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Related papers: Rotational Crofton Formulae with a Fixed Subspace

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Let K(X) be the collection of all non-zero finite dimensional subspaces of rational functions on an n-dimensional irreducible variety X. For any n-tuple L_1,..., L_n in K(X), we define an intersection index [L_1,..., L_n] as the number of…

Algebraic Geometry · Mathematics 2010-01-06 Kiumars Kaveh , A. G. Khovanskii

This paper introduces a natural definition for the volume of the unit ball in $n$-dimensional normed spaces $\mathbb{R}^n$. This definition preserves the Euclidean relation $P(B)/V(B)=n$ between the perimiter and the volume of the unit ball…

Metric Geometry · Mathematics 2026-05-05 Gershon Wolansky

The Dehn function and its higher-dimensional generalizations measure the difficulty of filling a sphere in a space by a ball. In nonpositively curved spaces, one can construct fillings using geodesics, but fillings become more complicated…

Group Theory · Mathematics 2017-10-03 Enrico Leuzinger , Robert Young

Let $M$ be a compact $n$-manifold of $\operatorname{Ric}_M\ge (n-1)H$ ($H$ is a constant). We are concerned with the following space form rigidity: $M$ is isometric to a space form of constant curvature $H$ under either of the following…

Differential Geometry · Mathematics 2023-08-25 Lina Chen , Xiaochun Rong , Shicheng Xu

We show that for every compact domain in a Euclidean space with d.c. (delta-convex) boundary there exists a unique Legendrian cycle such that the associated curvature measures fulfil a local version of the Gauss-Bonnet formula. This was…

Differential Geometry · Mathematics 2013-09-17 Dusan Pokorny , Jan Rataj

This paper is about conic intrinsic volumes and their associated integral geometry. We pay special attention to the biconic localizations of the conic intrinsic volumes, the so-called support measures. An analysis of these quantities has so…

Metric Geometry · Mathematics 2015-07-30 Dennis Amelunxen

In the first part of this paper, we develop the theory of anisotropic curvature measures for convex bodies in the Euclidean space. It is proved that any convex body whose boundary anisotropic curvature measure equals a linear combination of…

Differential Geometry · Mathematics 2021-08-05 Ben Andrews , Yitao Lei , Yong Wei , Changwei Xiong

We derive a closed formula for the matrix elements of the volume operator for canonical Lorentzian quantum gravity in four spacetime dimensions in the continuum in a spin-network basis. We also display a new technique of regularization…

General Relativity and Quantum Cosmology · Physics 2009-10-28 T. Thiemann

Motivated by long-standing conjectures on the discretization of classical inequalities in the Geometry of Numbers, we investigate a new set of parameters, which we call \emph{packing minima}, associated to a convex body $K$ and a lattice…

Metric Geometry · Mathematics 2021-01-20 Martin Henk , Matthias Schymura , Fei Xue

The formulation of General Relativity in which the 4-dimensional space-time is embedded in a flat host space of higher dimension is reconsidered. New classes of embeddings (modeled after Nash's classical free embeddings) are introduced.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Miguel D. Bustamante , Fabrice Debbasch , Marc-Etienne Brachet

We prove two principal kinematic formulas for germs of closed definable sets in $\mathbb{R}^n$, that generalize the Cauchy-Crofton formula for the density due to Comte and the infinitesimal linear kinematic formula due to the author. In…

Algebraic Geometry · Mathematics 2021-01-01 Nicolas Dutertre

We introduce a new volume definition on normed vector spaces. We show that the induced $k$-area functionals are convex for all $k$. In the particular case $k=2$, our theorem implies that Busemann's 2-volume density is convex, which was…

Differential Geometry · Mathematics 2015-09-24 Andreas Bernig

Approximating convex bodies is a fundamental question in geometry, which has a wide variety of applications. Given a convex body $K$ in $\textbf{R}^d$ for fixed $d$, the objective is to minimize the number of facets of an approximating…

Computational Geometry · Computer Science 2026-01-26 Sunil Arya , David M. Mount

We start by presenting the general set of structure equations for the 1+3 threading spacetime decomposition in 4 spacetime dimensions, valid for any theory of gravitation based on a metric compatible affine connection. We then apply these…

General Relativity and Quantum Cosmology · Physics 2023-04-18 Paulo Luz , José P. S. Lemos

For a sequence of immersed connected closed Hamiltonian stationary Lagrangian submaniolds in $\mathbb{C}^{n}$ with uniform bounds on their volumes and the total extrinsic curvatures, we prove that a subsequence converges either to a point…

Differential Geometry · Mathematics 2019-01-11 Jingyi Chen , Micah Warren

Let $K \subset \mathbb R^n$ be a convex body with barycenter at the origin. We show there is a simplex $S \subset K$ having also barycenter at the origin such that $\left(\frac{vol(S)}{vol(K)}\right)^{1/n} \geq \frac{c}{\sqrt{n}},$ where…

Metric Geometry · Mathematics 2019-07-18 Daniel Galicer , Mariano Merzbacher , Damián Pinasco

Hadwiger's Theorem states that Euclidean-invariant convex-continuous valuations of definable sets are linear combinations of intrinsic volumes. We lift this result from sets to data distributions over sets, specifically, to definable…

Differential Geometry · Mathematics 2013-07-02 Yuliy Baryshnikov , Robert Ghrist , Matthew Wright

We prove that for a continuum $K\subset \mathbb R^n$ the sum $K^{+n}$ of $n$ copies of $K$ has non-empty interior in $\mathbb R^n$ if and only if $K$ is not flat in the sense that the affine hull of $K$ coincides with $\mathbb R^n$.…

General Topology · Mathematics 2020-04-09 Taras Banakh , Eliza Jabłońska , Wojciech Jabłoński

Recent works of the authors have demonstrated the usefulness of considering moduli spaces of Artinian reductions of a given ring when studying standard graded rings and their Lefschetz properties. This paper illuminates a key aspect of…

Commutative Algebra · Mathematics 2024-07-17 Karim Alexander Adiprasito , Stavros Argyrios Papadakis , Vasiliki Petrotou

It is known, that every function on the unit sphere in $\bbr^n$, which is invariant under rotations about some coordinate axis, is completely determined by a function of one variable. Similar results, when invariance of a function reduces…

Functional Analysis · Mathematics 2008-01-03 Gestur Ólafsson , Boris Rubin