CENTER FOR COMPUTATIONAL MATHEMATICS COLLOQUIUM

                  UNIVERSITY OF COLORADO AT DENVER



TITLE:   Efficient algorithms for solving linear systems
         arising from Mixed Finite Element discretizations
         of elliptic problems
 

SPEAKER: Rossen Parashkevov, Department of Mathematics, UCD 

DATE:    Wednesday, April 17, 1996 

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

TIME:    2:30-3:30 pm (Refreshments at 2:15 pm)



ABSTRACT


Mixed finite element methods are popular techniques for discretizing second 
order elliptic PDE's, which arise in mathematical models of flow in porous 
medium and other applications.  These methods have certain advantages over 
the standard conforming finite elements, for example the local (element by 
element) conservation property. Unfortunately, Mixed FEM methods lead to a 
saddle point problem, which in turn, translates into a linear system of 
equations with a symmetric but indefinite matrix.

In this talk, we will answer the question "Is it possible to solve the
Mixed FEM problem at the computational cost of a standard conforming FEM ?".
In particular, new results will be presented for the  Domain Decomposition 
algorithms for the Raviart-Thomas-Nedelec Mixed FEM spaces in 3-D domains.