@phdthesis{Beilke2011, author = {Beilke, Steffen}, title = {... und fortzuentwickeln : Optionen zur Fortentwicklung der hergebrachten Grunds{\"a}tze des Berufsbeamtentums}, series = {Schriften zum {\"o}ffentlichen Dienstrecht}, volume = {1}, journal = {Schriften zum {\"o}ffentlichen Dienstrecht}, publisher = {Nomos}, address = {Baden-Baden}, isbn = {978-3-8329-6240-1}, pages = {248 S.}, year = {2011}, language = {de} } @phdthesis{Schoenheit2011, author = {Sch{\"o}nheit, J{\"o}rg}, title = {A phagocyte-specific Irf8 gene enhancer establishes early conventional dendritic cell commitment}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-55482}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Haematopoietic development is a complex process that is strictly hierarchically organized. Here, the phagocyte lineages are a very heterogeneous cell compartment with specialized functions in innate immunity and induction of adaptive immune responses. Their generation from a common precursor must be tightly controlled. Interference within lineage formation programs for example by mutation or change in expression levels of transcription factors (TF) is causative to leukaemia. However, the molecular mechanisms driving specification into distinct phagocytes remain poorly understood. In the present study I identify the transcription factor Interferon Regulatory Factor 8 (IRF8) as the specification factor of dendritic cell (DC) commitment in early phagocyte precursors. Employing an IRF8 reporter mouse, I showed the distinct Irf8 expression in haematopoietic lineage diversification and isolated a novel bone marrow resident progenitor which selectively differentiates into CD8α+ conventional dendritic cells (cDCs) in vivo. This progenitor strictly depends on Irf8 expression to properly establish its transcriptional DC program while suppressing a lineage-inappropriate neutrophile program. Moreover, I demonstrated that Irf8 expression during this cDC commitment-step depends on a newly discovered myeloid-specific cis-enhancer which is controlled by the haematopoietic transcription factors PU.1 and RUNX1. Interference with their binding leads to abrogation of Irf8 expression, subsequently to disturbed cell fate decisions, demonstrating the importance of these factors for proper phagocyte cell development. Collectively, these data delineate a transcriptional program establishing cDC fate choice with IRF8 in its center.}, language = {en} } @phdthesis{Zhang2011, author = {Zhang, Zhuodong}, title = {A regional scale study of wind erosion in the Xilingele grassland based on computational fluid dynamics}, address = {Potsdam}, pages = {143 S.}, year = {2011}, language = {en} } @phdthesis{Andorf2011, author = {Andorf, Sandra}, title = {A systems biological approach towards the molecular basis of heterosis in Arabidopsis thaliana}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51173}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Heterosis is defined as the superiority in performance of heterozygous genotypes compared to their corresponding genetically different homozygous parents. This phenomenon is already known since the beginning of the last century and it has been widely used in plant breeding, but the underlying genetic and molecular mechanisms are not well understood. In this work, a systems biological approach based on molecular network structures is proposed to contribute to the understanding of heterosis. Hybrids are likely to contain additional regulatory possibilities compared to their homozygous parents and, therefore, they may be able to correctly respond to a higher number of environmental challenges, which leads to a higher adaptability and, thus, the heterosis phenomenon. In the network hypothesis for heterosis, presented in this work, more regulatory interactions are expected in the molecular networks of the hybrids compared to the homozygous parents. Partial correlations were used to assess this difference in the global interaction structure of regulatory networks between the hybrids and the homozygous genotypes. This network hypothesis for heterosis was tested on metabolite profiles as well as gene expression data of the two parental Arabidopsis thaliana accessions C24 and Col-0 and their reciprocal crosses. These plants are known to show a heterosis effect in their biomass phenotype. The hypothesis was confirmed for mid-parent and best-parent heterosis for either hybrid of our experimental metabolite as well as gene expression data. It was shown that this result is influenced by the used cutoffs during the analyses. Too strict filtering resulted in sets of metabolites and genes for which the network hypothesis for heterosis does not hold true for either hybrid regarding mid-parent as well as best-parent heterosis. In an over-representation analysis, the genes that show the largest heterosis effects according to our network hypothesis were compared to genes of heterotic quantitative trait loci (QTL) regions. Separately for either hybrid regarding mid-parent as well as best-parent heterosis, a significantly larger overlap between the resulting gene lists of the two different approaches towards biomass heterosis was detected than expected by chance. This suggests that each heterotic QTL region contains many genes influencing biomass heterosis in the early development of Arabidopsis thaliana. Furthermore, this integrative analysis led to a confinement and an increased confidence in the group of candidate genes for biomass heterosis in Arabidopsis thaliana identified by both approaches.}, language = {en} } @phdthesis{Oppenheim2011, author = {Oppenheim, Robert}, title = {Abfindungsklauseln in Personengesellschaftvertr{\"a}gen : Pl{\"a}doyer f{\"u}r eine Verhandlungsklausel}, series = {Nomos Universit{\"a}tsschriften : Recht}, volume = {728}, journal = {Nomos Universit{\"a}tsschriften : Recht}, publisher = {Nomos}, address = {Baden-Baden}, isbn = {978-3-8329-6509-9}, pages = {140 S.}, year = {2011}, language = {de} } @phdthesis{Neigenfind2011, author = {Neigenfind, Jost}, title = {About a refined algorithm for the computation of absolute concentration robustness}, address = {Potsdam}, pages = {152 S.}, year = {2011}, language = {en} } @phdthesis{Kellermann2011, author = {Kellermann, Thorsten}, title = {Accurate numerical relativity simulations of non-vacuumspace-times in two dimensions and applications to critical collapse}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59578}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {This Thesis puts its focus on the physics of neutron stars and its description with methods of numerical relativity. In the first step, a new numerical framework the Whisky2D code will be developed, which solves the relativistic equations of hydrodynamics in axisymmetry. Therefore we consider an improved formulation of the conserved form of these equations. The second part will use the new code to investigate the critical behaviour of two colliding neutron stars. Considering the analogy to phase transitions in statistical physics, we will investigate the evolution of the entropy of the neutron stars during the whole process. A better understanding of the evolution of thermodynamical quantities, like the entropy in critical process, should provide deeper understanding of thermodynamics in relativity. More specifically, we have written the Whisky2D code, which solves the general-relativistic hydrodynamics equations in a flux-conservative form and in cylindrical coordinates. This of course brings in 1/r singular terms, where r is the radial cylindrical coordinate, which must be dealt with appropriately. In the above-referenced works, the flux operator is expanded and the 1/r terms, not containing derivatives, are moved to the right-hand-side of the equation (the source term), so that the left hand side assumes a form identical to the one of the three-dimensional (3D) Cartesian formulation. We call this the standard formulation. Another possibility is not to split the flux operator and to redefine the conserved variables, via a multiplication by r. We call this the new formulation. The new equations are solved with the same methods as in the Cartesian case. From a mathematical point of view, one would not expect differences between the two ways of writing the differential operator, but, of course, a difference is present at the numerical level. Our tests show that the new formulation yields results with a global truncation error which is one or more orders of magnitude smaller than those of alternative and commonly used formulations. The second part of the Thesis uses the new code for investigations of critical phenomena in general relativity. In particular, we consider the head-on-collision of two neutron stars in a region of the parameter space where two final states a new stable neutron star or a black hole, lay close to each other. In 1993, Choptuik considered one-parameter families of solutions, S[P], of the Einstein-Klein-Gordon equations for a massless scalar field in spherical symmetry, such that for every P > P⋆, S[P] contains a black hole and for every P < P⋆, S[P] is a solution not containing singularities. He studied numerically the behavior of S[P] as P → P⋆ and found that the critical solution, S[P⋆], is universal, in the sense that it is approached by all nearly-critical solutions regardless of the particular family of initial data considered. All these phenomena have the common property that, as P approaches P⋆, S[P] approaches a universal solution S[P⋆] and that all the physical quantities of S[P] depend only on |P - P⋆|. The first study of critical phenomena concerning the head-on collision of NSs was carried out by Jin and Suen in 2007. In particular, they considered a series of families of equal-mass NSs, modeled with an ideal-gas EOS, boosted towards each other and varied the mass of the stars, their separation, velocity and the polytropic index in the EOS. In this way they could observe a critical phenomenon of type I near the threshold of black-hole formation, with the putative solution being a nonlinearly oscillating star. In a successive work, they performed similar simulations but considering the head-on collision of Gaussian distributions of matter. Also in this case they found the appearance of type-I critical behaviour, but also performed a perturbative analysis of the initial distributions of matter and of the merged object. Because of the considerable difference found in the eigenfrequencies in the two cases, they concluded that the critical solution does not represent a system near equilibrium and in particular not a perturbed Tolmann-Oppenheimer-Volkoff (TOV) solution. In this Thesis we study the dynamics of the head-on collision of two equal-mass NSs using a setup which is as similar as possible to the one considered above. While we confirm that the merged object exhibits a type-I critical behaviour, we also argue against the conclusion that the critical solution cannot be described in terms of equilibrium solution. Indeed, we show that, in analogy with what is found in, the critical solution is effectively a perturbed unstable solution of the TOV equations. Our analysis also considers fine-structure of the scaling relation of type-I critical phenomena and we show that it exhibits oscillations in a similar way to the one studied in the context of scalar-field critical collapse.}, language = {en} } @phdthesis{Heinz2011, author = {Heinz, Kathrin}, title = {Achtsamkeit und Akzeptanz als sportpsychologische Intervention : Adaption, Weiterentwicklung und Wirksamkeitspr{\"u}fung}, address = {Potsdam}, pages = {125 S.}, year = {2011}, language = {de} } @phdthesis{Hoehne2011, author = {H{\"o}hne, Janet}, title = {Aktivit{\"a}ts- und Herzfrequenz-Monitoring zur Erfassung der Bewegungszeit und der Bewegungsintensit{\"a}t im schulischen und außerschulischen Kontext von Grundsch{\"u}lern im Land Brandenburg}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57937}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {"Kinderwelt ist Bewegungswelt" (Schmidt, 1997, S. 156, zitiert nach Schmidt, Hartmann-Tews \& Brettschneider, 2003, S. 31). Das kindliche Bewegungsverhalten hat sich bereits im Grundschulalter ver{\"a}ndert, so dass sich Bewegungsaktivit{\"a}ten von Kindern erheblich unterscheiden und keineswegs mehr verallgemeinert werden k{\"o}nnen. Richtet man den Fokus auf die Frage „Wie bewegt sind unsere Kinder?" so scheint diese von den Medien bereits beantwortet zu sein, da dort von ansteigendem Bewegungsmangel der heutigen Kinder gegen{\"u}ber fr{\"u}heren Generationen berichtet wird. Wenn es in den Diskussionen um den Gesundheitszustand unserer Kinder geht, nimmt die k{\"o}rperlich-sportliche Aktivit{\"a}t eine entscheidende Rolle ein. Bewegungsmangel ist hierbei ein zentraler Begriff der in der {\"O}ffentlichkeit diskutiert wird. Bei der Betrachtung der einzelnen Studien f{\"a}llt auf, dass deutliche Defizite in der Messung der k{\"o}rperlich-sportlichen Aktivit{\"a}t bestehen. Zentraler Kritikpunkt in den meisten Studien ist die subjektive Erfassung der k{\"o}rperlich-sportlichen Aktivit{\"a}t. Ein Großteil bisheriger Untersuchungen zum Bewegungsverhalten basiert auf Beobachtungen, Befragungen oder Bewegungstageb{\"u}chern. Diese liefern ausschließlich zum Teil subjektive Einsch{\"a}tzungen der Kinder oder Eltern {\"u}ber die tats{\"a}chliche Bewegungszeit und -intensit{\"a}t. Das objektive Erfassen der Aktivit{\"a}t bzw. Inaktivit{\"a}t ist zwar seit einigen Jahren zentraler Gegenstand vieler Studien, dennoch gilt es, dieses noch sachkundiger zu l{\"o}sen, um subjektive und objektive Daten zu vergleichen. Um dem Bewegungsmangel der heutigen Kinder entgegenzuwirken, sind empirisch abgesicherte Erkenntnisse {\"u}ber die Bedingungsfaktoren und die Folgen des ver{\"a}nderten Bewegungsverhaltens dringend n{\"o}tig. Die Quer- und L{\"a}ngsschnittuntersuchung umfasst die Bereiche Anthropometrie, die Erfassung der k{\"o}rperlich-sportlichen Aktivit{\"a}t und die Herzfrequenzmessung {\"u}ber 24h. F{\"u}r die Studie konnten 106 Jungen und M{\"a}dchen im Zeitraum von Januar 2007 bis April 2009 rekrutiert und {\"u}berpr{\"u}ft werden. Die physiologischen Parameter wurden mit Hilfe des ACTIHEART-Messsytems aufgezeichnet und berechnet. Die Ergebnisse zur k{\"o}rperlich-sportlichen Aktivit{\"a}t wurden in die Untersuchungsabschnitte Schulzeit gesamt, Pause, Sportunterricht, Nachmittag und 24h unterteilt. Durch das Messsystem werden die Bewegungsaktivit{\"a}t und die Herzfrequenz synchron aufgezeichnet. Das System nimmt die Beschleunigungswerte des K{\"o}rpers auf und speichert sie im frei w{\"a}hlbaren Zeitintervall, Short oder Long Term, in Form von „activity counts" ab. Das Messsytem berechnet weiterhin die Intensit{\"a}t k{\"o}rperlicher Aktivit{\"a}t.}, language = {de} } @phdthesis{Sarasit2011, author = {Sarasit, Napaporn}, title = {Algebraic properties of sets of terms}, address = {Potsdam}, pages = {91 S.}, year = {2011}, language = {en} } @phdthesis{Gomolka2011, author = {Gomolka, Johannes}, title = {Algorithmic Trading}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-125-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51009}, school = {Universit{\"a}t Potsdam}, pages = {383}, year = {2011}, abstract = {Die Elektronisierung der Finanzm{\"a}rkte ist in den letzten Jahren weit vorangeschritten. Praktisch jede B{\"o}rse verf{\"u}gt {\"u}ber ein elektronisches Handelssystem. In diesem Kontext beschreibt der Begriff Algorithmic Trading ein Ph{\"a}nomen, bei dem Computerprogramme den Menschen im Wertpapierhandel ersetzen. Sie helfen dabei Investmententscheidungen zu treffen oder Transaktionen durchzuf{\"u}hren. Algorithmic Trading selbst ist dabei nur eine unter vielen Innovationen, welche die Entwicklung des B{\"o}rsenhandels gepr{\"a}gt haben. Hier sind z.B. die Erfindung der Telegraphie, des Telefons, des FAX oder der elektronische Wertpapierabwicklung zu nennen. Die Frage ist heute nicht mehr, ob Computerprogramme im B{\"o}rsenhandel eingesetzt werden. Sondern die Frage ist, wo die Grenze zwischen vollautomatischem B{\"o}rsenhandel (durch Computer) und manuellem B{\"o}rsenhandel (von Menschen) verl{\"a}uft. Bei der Erforschung von Algorithmic Trading wird die Wissenschaft mit dem Problem konfrontiert, dass keinerlei Informationen {\"u}ber diese Computerprogramme zug{\"a}nglich sind. Die Idee dieser Dissertation bestand darin, dieses Problem zu umgehen und Informationen {\"u}ber Algorithmic Trading indirekt aus der Analyse von (Fonds-)Renditen zu extrahieren. Johannes Gomolka untersucht daher die Forschungsfrage, ob sich Aussagen {\"u}ber computergesteuerten Wertpapierhandel (kurz: Algorithmic Trading) aus der Analyse von (Fonds-)Renditen ziehen lassen. Zur Beantwortung dieser Forschungsfrage formuliert der Autor eine neue Definition von Algorithmic Trading und unterscheidet mit Buy-Side und Sell-Side Algorithmic Trading zwei grundlegende Funktionen der Computerprogramme (die Entscheidungs- und die Transaktionsunterst{\"u}tzung). F{\"u}r seine empirische Untersuchung greift Gomolka auf das Multifaktorenmodell zur Style-Analyse von Fung und Hsieh (1997) zur{\"u}ck. Mit Hilfe dieses Modells ist es m{\"o}glich, die Zeitreihen von Fondsrenditen in interpretierbare Grundbestandteile zu zerlegen und den einzelnen Regressionsfaktoren eine inhaltliche Bedeutung zuzuordnen. Die Ergebnisse dieser Dissertation zeigen, dass man mit Hilfe der Style-Analyse Aussagen {\"u}ber Algorithmic Trading aus der Analyse von (Fonds-)Renditen machen kann. Die Aussagen sind jedoch keiner technischen Natur, sondern auf die Analyse von Handelsstrategien (Investment-Styles) begrenzt.}, language = {de} } @phdthesis{Mueller2011, author = {M{\"u}ller, Kristine}, title = {Alltag im Abseits : Handlungsorientierungen {\"o}konomischer Akteure an der {\"o}stlichen Außengrenze der Europ{\"a}ischen Union}, address = {Potsdam}, pages = {219 S.}, year = {2011}, language = {de} } @phdthesis{Kristen2011, author = {Kristen, Juliane Ute}, title = {Amphiphilic BAB-triblock copolymers bearing fluorocarbon groups : synthesis and self-organization in aqueous media}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-61782}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {In this work new fluorinated and non-fluorinated mono- and bifunctional trithiocarbonates of the structure Z-C(=S)-S-R and Z-C(=S)-S-R-S-C(=S)-Z were synthesized for the use as chain transfer agents (CTAs) in the RAFT-process. All newly synthesized CTAs were tested for their efficiency to moderate the free radical polymerization process by polymerizing styrene (M3). Besides characterization of the homopolymers by GPC measurements, end- group analysis of the synthesized block copolymers via 1H-, 19F-NMR, and in some cases also UV-vis spectroscopy, were performed attaching suitable fluorinated moieties to the Z- and/or R-groups of the CTAs. Symmetric triblock copolymers of type BAB and non-symmetric fluorine end- capped polymers were accessible using the RAFT process in just two or one polymerization step. In particular, the RAFT-process enabled the controlled polymerization of hydrophilic monomers such as N-isopropylacrylamide (NIPAM) (M1) as well as N-acryloylpyrrolidine (NAP) (M2) for the A-blocks and of the hydrophobic monomers styrene (M3), 2-fluorostyrene (M4), 3-fluorostyrene (M5), 4-fluorostyrene (M6) and 2,3,4,5,6-pentafluorostyrene (M7) for the B-blocks. The properties of the BAB-triblock copolymers were investigated in dilute, concentrated and highly concentrated aqueous solutions using DLS, turbidimetry, 1H- and 19F-NMR, rheology, determination of the CMC, foam height- and surface tension measurements and microscopy. Furthermore, their ability to stabilize emulsions and microemulsions and the wetting behaviour of their aqueous solutions on different substrates was investigated. The behaviour of the fluorine end-functionalized polymers to form micelles was studied applying DLS measurements in diluted organic solution. All investigated BAB-triblock copolymers were able to form micelles and show surface activity at room temperature in dilute aqueous solution. The aqueous solutions displayed moderate foam formation. With different types and concentrations of oils, the formation of emulsions could be detected using a light microscope. A boosting effect in microemulsions could not be found adding BAB-triblock copolymers. At elevated polymer concentrations, the formation of hydrogels was proved applying rheology measurements.}, language = {en} } @phdthesis{Krause2011, author = {Krause, Jette}, title = {An expert-based Bayesian investigation of greenhouse gas emission reduction options for German passenger vehicles until 2030}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57671}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {The present thesis introduces an iterative expert-based Bayesian approach for assessing greenhouse gas (GHG) emissions from the 2030 German new vehicle fleet and quantifying the impacts of their main drivers. A first set of expert interviews has been carried out in order to identify technologies which may help to lower car GHG emissions and to quantify their emission reduction potentials. Moreover, experts were asked for their probability assessments that the different technologies will be widely adopted, as well as for important prerequisites that could foster or hamper their adoption. Drawing on the results of these expert interviews, a Bayesian Belief Network has been built which explicitly models three vehicle types: Internal Combustion Engine Vehicles (which include mild and full Hybrid Electric Vehicles), Plug-In Hybrid Electric Vehicles, and Battery Electric Vehicles. The conditional dependencies of twelve central variables within the BBN - battery energy, fuel and electricity consumption, relative costs, and sales shares of the vehicle types - have been quantified by experts from German car manufacturers in a second series of interviews. For each of the seven second-round interviews, an expert's individually specified BBN results. The BBN have been run for different hypothetical 2030 scenarios which differ, e.g., in regard to battery development, regulation, and fuel and electricity GHG intensities. The present thesis delivers results both in regard to the subject of the investigation and in regard to its method. On the subject level, it has been found that the different experts expect 2030 German new car fleet emission to be at 50 to 65\% of 2008 new fleet emissions under the baseline scenario. They can be further reduced to 40 to 50\% of the emissions of the 2008 fleet though a combination of a higher share of renewables in the electricity mix, a larger share of biofuels in the fuel mix, and a stricter regulation of car CO\$_2\$ emissions in the European Union. Technically, 2030 German new car fleet GHG emissions can be reduced to a minimum of 18 to 44\% of 2008 emissions, a development which can not be triggered by any combination of measures modeled in the BBN alone but needs further commitment. Out of a wealth of existing BBN, few have been specified by individual experts through elicitation, and to my knowledge, none of them has been employed for analyzing perspectives for the future. On the level of methods, this work shows that expert-based BBN are a valuable tool for making experts' expectations for the future explicit and amenable to the analysis of different hypothetical scenarios. BBN can also be employed for quantifying the impacts of main drivers. They have been demonstrated to be a valuable tool for iterative stakeholder-based science approaches.}, language = {en} } @phdthesis{Fettke2011, author = {Fettke, J{\"o}rg}, title = {Analysen St{\"a}rke-bezogener Kohlenstofffl{\"u}sse}, address = {Potsdam}, year = {2011}, language = {de} } @phdthesis{Hass2011, author = {Hass, Roland}, title = {Angewandte Photonendichtewellen Spektroskopie}, address = {Potsdam}, pages = {XX, 122, XXXIII S.}, year = {2011}, language = {de} } @phdthesis{Richter2011, author = {Richter, Michael}, title = {Anwendung nichtlinearer Codes zur Fehlererkennung und -korrektur}, address = {Potsdam}, pages = {134 S.}, year = {2011}, language = {de} } @phdthesis{Hogrefe2011, author = {Hogrefe, Katharina}, title = {Aphasie, Apraxie und Gestik : zur Produktion von Handgesten bei Patienten mit linkshemisph{\"a}rischer Hirnsch{\"a}digung}, publisher = {Der Andere Verl.}, address = {Uelvesb{\"u}ll}, isbn = {978-3-86247-171-3}, pages = {183 S.}, year = {2011}, language = {de} } @phdthesis{Avila2011, author = {Avila, Gast{\´o}n}, title = {Asymptotic staticity and tensor decompositions with fast decay conditions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-54046}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Corvino, Corvino and Schoen, Chruściel and Delay have shown the existence of a large class of asymptotically flat vacuum initial data for Einstein's field equations which are static or stationary in a neighborhood of space-like infinity, yet quite general in the interior. The proof relies on some abstract, non-constructive arguments which makes it difficult to calculate such data numerically by using similar arguments. A quasilinear elliptic system of equations is presented of which we expect that it can be used to construct vacuum initial data which are asymptotically flat, time-reflection symmetric, and asymptotic to static data up to a prescribed order at space-like infinity. A perturbation argument is used to show the existence of solutions. It is valid when the order at which the solutions approach staticity is restricted to a certain range. Difficulties appear when trying to improve this result to show the existence of solutions that are asymptotically static at higher order. The problems arise from the lack of surjectivity of a certain operator. Some tensor decompositions in asymptotically flat manifolds exhibit some of the difficulties encountered above. The Helmholtz decomposition, which plays a role in the preparation of initial data for the Maxwell equations, is discussed as a model problem. A method to circumvent the difficulties that arise when fast decay rates are required is discussed. This is done in a way that opens the possibility to perform numerical computations. The insights from the analysis of the Helmholtz decomposition are applied to the York decomposition, which is related to that part of the quasilinear system which gives rise to the difficulties. For this decomposition analogous results are obtained. It turns out, however, that in this case the presence of symmetries of the underlying metric leads to certain complications. The question, whether the results obtained so far can be used again to show by a perturbation argument the existence of vacuum initial data which approach static solutions at infinity at any given order, thus remains open. The answer requires further analysis and perhaps new methods.}, language = {en} } @phdthesis{Mielke2011, author = {Mielke, Moritz}, title = {Atmosph{\"a}rische Prozesstudien auf der Basis von Beobachtungen und regionalen Klimamodellsimulationen in der Arktis}, address = {Potsdam}, pages = {130 S.}, year = {2011}, language = {de} }