IP8* ~ Tuesday, May 23, 1995 ~ 1:30 PM*
## Invariant Manifolds and Singularly Perturbed Equations

Singularly perturbed equations often have "singular solutions",
which are unions of solutions to limiting equations. A very
general and central question, to which there have been many
approaches, is what hypotheses on the equations and singular
solutions guarantee that the singular solutions approximate some
solutions for the e > 0 problem. The speaker will present a
geometric approach to the problem based on the "Exchange Lemma",
which gives estimates on the position of an invariant manifold
and its tangent planes as the manifold passes close to a
normally hyperbolic piece of a slow manifold.
**Nancy Kopell**

Department of Mathematics, Boston University

*3/15/95*