Intrinsic volumes of sublevel sets

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
1. Verfasser: Jubin, Benoît
Format: Preprint
Veröffentlicht: 2019
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866914800769957888
author Jubin, Benoît
author_facet Jubin, Benoît
contents We establish formulas that give the intrinsic volumes, or curvature measures, of sublevel sets of functions defined on Riemannian manifolds as integrals of functionals of the function and its derivatives. For instance, in the Euclidean case, if $f \in \mathcal{C}^3(\mathbb{R}^n, \mathbb{R})$ and 0 is a regular value of $f$, then the intrinsic volume of degree $n-k$ of the sublevel set $M^0 = f^{-1}(]-\infty, 0])$, if the latter is compact, is given by \begin{equation*} \mathcal{L}_{n-k}(M^0) = \frac{Γ(k/2)}{2 π^{k/2} (k-1)!} \int_{M^0} \operatorname{div} \left( \frac{P_{n, k}(\operatorname{Hess}(f), \nabla f)}{\sqrt{f^{2(3k-2)} + \|\nabla f\|^{2(3k-2)}}} \nabla f \right) \operatorname{vol}_n \end{equation*} for $1 \leq k \leq n$, where the $P_{n, k}$'s are polynomials given in the text. This includes as special cases the Euler--Poincaré characteristic of sublevel sets and the nodal volumes of functions defined on Riemannian manifolds. Therefore, these formulas give what can be seen as generalizations of the Kac--Rice formula. Finally, we use these formulas to prove the Lipschitz continuity of the intrinsic volumes of sublevel sets.
format Preprint
id arxiv_https___arxiv_org_abs_1903_01592
institution arXiv
publishDate 2019
record_format arxiv
spellingShingle Intrinsic volumes of sublevel sets
Jubin, Benoît
Differential Geometry
28A75, 49Q15 (Primary) 26B15, 26B20 (Secondary)
We establish formulas that give the intrinsic volumes, or curvature measures, of sublevel sets of functions defined on Riemannian manifolds as integrals of functionals of the function and its derivatives. For instance, in the Euclidean case, if $f \in \mathcal{C}^3(\mathbb{R}^n, \mathbb{R})$ and 0 is a regular value of $f$, then the intrinsic volume of degree $n-k$ of the sublevel set $M^0 = f^{-1}(]-\infty, 0])$, if the latter is compact, is given by \begin{equation*} \mathcal{L}_{n-k}(M^0) = \frac{Γ(k/2)}{2 π^{k/2} (k-1)!} \int_{M^0} \operatorname{div} \left( \frac{P_{n, k}(\operatorname{Hess}(f), \nabla f)}{\sqrt{f^{2(3k-2)} + \|\nabla f\|^{2(3k-2)}}} \nabla f \right) \operatorname{vol}_n \end{equation*} for $1 \leq k \leq n$, where the $P_{n, k}$'s are polynomials given in the text. This includes as special cases the Euler--Poincaré characteristic of sublevel sets and the nodal volumes of functions defined on Riemannian manifolds. Therefore, these formulas give what can be seen as generalizations of the Kac--Rice formula. Finally, we use these formulas to prove the Lipschitz continuity of the intrinsic volumes of sublevel sets.
title Intrinsic volumes of sublevel sets
topic Differential Geometry
28A75, 49Q15 (Primary) 26B15, 26B20 (Secondary)
url https://arxiv.org/abs/1903.01592