Date: Tue, 25 Feb 1997 08:58:43 -0500 From: Edward Witten Reading for Witten's lecture this week: T. Buscher, ``Path Integral Derivation Of Quantum Duality In Nonlinear Sigma Models,'' Phys. Lett. B201 (1988) 466. E. Witten, ``On S-Duality In Abelian Gauge Theories,'' Selecta Math. 1 (1995) 383, section 2 ONLY. A. M. Polyakov, in {\it Gauge Fields And Strings}, pp. 62-72. Please note that Polyakov's treatment is based on a lattice approach; he only mentions the equivalent continuum version in the last 1-2 pages. The lecture will be phrased in continuum language. Reading for next week's lecture: The chapter on ``Lumps'' in Coleman's book {\it Secret Symmetry}. All selections will be available from P. Bozzay or V. Nowak in C building.