Tenth Algorithmic Number Theory Symposium ANTS-X University of California, San Diego July 9 – 13, 2012 Tenth Algorithmic Number Theory Symposium (ANTS-X) July 9 – 13, 2012

Haberland's formula and numerical computation of Petersson scalar products

Henri Cohen

Abstract: We study several methods for the numerical computation of Petersson scalar products, and in particular we prove a generalization of Haberland's formula to any subgroup of finite index G of PSL_2(Z), which gives a fast method to compute these scalar products when a Hecke eigenbasis is not necessarily available.

Files available: paper (PDF)