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arXiv · 1210.6364

Quermassintegrals of quasi-concave functions and generalized Prékopa-Leindler inequalities

Sergey Bobkov·Andrea Colesanti·Ilaria Fragalà
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Abstract

We extend to a functional setting the concept of quermassintegrals, well-known within the Minkowski theory of convex bodies. We work in the class of quasi-concave functions defined on the Euclidean space, and with the hierarchy of their subclasses given by $α$-concave functions. In this setting, we investigate the most relevant features of functional quermassintegrals, and we show they inherit the basic properties of their classical geometric counterpart. As a first main result, we prove a Steiner-type formula which holds true by choosing a suitable functional equivalent of the unit ball. Then, we establish concavity inequalities for quermassintegrals and for other general hyperbolic functionals, which generalize the celebrated Prékopa-Leindler and Brascamp-Lieb inequalities. Further issues that we transpose to this functional setting are: integral-geometric formulae of Cauchy-Kubota type, valuation property and isoperimetric/Uryshon-like inequalities.

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Sergey Bobkov, Andrea Colesanti, Ilaria Fragalà. 2012-10-23. Quermassintegrals of quasi-concave functions and generalized Prékopa-Leindler inequalities. https://arxiv.org/abs/1210.6364

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