on the pulse periods and amplitudes at nearby stations. Our results emphasize the importance of asperity characteristics, in addition to earthquake magnitudes for the occurrence and properties of pulses produced by the forward directivity effect. We finally quantify and discuss within- and between-event variabilities of pulse properties at short distances.}, language = {en} } @article{GrevenSchroeder2018, author = {Greven, Christoph and Schroeder, Ulrik}, title = {Wissenschaftliches Arbeiten lernen}, series = {Commentarii informaticae didacticae}, journal = {Commentarii informaticae didacticae}, number = {10}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416380}, pages = {151 -- 161}, year = {2018}, abstract = {Die Lehre von wissenschaftlichem Arbeiten stellt einen zentralen Aspekt in forschungsorientierten Studieng{\"a}ngen wie der Informatik dar. Trotz diverser Angebote werden mittel- und langfristig M{\"a}ngel in der Arbeitsqualit{\"a}t von Studierenden sichtbar. Dieses Paper analysiert daher das Profil der Studierenden, deren Anwendung des wissenschaftlichen Arbeitens, und das Angebot von Proseminaren zum Thema „Einf{\"u}hrung in das wissenschaftliche Arbeiten" einer deutschen Universit{\"a}t. Die Ergebnisse mehrerer Erhebungen zeigen dabei diverse Probleme bei Studierenden auf, u. a. bei dem Prozessverst{\"a}ndnis, dem Zeitmanagement und der Kommunikation.}, language = {de} } @article{Schmidt1994, author = {Schmidt, Hans-J{\"u}rgen}, title = {WIP-Projekt "Kosmologie"}, year = {1994}, language = {de} } @unpublished{BaerPfaeffle2012, author = {B{\"a}r, Christian and Pf{\"a}ffle, Frank}, title = {Wiener measures on Riemannian manifolds and the Feynman-Kac formula}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59998}, year = {2012}, abstract = {This is an introduction to Wiener measure and the Feynman-Kac formula on general Riemannian manifolds for Riemannian geometers with little or no background in stochastics. We explain the construction of Wiener measure based on the heat kernel in full detail and we prove the Feynman-Kac formula for Schr{\"o}dinger operators with bounded potentials. We also consider normal Riemannian coverings and show that projecting and lifting of paths are inverse operations which respect the Wiener measure.}, language = {en} } @book{Schmidt1994, author = {Schmidt, Hans-J{\"u}rgen}, title = {Why do all the curvature invariants of a gravitational wave vanish?}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik}, volume = {1994, 03}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik}, publisher = {Univ.}, address = {Potsdam}, pages = {7 Bl.}, year = {1994}, language = {en} } @article{Schmidt1996, author = {Schmidt, Hans-J{\"u}rgen}, title = {Why do all the curvature invariants of a gravitational wave vanish?}, year = {1996}, language = {en} } @article{Paycha2018, author = {Paycha, Sylvie}, title = {When the market wins over research and higher education}, series = {Sustainable Futures for Higher Education : the Making of Knowledge Makers}, volume = {7}, journal = {Sustainable Futures for Higher Education : the Making of Knowledge Makers}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-96035-7}, issn = {2364-6799}, doi = {10.1007/978-3-319-96035-7_2}, pages = {23 -- 28}, year = {2018}, abstract = {In this chapter, an overview of systematic eradication of basic science foci in European universities in the last two decades is given. This happens under the slogan of optimisation of the university education to the needs and demands of the society. It is pointed out that reliance on "market demands" brings with it long-term deficiencies in the maintenance of basic and advanced knowledge construction in societies necessary for long-term future technological advances. University policies that claim improvement of higher education towards more immediate efficiency may end up with the opposite effect of affecting its quality and long term expected positive impact on society.}, language = {en} } @article{LykovMalyshev2020, author = {Lykov, Alexander and Malyshev, Vadim}, title = {When bounded chaos becomes unbounded}, series = {Lectures in pure and applied mathematics}, journal = {Lectures in pure and applied mathematics}, number = {6}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-485-2}, issn = {2199-4951}, doi = {10.25932/publishup-47206}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472060}, pages = {97 -- 106}, year = {2020}, language = {en} } @unpublished{ManicciaMughetti2001, author = {Maniccia, L. and Mughetti, M.}, title = {Weyl calculus for a class of subelliptic operators}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26038}, year = {2001}, abstract = {Weyl-H{\"o}rmander calculus is used to get a parametrix in OPS¹-m sub(½, ½)(Ω)for a class of subelliptic pseudodifferential operators in OPS up(m)sub(1, 0)(Ω) with real non-negative principal symbol.}, language = {en} } @book{ManicciaMughetti2001, author = {Maniccia, L. and Mughetti, M.}, title = {Weyl calculus for a class of subelliptic operators}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, publisher = {Univ.}, address = {Potsdam}, issn = {1437-739X}, pages = {15 S.}, year = {2001}, language = {en} } @unpublished{BrauerKarp2008, author = {Brauer, Uwe and Karp, Lavi}, title = {Well-posedness of Einstein-Euler systems in asymptotically flat spacetimes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-30347}, year = {2008}, abstract = {We prove a local in time existence and uniqueness theorem of classical solutions of the coupled Einstein{Euler system, and therefore establish the well posedness of this system. We use the condition that the energy density might vanish or tends to zero at infinity and that the pressure is a certain function of the energy density, conditions which are used to describe simplified stellar models. In order to achieve our goals we are enforced, by the complexity of the problem, to deal with these equations in a new type of weighted Sobolev spaces of fractional order. Beside their construction, we develop tools for PDEs and techniques for hyperbolic and elliptic equations in these spaces. The well posedness is obtained in these spaces.}, language = {en} } @article{RungrottheeraSchulze2014, author = {Rungrottheera, Wannarut and Schulze, Bert-Wolfgang}, title = {Weighted spaces on corner manifolds}, series = {Complex variables and elliptic equations}, volume = {59}, journal = {Complex variables and elliptic equations}, number = {12}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1747-6933}, doi = {10.1080/17476933.2013.876416}, pages = {1706 -- 1738}, year = {2014}, abstract = {We study spaces on manifolds with double weights and iterated discrete and continuous asymptotics, and their relationship with corner pseudo-differential operators.}, language = {en} } @article{Boelling1998, author = {B{\"o}lling, Reinhard}, title = {Weierstraß and some members of his circle : Kovalevskaja, Fuchs, Schwarz, Schottky}, isbn = {3-7643-5943- 9}, year = {1998}, language = {en} } @article{JahnkeWippermann1994, author = {Jahnke, Thomas and Wippermann, Christina}, title = {Weg, Geschwindigkeit und Beschleunigung im Mathematikunterricht}, year = {1994}, language = {de} } @article{GlebovKiselevTarkhanov2010, author = {Glebov, Sergei and Kiselev, Oleg and Tarkhanov, Nikolai Nikolaevich}, title = {Weakly nonlinear dispersive waves under parametric resonance perturbation}, issn = {0022-2526}, doi = {10.1111/j.1467-9590.2009.00460.x}, year = {2010}, abstract = {We consider a solution of the nonlinear Klein-Gordon equation perturbed by a parametric driver. The frequency of parametric perturbation varies slowly and passes through a resonant value, which leads to a solution change. We obtain a new connection formula for the asymptotic solution before and after the resonance.}, language = {en} } @article{Menne2016, author = {Menne, Ulrich}, title = {Weakly Differentiable Functions on Varifolds}, series = {Indiana University mathematics journal}, volume = {65}, journal = {Indiana University mathematics journal}, publisher = {Indiana University, Department of Mathematics}, address = {Bloomington}, issn = {0022-2518}, doi = {10.1512/iumj.2016.65.5829}, pages = {977 -- 1088}, year = {2016}, abstract = {The present paper is intended to provide the basis for the study of weakly differentiable functions on rectifiable varifolds with locally bounded first variation. The concept proposed here is defined by means of integration-by-parts identities for certain compositions with smooth functions. In this class, the idea of zero boundary values is realised using the relative perimeter of superlevel sets. Results include a variety of Sobolev Poincare-type embeddings, embeddings into spaces of continuous and sometimes Holder-continuous functions, and point wise differentiability results both of approximate and integral type as well as coarea formulae. As a prerequisite for this study, decomposition properties of such varifolds and a relative isoperimetric inequality are established. Both involve a concept of distributional boundary of a set introduced for this purpose. As applications, the finiteness of the geodesic distance associated with varifolds with suitable summability of the mean curvature and a characterisation of curvature varifolds are obtained.}, language = {en} } @article{DeneckeLeeratanavalee1999, author = {Denecke, Klaus-Dieter and Leeratanavalee, Sorasak}, title = {Weak hypersubstitutions and weakly derived algebras}, year = {1999}, language = {en} } @phdthesis{Leeratanavalee2002, author = {Leeratanavalee, Sorasak}, title = {Weak Hypersubstitutions}, pages = {105 S.}, year = {2002}, language = {en} } @unpublished{AlsaedyTarkhanov2015, author = {Alsaedy, Ammar and Tarkhanov, Nikolai Nikolaevich}, title = {Weak boundary values of solutions of Lagrangian problems}, volume = {4}, number = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {2193-6943}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72617}, pages = {24}, year = {2015}, abstract = {We define weak boundary values of solutions to those nonlinear differential equations which appear as Euler-Lagrange equations of variational problems. As a result we initiate the theory of Lagrangian boundary value problems in spaces of appropriate smoothness. We also analyse if the concept of mapping degree of current importance applies to the study of Lagrangian problems.}, language = {en} } @article{LouisMaassRiederetal.1994, author = {Louis, Alfred K. and Maaß, Peter and Rieder, Andreas and Stark, H.-G.}, title = {Wavelets and digital image processing}, year = {1994}, language = {en} } @book{LouisMaassRieder1998, author = {Louis, Alfred K. and Maaß, Peter and Rieder, Andreas}, title = {Wavelets : Theorie und Anwendungen}, publisher = {Vieweg+Teubner Verlag}, address = {Wiesbaden}, isbn = {3-519-12094-1}, doi = {10.1007/978-3-322-80136-4}, pages = {330 S.}, year = {1998}, language = {de} } @book{LouisMaassRieder1994, author = {Louis, Alfred K. and Maaß, Peter and Rieder, Andreas}, title = {Wavelets : Theorie und Anwendungen}, publisher = {Teubner}, address = {Stuttgart}, pages = {315 S.}, year = {1994}, language = {de} } @article{HaynPanetDiamentetal.2012, author = {Hayn, Michael and Panet, I. and Diament, M. and Holschneider, Matthias and Mandea, Mioara and Davaille, A.}, title = {Wavelet-based directional analysis of the gravity field evidence for large-scale undulations}, series = {Geophysical journal international}, volume = {189}, journal = {Geophysical journal international}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0956-540X}, doi = {10.1111/j.1365-246X.2012.05455.x}, pages = {1430 -- 1456}, year = {2012}, abstract = {In the eighties, the analysis of satellite altimetry data leads to the major discovery of gravity lineations in the oceans, with wavelengths between 200 and 1400 km. While the existence of the 200 km scale undulations is widely accepted, undulations at scales larger than 400 km are still a matter of debate. In this paper, we revisit the topic of the large-scale geoid undulations over the oceans in the light of the satellite gravity data provided by the GRACE mission, considerably more precise than the altimetry data at wavelengths larger than 400 km. First, we develop a dedicated method of directional Poisson wavelet analysis on the sphere with significance testing, in order to detect and characterize directional structures in geophysical data on the sphere at different spatial scales. This method is particularly well suited for potential field analysis. We validate it on a series of synthetic tests, and then apply it to analyze recent gravity models, as well as a bathymetry data set independent from gravity. Our analysis confirms the existence of gravity undulations at large scale in the oceans, with characteristic scales between 600 and 2000 km. Their direction correlates well with present-day plate motion over the Pacific ocean, where they are particularly clear, and associated with a conjugate direction at 1500 km scale. A major finding is that the 2000 km scale geoid undulations dominate and had never been so clearly observed previously. This is due to the great precision of GRACE data at those wavelengths. Given the large scale of these undulations, they are most likely related to mantle processes. Taking into account observations and models from other geophysical information, as seismological tomography, convection and geochemical models and electrical conductivity in the mantle, we conceive that all these inputs indicate a directional fabric of the mantle flows at depth, reflecting how the history of subduction influences the organization of lower mantle upwellings.}, language = {en} } @article{Maass1994, author = {Maaß, Peter}, title = {Wavelet galerkin methods for inverse problems}, year = {1994}, language = {en} } @phdthesis{Hayn2010, author = {Hayn, Michael}, title = {Wavelet analysis and spline modeling of geophysical data on the sphere}, address = {Potsdam}, pages = {95 S. : graph. Darst.}, year = {2010}, language = {en} } @article{MaassRamlau1996, author = {Maaß, Peter and Ramlau, Ronny}, title = {Wavelet accelerated iteration methods for hyperthermia treatment planning}, year = {1996}, language = {en} } @book{BaerGinouxPfaeffle2007, author = {B{\"a}r, Christian and Ginoux, Nicolas and Pf{\"a}ffle, Frank}, title = {Wave equations on lorentzian manifolds and quantization}, publisher = {European Math. Society}, address = {Z{\"u}rich}, isbn = {978-3-03719-037-1}, pages = {194 S.}, year = {2007}, language = {en} } @phdthesis{Meyerhoefer2003, author = {Meyerh{\"o}fer, Wolfram}, title = {Was testen Tests? Objektiv-hermeneutische Analysen am Beispiel von TIMSS und PISA}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12848}, school = {Universit{\"a}t Potsdam}, year = {2003}, abstract = {Als ich anfing, ein Thema f{\"u}r meine Promotion zu erarbeiten, fand ich Massentests ziemlich beeindruckend. TIMSS: {\"u}ber 500000 Sch{\"u}ler getestet. PISA: 180000 Sch{\"u}ler getestet. Ich wollte diese Datenbasis nutzen, um Erkenntnisse f{\"u}r die Gestaltung von Unterricht zu gewinnen. Leider kam ich damit nicht weit. Je tiefer ich mich mit den Tests und den dahinterstehenden Theorien befasste, desto deutlicher sch{\"a}lte sich heraus, dass mit diesen Tests keine neue Erkenntnis generiert werden kann. Fast alle Schlussfolgerungen, die aus den Tests gezogen werden, konnten gar nicht aus den Tests selbst gewonnen werden. Ich konzentrierte mich zunehmend auf die Testaufgaben, weil die Geltung der Aussage eines Tests an der Aufgabe erzeugt wird: In der Aufgabe gerinnt das, was die Tester als „mathematische Leistungsf{\"a}higkeit" konstruieren. Der Sch{\"u}ler wiederum hat nur die Aufgabe vor sich. Es gibt nur „gel{\"o}st" (ein Punkt) und „ungel{\"o}st" (kein Punkt). Damit der Sch{\"u}ler den Punkt bekommt, muss er an der richtigen Stelle ankreuzen, oder er muss etwas hinschrei-ben, wof{\"u}r der Auswerter einen Punkt gibt. In der Dissertation wird untersucht, was die Aufgaben testen, was also alles in das Konstrukt von „mathematischer Leistungsf{\"a}higkeit" einfließt, und ob es das ist, was der Test testen soll. Es stellte sich durchaus erstaunliches heraus: - Oftmals gibt es so viele M{\"o}glichkeiten, zur gew{\"u}nschten L{\"o}sung (die nicht in jedem Fall die richtige L{\"o}sung ist) zu gelangen, dass man nicht benennen kann, welche F{\"a}higkeit die Aufgabe eigentlich misst. Das Konstrukt „mathematische Leistungsf{\"a}higkeit" wird damit zu einem zuf{\"a}lligen. - Es werden Komponenten von Testf{\"a}higkeit mitgemessen: Viele Aufgaben enthalten Irritationen, welche von testerfahrenen Sch{\"u}lern leichter {\"u}berwunden werden k{\"o}nnen als von testunerfahrenen. Es gibt Aufgaben, die gel{\"o}st werden k{\"o}nnen, ohne dass man {\"u}ber die F{\"a}higkeit verf{\"u}gt, die getestet werden soll. Umgekehrt gibt es Aufgaben, die man eventuell nicht l{\"o}sen kann, obwohl man {\"u}ber diese F{\"a}higkeit verf{\"u}gt. Als Kernkompetenz von Testf{\"a}higkeit stellt sich heraus, weder das gestellte mathematische Problem noch die angeblichen realen Proble-me ernst zu nehmen, sondern sich statt dessen auf das zu konzentrieren, was die Tester angekreuzt oder hinge-schrieben sehen wollen. Prinzipiell erweist es sich als g{\"u}nstig, mittelm{\"a}ßig zu arbeiten, auf intellektuelle Tiefe in der Auseinandersetzung mit den Aufgaben also zu verzichten. - Man kann bei Multiple-Choice-Tests raten. Die PISA-Gruppe behauptet zwar, dieses Problem technisch {\"u}ber-winden zu k{\"o}nnen, dies erweist sich aber als Fehleinsch{\"a}tzung. - Sowohl bei TIMSS als auch bei PISA stellt sich heraus, dass die vorgeblich verwendeten didaktischen und psychologischen Theorien lediglich theoretische M{\"a}ntel f{\"u}r eine theoriearme Testerstellung sind. Am Beispiel der Theorie der mentalen Situationsmodelle (zur Bearbeitung von realit{\"a}tsnahen Aufgaben) wird dies ausf{\"u}hrlich exemplarisch ausgearbeitet. Das Problem reproduziert sich in anderen Theoriefeldern. Die Tests werden nicht durch Operationalisierungen von Messkonstrukten erstellt, sondern durch systematisches Zusammenst{\"u}ckeln von Aufgaben. - Bei PISA sollte „Mathematical Literacy" getestet werden. Verk{\"u}rzt sollte das die F{\"a}higkeit sein, „die Rolle, die Mathematik in der Welt spielt, zu erkennen und zu verstehen, begr{\"u}ndete mathematische Urteile abzugeben und sich auf eine Weise mit der Mathematik zu befassen, die den Anforderungen des gegenw{\"a}rtigen und k{\"u}nftigen Lebens einer Person als eines konstruktiven, engagierten und reflektierten B{\"u}rgers entspricht" (PISA-Eigendarstellung). Von all dem kann angesichts der Aufgaben keine Rede sein. - Bei der Untersuchung des PISA-Tests dr{\"a}ngte sich ein mathematikdidaktischer Habitus auf, der eine separate Untersuchung erzwang. Ich habe ihn unter dem Stichwort der „Abkehr von der Sache" zusammengefasst. Er ist gepr{\"a}gt von Zerst{\"o}rungen des Mathematischen bei gleichzeitiger {\"U}berbetonung des Fachsprachlichen und durch Verwerfungen des Mathematischen und des Realen bei realit{\"a}tsnahen Aufgaben. Letzteres gr{\"u}ndet in der Nicht-beachtung der Authentizit{\"a}t sowohl des Realen als auch des Mathematischen. Die Arbeit versammelt neben den Untersuchungen zu TIMSS und PISA ein ausf{\"u}hrliches Kapitel {\"u}ber das Prob-lem des Testens und eine Darstellung der Methodologie und Praxis der Objektiven Hermeneutik.}, language = {de} } @phdthesis{Meyerhoefer2003, author = {Meyerh{\"o}fer, Wolfram}, title = {Was testen Tests? : Objektiv-hermeneutische Analysen am Beispiel von TIMSS und PISA}, pages = {244 S.}, year = {2003}, language = {de} } @article{Meyerhoefer2001, author = {Meyerh{\"o}fer, Wolfram}, title = {Was misst TIMSS?}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-224}, pages = {1 -- 11}, year = {2001}, abstract = {Bei der Erstellung und Interpretation mathematischer Leistungstests steht die Frage, was eine Aufgabe mißt. Der Artikel stellt mit der strukturalen oder objektiven Hermeneutik eine Methode vor, mit der die verschiedenen Dimensionen der von einer Aufgabe erfassten F{\"a}higkeiten herausgearbeitet werden k{\"o}nnen. Dabei werden fachliche Anforderungen, Irritationsmomente und das durch die Aufgabe transportierte Bild vom jeweiligen Fach ebenso erfasst wie Momente, die man eher als Testf{\"a}higkeit bezeichnen w{\"u}rde.Am Beispiel einer TIMSS-Aufgabe wird diskutiert, dass das von den Testerstellern benutzte theoretische Konstrukt kaum geeignet ist, nachhaltig zu beschreiben, was eine Aufgabe misst.}, language = {de} } @article{Jahnke1998, author = {Jahnke, Thomas}, title = {Was man zum Thema Wahlen wissen sollte}, year = {1998}, language = {de} } @article{SeegererRomeike2018, author = {Seegerer, Stefan and Romeike, Ralf}, title = {Was jeder {\"u}ber Informatik lernen sollte}, series = {Commentarii informaticae didacticae}, journal = {Commentarii informaticae didacticae}, number = {12}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416298}, pages = {13 -- 28}, year = {2018}, abstract = {Um f{\"u}r ein Leben in der digitalen Gesellschaft vorbereitet zu sein, braucht jeder heute in verschiedenen Situationen umfangreiche informatische Grundlagen. Die Bedeutung von Informatik nimmt nicht nur in immer mehr Bereichen unseres t{\"a}glichen Lebens zu, sondern auch in immer mehr Ausbildungsrichtungen. Um junge Menschen auf ihr zuk{\"u}nftiges Leben und/oder ihre zuk{\"u}nftige berufliche T{\"a}tigkeit vorzubereiten, bieten verschiedene Hochschulen Informatikmodule f{\"u}r Studierende anderer Fachrichtungen an. Die Materialien jener Kurse bilden einen umfangreichen Datenpool, um die f{\"u}r Studierende anderer F{\"a}cher bedeutenden Aspekte der Informatik mithilfe eines empirischen Ansatzes zu identifizieren. Im Folgenden werden 70 Module zu informatischer Bildung f{\"u}r Studierende anderer Fachrichtungen analysiert. Die Materialien - Publikationen, Syllabi und Stundentafeln - werden zun{\"a}chst mit einer qualitativen Inhaltsanalyse nach Mayring untersucht und anschließend quantitativ ausgewertet. Basierend auf der Analyse werden Ziele, zentrale Themen und Typen eingesetzter Werkzeuge identifiziert.}, language = {de} } @article{GrillenbergerRomeike2018, author = {Grillenberger, Andreas and Romeike, Ralf}, title = {Was ist Data Science?}, series = {Commentarii informaticae didacticae}, journal = {Commentarii informaticae didacticae}, number = {10}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416369}, pages = {119 -- 134}, year = {2018}, abstract = {In Zusammenhang mit den Entwicklungen der vergangenen Jahre, insbesondere in den Bereichen Big Data, Datenmanagement und Maschinenlernen, hat sich der Umgang mit Daten und deren Analyse wesentlich weiterentwickelt. Mittlerweile wird die Datenwissenschaft als eigene Disziplin angesehen, die auch immer st{\"a}rker durch entsprechende Studieng{\"a}nge an Hochschulen repr{\"a}sentiert wird. Trotz dieser zunehmenden Bedeutung ist jedoch oft unklar, welche konkreten Inhalte mit ihr in Verbindung stehen, da sie in verschiedensten Auspr{\"a}gungen auftritt. In diesem Beitrag werden daher die hinter der Data Science stehenden informatischen Inhalte durch eine qualitative Analyse der Modulhandb{\"u}cher etablierter Studieng{\"a}nge aus diesem Bereich ermittelt und so ein Beitrag zur Charakterisierung dieser Disziplin geleistet. Am Beispiel der Entwicklung eines Data-Literacy-Kompetenzmodells, die als Ausblick skizziert wird, wird die Bedeutung dieser Charakterisierung f{\"u}r die weitere Forschung expliziert.}, language = {de} } @article{Jahnke1995, author = {Jahnke, Thomas}, title = {Warum sollen Sch{\"u}ler (nicht) Mathematik lernen}, year = {1995}, language = {de} } @article{Jahnke1998, author = {Jahnke, Thomas}, title = {Wahlen}, year = {1998}, language = {de} } @article{Weicker2018, author = {Weicker, Karsten}, title = {Vorlesungs-Pflege}, series = {Commentarii informaticae didacticae}, journal = {Commentarii informaticae didacticae}, number = {12}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416315}, pages = {47 -- 59}, year = {2018}, abstract = {{\"A}hnlich zu Alterungsprozessen bei Software degenerieren auch Vorlesungen, wenn sie nicht hinreichend gepflegt werden. Die Gr{\"u}nde hierf{\"u}r werden ebenso beleuchtet wie m{\"o}gliche Indikatoren und Maßnahmen - der Blick ist dabei immer der eines Informatikers. An drei Vorlesungen wird erl{\"a}utert, wie der Degeneration von Lehrveranstaltungen gegengewirkt werden kann. Mangels hinreichend großer empirischer Daten liefert das Paper keine unumst{\"o}ßlichen Wahrheiten. Ein Ziel ist es vielmehr Kollegen, die {\"a}hnliche Ph{\"a}nomene beobachten, einen ersten Anker f{\"u}r einen inneren Diskurs zu bieten. Ein langfristiges Ziel ist die Sammlung eines Katalogs an Maßnahmen zur Pflege von Informatikvorlesungen.}, language = {de} } @article{ChangMahmoudiSchulze2018, author = {Chang, Der-Chen and Mahmoudi, Mahdi Hedayat and Schulze, Bert-Wolfgang}, title = {Volterra operators in the edge-calculus}, series = {Analysis and Mathematical Physics}, volume = {8}, journal = {Analysis and Mathematical Physics}, number = {4}, publisher = {Springer}, address = {Basel}, issn = {1664-2368}, doi = {10.1007/s13324-018-0238-4}, pages = {551 -- 570}, year = {2018}, abstract = {We study the Volterra property of a class of anisotropic pseudo-differential operators on R x B for a manifold B with edge Y and time-variable t. This exposition belongs to a program for studying parabolicity in such a situation. In the present consideration we establish non-smoothing elements in a subalgebra with anisotropic operator-valued symbols of Mellin type with holomorphic symbols in the complex Mellin covariable from the cone theory, where the covariable t of t extends to symbolswith respect to t to the lower complex v half-plane. The resulting space ofVolterra operators enlarges an approach of Buchholz (Parabolische Pseudodifferentialoperatoren mit operatorwertigen Symbolen. Ph. D. thesis, Universitat Potsdam, 1996) by necessary elements to a new operator algebra containing Volterra parametrices under an appropriate condition of anisotropic ellipticity. Our approach avoids some difficulty in choosing Volterra quantizations in the edge case by generalizing specific achievements from the isotropic edge-calculus, obtained by Seiler (Pseudodifferential calculus on manifolds with non-compact edges, Ph. D. thesis, University of Potsdam, 1997), see also Gil et al. (in: Demuth et al (eds) Mathematical research, vol 100. Akademic Verlag, Berlin, pp 113-137, 1997; Osaka J Math 37: 221-260, 2000).}, language = {en} } @unpublished{BuchholzSchulze1998, author = {Buchholz, Thilo and Schulze, Bert-Wolfgang}, title = {Volterra operators and parabolicity : anisotropic pseudo-differential operators}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25231}, year = {1998}, abstract = {Parabolic equations on manifolds with singularities require a new calculus of anisotropic pseudo-differential operators with operator-valued symbols. The paper develops this theory along the lines of sn abstract wedge calculus with strongly continuous groups of isomorphisms on the involved Banach spaces. The corresponding pseodo-diferential operators are continuous in anisotropic wedge Sobolev spaces, and they form an alegbra. There is then introduced the concept of anisotropic parameter-dependent ellipticity, based on an order reduction variant of the pseudo-differential calculus. The theory is appled to a class of parabolic differential operators, and it is proved the invertibility in Sobolev spaces with exponential weights at infinity in time direction.}, language = {en} } @book{BuchholzSchulze1998, author = {Buchholz, Thilo and Schulze, Bert-Wolfgang}, title = {Volterra operators and parabolicity : anisotropic pseudo-differential operators}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik}, volume = {1998, 11}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik}, publisher = {Univ.}, address = {Potsdam}, pages = {57 S.}, year = {1998}, language = {en} } @unpublished{LiuYangLu2002, author = {Liu, Weian and Yang, Yin and Lu, Gang}, title = {Viscosity solutions of fully nonlinear parabolic systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26215}, year = {2002}, abstract = {In this paper, we discuss the viscosity solutions of the weakly coupled systems of fully nonlinear second order degenerate parabolic equations and their Cauchy-Dirichlet problem. We prove the existence, uniqueness and continuity of viscosity solution by combining Perron's method with the technique of coupled solutions. The results here generalize those in [2] and [3].}, language = {en} } @book{Weian2002, author = {Weian, Liu}, title = {Viscosity Solutions of Fully Nonlinea Parabolic Systems}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, publisher = {Univ.}, address = {Potsdam}, issn = {1437-739X}, pages = {31 S.}, year = {2002}, language = {en} } @article{JansenKunaTsagkarogiannis2020, author = {Jansen, Sabine and Kuna, Tobias and Tsagkarogiannis, Dimitrios}, title = {Virial inversion for inhomogeneous systems}, series = {Lectures in pure and applied mathematics}, journal = {Lectures in pure and applied mathematics}, number = {6}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-485-2}, issn = {2199-4951}, doi = {10.25932/publishup-47211}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472111}, pages = {135 -- 144}, year = {2020}, language = {en} } @article{JahnkeWippermann1994, author = {Jahnke, Thomas and Wippermann, Christina}, title = {Vern{\"u}nftig bremsen und rechnen! : zehn Aufgaben f{\"u}r Bahn-, Auto- und Radfahrer}, year = {1994}, language = {de} } @misc{Klotzek1995, author = {Klotzek, Benno}, title = {Vermes, I., {\"U}ber die synthetische Behandlung der Kr{\"u}mmung und des Schmiegzykels der ebenen Kurven in der Bolyai-Lobatschefskyschen Geometrie}, year = {1995}, language = {de} } @article{Ludewig2014, author = {Ludewig, Matthias}, title = {Vector fields with a non-degenerate source}, series = {Journal of geometry and physics}, volume = {79}, journal = {Journal of geometry and physics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0393-0440}, doi = {10.1016/j.geomphys.2014.01.014}, pages = {59 -- 76}, year = {2014}, abstract = {We discuss the solution theory of operators of the form del(x) + A, acting on smooth sections of a vector bundle with connection del over a manifold M, where X is a vector field having a critical point with positive linearization at some point p is an element of M. As an operator on a suitable space of smooth sections Gamma(infinity)(U, nu), it fulfills a Fredholm alternative, and the same is true for the adjoint operator. Furthermore, we show that the solutions depend smoothly on the data del, X and A.}, language = {en} } @article{ZolotovProkhorovNamgaladzeetal.2011, author = {Zolotov, O. V. and Prokhorov, Boris E. and Namgaladze, Alexander A. and Martynenko, O. V.}, title = {Variations in the total electron content of the ionosphere during preparation of earthquakes}, series = {Russian journal of physical chemistry : B, Focus on physics}, volume = {5}, journal = {Russian journal of physical chemistry : B, Focus on physics}, number = {3}, publisher = {Pleiades Publ.}, address = {New York}, issn = {1990-7931}, doi = {10.1134/S1990793111030146}, pages = {435 -- 438}, year = {2011}, abstract = {The morphological features in the deviations of the total electron content (TEC) of the ionosphere from the background undisturbed state as possible precursors of the earthquake of January 12, 2010 (21:53 UT (16:53 LT), 18.46A degrees N, 72.5A degrees W, 7.0 M) in Haiti are analyzed. To identify these features, global and regional differential TEC maps based on global 2-h TEC maps provided by NASA in the IONEX format were plotted. For the considered earthquake, long-lived disturbances, presumably of seismic origin, were localized in the near-epicenter area and were accompanied by similar effects in the magnetoconjugate region. Both decreases and increases in the local TEC over the period from 22 UT of January 10 to 08 UT of January 12, 2010 were observed. The horizontal dimensions of the anomalies were similar to 40A degrees in longitude and similar to 20A degrees in latitude, with the magnitude of TEC disturbances reaching similar to 40\% relative to the background near the epicenter and more than 50\% in the magnetoconjugate area. No significant geomagnetic disturbances within January 1-12, 2010 were observed, i.e., the detected TEC anomalies were manifestations of interplay between processes in the lithosphere-atmosphere-ionosphere system.}, language = {en} } @phdthesis{Hanisch2011, author = {Hanisch, Florian}, title = {Variational problems on supermanifolds}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59757}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {In this thesis, we discuss the formulation of variational problems on supermanifolds. Supermanifolds incorporate bosonic as well as fermionic degrees of freedom. Fermionic fields take values in the odd part of an appropriate Grassmann algebra and are thus showing an anticommutative behaviour. However, a systematic treatment of these Grassmann parameters requires a description of spaces as functors, e.g. from the category of Grassmann algberas into the category of sets (or topological spaces, manifolds). After an introduction to the general ideas of this approach, we use it to give a description of the resulting supermanifolds of fields/maps. We show that each map is uniquely characterized by a family of differential operators of appropriate order. Moreover, we demonstrate that each of this maps is uniquely characterized by its component fields, i.e. by the coefficients in a Taylor expansion w.r.t. the odd coordinates. In general, the component fields are only locally defined. We present a way how to circumvent this limitation. In fact, by enlarging the supermanifold in question, we show that it is possible to work with globally defined components. We eventually use this formalism to study variational problems. More precisely, we study a super version of the geodesic and a generalization of harmonic maps to supermanifolds. Equations of motion are derived from an energy functional and we show how to decompose them into components. Finally, in special cases, we can prove the existence of critical points by reducing the problem to equations from ordinary geometric analysis. After solving these component equations, it is possible to show that their solutions give rise to critical points in the functor spaces of fields.}, language = {en} } @unpublished{Alsaedy2016, author = {Alsaedy, Ammar}, title = {Variational primitive of a differential form}, volume = {5}, number = {4}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {2193-6943}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89223}, pages = {8}, year = {2016}, abstract = {In this paper we specify the Dirichlet to Neumann operator related to the Cauchy problem for the gradient operator with data on a part of the boundary. To this end, we consider a nonlinear relaxation of this problem which is a mixed boundary problem of Zaremba type for the p-Laplace equation.}, language = {en} } @article{MalemShinitskiOjedaOpper2022, author = {Malem-Shinitski, Noa and Ojeda, Cesar and Opper, Manfred}, title = {Variational bayesian inference for nonlinear hawkes process with gaussian process self-effects}, series = {Entropy}, volume = {24}, journal = {Entropy}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {1099-4300}, doi = {10.3390/e24030356}, pages = {22}, year = {2022}, abstract = {Traditionally, Hawkes processes are used to model time-continuous point processes with history dependence. Here, we propose an extended model where the self-effects are of both excitatory and inhibitory types and follow a Gaussian Process. Whereas previous work either relies on a less flexible parameterization of the model, or requires a large amount of data, our formulation allows for both a flexible model and learning when data are scarce. We continue the line of work of Bayesian inference for Hawkes processes, and derive an inference algorithm by performing inference on an aggregated sum of Gaussian Processes. Approximate Bayesian inference is achieved via data augmentation, and we describe a mean-field variational inference approach to learn the model parameters. To demonstrate the flexibility of the model we apply our methodology on data from different domains and compare it to previously reported results.}, language = {en} } @phdthesis{Beinrucker2015, author = {Beinrucker, Andre}, title = {Variable selection in high dimensional data analysis with applications}, school = {Universit{\"a}t Potsdam}, pages = {VII, 107}, year = {2015}, language = {en} } @article{DeneckeWismath2003, author = {Denecke, Klaus-Dieter and Wismath, Shelly}, title = {Valuations of Terms}, year = {2003}, abstract = {Let tau be a type of algebras. There are several commonly used measurements of the complexity of terms of type tau, including the depth or height of a term and the number of variable symbols appearing in a term. In this paper we formalize these various measurements, by defining a complexity or valuation mapping on terms. A valuation of terms is thus a mapping from the absolutely free term algebra of type tau into another algebra of the same type on which an order relation is defined. We develop the interconnections between such term valuations and the equational theory of Universal Algebra. The collection of all varieties of a given type forms a complete lattice which is very complex and difficult to study; valuations of terms offer a new method to study complete sublattices of this lattice}, language = {en} } @article{DeneckeWismath2003, author = {Denecke, Klaus-Dieter and Wismath, Shelly}, title = {Valuations and Hypersubstitutions}, year = {2003}, language = {en} } @article{CanforaSchmidt2003, author = {Canfora, Fabrizio and Schmidt, Hans-J{\"u}rgen}, title = {Vacuum solutions which cannot be written in diagonal form}, year = {2003}, abstract = {A vacuum solution of the Einstein gravitational field equation is shown to follow from a general ansatz but fails to follow from it if the symmetric matrix in it is assumed to be in diagonal form.}, language = {en} } @phdthesis{Vu2014, author = {Vu, Dinh Phuong}, title = {Using video study to investigate eighth-grade mathematics classrooms in Vietnam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72464}, school = {Universit{\"a}t Potsdam}, pages = {273}, year = {2014}, abstract = {The International Project for the Evaluation of Educational Achievement (IEA) was formed in the 1950s (Postlethwaite, 1967). Since that time, the IEA has conducted many studies in the area of mathematics, such as the First International Mathematics Study (FIMS) in 1964, the Second International Mathematics Study (SIMS) in 1980-1982, and a series of studies beginning with the Third International Mathematics and Science Study (TIMSS) which has been conducted every 4 years since 1995. According to Stigler et al. (1999), in the FIMS and the SIMS, U.S. students achieved low scores in comparison with students in other countries (p. 1). The TIMSS 1995 "Videotape Classroom Study" was therefore a complement to the earlier studies conducted to learn "more about the instructional and cultural processes that are associated with achievement" (Stigler et al., 1999, p. 1). The TIMSS Videotape Classroom Study is known today as the TIMSS Video Study. From the findings of the TIMSS 1995 Video Study, Stigler and Hiebert (1999) likened teaching to "mountain ranges poking above the surface of the water," whereby they implied that we might see the mountaintops, but we do not see the hidden parts underneath these mountain ranges (pp. 73-78). By watching the videotaped lessons from Germany, Japan, and the United States again and again, they discovered that "the systems of teaching within each country look similar from lesson to lesson. At least, there are certain recurring features [or patterns] that typify many of the lessons within a country and distinguish the lessons among countries" (pp. 77-78). They also discovered that "teaching is a cultural activity," so the systems of teaching "must be understood in relation to the cultural beliefs and assumptions that surround them" (pp. 85, 88). From this viewpoint, one of the purposes of this dissertation was to study some cultural aspects of mathematics teaching and relate the results to mathematics teaching and learning in Vietnam. Another research purpose was to carry out a video study in Vietnam to find out the characteristics of Vietnamese mathematics teaching and compare these characteristics with those of other countries. In particular, this dissertation carried out the following research tasks: - Studying the characteristics of teaching and learning in different cultures and relating the results to mathematics teaching and learning in Vietnam - Introducing the TIMSS, the TIMSS Video Study and the advantages of using video study in investigating mathematics teaching and learning - Carrying out the video study in Vietnam to identify the image, scripts and patterns, and the lesson signature of eighth-grade mathematics teaching in Vietnam - Comparing some aspects of mathematics teaching in Vietnam and other countries and identifying the similarities and differences across countries - Studying the demands and challenges of innovating mathematics teaching methods in Vietnam - lessons from the video studies Hopefully, this dissertation will be a useful reference material for pre-service teachers at education universities to understand the nature of teaching and develop their teaching career.}, language = {en} } @article{SamarasNicolaeBoeckmannetal.2015, author = {Samaras, Stefanos and Nicolae, Doina and B{\"o}ckmann, Christine and Vasilescu, Jeni and Binietoglou, Ioannis and Labzovskii, Lev and Toanca, Florica and Papayannis, Alexandros}, title = {Using Raman-lidar-based regularized microphysical retrievals and Aerosol Mass Spectrometer measurements for the characterization of biomass burning aerosols}, series = {Journal of computational physics}, volume = {299}, journal = {Journal of computational physics}, publisher = {Elsevier}, address = {San Diego}, issn = {0021-9991}, doi = {10.1016/j.jcp.2015.06.045}, pages = {156 -- 174}, year = {2015}, abstract = {In this work we extract the microphysical properties of aerosols for a collection of measurement cases with low volume depolarization ratio originating from fire sources captured by the Raman lidar located at the National Institute of Optoelectronics (INOE) in Bucharest. Our algorithm was tested not only for pure smoke but also for mixed smoke and urban aerosols of variable age and growth. Applying a sensitivity analysis on initial parameter settings of our retrieval code was proved vital for producing semi-automatized retrievals with a hybrid regularization method developed at the Institute of Mathematics of Potsdam University. A direct quantitative comparison of the retrieved microphysical properties with measurements from a Compact Time of Flight Aerosol Mass Spectrometer (CToF-AMS) is used to validate our algorithm. Microphysical retrievals performed with sun photometer data are also used to explore our results. Focusing on the fine mode we observed remarkable similarities between the retrieved size distribution and the one measured by the AMS. More complicated atmospheric structures and the factor of absorption appear to depend more on particle radius being subject to variation. A good correlation was found between the aerosol effective radius and particle age, using the ratio of lidar ratios (LR: aerosol extinction to backscatter ratios) as an indicator for the latter. Finally, the dependence on relative humidity of aerosol effective radii measured on the ground and within the layers aloft show similar patterns. (C) 2015 Elsevier Inc. All rights reserved.}, language = {en} } @article{KretschmerCoumouDongesetal.2016, author = {Kretschmer, Marlene and Coumou, Dim and Donges, Jonathan and Runge, Jakob}, title = {Using Causal Effect Networks to Analyze Different Arctic Drivers of Midlatitude Winter Circulation}, series = {Journal of climate}, volume = {29}, journal = {Journal of climate}, publisher = {American Meteorological Soc.}, address = {Boston}, issn = {0894-8755}, doi = {10.1175/JCLI-D-15-0654.1}, pages = {4069 -- 4081}, year = {2016}, abstract = {In recent years, the Northern Hemisphere midlatitudes have suffered from severe winters like the extreme 2012/13 winter in the eastern United States. These cold spells were linked to a meandering upper-tropospheric jet stream pattern and a negative Arctic Oscillation index (AO). However, the nature of the drivers behind these circulation patterns remains controversial. Various studies have proposed different mechanisms related to changes in the Arctic, most of them related to a reduction in sea ice concentrations or increasing Eurasian snow cover. Here, a novel type of time series analysis, called causal effect networks (CEN), based on graphical models is introduced to assess causal relationships and their time delays between different processes. The effect of different Arctic actors on winter circulation on weekly to monthly time scales is studied, and robust network patterns are found. Barents and Kara sea ice concentrations are detected to be important external drivers of the midlatitude circulation, influencing winter AO via tropospheric mechanisms and through processes involving the stratosphere. Eurasia snow cover is also detected to have a causal effect on sea level pressure in Asia, but its exact role on AO remains unclear. The CEN approach presented in this study overcomes some difficulties in interpreting correlation analyses, complements model experiments for testing hypotheses involving teleconnections, and can be used to assess their validity. The findings confirm that sea ice concentrations in autumn in the Barents and Kara Seas are an important driver of winter circulation in the midlatitudes.}, language = {en} } @article{Schmidt2005, author = {Schmidt, Hans-J{\"u}rgen}, title = {Untitled}, year = {2005}, language = {de} } @phdthesis{Butkote2009, author = {Butkote, Runglawan}, title = {Universal-algebraic and Semigroup-theoretical Properties of Boolean Operations}, address = {Potsdam}, pages = {123 S.}, year = {2009}, language = {en} } @book{DeneckeWismath2009, author = {Denecke, Klaus-Dieter and Wismath, Shelly L.}, title = {Universal Algebra and Coalgebra}, publisher = {World Scientific Publ. Co}, address = {Singapore}, isbn = {978-981-283745-5}, pages = {278 S.}, year = {2009}, language = {en} } @book{DeneckeWismath2002, author = {Denecke, Klaus-Dieter and Wismath, Shelly}, title = {Universal algebra and applications in theoretical computer science}, publisher = {Chapman \& Hall/CRC}, address = {Boca Raton}, isbn = {1-584-88254-9}, pages = {383 S.}, year = {2002}, language = {en} } @unpublished{Tarkhanov2005, author = {Tarkhanov, Nikolai Nikolaevich}, title = {Unitary solutions of partial differential equations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-29852}, year = {2005}, abstract = {We give an explicit construction of a fundamental solution for an arbitrary non-degenerate partial differential equation with smooth coefficients.}, language = {en} } @book{Tarkhanov2005, author = {Tarkhanov, Nikolai Nikolaevich}, title = {Unitary solutions of paratial differential equations}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, publisher = {Univ.}, address = {Potsdam}, issn = {1437-739X}, pages = {35 S.}, year = {2005}, language = {en} } @article{EichmairMetzger2013, author = {Eichmair, Michael and Metzger, Jan}, title = {Unique isoperimetric foliations of asymptotically flat manifolds in all dimensions}, series = {Inventiones mathematicae}, volume = {194}, journal = {Inventiones mathematicae}, number = {3}, publisher = {Springer}, address = {New York}, issn = {0020-9910}, doi = {10.1007/s00222-013-0452-5}, pages = {591 -- 630}, year = {2013}, language = {en} } @book{SchulzeQin2005, author = {Schulze, Bert-Wolfgang and Qin, Yuming}, title = {Uniform compact attractors for a nonlinear non-autonomous equation of viscoelasticity}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, publisher = {Univ.}, address = {Potsdam}, issn = {1437-739X}, pages = {53 S.}, year = {2005}, language = {en} } @unpublished{SchulzeQin2005, author = {Schulze, Bert-Wolfgang and Qin, Yuming}, title = {Uniform compact attractors for a nonlinear non-autonomous equation of viscoelasticity}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-29892}, year = {2005}, abstract = {In this paper we establish the regularity, exponential stability of global (weak) solutions and existence of uniform compact attractors of semiprocesses, which are generated by the global solutions, of a two-parameter family of operators for the nonlinear 1-d non-autonomous viscoelasticity. We employ the properties of the analytic semigroup to show the compactness for the semiprocess generated by the global solutions.}, language = {en} } @article{Jahnke2001, author = {Jahnke, Thomas}, title = {Unendlich : oder darf es etwas mehr sein?}, year = {2001}, language = {de} } @misc{Ginoux2003, author = {Ginoux, Nicolas}, title = {Une nouvelle estimation extrins{\`e}que du spectre de l'op{\´e}rateur de Dirac}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-5644}, year = {2003}, abstract = {Nous {\´e}tablissons une nouvelle majoration optimale pour les plus petites valeurs propres de l'op{\´e}rateur de Dirac sur une hypersurface compacte de l'espace hyperbolique.}, language = {fr} } @article{KnoechelKloftHuisinga2018, author = {Kn{\"o}chel, Jane and Kloft, Charlotte and Huisinga, Wilhelm}, title = {Understanding and reducing complex systems pharmacology models based on a novel input-response index}, series = {Journal of pharmacokinetics and pharmacodynamics}, volume = {45}, journal = {Journal of pharmacokinetics and pharmacodynamics}, number = {1}, publisher = {Springer Science + Business Media B.V.}, address = {New York}, issn = {1567-567X}, doi = {10.1007/s10928-017-9561-x}, pages = {139 -- 157}, year = {2018}, abstract = {A growing understanding of complex processes in biology has led to large-scale mechanistic models of pharmacologically relevant processes. These models are increasingly used to study the response of the system to a given input or stimulus, e.g., after drug administration. Understanding the input-response relationship, however, is often a challenging task due to the complexity of the interactions between its constituents as well as the size of the models. An approach that quantifies the importance of the different constituents for a given input-output relationship and allows to reduce the dynamics to its essential features is therefore highly desirable. In this article, we present a novel state- and time-dependent quantity called the input-response index that quantifies the importance of state variables for a given input-response relationship at a particular time. It is based on the concept of time-bounded controllability and observability, and defined with respect to a reference dynamics. In application to the brown snake venom-fibrinogen (Fg) network, the input-response indices give insight into the coordinated action of specific coagulation factors and about those factors that contribute only little to the response. We demonstrate how the indices can be used to reduce large-scale models in a two-step procedure: (i) elimination of states whose dynamics have only minor impact on the input-response relationship, and (ii) proper lumping of the remaining (lower order) model. In application to the brown snake venom-fibrinogen network, this resulted in a reduction from 62 to 8 state variables in the first step, and a further reduction to 5 state variables in the second step. We further illustrate that the sequence, in which a recursive algorithm eliminates and/or lumps state variables, has an impact on the final reduced model. The input-response indices are particularly suited to determine an informed sequence, since they are based on the dynamics of the original system. In summary, the novel measure of importance provides a powerful tool for analysing the complex dynamics of large-scale systems and a means for very efficient model order reduction of nonlinear systems.}, language = {en} } @unpublished{Roelly2010, author = {Roelly, Sylvie}, title = {Unas propiedades basicas de procesos de ramificaci{\´o}n : Lectures held at ICIMAF La Habana, Cuba, 2009 and 2010}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49620}, year = {2010}, abstract = {Aus dem Inhalt: 1. Unas propiedades de los procesos de Bienaym{\´e}-Galton-Watson de tiempo dis- creto (BGW) 2. Unas propiedades del proceso BGW de tiempo continuo 3. Limites de procesos de BGW cuando la poblaci{\´o}n es numerosa}, language = {mul} } @article{Pincus1999, author = {Pincus, Richard}, title = {UMPI-character of Hotelling's T2 for testing non-centralities in the denominator}, year = {1999}, language = {en} } @article{DemarisWidigsonIlvemarketal.2022, author = {D{\´e}maris, Alix and Widigson, Ella S. K. and Ilvemark, Johan F. K. F. and Steenholdt, Casper and Seidelin, Jakob B. and Huisinga, Wilhelm and Michelet, Robin and Aulin, Linda B. S. and Kloft, Charlotte}, title = {Ulcerative colitis and acute severe ulcerative colitis patients are overlooked in infliximab population pharmacokinetic models}, series = {Pharmaceutics / Molecular Diversity Preservation International}, volume = {14}, journal = {Pharmaceutics / Molecular Diversity Preservation International}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {1999-4923}, doi = {10.3390/pharmaceutics14102095}, pages = {32}, year = {2022}, abstract = {Ulcerative colitis (UC) is part of the inflammatory bowels diseases, and moderate to severe UC patients can be treated with anti-tumour necrosis alpha monoclonal antibodies, including infliximab (IFX). Even though treatment of UC patients by IFX has been in place for over a decade, many gaps in modelling of IFX PK in this population remain. This is even more true for acute severe UC (ASUC) patients for which early prediction of IFX pharmacokinetic (PK) could highly improve treatment outcome. Thus, this review aims to compile and analyse published population PK models of IFX in UC and ASUC patients, and to assess the current knowledge on disease activity impact on IFX PK. For this, a semi-systematic literature search was conducted, from which 26 publications including a population PK model analysis of UC patients receiving IFX therapy were selected. Amongst those, only four developed a model specifically for UC patients, and only three populations included severe UC patients. Investigations of disease activity impact on PK were reported in only 4 of the 14 models selected. In addition, the lack of reported model codes and assessment of predictive performance make the use of published models in a clinical setting challenging. Thus, more comprehensive investigation of PK in UC and ASUC is needed as well as more adequate reports on developed models and their evaluation in order to apply them in a clinical setting.}, language = {en} } @book{SchmidtMignemi1995, author = {Schmidt, Hans-J{\"u}rgen and Mignemi, Salvatore}, title = {Two-dimensional higher-derivative gravity and conformal transformations}, year = {1995}, language = {en} } @article{SchmidtMignemi1995, author = {Schmidt, Hans-J{\"u}rgen and Mignemi, Salvatore}, title = {Two-dimensional higher-derivative gravity and conformal transformations}, year = {1995}, language = {en} } @article{AzzaliWahl2019, author = {Azzali, Sara and Wahl, Charlotte}, title = {Two-cocycle twists and Atiyah-Patodi-Singer index theory}, series = {Mathematical Proceedings of the Cambridge Philosophical Society}, volume = {167}, journal = {Mathematical Proceedings of the Cambridge Philosophical Society}, number = {3}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {0305-0041}, doi = {10.1017/S0305004118000427}, pages = {437 -- 487}, year = {2019}, abstract = {We construct eta- and rho-invariants for Dirac operators, on the universal covering of a closed manifold, that are invariant under the projective action associated to a 2-cocycle of the fundamental group. We prove an Atiyah-Patodi-Singer index theorem in this setting, as well as its higher generalisation. Applications concern the classification of positive scalar curvature metrics on closed spin manifolds. We also investigate the properties of these twisted invariants for the signature operator and the relation to the higher invariants.}, language = {en} } @article{BaumgaertelJurkeLledo2002, author = {Baumg{\"a}rtel, Hellmut and Jurke, Matthias and Lled{\´o}, Fernando}, title = {Twisted duality for the CAR-algebra}, year = {2002}, language = {en} } @book{BaumgaertelJurkeLledo1999, author = {Baumg{\"a}rtel, Hellmut and Jurke, Matthias and Lled{\´o}, Fernando}, title = {Twisted duality for the CAR-algebra}, series = {Preprint / SFB 288, Differentialgeometrie und Quantenphysik}, volume = {401}, journal = {Preprint / SFB 288, Differentialgeometrie und Quantenphysik}, publisher = {Techn. Univ.}, address = {Berlin}, year = {1999}, language = {en} } @misc{Boelling1995, author = {B{\"o}lling, Reinhard}, title = {Tuschmann, W., Hawig, P., Sofia Kowalewskaja, ein Leben f{\"u}r Mathematik und Emanzipation; Basel [u.a.], Birkh{\"a}user, 1993}, year = {1995}, language = {de} } @article{GurovichSchmidtTokareva2001, author = {Gurovich, Viktor and Schmidt, Hans-J{\"u}rgen and Tokareva, Ira}, title = {Tunneling of the closed Friedmann Universe with generation of scalar waves}, year = {2001}, abstract = {The evolution of the closed Friedmann Universe with a packet of short scalar waves is considered with the help of the Wheeler-DeWitt equation. The packet ensures conservation of homogeneity and isotropy of the metric on average. It is shown that during tunneling the amplitudes of short waves of a scalar field can increase catastrophically promptly if their influence to the metric is not taken into account. This effect is similar to the Rubakov-effect of catastrophic particle creation calculated already in 1984. In our approach to the problem it is possible to consider a self- consistent dynamics of the expansion of the Universe and amplification of short waves. It results in a decrease of the barrier and interruption of amplification of waves, and we get an exit of the wave function from the quantum to the classically available region.}, language = {en} }