Sökning: "weak compactness"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden weak compactness.

1. 1. Two Problems on Existence and Approximation Related to the Boltzmann Equation

   Författare :Vladislav Panferov; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boltzmann equation; Povzner type models; diffuse reflection; discrete-velocity models; existence for large data; weak compactness; consistency; convergence; diffuse reflection;

   Sammanfattning : In this thesis, two different types of problems related to the Boltzmann equation of kinetic theory are studied. The first part is devoted to establishing consistency and convergence for discrete-velocity models of the Boltzmann equation. For a new such model, introduced by the author jointly with A. LÄS MER

3. 2. Critical point theory with applications to semilinear problems without compactness

   Författare :Sara Maad; Jacqueline Fleckinger; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; MATEMATIK; MATHEMATICS; MATEMATIK; Mathematics; Matematik;

   Sammanfattning : The thesis consists of four papers which all regard the study of critical point theory and its applications to boundary value problems of semilinear elliptic equations. More specifically, let Ω be a domain, and consider a boundary value problem of the form -L u + u = f(x,u) in Ω, and with the boundary condition u=0. LÄS MER

4. 3. Homogenization of Partial Differential Equations using Multiscale Convergence Methods

   Författare :Pernilla Johnsen; Liselott Flodén; Anders Holmbom; Marianne Olsson Lindberg; Jens Persson; Niklas Wellander; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; homogenization theory; two-scale convergence; multiscale convergence; very weak multiscale convergence; evolution multiscale convergence; very weak evolution multiscale convergence; linear parabolic problems; linear hyperbolic-parabolic problems;

   Sammanfattning : The focus of this thesis is the theory of periodic homogenization of partial differential equations and some applicable concepts of convergence. More precisely, we study parabolic problems exhibiting both spatial and temporal microscopic oscillations and a vanishing volumetric heat capacity type of coefficient. LÄS MER

5. 4. Some new results concerning boundedness and compactness for embeddings between spaces with multiweighted derivatives

   Författare :Zamira Abdikalikova; Victor Burenkov; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

   Sammanfattning : This Doctoral Thesis consists of five chapters, which deal with a new Sobolev type function space called the space with multiweighted derivatives. This space is a generalization of the usual one dimensional Sobolev space. As basis for this space serves some differential operators containing weight functions. LÄS MER

7. 5. Further Investigations of Convergence Results for Homogenization Problems with Various Combinations of Scales

   Författare :Tatiana Danielsson; Anders Holmbom; Liselott Flodén; Marianne Olsson Lindberg; Erika Schagatay; Peter Wall; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis is based on six papers. We study the homogenization of selected parabolic problems with one or more microscopic scales in space and time, respectively. LÄS MER