# Accession Number:

## ADP013716

# Title:

## Iterative Refinement Schemes for an Ill-Conditioned Transfer Equation in Astrophysics

# Descriptive Note:

## Conference paper

# Corporate Author:

## SAINT-ETIENNE UNIV (FRANCE)

# Personal Author(s):

# Report Date:

## 2001-07-01

# Pagination or Media Count:

## 8.0

# Abstract:

The transfer problem given f is an element of X, find phi is an element of X such that Tsub phi equals phi plus f is ill-conditioned, and the convergence of the fixed-point iteration phisub k 1 equals T sub phisub k minus f, which is commonly used by numerical astronomers, becomes prohibitively slow. The purposes of this work are to approximate phi through different sequences whose terms solve well-conditioned approximate equations, and to compare their efficiency and computational costs.

# Descriptors:

# Subject Categories:

- Numerical Mathematics
- Theoretical Mathematics
- Astrophysics