Fundamental Fourier coefficients of Siegel modular forms of higher degrees and levels

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Anamby, Pramath, Das, Soumya
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914315193286656
author Anamby, Pramath
Das, Soumya
author_facet Anamby, Pramath
Das, Soumya
contents We prove the following statement about any Siegel modular form $F$ of degree $n$ and arbitrary odd level $N$ on the group $Γ_{0}^{(n)}(N)$. Let $A(F,T)$ denote the Fourier coefficients of $F$ and write $T=(T(i,j))$. Suppose that $F$ has a non-zero Fourier coefficient $A(F,T_0)$ such that $(T_0(n,n),N)=1$. Then there exist infinitely many odd and square-free (and thus fundamental) integers $m$ such that $m=\mathrm{discriminant}(T)$ and $A(F,T)\neq 0$. In the case of odd degrees, we prove a stronger result by replacing odd and square-free with odd and prime. We also prove quantitative results in this direction. As a consequence, we can show in particular that the statement of the main result in arXiv:2408.03442 about the algebraicity of certain critical values (and the expected functional equation) of the spinor $L$-functions of holomorphic newforms (in the ambit of Deligne's conjectures) on congruence subgroups of $\mathrm{GSp}(3)$ is unconditional.
format Preprint
id arxiv_https___arxiv_org_abs_2509_12148
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Fundamental Fourier coefficients of Siegel modular forms of higher degrees and levels
Anamby, Pramath
Das, Soumya
Number Theory
Primary 11F30, 11F46, Secondary 11F50, 11F37
We prove the following statement about any Siegel modular form $F$ of degree $n$ and arbitrary odd level $N$ on the group $Γ_{0}^{(n)}(N)$. Let $A(F,T)$ denote the Fourier coefficients of $F$ and write $T=(T(i,j))$. Suppose that $F$ has a non-zero Fourier coefficient $A(F,T_0)$ such that $(T_0(n,n),N)=1$. Then there exist infinitely many odd and square-free (and thus fundamental) integers $m$ such that $m=\mathrm{discriminant}(T)$ and $A(F,T)\neq 0$. In the case of odd degrees, we prove a stronger result by replacing odd and square-free with odd and prime. We also prove quantitative results in this direction. As a consequence, we can show in particular that the statement of the main result in arXiv:2408.03442 about the algebraicity of certain critical values (and the expected functional equation) of the spinor $L$-functions of holomorphic newforms (in the ambit of Deligne's conjectures) on congruence subgroups of $\mathrm{GSp}(3)$ is unconditional.
title Fundamental Fourier coefficients of Siegel modular forms of higher degrees and levels
topic Number Theory
Primary 11F30, 11F46, Secondary 11F50, 11F37
url https://arxiv.org/abs/2509.12148