# Colloquia

**Colloquium**

Friday, January 27, 2012

4:00 PM

Physics Building, Room 204

Note special time.

ABSTRACT:

The polaron is a mathematical model for a “dressed”
particle consisting of an electron together with its entourage of
local excitations of a quantized phonon field. We will give a brief
historical review of the polaron, including the analysis of its ground
state by a Brownian motion functional integral and by a related
variational expression.

For the case of two or more electrons, the interaction of the electrons with the phonon field gives rise to an effective attraction between electrons that causes the particles to bind together. For

For the case of two or more electrons, the interaction of the electrons with the phonon field gives rise to an effective attraction between electrons that causes the particles to bind together. For

*N*electrons,*N*→ ∞, the systems are unstable in the sense that the binding energy grows faster than linearly in*N*. We will discuss recent work with Frank, Lieb, and Seiringer which shows that sufficiently strong Coulomb repulsion between electrons can compensate for this binding and provide stability for polaron systems for large*N*.To add a speaker, send an email to phys-speakers@Virginia.EDU. Please include the seminar type (e.g. Colloquia), date, name of the speaker, title of talk, and an abstract (if available).