# Locally polynomially integrable surfaces and finite stationary phase expansions

## TL;DR

This paper investigates the property of locally polynomially integrable convex hypersurfaces in relation to stationary phase expansions, providing partial confirmation of a conjecture that only quadrics in odd dimensions have this property.

## Contribution

It offers a partial proof supporting the conjecture that only quadrics in odd-dimensional spaces are locally polynomially integrable.

## Key findings

- Partial confirmation of the conjecture for certain hypersurfaces.
- Connection between polynomial integrability and finite stationary phase expansions.
- Insights into oscillating integrals and their asymptotic behavior.

## Abstract

Let $M$ be a strictly convex smooth connected hypersurface in $\mathbb R^n$ and $\widehat{M}$ its convex hull. We say that $M$ is locally polynomially integrable if the $(n-1)-$ dimensional volumes of the sections of $\widehat M$ by hyperplanes, sufficiently close to the tangent hyperplanes to $M,$ depend polynomially on the distance of the hyperplanes to the origin. It is conjectured that only quadrics in odd dimensional spaces possess such a property. The main result of this article partially confirms the conjecture. The study of integrable domains and surfaces is motivated by a conjecture of V.I. Arnold about algebraically integrable domains. The result and the proof are related to study oscillating integrals for which the asymptotic stationary phase expansions consist of finite number of terms.