Browsing Institut für Mathematik by Title
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20110927BuchBaxter QOperators and Representations of Yangians We develop a new approach to Baxter Qoperators by relating them to the theory of Yangians, which are the simplest examples for quantum groups. Here we open up a new chapter in this theory and study certain degenerate ...

20060101BuchBilateral Gamma Distributions and Processes in Financial Mathematics We present a class of Lévy processes for modelling financial market fluctuations: Bilateral Gamma processes. Our starting point is to explore the properties of bilateral Gamma distributions, and then we turn to their ...

20110811BuchBoundary Layer Solutions to Problems with Infinite Dimensional Singular and Regular Perturbations We prove existence, local uniqueness and asymptotic estimates for boundary layer solutions to singularly perturbed equations of the type $(\varepsilon(x)^2 u'(x))'=f(x,u(x))+ g(x,u(x),\varepsilon(x) u'(x)), 0< x

20110811BuchBoundary Layer Solutions to Singularly Perturbed Problems via the Implicit Function Theorem We prove existence, local uniqueness and asymptotic estimates for boundary layer solutions to singularly perturbed problems of the type $\varepsilon^2 u''=f(x,u,\varepsilon u',\varepsilon), 0< x

20040503BuchCharacterization and Computation of a "Good Control" Models for physical systems often take the form of implicit or behavioral models. One important problem is the identification of which combinations of variables are good candidtates for control variables. This paper first ...

20061101BuchCharacterization of Calmness for Banach space mappings We characterize calmness of multifunctions explicitly by calmness of level sets to globally Lipschitz functions, by convergence of specific solution methods for the related inclusions as well as by solvability of crucial ...

20051026BuchCharacterization of stability for cone increasing constraint mappings We investigate stability (in terms of metric regularity) for the specific class of cone increasing constraint mappings. This class is of interest in problems with additional knowledge on some nondecreasing behavior of the ...

20051104BuchCharacterizing differential algebraic equations without the use of derivative arrays For a large class of differential algebraic equations with properly stated leading terms and nonsmooth data, an index characterization in terms of the original coefficients and their only first partial derivatives is given. ...

20110920BuchComputation of Iterative operatorsplitting methods In this paper we describe a computation of iterative operatorsplitting method, which are known as competitive splitting methods. We derived a closed form, based on commutators for the iterative method. The schemes apply ...

20000704BuchComputing Green Currents via the Heat Kernel Let X be a compact Kähler manifold. We show that there exists a unique Green current gY for any cycle Y in X. We show that the current gY is a form with L1coefficients. The heat kernel applied to the Dirac distribution ...

20110811BuchConsistency of Iterative OperatorSplitting Methods In this paper we describe a different operatorsplitting method for decoupling complex equations with multidimensional and multiphysical processes for applications for porous media and phasetransitions. We introduce ...

20051109BuchConsistent initial values for DAE systems in circuit simulation One of the difficulties of the numerical integration methods for differentialalgebraic equations (DAEs) is computing consistent initial values before starting the integration, i.e. calculating values that satisfy the given ...

20060101BuchConvergence of adaptive FEM for a class of degenerate convex minimization problems A class of degenerate convex minimization problems allows for some adaptive finite element method (AFEM) to compute strongly converging stress approximations. The algorithm AFEM consists of successive loops of the form ...

20110920BuchCoupled Navier StokesMolecular Dynamics Simulation using Iterative OperatorSplitting Methods In this paper, we contribute a multiscale method based on an iterative operator splitting method, which takes into account the disparity of the macro and microscopic scales. We couple Navier Stokes and Molecular Dynamics ...

20051117BuchCriteria for the trivial solution of differential algebraic equations with small nonlinearities to be asymptotically stable Differential algebraic equations consisting of a constant coefficient linear part and a small nonlinearity are considered. Conditions that enable linearizations to work well are discussed. In particular, for index2 ...

19970127BuchCurves in P3 with good restriction of the tangent bundle Restriction of a stable vector bundle on a variety to a subvariety does not always preserves stability. Here we consider this situation for the P3 the tangent bundle E of the projective space and its restriction to space ...

20000328BuchCyclotomic Curve Families over Elliptic Curves with Complete PicardEinstein Metric According to a problem of Hirzebruch we look for models of biproducts of elliptic CMcurves with Picard modular structure. We introduce the singular mean value of crossing elliptic divisors on surfaces and determine its ...

20051102BuchDecoding of codes on Picard curves The Picard curves are genus three curves with a non trivial automorphism, which have been intensively studied due their connection with interesting number theoretic problems. In 1989, R. Pellikaan obtained an algorithm ...

20051020BuchDecomposition of a MultiStage Stochastic Programfor Power Dispatch We develop a multistage stochastic program for the optimal dispatch of electric power under uncertain demand in a generation system comprising thermal and pumped storage hydro plants. Based on an abstract duality argument ...

20051102BuchDelay differential equations driven by Lévy processes: stationarity and Feller properties We consider a stochastic delay differential equation driven by a general Lévy process. Both, the drift and the noise term may depend on the past, but only the drift term is assumed to be linear. We show that the segment ...