DIFFERENTIAL GEOMETRY/PDE SEMINAR Monday, April 22 Padelford C401 3:45 PM KOHN-ROSSI COHOMOLOGY OF CR MANIFOLDS Peter M. Garfield (University of Washington) A CR manifold is an abstract model of a real hypersurface in C^n. In another sense, a CR manifold is the generalization of a complex structure to a real odd-dimensional manifold. As such, the Kohn-Rossi cohomology is the analogue of the cohomology generated by the Cauchy-Riemann complex. This cohomology is linked to various CR embedding questions, and is thus of significant interest. In 1994, M. Rumin reproduced de Rham cohomology on contact manifolds (including, for example, a certain class of CR manifolds) using a resolution of the constant sheaf R. In 1993, T. Akahori and K. Miyajima produced a finer double complex that corresponded to the second half of Rumin's complex. Moreover, Akahori and Miyajima's complex reproduced Kohn-Rossi cohomology in these upper dimensions. We produce a collection of resolutions that generalize Rumin's resolution and incorporate the complexes of Akahori and Miyajima. These resolutions reproduce Kohn-Rossi cohomology. Finally, we will briefly remark on recent work by S. Yau and H. S. Luk relating the CR embeddability of certain CR manifolds to their Kohn-Rossi cohomology. For more information about this seminar, view the Differential Geometry Seminar World-Wide Web page at https://www.math.washington.edu/~lee/Seminars/dg.html To request disability accommodations, contact the Office of the ADA Coordinator as soon as possible: 543-6450 (voice); 543-6452 (TDD); 685-3885 (FAX); access@u.washington.edu (E-mail).