Sum of Square Proof for Brascamp-Lieb Type Inequality

TL;DR

This paper provides a sum of squares proof for specific cases of the Brascamp-Lieb inequality, demonstrating its applicability in analysis, geometry, and information theory, and exploring its implications on Abelian groups and Euclidean spheres.

Contribution

It introduces a sum of squares proof for certain Brascamp-Lieb inequalities, linking polynomial nonnegativity certificates with these inequalities and their applications.

Findings

Sum of squares proof applies to special Brascamp-Lieb cases

Proof degree remains constant when original inequality degree is constant

Low degree sum of squares algorithms effectively capture low degree inequalities

Abstract

Brascamp-Lieb inequality is an important mathematical tool in analysis, geometry and information theory. There are various ways to prove Brascamp-Lieb inequality such as heat flow method, Brownian motion and subadditivity of the entropy. While Brascamp-Lieb inequality is originally stated in Euclidean Space, discussed Brascamp-Lieb inequality for discrete Abelian group and discussed Brascamp-Lieb inequality for Markov semigroups. Many mathematical inequalities can be formulated as algebraic inequalities which asserts some given polynomial is nonnegative. In 1927, Artin proved that any non- negative polynomial can be represented as a sum of squares of rational functions, which can be further formulated as a polynomial certificate of the nonnegativity of the polynomial. This is a Sum of Square proof of the inequality. Take the degree of the polynomial certificate as the degree of Sum of Square proof. The degree of an Sum of Square proof determines the complexity of generating such proof by Sum of Square algorithm which is a powerful tool for optimization and computer aided proof. In this paper, we give a Sum of Square proof for some special settings of Brascamp- Lieb inequality following and and discuss some applications of Brascamp-Lieb inequality on Abelian group and Euclidean Sphere. If the original description of the inequality has constant degree and d is constant, the degree of the proof is also constant. Therefore, low degree sum of square algorithm can fully capture the power of low degree finite Brascamp-Lieb inequality.