English

Epstein zeta-functions, subconvexity, and the purity conjecture

Number Theory 2016-02-09 v1

Abstract

Subconvexity bounds are proved for general Epstein zeta functions of k-ary quadratic forms. This is related to sup-norm bounds for Eisenstein series on GL(k), and the exact sup-norm exponent is determined to be (k-2)/8 for k >= 2. In particular, if kk is odd, this exponent is not in Z/4, which shows that Sarnak's purity conjecture does not hold for Eisenstein series.

Keywords

Cite

@article{arxiv.1602.02326,
  title  = {Epstein zeta-functions, subconvexity, and the purity conjecture},
  author = {Valentin Blomer},
  journal= {arXiv preprint arXiv:1602.02326},
  year   = {2016}
}