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Uniform bounds for norms of theta series and arithmetic applications

Published online by Cambridge University Press:  28 February 2022

FABIAN WAIBEL*
Affiliation:
Department of Mathematics, University of Bonn, Endenicher Allee 60, 53115 Bonn, Germany. e-mails: [email protected]

Abstract

We prove uniform bounds for the Petersson norm of the cuspidal part of the theta series. This gives an improved asymptotic formula for the number of representations by a quadratic form. As an application, we show that every integer $n \neq 0,4,7 \,(\textrm{mod}\ 8)$ is represented as $n= x_1^2 + x_2^2 + x_3^3$ for integers $x_1,x_2,x_3$ such that the product $x_1x_2x_3$ has at most 72 prime divisors.

Type
Research Article
Copyright
© The Author(s), 2022. Published by Cambridge University Press on behalf of Cambridge Philosophical Society

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