CENTER FOR COMPUTATIONAL MATHEMATICS COLLOQUIUM
                  UNIVERSITY OF COLORADO AT DENVER


TITLE:   Multigrid and Krylov Subspace Methods for Transport Equations

SPEAKER: Suely Oliveira, Computer Science Dept., Texas A&M University

DATE:    Wednesday, April 5, 1995 

PLACE:   Math Conference Room - Suite 540
         UCD Building, 1250 14th St., Denver

TIME:    2:30 pm (Refreshments served at 2:15 pm)

ABSTRACT: 
Transport equations describe the behavior of particles or radiation, such
as neutrons in a nuclear reactor, or infra-red radiation in the atmosphere.
For anisotropic scattering case the probability of scattering
changes with the angle. For isotropic scattering the probability of
scattering in all directions is the same.
Efficient multigrid algorithms have been developed for both cases.
In the first case a new relaxation, rather than the well known source
iteration was used. The multigrid algorithm was rapidly convergent and the
parallel algorithm had O(log m) time complexity, where m is the number of
spatial cells used in the discretization. The discretization used was a MLD
finite element in 1-D with a slab geometry. For the anisotropic case a parallel
algorithm which involved parallel cyclic reduction was very efficient.
In this talk I will show these methods and also present new Preconditioned
Krylov Subspace results for this non-symmetric problem.
~
~