@unpublished{ShlapunovTarkhanov2001, author = {Shlapunov, Alexander and Tarkhanov, Nikolai Nikolaevich}, title = {Duality by reproducing kernels}, url =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takes place only for those domains D which possess certain convexity properties with respect to A.}, language = {en} } @unpublished{Paneah2001, author = {Paneah, Boris}, title = {On a new problem in integral geometry related to boundary problems for partial differential equations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26089}, year = {2001}, abstract = {Contents: 1 Introduction 2 Statement of the problem and definitions 3 The main results 4 Proof of theorem 2 4.1 Reduction of problem (2) to functional - integral equations 4.2 The uniqueness of a solution of equation (2) 4.3 The existence of a solution of equation (2) 5 Proof of theorem 1 6 Proof of theorem 3 7 First boundary problem for hyperbolic differential equations 7.1 Statement of the problem 7.2 The formulation of the result and a sketch of the proof}, language = {en} } @unpublished{Galstian2001, author = {Galstian, Anahit}, title = {Lp - Lq decay estimates for the equation with exponentially growing coefficient}, url =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pseudodifferential zone: e up(t) |ξ| ≤ 1 3 Consideration in he hyperbolic zone: e up(t) |ξ| ≥ 1}, language = {en} } @unpublished{Witt2001, author = {Witt, Ingo}, title = {Asymptotic algebras}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26069}, year = {2001}, abstract = {The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 Especially, asymptotic algebras are introduced.}, language = {en} } @unpublished{Yagdjian2001, author = {Yagdjian, Karen}, title = {Geometric optics for the nonlinear hyperbolic systems of Kirchhoff-type}, url =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{KapanadzeSchulze2001, author = {Kapanadze, David and Schulze, Bert-Wolfgang}, title = {Symbolic calculus for boundary value problems on manifolds with edges}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26046}, year = {2001}, abstract = {Boundary value problems for (pseudo-) differential operators on a manifold with edges can be characterised by a hierarchy of symbols. The symbol structure is responsible or ellipicity and for the nature of parametrices within an algebra of "edge-degenerate" pseudo-differential operators. The edge symbol component of that hierarchy takes values in boundary value problems on an infinite model cone, with edge variables and covariables as parameters. Edge symbols play a crucial role in this theory, in particular, the contribution with holomorphic operatot-valued Mellin symbols. We establish a calculus in s framework of "twisted homogenity" that refers to strongly continuous groups of isomorphisms on weighted cone Sobolev spaces. We then derive an equivalent representation with a particularly transparent composition behaviour.}, 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{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{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{KrainerSchulze2001, author = {Krainer, Thomas and Schulze, Bert-Wolfgang}, title = {On the inverse of parabolic systems of partial differential equations of general form in an infinite space-time cylinder [Part 3: Chapter 6+7]}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26000}, year = {2001}, abstract = {We consider general parabolic systems of equations on the infinite time interval in case of the underlying spatial configuration is a closed manifold. The solvability of equations is studied both with respect to time and spatial variables in exponentially weighted anisotropic Sobolev spaces, and existence and maximal regularity statements for parabolic equations are proved. Moreover, we analyze the long-time behaiour of solutions in terms of complete asymptotic expansions. These results are deduced from a pseudodifferential calculus that we construct explicitly. This algebra of operators is specifically designed to contain both the classical systems of parabolic equations of general form and their inverses, parabolicity being reflected purely on symbolic level. To this end, we assign t = ∞ the meaning of an anisotropic conical point, and prove that this interprtation is consistent with the natural setting in the analysis of parabolic PDE. Hence, major parts of this work consist of the construction of an appropriate anisotropiccone calculus of so-called Volterra operators. In particular, which is the most important aspect, we obtain the complete characterization of the microlocal and the global kernel structure of the inverse of parabolicsystems in an infinite space-time cylinder. Moreover, we obtain perturbation results for parabolic equations from the investigation of the ideal structure of the calculus.}, language = {en} }