-semisymmetric spaces and concircular vector fields
Table of contents
Table of contents
Table of Contents
Table of Contents
The accuracy of numerically computed orbits of dynamical systems
The approximate symmetries of the vacuum Einstein equations
The author reviews the theory of approximate infinitesimal symmetries of partial differential equations. Based on this and on Ibragimov's result on the general symmetries of the vacuum Einstein equation, he proposes a method to calculate approximate symmetries of the non-vacuum Einstein equation: the energy-momentum tensor is treated like a perturbation.
The boundary of the spectrum of a linear Operatoro
The box method and some error estimation
This article focuses its attention on practical use of the box method for solving certain type of partial differential equations. The heat conduction problem of the oil transformer under stationary load is described by this equation. The knowledge of the transformer operating temperature is important for ensuring correct functionality and lifespan of transformer. We consider an elliptic partial differential equation of second order with the Newton boundary condition on a rectangular domain. The...
The cohomology of with integer coefficients
The cohomology of the diffeomorphism group of a manifold is a Gelfand-Fuks cohomology
The compactness operator in general topology
The convergence of explicit Runge-Kutta methods combined with Richardson extrapolation
Runge-Kutta methods are widely used in the solution of systems of ordinary differential equations. Richardson extrapolation is an efficient tool to enhance the accuracy of time integration schemes. In this paper we investigate the convergence of the combination of any explicit Runge-Kutta method with active Richardson extrapolation and show that the obtained numerical solution converges under rather natural conditions.
The decomposition of tensor spaces with almost complex structure
The dimension of a set of singularities of weak solutions to the Navier-Stokes equations
The Dirichlet problem for sublaplacians on nilpotent Lie groups - geometric criteria for regularity
The double covering of the quantum group
The enveloping group of a lie algebra
The Euler characteristic and signature for open manifolds
The Evolving Digital Mathematics Network
The grand vision of a Digital Mathematics Library (DML), coordinated by a group of institutions that establish polices and practices regarding digitization, management, access, and preservation, has not come to pass. The project encountered two related problems: it was overly ambitious, and the approach to realizing it confused local and community responsibilities. While the vision called for a network of distributed, interoperable repositories, we approached and planned the project as if we were...