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arXiv · 2609.25671

A colorful quantitative Helly theorem for volume

Grigory Ivanov
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Abstract

We prove a colorful quantitative Helly theorem for volume with the optimal number $2d$ of colors. If every rainbow intersection from $2d$ finite families of convex sets in $\R^d$ has volume at least one, then the intersection of one family has volume at least $d^{-O(d^2)}$. We also prove a colorful quantitative Steinitz theorem for origin-centered ellipsoids of different shapes. The proof uses a common normalization of positive operators and a lift that produces two rainbow bases with large determinants.

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Grigory Ivanov. 2026-09-22. A colorful quantitative Helly theorem for volume. https://arxiv.org/abs/2609.25671

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