Mon, 15 Nov 2004
14:45
DH 3rd floor SR

On the inviscid limit for randomly forced nonlinear PDE

Professor Sergei Kuksin
(Heriot-Watt University, Edinburgh)
Abstract

I shall talk on recent results on behaviour of solutions of

2D Navier-Stokes Equation (and some other related equations), perturbed by a random force, proportional to the square root of the viscosity. I shall discuss some properties of the solutions, uniform in the viscosity, as well as the inviscid limit.

Mon, 15 Nov 2004
14:15
DH 3rd floor SR

Feynman integrals over trajectories in the phase space

Professor Oleg Smolyanov
(Moscow University)
Abstract

Hamiltonian Feynman path integrals, or Feynman (path) integrals over

trajectories in the phase space, are values, which some

pseudomeasures, usually called Feynman (pseudo)measures (they are

distributions, in the sense of the Sobolev-Schwartz theory), take on

functions defined on trajectories in the phase space; so such

functions are integrands in the Feynman path integrals. Hamiltonian

Feynman path integrals (and also Feynman path integrals over

trajectories in the configuration space) are used to get some

representations of solutions for Schroedinger type equations. In the

talk one plans to discuss the following problems.

Thu, 11 Nov 2004

14:00 - 15:00
Comlab

The Trapezoidal rule in the complex plane

Prof Andre Weideman
(University of Stellenbosch / Oxford)
Abstract

The trapezoidal rule for numerical integration is remarkably accurate when

the integrand under consideration is smooth and periodic. In this

situation it is superior to more sophisticated methods like Simpson's rule

and even the Gauss-Legendre rule. In the first part of the talk we

discuss this phenomenon and give a few elementary examples. In the second

part of the talk we discuss the application of this idea to the numerical

evaluation of contour integrals in the complex plane.

Demonstrations involving numerical differentiation, the computation

of special functions, and the inversion of the Laplace transform will be

presented.