Logo image
Improved subconvexity bounds for GL(2)xGL(3) and GL(3) L-functions by weighted stationary phase
Journal article   Open access   Peer reviewed

Improved subconvexity bounds for GL(2)xGL(3) and GL(3) L-functions by weighted stationary phase

 Mark McKee,  Haiwei Sun and  Yangbo Ye
Transactions of the American Mathematical Society, Vol.370(5), pp.3745-3769
2018
DOI: 10.1090/tran/7159
url
https://doi.org/10.1090/tran/7159View
Published (Version of record) Open Access

Abstract

Let f be a fixed self-contragradient Hecke–Maass form for SL(3, Z), and let u be an even Hecke–Maass form for SL(2, Z) with Laplace eigenvalue 1/4+k2, k ≥ 0. A subconvexity bound O((1+k)4/3+ε) in the eigenvalue aspect is proved for the central value at s = 1/2 of the Rankin–Selberg L-function L(s, f × u). Meanwhile, a subconvexity bound O((1 + |t|)2/3+ε) in the t aspect is proved for L(1/2+it, f). These bounds improved corresponding subconvexity bounds proved by Xiaoqing Li (Annals of Mathematics, 2011). The main techniques in the proofs, other than those used by Li, are nth-order asymptotic expansions of exponential integrals in the cases of the explicit first derivative test, the weighted first derivative test, and the weighted stationary phase integral, for arbitrary n ≥ 1. These asymptotic expansions sharpened the classical results for n = 1 by Huxley.
Mathematics - Number Theory

Details

Metrics

Logo image