@unpublished{XiaochunWitt2002, author = {Xiaochun, Liu and Witt, Ingo}, title = {Pseudodifferential calculi on the half-line respecting prescribed asymptotic types}, url =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 Further Elements of the Calculus}, language = {en} } @unpublished{Tarkhanov2002, author = {Tarkhanov, Nikolai Nikolaevich}, title = {Anisotropic edge problems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26280},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construct left and right regularisers and prove theorems on hypoellipticity and local solvability.}, language = {en} } @unpublished{Witt2002, author = {Witt, Ingo}, title = {A calculus for a class of finitely degenerate pseudodifferential operators}, url =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of trace and potential type, respectively, along the boundary on which the operators degenerate.}, language = {en} } @unpublished{LiuYangLu2002, author = {Liu, Weian and Yang, Yin and Lu, Gang}, title = {Viscosity solutions of fully nonlinear parabolic systems}, url =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 The results here generalize those in [2] and [3].}, language = {en} } @unpublished{Krainer2002, author = {Krainer, Thomas}, title = {On the inverse of parabolic boundary value problems for large times}, url =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{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{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{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} }