Hasse invariant and group cohomology

  • Bas Edixhoven

    Mathematisch Instituut Department of Mathematics Universiteit Leiden University of Utah P.O. Box 9512 155 South 1400 East 2300 RA Leiden Salt Lake City The Netherlands UT 84112
  • Chandrashekhar Khare

    U.S.A
Hasse invariant and group cohomology cover
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Abstract

Let be a prime number. The Hasse invariant is a modular form modulo that is often used to produce congruences between modular forms of different weights. We show how to produce such congruences between eigenforms of weights 2 and , in terms of group cohomology. We also illustrate how our method works for inert primes in the contexts of quadratic imaginary fields (where there is no Hasse invariant available) and Hilbert modular forms over totally real fields, cyclic and of even degree over the rationals.

Cite this article

Bas Edixhoven, Chandrashekhar Khare, Hasse invariant and group cohomology. Doc. Math. 8 (2003), pp. 43–50

DOI 10.4171/DM/136