The Leonard E Parker Center for Gravitation, Cosmology and Astrophysics holds frequent seminars on a broad range of ongoing cosmology and gravitation research topics. Unless otherwise noted, seminars are on Friday afternoons at 1:00 PM in KIRC 2175; there is a gathering for a brown bag lunch at 12:30.

A Variational Principle for the Axisymmetric Stability of Rotating Relativistic Stars
Dr. Kartik Prabhu, University of Chicago

In this talk, I will discuss a recently obtained variational principle for testing the stability of perfect fluid stars to axisymmetric perturbations, which generalizes to axisymmetric perturbations of rotating stars a variational principle given by Chandrasekhar for spherical perturbations of static, spherical stars. The variational principle gives a lower bound to the rate of exponential growth in the case of instability. The derivation closely parallels the derivation of a recently obtained variational principle for analyzing the axisymmetric stability of black holes.