Applied Mathematics Colloquium

THE DEPARTMENT OF MATHEMATICAL SCIENCES AND
THE CENTER FOR APPLIED MATHEMATICS AND STATISTICS,
NEW JERSEY INSTITUTE OF TECHNOLOGY

11:30 AM
Friday, March 14, 2003

Cullimore Hall Lecture Room II
New Jersey Institute of Technology





John Ball

Oxford University
&
Institute for Advanced Study, Princeton

" The regularity of minimizers in elasticity "

It is a major open problem of nonlinear elasticity theory to decide whether or not energy minimizers are smooth or can have singularities. Although some singular minimizers related to phase transformations or fracture are known, there remains the possibility that there is a large class of realistic stored-energy functions for which minimizers are smooth. On the other hand there is apparently not a single example known of a stored-energy function for which smoothness can be proved for arbitrary large boundary data. The talk will survey what is known about this problem, and about related questions such as satisfaction of the Euler-Lagrange equation and uniform positivity of the Jacobian.