W. G. Pritchard Lab Seminar - 109 Boucke Building

	     **October 17, 2001**
	
Geometry, Topology, and Plasma Physics.

Herman Gluck

Department of Mathematics
University of Pennsylvania

Abstract:

In this talk, I'll report on the work of a number of people at U Penn
in recent years involving mathematical methods in plasma physics. 
From the physics point of view, our goal is to determine and study
the persistent plasma states observed in astrophysical, solar and
laboratory settings.  From the  mathematics point of view, our goal
is to develop the tools to carry this out, and to work on a number of
mathematical problems suggested by this enterprise.  Key roles in the
story are played by the notion of "helicity" of a vector field, which
measures the extent to which the field lines wrap and coil around one
another, and spectral problems for the curl operator.  Because
helicity of vector fields is the analogue of "writhing number" of
knots, the methods we use also provide an upper bound for the
writhing number of a given strand of DNA.