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We investigate threshold phenomena for random polytopes $K_N=\conv\{X_1,\dots,X_N\}$ generated by i.i.d.\ samples from an atomic law $\mu$. We identify and provide a missing justification in the discrete-hypercube threshold argument of…

Probability · Mathematics 2026-01-23 Silouanos Brazitikos , Minas Pafis

Caffarelli's contraction theorem and the analogous Laplacian result in [arXiv:2411.12109, arXiv:2501.11382] are two examples of how log-Hessian bounds on probability densities yield estimates on the derivative of the corresponding Brenier…

Analysis of PDEs · Mathematics 2026-05-25 Andrea Bidoia

We partly extend the localisation technique from convex geometry to the multiple constraints setting. For a given $1$-Lipschitz map $u\colon\mathbb{R}^n\to\mathbb{R}^m$, $m\leq n$, we define and prove the existence of a partition of…

Metric Geometry · Mathematics 2021-08-17 Krzysztof J. Ciosmak

We give an alternative proof of a recent result of Klartag on the existence of almost subgaussian linear functionals on convex bodies. If $K$ is a convex body in ${\mathbb R}^n$ with volume one and center of mass at the origin, there exists…

Functional Analysis · Mathematics 2007-05-23 Apostolos Giannopoulos , Alain Pajor , Grigoris Paouris

We show how a set of POVMs, expressed as a set of $\mu$ linear maps, can be performed with a unitary transformation followed by a von-Neumann measurement with an ancillary system of no more than $\mu N^2$ dimensions. This result shows that…

Quantum Physics · Physics 2007-05-23 Aik-meng Kuah , E. C. G. Sudarshan

We introduce an extension of the standard Local-to-Global Principle used in the proof of the convexity theorems for the momentum map to handle closed maps that take values in a length metric space. This extension is used to study the…

Symplectic Geometry · Mathematics 2007-05-23 Petre Birtea , Juan-Pablo Ortega , Tudor S. Ratiu

We establish sharp exponential deviation estimates of the information content as well as a sharp bound on the varentropy for the class of convex measures on Euclidean spaces. This generalizes a similar development for log-concave measures…

Probability · Mathematics 2020-02-25 Matthieu Fradelizi , Jiange Li , Mokshay Madiman

Let G be a complex reductive Lie group acting on a compact K\"ahler manifold X and assume that the action of a maximal compact subgroup K of G is Hamiltonian. For each extreme point of the convex hull of the momentum map image, there is an…

Complex Variables · Mathematics 2025-05-13 Peter Heinzner , Christian Zöller

The estimation of a log-concave density on $\mathbb{R}$ is a canonical problem in the area of shape-constrained nonparametric inference. We present a Bayesian nonparametric approach to this problem based on an exponentiated Dirichlet…

Statistics Theory · Mathematics 2020-07-14 Ester Mariucci , Kolyan Ray , Botond Szabo

The moduli space of twisted holomorphic 1-forms on Riemann surfaces, equivalently dilation surfaces with scaling, admits a stratification and GL(2,R)-action as in the case of moduli spaces of translation surfaces. We produce an analogue of…

Geometric Topology · Mathematics 2025-07-16 Paul Apisa , Nick Salter

In this paper, a class of $\log$-polyharmonic mappings $\mathcal{L}_p\mathcal{H}$ together with its subclass $\mathcal{L}_p\mathcal{H}(G)$ in the unit disk $\mathbb{D}=\{z: |z|<1\}$ is introduced, and several geometrical properties such as…

Complex Variables · Mathematics 2016-11-08 Jiaolong Chen , Bin Sheng , Xiaotao Wang

We introduce the notion of a Hamiltonian action of an \'etale Lie group stack on an \'etale symplectic stack and establish versions of the Kirwan convexity theorem, the Meyer-Marsden-Weinstein symplectic reduction theorem, and the…

Symplectic Geometry · Mathematics 2023-11-27 Benjamin Hoffman , Reyer Sjamaar , Chenchang Zhu

In the first part of the paper, we build a foundation for further work on Hamiltonian actions on symplectic orbifolds. Most importantly we prove the orbifold versions of the abelian connectedness and convexity theorems. In the second half,…

dg-ga · Mathematics 2008-02-03 Eugene Lerman , Susan Tolman

Given an increasing odd homeomorphism $\sigma$ : R $\rightarrow$ R, the two bijective maps h $\sigma$ , v $\sigma$ : R 2 $\rightarrow$ R 2 dened by h $\sigma$ (x, y) = (x + $\sigma$ --1 (y), y) and v $\sigma$ (x, y) = (x, $\sigma$(x) + y).…

Dynamical Systems · Mathematics 2019-06-19 Guido Ahumada , Nicolas Chevallier

We prove that for two-component maps in dimension two, rank-one convexity is equivalent to quasiconvexity. The essential tool for the proof is a fixed-point argument for a suitable set-valued map going from one component to the other that…

Optimization and Control · Mathematics 2025-05-14 Pablo Pedregal

It has been shown recently by Kapustin and Tomasiello that the mathematical notion of Hamiltonian actions on twisted generalized K\"ahler manifolds is in perfect agreement with the physical notion of general $(2,2)$ gauged sigma models with…

Differential Geometry · Mathematics 2008-11-26 Yi Lin

In this book chapter we study the Riemannian Geometry of the density registration problem: Given two densities (not necessarily probability densities) defined on a smooth finite dimensional manifold find a diffeomorphism which transforms…

Optimization and Control · Mathematics 2018-07-24 Martin Bauer , Sarang Joshi , Klas Modin

We show that the multivariate generating function of appropriately normalized moments of a measure with homogeneous polynomial density supported on a compact polytope P in R^d is a rational function. Its denominator is the product of linear…

Metric Geometry · Mathematics 2018-04-09 Nick Gravin , Dmitrii V. Pasechnik , Boris Shapiro , Michael Shapiro

Let a torus $T$ act on a symplectic manifold $(M,\omega)$ with moment map $\phi$. We say that the Hamiltonian $T$-manifold $(M,\omega,\phi)$ has complexity one if $\frac{1}{2} \dim M - \dim T = 1$, and that it is K\"ahler if it admits an…

Symplectic Geometry · Mathematics 2026-03-16 Isabelle Charton , Liat Kessler , Susan Tolman

We review and formulate results concerning log-concavity and strong-log-concavity in both discrete and continuous settings. We show how preservation of log-concavity and strongly log-concavity on $\mathbb{R}$ under convolution follows from…

Statistics Theory · Mathematics 2014-04-24 Adrien Saumard , Jon A. Wellner