Sökning: "Semigroup"

Visar resultat 1 - 5 av 16 avhandlingar innehållade ordet Semigroup.

  1. 1. Some Markov Processes in Finance and Kinetics : Markov Processes

    Författare :Mattias Sunden; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; CGMY process; Collision kernel; Direct simulation Monte Carlo; Diffusion approximation; Extreme value theory; Feller process; Generalized hyperbolic process; Generalized $z$-process; Infinitesimal generator; Laplace-Beltrami operator; L evy Processes; Long-tailed distribution; Kac equation; Kac model; Markov process; Semigroup; Semi-heavy tailed distirbution; Spectral gap; Subexponential distibrution; Superexponential distribution; Tauberian theorem; Thermostat.; Diffusion approximation;

    Sammanfattning : This thesis consists of four papers. The first two papers treat extremes for L\'evy processes, while papers three and four treat the Kac model with unbounded collision kernel. LÄS MER

  3. 2. Ekedahl Invariants, Veronese Modules and Linear Recurrence Varieties

    Författare :Ivan Martino; Anders Björner; Volkmar Welker; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ekedahl Invariants; Noether Problem; Bogomolov Multiplier; Cyclic quotient singularities; Veronese Modules; Pile simplicial complex; Semigroup Rings; Betti Numbers; Mathematics; matematik;

    Sammanfattning : The title of this thesis refers to the three parts of which it is composed.The first part concerns the Ekedahl Invariants, new geometric invariants for finite groups introduced in 2009 by Torsten Ekedahl. LÄS MER

  4. 3. The Diamond Lemma for Power Series Algebras

    Författare :Lars Hellström; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematical analysis; diamond lemma; power series algebra; Gröbner basis; embedding into skew fields; archimedean element in semigroup; q-deformed Heisenberg--Weyl algebra; polynomial degree; ring norm; Birkhoff orthogonality; filtered structure; Matematisk analys; Mathematical analysis; Analys; Mathematics; matematik;

    Sammanfattning : The main result in this thesis is the generalisation of Bergman's diamond lemma for ring theory to power series rings. This generalisation makes it possible to treat problems in which there arise infinite descending chains. LÄS MER

  5. 4. Semigroups, multisemigroups and representations

    Författare :Love Forsberg; Volodymyr Mazorchuk; Ernst Dieterich; Stuart Margolis; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; representation theory; semigroups; multisemigroups; category theory; 2-categories;

    Sammanfattning : This thesis consists of four papers about the intersection between semigroup theory, category theory and representation theory. We say that a representation of a semigroup by a matrix semigroup is effective if it is injective and define the effective dimension of a semigroup S as the minimal n such that S has an effective representation by square matrices of size n. LÄS MER

  7. 5. The Continuous Galerkin Method for Fractional Order Viscoelasticity

    Författare :Fardin Saedpanah; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : We consider a fractional order integro-differential equation with a weakly singular convolution kernel. The equation with homogeneous Dirichlet boundary conditions is reformulated as an abstract Cauchy problem, and well-posedness is verified in the context of linear semigroup theory. LÄS MER