Pair creation in inhomogeneous fields from worldline instantons

Abstract

We show how to do semiclassical nonperturbative computations within the worldline approach to quantum field theory using ``worldline instantons''. These worldline instantons are classical solutions to the Euclidean worldline loop equations of motion, and are closed spacetime loops parametrized by the proper-time. Specifically, we compute the imaginary part of the one loop effective action in scalar and spinor QED using worldline instantons, for a wide class of inhomogeneous electric field backgrounds.

Comments: 10 pages, 2 figures, talk given by C.S. at X Mexican Workshop on Particles and Fields, Morelia, Mexico, Nov. 6 - 12, 2005 (to appear in the conference proceedings)