Events on Monday, February 7th, 2011
- Plasma Physics (Physics/ECE/NE 922) Seminar
- MHD Simulations of Magnetic Reconnection with Application to Solar Flares and Magnetospheric Substorms
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Speaker: Joachim Birn, Los Alamos National Laboratory
- Department Meeting
- Time: 12:15 pm
- Place: 5310 Chamberlin Hall
- Condensed Matter Theory Group Seminar
- Weyl Problem and the Casimir Effect in Spherical Shell Geometry
- Time: 4:30 pm
- Place: 5310 Chamberlin
- Speaker: Hussain Zaidi, University of Virginia
- Abstract: We compute the generic mode sum that quantifies the effect of the change of spectrum of a harmonic field when a spherical shell is inserted into the vacuum. This encompasses a variety of problems including the Weyl spectral problem and the Casimir effect of quantum electrodynamics. The connection between the Weyl problem and the Casimir energy allows us to resolve a long-standing controversy regarding the question of universality of the Casimir self-energy. Specifically we demonstrate that in the case of a scalar field obeying Dirichlet boundary conditions on the shell surface the Casimir self-energy is cutoff-dependent, while in the case of a conductive shell the Casimir self-energy is universal.
- Host: Maxim Vavilov