Leif Melkersson: Mittag-Leffler modules.

Raynaud and Gruson introduced Mittag-Leffler modules in the second part of their difficult but rewarding paper: Critères de platitude et de projectivité. The properties of these modules  are reviewed in the first part of my talk, with special attention to flat strict Mittag-Leffler modules.  These are also known in the literature under other names (trace modules, locally projective modules).  In the second half of my talk I will define the trace and the characteristic polynomials of certain endomorphisms on such modules.