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arXiv · 2502.12294

Connections between $\mathcal{S}$-operators and restriction estimates for spheres over finite fields

Hunseok Kang·Doowon Koh
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Abstract

In this paper, we introduce a new operator, $\mathcal{S}$, which is closely related to the restriction problem for spheres in $\mathbb{F}_q^d$, the $d$-dimensional vector space over the finite field $\mathbb{F}_q$ with $q$ elements. The $\mathcal{S}$ operator is considered as a specific operator that maps functions on $\mathbb{F}_q^d$ to functions on $\mathbb{F}_q^{d+1}$. We explore a relationship between the boundedness of the $\mathcal{S}$ operator and the restriction estimate for spheres in $\mathbb{F}_q^d$. Consequently, using this relationship, we prove that the $L^2$ restriction conjectures for spheres hold in all dimensions when the test functions are restricted to homogeneous functions of degree zero.

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Hunseok Kang, Doowon Koh. 2025-02-17. Connections between $\mathcal{S}$-operators and restriction estimates for spheres over finite fields. https://arxiv.org/abs/2502.12294

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