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Saturday, May 15

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IP5

Instabilities in Fluid Motion

12:30
PM-1:15 PM

*Room: Capitol Center/South*

*Chair: Barbara L. Keyfitz, University of Houston*

The issue of stability/instability of fluid flows presents an
important example of a physical problem which may be addressed
through sophisticated mathematical techniques. The answers have
direct physical interpretations: stable flows are robust under
inevitable disturbances in the environment while unstable flows may
break up rapidly. The question of stability/instability of a fluid
flow is a classical one, however there remain many open problems that
are mathematically challenging. In this presentation, the speaker
will introduce the concept of a "fluid Lyapunov exponent"
and describe an effective sufficient condition for detecting
instabilities in an inviscid fluid. She will discuss a recent result
which proves that under certain conditions, linear instability
implies nonlinear instability. This is joint work with Walter Strauss
and Misha Vishik.

**Susan Friedlander**

*Department of Mathematics*

*University of Illinois, Chicago*

*MMD, 4/22/99*