English

Endoscopy and cohomology of a quasi-split U(4)

Number Theory 2016-11-04 v2

Abstract

We prove asymptotic upper bounds for the L2L^2 Betti numbers of the locally symmetric spaces associated to a quasi-split U(4)U(4). These manifolds are 8-dimensional, and we prove bounds in degrees 2 and 3, with the behaviour in the other degrees being well understood. In degree 3, we conjecture that these bounds are sharp. Our main tool is the endoscopic classification of automorphic representations of U(N) by Mok.

Keywords

Cite

@article{arxiv.1409.0239,
  title  = {Endoscopy and cohomology of a quasi-split U(4)},
  author = {Simon Marshall},
  journal= {arXiv preprint arXiv:1409.0239},
  year   = {2016}
}

Comments

To appear in the proceedings of the 2014 Simons Symposium `Families of Automorphic Forms and the Trace Formula'