
Unpublished Paper
Mod 2 Homology For GL(4) And Galois Representations
Journal of Number Theory
(2014)
Abstract
We extend the computations in [AGM11] to find the mod 2 homology in degree 1 of a congruence subgroup Γ of SL(4,Z) with coefficients in the sharbly complex, along with the action of the Hecke algebra. This homology group is related to the cohomology of Γ with F2 coefficients in the top cuspidal degree. These computations require a modification of the algorithm to compute the action of the Hecke operators, whose previous versions required division by 2. We verify experimentally that every mod 2 Hecke eigenclass found appears to have an attached Galois representation, giving evidence for a conjecture in [AGM11]. Our method of computation was justified in [AGM12].
Keywords
- Cohomology of arithmetic groups,
- Galois representations,
- Voronoi complex,
- Steinberg module,
- Modular symbols
Disciplines
Publication Date
January 9, 2014
Comments
Pre-published version downloaded from archive ArXiv.org. Published version located at http://www.sciencedirect.com/science/journal/0022314X/146.
Citation Information
Avner Ash, Paul E. Gunnells and Mark McConnell. "Mod 2 Homology For GL(4) And Galois Representations" Journal of Number Theory (2014) Available at: http://works.bepress.com/paul_gunnells/34/