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arXiv · 2112.13881

Geometric representation of classes of concave functions and duality

Grigory Ivanov·Elisabeth M. Werner
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Abstract

Using a natural representation of a $1/s$-concave function on $\mathbb{R}^d$ as a convex set in $\mathbb{R}^{d+1},$ we derive a simple formula for the integral of its $s$-polar. This leads to convexity properties of the integral of the $s$-polar function with respect to the center of polarity. In particular, we prove that that the reciprocal of the integral of the polar function of a log-concave function is log-concave as a function of the center of polarity. Also, we define the Santal\'o regions for $s$-concave and log-concave functions and generalize the Santal\'o inequality for them in the case the origin is not the Santal\'o point.

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Grigory Ivanov, Elisabeth M. Werner. 2021-12-27. Geometric representation of classes of concave functions and duality. https://arxiv.org/abs/2112.13881

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