Visit: Nov. 8 - Nov. 15, 2003

Fluid Dynamics Seminar
The Onset of Oscillations
Mon, Nov 10, 2 PM, MS 6221
Abstract: In certain dispersive approximations of compressible flow oscillations develop; this can be traced to incompatible conservation laws that approximate solutions are forced to satisfy.

Lecture for Undergraduates
The Change of Variables Formula for Multiple Integrals
Wednesday, Nov 12, 3PM, Boelter Hall 5420
Abstract: A completely elementary proof will be presented and used to give a one-line proof of the Brouwer fixed pont theorem.

Special Colloquium
Multiple Eigenvalues of Symmetric Matrices
Thursday, Nov 13, 2PM, MS 6627
Abstract: Two parameter families of symmetric matrices in certain dimensions contain degenerate matrices; this has interesting consequences for solutions of first order hyperbolic equations.

A matrix is degenerate when its discriminant is zero; we show that the discriminant of symmetric matrices can be written as a sum of squares.

Background:
Peter Lax is one of the greatest figures in pure and applied mathematics of our times. His work has been seminal and extraordinarily influential in almost all areas of mathematics and its applications where differential equations are involved, such as integrable systems, fluid dynamics and shock waves, solitonic physics, hyperbolic conservation laws, and so on. His contributions to mathematical and scientific computing are very significant.

Professor Lax's work has been recognized by many honors and awards. He is a member of the National Academy of Sciences, USA. He was awarded the National Medal of Science in 1986 and the Wolf Prize in 1987.