Mathematical Research Letters

Volume 18 (2011)

Number 6

Self cup products and the theta characteristic torsor

Pages: 1305 – 1318



Bjorn Poonen (Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, U.S.A.)

Eric Rains (Department of Mathematics, California Institute of Technology, Pasadena, CA 91125, U.S.A.)


We give a general formula relating self cup products in cohomology to connecting maps in nonabelian cohomology, and apply it to obtain a formula for the self cup product associated to the Weil pairing.

Published 20 February 2012