Almost continuous functions with closed graphs
An adaptive -discontinuous Galerkin approach for nonlinear convection-diffusion problems
We deal with a numerical solution of nonlinear convection-diffusion equations with the aid of the discontinuous Galerkin method (DGM). We propose a new -adaptation technique, which is based on a combination of a residuum estimator and a regularity indicator. The residuum estimator as well as the regularity indicator are easily evaluated quantities without the necessity to solve any local problem and/or any reconstruction of the approximate solution. The performance of the proposed -DGM is demonstrated....
An application of principal bundles to coloring of graphs and hypergraphs
An interesting connection between the chromatic number of a graph and the connectivity of an associated simplicial complex , its “neighborhood complex”, was found by Lovász in 1978 (cf. L. Lovász [J. Comb. Theory, Ser. A 25, 319-324 (1978; Zbl 0418.05028)]). In 1986 a generalization to the chromatic number of a -uniform hypergraph , for an odd prime, using an associated simplicial complex , was found ([N. Alon, P. Frankl and L. Lovász, Trans. Am. Math. Soc. 298, 359-370 (1986; Zbl 0605.05033)],...
An application of quaternionic analysis to the solution of time-independent Maxwell equations and of Stokes’ equation
An application of the averaged gradient technique
An Approach to Similarity Search for Mathematical Expressions using MathML
The recent global computerization and digitization trend has helped to increase the numbers of documents with mathematical expressions on the Web. These mathematical expressions have their own unique structures, and therefore, it is not an easy task for traditional search systems targeting natural languages to deal with them. We propose a similarity search method for mathematical equations that is particularly adapted to the tree structures expressed by MathML based on this background. The similarity...
An electromagnetic free-boundary problem
An infinite dimensional version of the third Lie theorem
The concept of evolution operator is used to introduce a weak Lie subgroup of a regular Lie group, and to give a new version of the third Lie theorem. This enables the author to formulate and to study the problem of integrability of infinite-dimensional Lie algebras. Several interesting examples are presented.
An international symposium honouring professor Karel Rektorys' eightieth. Foreword
An introduction to algebraic K-theory
This paper gives an exposition of algebraic K-theory, which studies functors , an integer. Classically introduced by Bass in the mid 60’s (based on ideas of Grothendieck and others) and introduced by Milnor [Introduction to algebraic K-theory, Annals of Math. Studies, 72, Princeton University Press, 1971: Zbl 0237.18005]. These functors are defined and applications to topological K-theory (Swan), number theory, topology and geometry (the Wall finiteness obstruction to a CW-complex being finite,...
An introduction to Cartan Geometries
A principal bundle with a Lie group consists of a manifold and a free proper smooth -action . There is a unique smooth manifold structure on the quotient space such that the canonical map is smooth. is called a base manifold and stands for the bundle. The most fundamental examples of principal bundles are the homogeneous spaces , where is a closed subgroup of . The pair is a Klein pair. A model geometry consists of a Klein pair and a Lie group with Lie algebra . In this...
An introduction to spectral and differential geometry in Carnot-Carathéodory spaces
An Online Repository of Mathematical Samples
With a growing community of researchers working on the recognition, parsing and digital exploitation of mathematical formulae, a need has arisen for a set of samples or benchmarks which can be used to compare, evaluate and help to develop different implementations and algorithms. The benchmark set would have to cover a wide range of mathematics, contain enough information to be able to search for specific samples and be accessible to the whole community. In this paper, we propose an on-line system...
Analysis of the discontinuous Galerkin finite element method applied to a scalar nonlinear convection-diffusion equation
We deal with a scalar nonstationary convection-diffusion equation with nonlinear convective as well as diffusive terms which represents a model problem for the solution of the system of the compressible Navier-Stokes equations describing a motion of viscous compressible fluids. We present a discretization of this model equation by the discontinuous Galerkin finite element method. Moreover, under some assumptions on the nonlinear terms, domain partitions and the regularity of the exact solution,...
Analytical solution of rotationally symmetric Stokes flow near corners
We present analytical solution of the Stokes problem in rotationally symmetric domains. This is then used to find the asymptotic behaviour of the solution in the vicinity of corners, also for Navier-Stokes equations. We apply this to construct very precise numerical finite element solution.
Analytical solution of Stokes flow near corners and applications to numerical solution of Navier-Stokes equations with high precision
We present analytical solution of the Stokes problem in 2D domains. This is then used to find the asymptotic behavior of the solution in the vicinity of corners, also for Navier-Stokes equations in 2D. We apply this to construct very precise numerical finite element solution.
Announcement of an international symposium on semigroup theory and related fields.
Application of Richardson extrapolation with the Crank-Nicolson scheme for multi-dimensional advection
Multi-dimensional advection terms are an important part of many large-scale mathematical models which arise in different fields of science and engineering. After applying some kind of splitting, these terms can be handled separately from the remaining part of the mathematical model under consideration. It is important to treat the multi-dimensional advection in a sufficiently accurate manner. It is shown in this paper that high order of accuracy can be achieved when the well-known Crank-Nicolson...
Applications of the side approximation theorem for surfaces
Applications of topology to foundations of mathematics