@unpublished{Krainer2001,
  author    = {Krainer, Thomas},
  title     = {The calculus of Volterra Mellin pseudodifferential operators with operator-valued symbols},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26185},
  year      = {2001},
  abstract  = {We introduce the calculus of Mellin pseudodifferential operators parameters based on "twisted" operator-valued Volterra symbols as well aas the abstract Mellin calclus with holomorphic symbols. We establish the properties of the symblic and operational calculi, and we give and make use of explicit oscillatory integral formulas on the symbolic side, e. g., for the Leibniz-product, kernel cut-off, and Mellin quantization. Moreover, we introduce the notion of parabolicity for the calculi of Volterra Mellin operators, and construct Volterra parametrices for parabolic operators within the calculi.},
  language  = {en}
}
@unpublished{XiaochunWitt2002,
  author    = {Xiaochun, Liu and Witt, Ingo},
  title     = {Pseudodifferential calculi on the half-line respecting prescribed asymptotic types},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26255},
  year      = {2002},
  abstract  = {Contents: 1. Introduction 2. Preliminaries 3. Basic Elements of the Calculus 4. Further Elements of the Calculus},
  language  = {en}
}
@unpublished{Tarkhanov2002,
  author    = {Tarkhanov, Nikolai Nikolaevich},
  title     = {Anisotropic edge problems},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26280},
  year      = {2002},
  abstract  = {We investigate elliptic pseudodifferential operators which degenerate in an anisotropic way on a submanifold of arbitrary codimension. To find Fredholm problems for such operators we adjoint to them boundary and coboundary conditions on the submanifold.The algebra obtained this way is a far reaching generalisation of Boutet de Monvel's algebra of boundary value problems with transmission property. We construct left and right regularisers and prove theorems on hypoellipticity and local solvability.},
  language  = {en}
}
@unpublished{Witt2002,
  author    = {Witt, Ingo},
  title     = {A calculus for a class of finitely degenerate pseudodifferential operators},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26246},
  year      = {2002},
  abstract  = {For a class of degenerate pseudodifferential operators, local parametrices are constructed. This is done in the framework of a pseudodifferential calculus upon adding conditions of trace and potential type, respectively, along the boundary on which the operators degenerate.},
  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}
}
@unpublished{SchroheSeiler1999,
  author    = {Schrohe, Elmar and Seiler, J{\"o}rg},
  title     = {Ellipticity and invertibility in the cone algebra on Lp-Sobolev spaces},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25621},
  year      = {1999},
  abstract  = {Given a manifold B with conical singularities, we consider the cone algebra with discrete asymptotics, introduced by Schulze, on a suitable scale of Lp-Sobolev spaces. Ellipticity is proven to be equivalent to the Fredholm property in these spaces, it turns out to be independent of the choice of p. We then show that the cone algebra is closed under inversion: whenever an operator is invertible between the associated Sobolev spaces, its inverse belongs to the calculus. We use these results to analyze the behaviour of these operators on Lp(B).},
  language  = {en}
}
@unpublished{Fedosov1999,
  author    = {Fedosov, Boris},
  title     = {Pseudo-differential operators and deformation quantization},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25651},
  year      = {1999},
  abstract  = {Using the Riemannian connection on a compact manifold X, we show that the algebra of classical pseudo-differential operators on X generates a canonical deformation quantization on the cotangent manifold T*X. The corresponding Abelian connection is calculated explicitly in terms of the of the exponential mapping. We prove also that the index theorem for elliptic operators may be obtained as a consequence of the index theorem for deformation quantization.},
  language  = {en}
}
@unpublished{Sadykov1999,
  author    = {Sadykov, Timour},
  title     = {Hypergeometric systems of differential equations and amoebas of rational functions},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25665},
  year      = {1999},
  abstract  = {We study the approach to the theory of hypergeometric functions in several variables via a generalization of the Horn system of differential equations. A formula for the dimension of its solution space is given. Using this formula we construct an explicit basis in the space of holomorphic solutions to the generalized Horn system under some assumptions on its parameters. These results are applied to the problem of describing the complement of the amoeba of a rational function, which was posed in [12].},
  language  = {en}
}
@unpublished{Shlapunov2000,
  author    = {Shlapunov, Alexander},
  title     = {On Iterations of double layer potentials},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25687},
  year      = {2000},
  abstract  = {We prove the existence of Hp(D)-limit of iterations of double layer potentials constructed with the use of Hodge parametrix on a smooth compact manifold X, D being an open connected subset of X. This limit gives us an orthogonal projection from Sobolev space Hp(D) to a closed subspace of Hp(D)-solutions of an elliptic operator P of order p ≥ 1. Using this result we obtain formulae for Sobolev solutions to the equation Pu = f in D whenever these solutions exist. This representation involves the sum of a series whose terms are iterations of double layer potentials. Similar regularization is constructed also for a P-Neumann problem in D.},
  language  = {en}
}
@unpublished{Myslivets2000,
  author    = {Myslivets, Simona},
  title     = {On the boundary behaviour of the logarithmic residue integral},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25733},
  year      = {2000},
  abstract  = {A formula of multidimensional logarithmic residue is proved for holomorphic maps with zeroes on the boundary of a bounded domain in Cn.},
  language  = {en}
}
@unpublished{CoriascoSchroheSeiler2001,
  author    = {Coriasco, Sandro and Schrohe, Elmar and Seiler, J{\"o}rg},
  title     = {Bounded imaginary powers of differential operators on manifolds with conical singularities},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25962},
  year      = {2001},
  abstract  = {We study the minimal and maximal closed extension of a differential operator A on a manifold B with conical singularities, when A acts as an unbounded operator on weighted Lp-spaces over B,1 < p < ∞. Under suitable ellipticity assumptions we can define a family of complex powers A up(z), z ∈ C. We also obtain sufficient information on the resolvent of A to show the boundedness of the pure imaginary powers. Examples concern unique solvability and maximal regularity of the solution of the Cauchy problem u' - Δu = f, u(0) = 0, for the Laplacian on conical manifolds.},
  language  = {en}
}
@unpublished{XiaochunWitt2001,
  author    = {Xiaochun, Liu and Witt, Ingo},
  title     = {Asymptotic expansions for bounded solutions to semilinear Fuchsian equations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25912},
  year      = {2001},
  abstract  = {It is shown that bounded solutions to semilinear elliptic Fuchsian equations obey complete asymptoic expansions in terms of powers and logarithms in the distance to the boundary. For that purpose, Schuze's notion of asymptotic type for conormal asymptotics close to a conical point is refined. This in turn allows to perform explicit calculations on asymptotic types - modulo the resolution of the spectral problem for determining the singular exponents in the asmptotic expansions.},
  language  = {en}
}
@unpublished{MaXu2001,
  author    = {Ma, Li and Xu, Xingwang},
  title     = {Positive solutions of a logistic equation on unbounded intervals},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26015},
  year      = {2001},
  abstract  = {In this paper, we study the existence of positive solutions of a one-parameter family of logistic equations on R+ or on R. These equations are stationary versions of the Fisher equations and the KPP equations. We also study the blow up region of a sequence of the solutions when the parameter approachs a critical value and the nonexistence of positive solutions beyond the critical value. We use the direct method and the sub and super solution method.},
  language  = {en}
}
@unpublished{Tarkhanov2004,
  author    = {Tarkhanov, Nikolai Nikolaevich},
  title     = {Harmonic integrals on domains with edges},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26800},
  year      = {2004},
  abstract  = {We study the Neumann problem for the de Rham complex in a bounded domain of Rn with singularities on the boundary. The singularities may be general enough, varying from Lipschitz domains to domains with cuspidal edges on the boundary. Following Lopatinskii we reduce the Neumann problem to a singular integral equation of the boundary. The Fredholm solvability of this equation is then equivalent to the Fredholm property of the Neumann problem in suitable function spaces. The boundary integral equation is explicitly written and may be treated in diverse methods. This way we obtain, in particular, asymptotic expansions of harmonic forms near singularities of the boundary.},
  language  = {en}
}
@unpublished{Krainer2002,
  author    = {Krainer, Thomas},
  title     = {On the inverse of parabolic boundary value problems for large times},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26310},
  year      = {2002},
  abstract  = {We construct algebras of Volterra pseudodifferential operators that contain, in particular, the inverses of the most natural classical systems of parabolic boundary value problems of general form. Parabolicity is determined by the invertibility of the principal symbols, and as a result is equivalent to the invertibility of the operators within the calculus. Existence, uniqueness, regularity, and asymptotics of solutions as t → ∞ are consquences of the mapping properties of the operators in exponentially weighted Sobolev spaces and subspaces with asymptotics. An important aspect of this work is that the microlocal and global kernel structure of the inverse operator (solution operator) of a parabolic boundary value problem for large times is clarified. Moreover, our approach naturally yields qualitative pertubation results for the solvability theory of parabolic boundary value problems. To achieve these results, we assign t = ∞ the meaning of a conical point and treat the operators as totally characteristic pseudodifferential boundary value problems.},
  language  = {en}
}
@unpublished{NazaikinskiiSternin2002,
  author    = {Nazaikinskii, Vladimir and Sternin, Boris},
  title     = {Relative elliptic theory},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26400},
  year      = {2002},
  abstract  = {This paper is a survey of relative elliptic theory (i.e. elliptic theory in the category of smooth embeddings), closely related to the Sobolev problem, first studied by Sternin in the 1960s. We consider both analytic aspects to the theory (the structure of the algebra of morphismus, ellipticity, Fredholm property) and topological aspects (index formulas and Riemann-Roch theorems). We also study the algebra of Green operators arising as a subalgebra of the algebra of morphisms.},
  language  = {en}
}
@unpublished{Davis2002,
  author    = {Davis, Simon},
  title     = {On the absence of large-order divergences in superstring theory},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26452},
  year      = {2002},
  abstract  = {The genus-dependence of multi-loop superstring ams is estimated at large orders in perturbation theory using the super-Schottky group parameterization of supermoduli space. Restriction of the integration region to a subset of supermoduli space and a single fundamental domain of the super-modular group suggests an exponential dependence on the genus. Upper bounds for these estimates are obtained for arbitrary N-point superstring scattering amplitudes and are shown to be consistent with exact results obtained for special type II string amplitudes for orbifold or Calabi-Yau compactifications. The genus-dependence is then obtained by considering the effect of the remaining contribution to the superstring amplitudes after the coefficients of the formally divergent parts of the integrals vanish as a result of a sum over spin structures. The introduction of supersymmetry therefore leads to the elimination of large-order divergences in string pertubation theory, a result which is based only on the supersymmetric generalization of the polyakov measure and not the gauge group of the string model.},
  language  = {en}
}
@unpublished{JunkerSchrohe2001,
  author    = {Junker, Wolfgang and Schrohe, Elmar},
  title     = {Adiabatic vacuum states on general spacetime manifolds : definition, construction, and physical properties},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26100},
  year      = {2001},
  abstract  = {Adiabatic vacuum states are a well-known class of physical states for linear quantum fields n Robertson-Walker spacetimes. We extend the definition of adiabatic vacua to general spacetime manifolds by using the notion of the Sobolev wavefront set. This definition is also applicable to interacting field theories. Hadamard states form a special subclass of the adiabatic vacua. We analyze physical properties of adiabatic vacuum representations of the Klein-Gordon field on globally hyperbolic spacetme manifolds (factoriality, quasiequivalence, local definteness, Haag duality) and construct them explicitly, if the manifold has a compact Cauchy surface.},
  language  = {en}
}
@unpublished{Yagdjian2001,
  author    = {Yagdjian, Karen},
  title     = {Geometric optics for the nonlinear hyperbolic systems of Kirchhoff-type},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26059},
  year      = {2001},
  abstract  = {Contents: 1 Introduction 2 Main result 3 Construction of the asymptotic solutions 3.1 Derivation of the equations for the profiles 3.2 Exsistence of the principal profile 3.3 Determination of Usub(2) and the remaining profiles 4 Stability of the samll global solutions. Justification of One Phase Nonlinear Geometric Optics for the Kirchhoff-type equations 4.1 Stability of the global solutions to the Kirchhoff-type symmetric hyperbolic systems 4.2 The nonlinear system of ordinary differential equations with the parameter 4.3 Some energies estimates 4.4 The dependence of the solution W(t, ξ) on the function s(t) 4.5 The oscillatory integrals of the bilinear forms of the solutions 4.6 Estimates for the basic bilinear form Γsub(s)(t) 4.7 Contraction mapping 4.8 Stability of the global solution 4.9 Justification of One Phase Nonlinear Geometric Optics for the Kirchhoff-type equations},
  language  = {en}
}
@unpublished{YihongLi2001,
  author    = {Yihong, Du and Li, Ma},
  title     = {Some remarks related to De Giorgi's conjecture},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26027},
  year      = {2001},
  abstract  = {For several classes of functions including the special case f(u) = u - u³, we obtain boundedness and symmetry results for solutions of the problem -Δu = f(u) defined on R up(n). Our results complement a number of recent results related to a conjecture of De Giorgi.},
  language  = {en}
}
@unpublished{Galstian2001,
  author    = {Galstian, Anahit},
  title     = {Lp - Lq decay estimates for the equation with exponentially growing coefficient},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26079},
  year      = {2001},
  abstract  = {Contents: 1 Introduction 1 Representation formulas 2 Consideration in the pseudodifferential zone: e up(t) |ξ| ≤ 1 3 Consideration in he hyperbolic zone: e up(t) |ξ| ≥ 1},
  language  = {en}
}
@unpublished{Harutyunyan2001,
  author    = {Harutyunyan, Anahit V.},
  title     = {Toeplitz operators and division theorems in anisotropic spaces of holomorphic functions in the polydisc},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26110},
  year      = {2001},
  abstract  = {This work is an introduction to anisotropic spaces, which have an ω-weight of analytic functions and are generalizations of Lipshitz classes in the polydisc. We prove that these classes form an algebra and are invariant with respect to monomial multiplication. These operators are bounded in these (Lipshitz and Djrbashian) spaces. As an application, we show a theorem about the division by good-inner functions in the mentioned classes is proved.},
  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}
}
@unpublished{NazaikinskiiSternin2001,
  author    = {Nazaikinskii, Vladimir and Sternin, Boris},
  title     = {Some problems of control of semiclassical states for the Schr{\"o}dinger equation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26130},
  year      = {2001},
  abstract  = {Contents: Introduction Controlled Quantum Systems The Asymptotic Controllability Problem The Stabilization Problem Unitarily Nonlinear Equations The Quantum Problem The Stabilization Problem for the Schr{\"o}dinger Equation with a Unitarily Non-linear Control},
  language  = {en}
}
@unpublished{Witt2001,
  author    = {Witt, Ingo},
  title     = {Asymptotic algebras},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26069},
  year      = {2001},
  abstract  = {The concept of asymptotic type that primarily appears in singular and asymptotic analysis is developed. Especially, asymptotic algebras are introduced.},
  language  = {en}
}
@unpublished{Rozenblum2000,
  author    = {Rozenblum, G.},
  title     = {On some analytical index formulas related to operator-valued symbols},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25811},
  year      = {2000},
  abstract  = {For several classes of pseudodifferential operators with operator-valued symbol analytic index formulas are found. The common feature is that uasual index formulas are not valid for these operators. Applications are given to pseudodifferential operators on singular manifolds.},
  language  = {en}
}
@unpublished{SchroheSeiler2002,
  author    = {Schrohe, Elmar and Seiler, J{\"o}rg},
  title     = {The resolvent of closed extensions of cone differential operators},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26378},
  year      = {2002},
  abstract  = {We study an elliptic differential operator on a manifold with conical singularities, acting as an unbounded operator on a weighted Lp-space. Under suitable conditions we show that the resolvent (λ - A )-¹ exists in a sector of the complex plane and decays like 1/|λ| as |λ| -> ∞. Moreover, we determine the structure of the resolvent with enough precision to guarantee existence and boundedness of imaginary powers of A. As an application we treat the Laplace-Beltrami operator for a metric with striaght conical degeneracy and establish maximal regularity for the Cauchy problem u - Δu = f, u(0) = 0.},
  language  = {en}
}
@unpublished{CalinDerChen2004,
  author    = {Calin, Ovidium and Der-Chen, Chang},
  title     = {The geometry on a step 3 Grushin model},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26724},
  year      = {2004},
  abstract  = {In this article we study the geometry associated with the sub-elliptic operator ½ (X²1 +X²2), where X1 = ∂x and X2 = x²/2 ∂y are vector fields on R². We show that any point can be connected with the origin by at least one geodesic and we provide an approximate formula for the number of the geodesics between the origin and the points situated outside of the y-axis. We show there are in¯nitely many geodesics between the origin and the points on the y-axis.},
  language  = {en}
}
@unpublished{GauthierTarkhanov2004,
  author    = {Gauthier, Paul M. and Tarkhanov, Nikolai Nikolaevich},
  title     = {A covering property of the Riemann zeta-function},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26683},
  year      = {2004},
  abstract  = {For each compact subset K of the complex plane C which does not surround zero, the Riemann surface Sζ of the Riemann zeta function restricted to the critical half-strip 0 < Rs < 1/2 contains infinitely many schlicht copies of K lying 'over' K. If Sζ also contains at least one such copy, for some K which surrounds zero, then the Riemann hypothesis fails.},
  language  = {en}
}
@unpublished{KytmanovMyslivetsTarkhanov2002,
  author    = {Kytmanov, Alexander and Myslivets, Simona and Tarkhanov, Nikolai Nikolaevich},
  title     = {Holomorphic Lefschetz formula for manifolds with boundary},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26354},
  year      = {2002},
  abstract  = {The classical Lefschetz fixed point formula expresses the number of fixed points of a continuous map f : M -> M in terms of the transformation induced by f on the cohomology of M. In 1966 Atiyah and Bott extended this formula to elliptic complexes over a compact closed manifold. In particular, they presented a holomorphic Lefschtz formula for compact complex manifolds without boundary, a result, in the framework of algebraic geometry due to Eichler (1957) for holomorphic curves. On compact complex manifolds with boundary the Dolbeault complex is not elliptic, hence the Atiyah-Bott theory is no longer applicable. To get rid of the difficulties related to the boundary behaviour of the Dolbeault cohomology, Donelli and Fefferman (1986) derived a fixed point formula for the Bergman metric. The purpose of this paper is to present a holomorphic Lefschtz formula on a compact complex manifold with boundary},
  language  = {en}
}
@unpublished{DeXingHui2003,
  author    = {De-Xing, Kong and Hui, Yao},
  title     = {Global exact boundary controllability of a class of quasilinear hyperbolic systems of conservation laws II},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26565},
  year      = {2003},
  abstract  = {In this paper, by a new constructive method, the authors reprove the global exact boundary controllability of a class of quasilinear hyperbolic systems of conservation laws with linearly degenerate fields. It is shown that the system with nonlinear boundary conditions is globally exactly boundary controllable in the class of piecewise C¹ functions. In particular, the authors give the optimal control time of the system. Finally, a new application is also given.},
  language  = {en}
}
@unpublished{HuichengWitt2002,
  author    = {Huicheng, Yin and Witt, Ingo},
  title     = {Global singularity structure of weak solutions to 3-D semilinear dispersive wave equations with discontinuous initial data},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26395},
  year      = {2002},
  language  = {en}
}
@unpublished{Camales2003,
  author    = {Camal{\`e}s, Renaud},
  title     = {A note on the ramified Cauchy problem},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26646},
  year      = {2003},
  abstract  = {In this paper, the ramified Cauchy problem in C² for operator with multiple characteristics of constant multiplicity and second member ramified around some analytic set is studied.},
  language  = {en}
}
@techreport{SultanowVolkovCox2017,
  author    = {Sultanow, Eldar and Volkov, Denis and Cox, Sean},
  title     = {Introducing a Finite State Machine for processing Collatz Sequences},
  edition   = {1st version},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-399223},
  year      = {2017},
  abstract  = {The present work will introduce a Finite State Machine (FSM) that processes any Collatz Sequence; further, we will endeavor to investigate its behavior in relationship to transformations of a special infinite input. Moreover, we will prove that the machine's word transformation is equivalent to the standard Collatz number transformation and subsequently discuss the possibilities for use of this approach at solving similar problems. The benefit of this approach is that the investigation of the word transformation performed by the Finite State Machine is less complicated than the traditional number-theoretical transformation.},
  language  = {en}
}
@unpublished{SultanovKalyakinTarkhanov2014,
  author    = {Sultanov, Oskar and Kalyakin, Leonid and Tarkhanov, Nikolai Nikolaevich},
  title     = {Elliptic perturbations of dynamical systems with a proper node},
  volume    = {3},
  number    = {4},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {2193-6943},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70460},
  pages     = {12},
  year      = {2014},
  abstract  = {The paper is devoted to asymptotic analysis of the Dirichlet problem for a second order partial differential equation containing a small parameter multiplying the highest order derivatives. It corresponds to a small perturbation of a dynamical system having a stationary solution in the domain. We focus on the case where the trajectories of the system go into the domain and the stationary solution is a proper node.},
  language  = {en}
}
@phdthesis{Etzold2021,
  author    = {Etzold, Heiko},
  title     = {Neue Zug{\"a}nge zum Winkelbegriff},
  doi       = {10.25932/publishup-50418},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-504187},
  school      = {Universit{\"a}t Potsdam},
  pages     = {300},
  year      = {2021},
  abstract  = {Die Vielf{\"a}ltigkeit des Winkelbegriffs ist gleichermaßen spannend wie herausfordernd in Hinblick auf seine Zug{\"a}nge im Mathematikunterricht der Schule. Ausgehend von verschiedenen Vorstellungen zum Winkelbegriff wird in dieser Arbeit ein Lehrgang zur Vermittlung des Winkelbegriffs entwickelt und letztlich in konkrete Umsetzungen f{\"u}r den Schulunterricht {\"u}berf{\"u}hrt. Dabei erfolgt zun{\"a}chst eine stoffdidaktische Auseinandersetzung mit dem Winkelbegriff, die von einer informationstheoretischen Winkeldefinition begleitet wird. In dieser wird eine Definition f{\"u}r den Winkelbegriff unter der Fragestellung entwickelt, welche Informationen man {\"u}ber einen Winkel ben{\"o}tigt, um ihn beschreiben zu k{\"o}nnen. So k{\"o}nnen die in der fachdidaktischen Literatur auftretenden Winkelvorstellungen aus fachmathematischer Perspektive erneut abgeleitet und validiert werden. Parallel dazu wird ein Verfahren beschrieben, wie Winkel - auch unter dynamischen Aspekten - informationstechnisch verarbeitet werden k{\"o}nnen, so dass Schlussfolgerungen aus der informationstheoretischen Winkeldefinition beispielsweise in dynamischen Geometriesystemen zur Verf{\"u}gung stehen. Unter dem Gesichtspunkt, wie eine Abstraktion des Winkelbegriffs im Mathematikunterricht vonstatten gehen kann, werden die Grundvorstellungsidee sowie die Lehrstrategie des Aufsteigens vom Abstrakten zum Konkreten miteinander in Beziehung gesetzt. Aus der Verkn{\"u}pfung der beiden Theorien wird ein grunds{\"a}tzlicher Weg abgeleitet, wie im Rahmen der Lehrstrategie eine Ausgangsabstraktion zu einzelnen Winkelaspekten aufgebaut werden kann, was die Generierung von Grundvorstellungen zu den Bestandteilen des jeweiligen Winkelaspekts und zum Operieren mit diesen Begriffsbestandteilen erm{\"o}glichen soll. Hierf{\"u}r wird die Lehrstrategie angepasst, um insbesondere den {\"U}bergang von Winkelsituationen zu Winkelkontexten zu realisieren. Explizit f{\"u}r den Aspekt des Winkelfeldes werden, anhand der Untersuchung der Sichtfelder von Tieren, Lernhandlungen und Forderungen an ein Lernmodell beschrieben, die Sch{\"u}lerinnen und Sch{\"u}ler bei der Begriffsaneignung unterst{\"u}tzen. Die T{\"a}tigkeitstheorie, der die genannte Lehrstrategie zuzuordnen ist, zieht sich als roter Faden durch die weitere Arbeit, wenn nun theoriebasiert Designprinzipien generiert werden, die in die Entwicklung einer interaktiven Lernumgebung m{\"u}nden. Hierzu wird u. a. das Modell der Artifact-Centric Activity Theory genutzt, das das Beziehungsgef{\"u}ge aus Sch{\"u}lerinnen und Sch{\"u}lern, dem mathematischen Gegenstand und einer zu entwickelnden App als vermittelndes Medium beschreibt, wobei der Einsatz der App im Unterrichtskontext sowie deren regelgeleitete Entwicklung Bestandteil des Modells sind. Gem{\"a}ß dem Ansatz der Fachdidaktischen Entwicklungsforschung wird die Lernumgebung anschließend in mehreren Zyklen erprobt, evaluiert und {\"u}berarbeitet. Dabei wird ein qualitatives Setting angewandt, das sich der Semiotischen Vermittlung bedient und untersucht, inwiefern sich die Qualit{\"a}t der von den Sch{\"u}lerinnen und Sch{\"u}lern gezeigten Lernhandlungen durch die Designprinzipien und deren Umsetzung erkl{\"a}ren l{\"a}sst. Am Ende der Arbeit stehen eine finale Version der Designprinzipien und eine sich daraus ergebende Lernumgebung zur Einf{\"u}hrung des Winkelfeldbegriffs in der vierten Klassenstufe.},
  language  = {de}
}
@phdthesis{Zass2021,
  author    = {Zass, Alexander},
  title     = {A multifaceted study of marked Gibbs point processes},
  doi       = {10.25932/publishup-51277},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-512775},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 104},
  year      = {2021},
  abstract  = {This thesis focuses on the study of marked Gibbs point processes, in particular presenting some results on their existence and uniqueness, with ideas and techniques drawn from different areas of statistical mechanics: the entropy method from large deviations theory, cluster expansion and the Kirkwood--Salsburg equations, the Dobrushin contraction principle and disagreement percolation. We first present an existence result for infinite-volume marked Gibbs point processes. More precisely, we use the so-called entropy method (and large-deviation tools) to construct marked Gibbs point processes in R^d under quite general assumptions. In particular, the random marks belong to a general normed space S and are not bounded. Moreover, we allow for interaction functionals that may be unbounded and whose range is finite but random. The entropy method relies on showing that a family of finite-volume Gibbs point processes belongs to sequentially compact entropy level sets, and is therefore tight. We then present infinite-dimensional Langevin diffusions, that we put in interaction via a Gibbsian description. In this setting, we are able to adapt the general result above to show the existence of the associated infinite-volume measure. We also study its correlation functions via cluster expansion techniques, and obtain the uniqueness of the Gibbs process for all inverse temperatures β and activities z below a certain threshold. This method relies in first showing that the correlation functions of the process satisfy a so-called Ruelle bound, and then using it to solve a fixed point problem in an appropriate Banach space. The uniqueness domain we obtain consists then of the model parameters z and β for which such a problem has exactly one solution. Finally, we explore further the question of uniqueness of infinite-volume Gibbs point processes on R^d, in the unmarked setting. We present, in the context of repulsive interactions with a hard-core component, a novel approach to uniqueness by applying the discrete Dobrushin criterion to the continuum framework. We first fix a discretisation parameter a>0 and then study the behaviour of the uniqueness domain as a goes to 0. With this technique we are able to obtain explicit thresholds for the parameters z and β, which we then compare to existing results coming from the different methods of cluster expansion and disagreement percolation. Throughout this thesis, we illustrate our theoretical results with various examples both from classical statistical mechanics and stochastic geometry.},
  language  = {en}
}
@phdthesis{Berner2016,
  author    = {Berner, Nadine},
  title     = {Deciphering multiple changes in complex climate time series using Bayesian inference},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100065},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 135},
  year      = {2016},
  abstract  = {Change points in time series are perceived as heterogeneities in the statistical or dynamical characteristics of the observations. Unraveling such transitions yields essential information for the understanding of the observed system's intrinsic evolution and potential external influences. A precise detection of multiple changes is therefore of great importance for various research disciplines, such as environmental sciences, bioinformatics and economics. The primary purpose of the detection approach introduced in this thesis is the investigation of transitions underlying direct or indirect climate observations. In order to develop a diagnostic approach capable to capture such a variety of natural processes, the generic statistical features in terms of central tendency and dispersion are employed in the light of Bayesian inversion. In contrast to established Bayesian approaches to multiple changes, the generic approach proposed in this thesis is not formulated in the framework of specialized partition models of high dimensionality requiring prior specification, but as a robust kernel-based approach of low dimensionality employing least informative prior distributions. First of all, a local Bayesian inversion approach is developed to robustly infer on the location and the generic patterns of a single transition. The analysis of synthetic time series comprising changes of different observational evidence, data loss and outliers validates the performance, consistency and sensitivity of the inference algorithm. To systematically investigate time series for multiple changes, the Bayesian inversion is extended to a kernel-based inference approach. By introducing basic kernel measures, the weighted kernel inference results are composed into a proxy probability to a posterior distribution of multiple transitions. The detection approach is applied to environmental time series from the Nile river in Aswan and the weather station Tuscaloosa, Alabama comprising documented changes. The method's performance confirms the approach as a powerful diagnostic tool to decipher multiple changes underlying direct climate observations. Finally, the kernel-based Bayesian inference approach is used to investigate a set of complex terrigenous dust records interpreted as climate indicators of the African region of the Plio-Pleistocene period. A detailed inference unravels multiple transitions underlying the indirect climate observations, that are interpreted as conjoint changes. The identified conjoint changes coincide with established global climate events. In particular, the two-step transition associated to the establishment of the modern Walker-Circulation contributes to the current discussion about the influence of paleoclimate changes on the environmental conditions in tropical and subtropical Africa at around two million years ago.},
  language  = {en}
}
@misc{GoychukKharchenko2013,
  author    = {Goychuk, Igor and Kharchenko, Vasyl O.},
  title     = {Rocking subdiffusive ratchets},
  series = {Mathematical Modelling of Natural Phenomena},
  journal   = {Mathematical Modelling of Natural Phenomena},
  number    = {622},
  issn      = {1866-8372},
  doi       = {10.1051/mmnp/20138210},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416138},
  pages     = {15},
  year      = {2013},
  abstract  = {We study origin, parameter optimization, and thermodynamic efficiency of isothermal rocking ratchets based on fractional subdiffusion within a generalized non-Markovian Langevin equation approach. A corresponding multi-dimensional Markovian embedding dynamics is realized using a set of auxiliary Brownian particles elastically coupled to the central Brownian particle (see video on the journal web site). We show that anomalous subdiffusive transport emerges due to an interplay of nonlinear response and viscoelastic effects for fractional Brownian motion in periodic potentials with broken space-inversion symmetry and driven by a time-periodic field. The anomalous transport becomes optimal for a subthreshold driving when the driving period matches a characteristic time scale of interwell transitions. It can also be optimized by varying temperature, amplitude of periodic potential and driving strength. The useful work done against a load shows a parabolic dependence on the load strength. It grows sublinearly with time and the corresponding thermodynamic efficiency decays algebraically in time because the energy supplied by the driving field scales with time linearly. However, it compares well with the efficiency of normal diffusion rocking ratchets on an appreciably long time scale.},
  language  = {en}
}
@phdthesis{Oancea2021,
  author    = {Oancea, Marius-Adrian},
  title     = {Spin Hall effects in general relativity},
  doi       = {10.25932/publishup-50229},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-502293},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 123},
  year      = {2021},
  abstract  = {The propagation of test fields, such as electromagnetic, Dirac or linearized gravity, on a fixed spacetime manifold is often studied by using the geometrical optics approximation. In the limit of infinitely high frequencies, the geometrical optics approximation provides a conceptual transition between the test field and an effective point-particle description. The corresponding point-particles, or wave rays, coincide with the geodesics of the underlying spacetime. For most astrophysical applications of interest, such as the observation of celestial bodies, gravitational lensing, or the observation of cosmic rays, the geometrical optics approximation and the effective point-particle description represent a satisfactory theoretical model. However, the geometrical optics approximation gradually breaks down as test fields of finite frequency are considered. In this thesis, we consider the propagation of test fields on spacetime, beyond the leading-order geometrical optics approximation. By performing a covariant Wentzel-Kramers-Brillouin analysis for test fields, we show how higher-order corrections to the geometrical optics approximation can be considered. The higher-order corrections are related to the dynamics of the spin internal degree of freedom of the considered test field. We obtain an effective point-particle description, which contains spin-dependent corrections to the geodesic motion obtained using geometrical optics. This represents a covariant generalization of the well-known spin Hall effect, usually encountered in condensed matter physics and in optics. Our analysis is applied to electromagnetic and massive Dirac test fields, but it can easily be extended to other fields, such as linearized gravity. In the electromagnetic case, we present several examples where the gravitational spin Hall effect of light plays an important role. These include the propagation of polarized light rays on black hole spacetimes and cosmological spacetimes, as well as polarization-dependent effects on the shape of black hole shadows. Furthermore, we show that our effective point-particle equations for polarized light rays reproduce well-known results, such as the spin Hall effect of light in an inhomogeneous medium, and the relativistic Hall effect of polarized electromagnetic wave packets encountered in Minkowski spacetime.},
  language  = {en}
}
@unpublished{ShlapunovTarkhanov2001,
  author    = {Shlapunov, Alexander and Tarkhanov, Nikolai Nikolaevich},
  title     = {Duality by reproducing kernels},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26095},
  year      = {2001},
  abstract  = {Let A be a determined or overdetermined elliptic differential operator on a smooth compact manifold X. Write Ssub(A)(D) for the space of solutions to thesystem Au = 0 in a domain D ⊂ X. Using reproducing kernels related to various Hilbert structures on subspaces of Ssub(A)(D) we show explicit identifications of the dual spaces. To prove the "regularity" of reproducing kernels up to the boundary of D we specify them as resolution operators of abstract Neumann problems. The matter thus reduces to a regularity theorem for the Neumann problem, a well-known example being the ∂-Neumann problem. The duality itself takes place only for those domains D which possess certain convexity properties with respect to A.},
  language  = {en}
}
@misc{Reich1990,
  author    = {Reich, Sebastian},
  title     = {On a geometrical interpretation of differential-algebraic equations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-46683},
  year      = {1990},
  abstract  = {The subject of this paper is the relation of differential-algebraic equations (DAEs) to vector fields on manifolds. For that reason, we introduce the notion of a regular DAE as a DAE to which a vector field uniquely corresponds. Furthermore, a technique is described which yields a family of manifolds for a given DAE. This socalled family of constraint manifolds allows in turn the formulation of sufficient conditions for the regularity of a DAE. and the definition of the index of a regular DAE. We also state a method for the reduction of higher-index DAEs to lowsr-index ones that can be solved without introducing additional constants of integration. Finally, the notion of realizability of a given vector field by a regular DAE is introduced, and it is shown that any vector field can be realized by a regular DAE. Throughout this paper the problem of path-tracing is discussed as an illustration of the mathematical phenomena.},
  language  = {en}
}
@misc{ChampagnatRoelly2008,
  author    = {Champagnat, Nicolas and Roelly, Sylvie},
  title     = {Limit theorems for conditioned multitype Dawson-Watanabe processes and Feller diffusions},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18610},
  year      = {2008},
  abstract  = {A multitype Dawson-Watanabe process is conditioned, in subcritical and critical cases, on non-extinction in the remote future. On every finite time interval, its distribution is absolutely continuous with respect to the law of the unconditioned process. A martingale problem characterization is also given. Several results on the long time behavior of the conditioned mass process - the conditioned multitype Feller branching diffusion - are then proved. The general case is first considered, where the mutation matrix which models the interaction between the types, is irreducible. Several two-type models with decomposable mutation matrices are analyzed too .},
  language  = {en}
}
@unpublished{ConfortiLeonardMurretal.2014,
  author    = {Conforti, Giovanni and L{\´e}onard, Christian and Murr, R{\"u}diger and Roelly, Sylvie},
  title     = {Bridges of Markov counting processes : reciprocal classes and duality formulas},
  volume    = {3},
  number    = {9},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {2193-6943},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71855},
  pages     = {12},
  year      = {2014},
  abstract  = {Processes having the same bridges are said to belong to the same reciprocal class. In this article we analyze reciprocal classes of Markov counting processes by identifying their reciprocal invariants and we characterize them as the set of counting processes satisfying some duality formula.},
  language  = {en}
}
@misc{Reich1994,
  author    = {Reich, Sebastian},
  title     = {Momentum conserving symplectic integrators},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16824},
  year      = {1994},
  abstract  = {In this paper, we show that symplectic partitioned Runge-Kutta methods conserve momentum maps corresponding to linear symmetry groups acting on the phase space of Hamiltonian differential equations by extended point transformation. We also generalize this result to constrained systems and show how this conservation property relates to the symplectic integration of Lie-Poisson systems on certain submanifolds of the general matrix group GL(n).},
  language  = {en}
}
@misc{ImkellerRoelly2007,
  author    = {Imkeller, Peter and Roelly, Sylvie},
  title     = {Die Wiederentdeckung eines Mathematikers: Wolfgang D{\"o}blin},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16397},
  year      = {2007},
  abstract  = {"Considerons une particule mobile se mouvant aleatoirement sur la droite (ou sur un segment de droite). Supposons qu'il existe une probabilite F(x,y;s,t) bien definie pour que la particule se trouvant a l'instant s dans la position x se trouve a l'instant t (> s) a gauche de y, probabilite independante du mouvement anterieur de la particule...." Mit diesen Worten beginnt eines der ber{\"u}hmtesten mathematischen Manuskripte des letzten Jahrhunderts. Es stammt vom Soldaten Wolfgang D{\"o}blin, Sohn des deutschen Schriftstellers Alfred D{\"o}blin, und tr{\"a}gt den Titel "Sur l'equation de Kolmogoroff". Seine Ver{\"o}ffentlichung verbindet sich mit einer unglaublichen Geschichte. Wolfgang D{\"o}blin, stationiert mit seiner Einheit in den Ardennen im Winter 1939/1940, arbeitete an diesem Manuskript. Er entschloss sich, es als versiegeltes Manuskript an die Academie des Sciences in Paris zu schicken. Aber er kehrte nie aus diesem Krieg zur{\"u}ck. Sein Manuskript blieb 60 Jahre unter Verschluss im Archiv, und wurde erst im Jahre 2000 ge{\"o}ffnet. Wie weit D{\"o}blin damit seiner Zeit voraus war, wurde erkannt, nachdem es von Bernard Bru und Marc Yor ausgewertet worden war. Im ersten Satz umschreibt W. D{\"o}blin gleichzeitig das Programm des Manuskripts: "Wir betrachten ein bewegliches Teilchen, das sich zuf{\"a}llig auf der Geraden (oder einem Teil davon) bewegt." Er widmet sich damit der Aufgabe, die Fundamente eines Gebiets zu legen, das wir heute als stochastische Analysis bezeichnen.},
  language  = {de}
}
@unpublished{Siegert2010,
  author    = {Siegert, Sabine},
  title     = {Das Sankt-Petersburg-Paradoxon},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49595},
  year      = {2010},
  abstract  = {Aus dem Inhalt: 1 Einleitung 2 Historische L{\"o}sungsans{\"a}tze 3 Martingal-Ansatz 4 Markovketten-Ansatz 5 Asymptotische Interpretationen 6 Bezug zur Praxis 7 R{\´e}sum{\´e} Anhang Literaturverzeichnis},
  language  = {de}
}
@unpublished{PraLouisMinelli2008,
  author    = {Pra, Paolo Dai and Louis, Pierre-Yves and Minelli, Ida G.},
  title     = {Complete monotone coupling for Markov processes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18286},
  year      = {2008},
  abstract  = {We formalize and analyze the notions of monotonicity and complete monotonicity for Markov Chains in continuous-time, taking values in a finite partially ordered set. Similarly to what happens in discrete-time, the two notions are not equivalent. However, we show that there are partially ordered sets for which monotonicity and complete monotonicity coincide in continuoustime but not in discrete-time.},
  language  = {de}
}
@unpublished{Paneah2002,
  author    = {Paneah, Boris},
  title     = {Dynamic methods in the general theory of cauchy type functional equations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26295},
  year      = {2002},
  abstract  = {Contents: 1 Introduction. Denfitions and Discussions 2 Solvability of the Cauchy Type Functional Equations 2.1 The Case of a P-configuration 2.2 The Case of a Z-configuration 2.3 Multiplicative Cauchy type functional equations 3 Problems in Analysis Reducing to Cauchy Type Functional Equations 3.1 Some problems in Integral Geometry and Cauchy Functional Equations 3.2 First Boundary Problem for Hyperbolic Differential Equations and Cauchy Type Functional Equations 4 Functional Equations Determining Polynomials},
  language  = {en}
}
@unpublished{Karp2009,
  author    = {Karp, Lavi},
  title     = {On the well-posedness of the vacuum Einstein's equations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-36593},
  year      = {2009},
  abstract  = {The Cauchy problem of the vacuum Einstein's equations aims to find a semimetric g(αβ) of a spacetime with vanishing Ricci curvature Rα,β and prescribed initial data. Under the harmonic gauge condition, the equations Rα,β = 0 are transferred into a system of quasi-linear wave equations which are called the reduced Einstein equations. The initial data for Einstein's equations are a proper Riemannian metric h(αβ) and a second fundamental form K(αβ). A necessary condition for the reduced Einstein equation to satisfy the vacuum equations is that the initial data satisfy Einstein constraint equations. Hence the data (h(αβ),K(αβ)) cannot serve as initial data for the reduced Einstein equations. Previous results in the case of asymptotically flat spacetimes provide a solution to the constraint equations in one type of Sobolev spaces, while initial data for the evolution equations belong to a different type of Sobolev spaces. The goal of our work is to resolve this incompatibility and to show that under the harmonic gauge the vacuum Einstein equations are well-posed in one type of Sobolev spaces.},
  language  = {en}
}