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Related papers: A numerical proof of the Grunbaum conjecture

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In 1967, Gr\"unbaum conjectured that any $d$-dimensional polytope with $d+s\leq 2d$ vertices has at least \[\phi_k(d+s,d) = {d+1 \choose k+1 }+{d \choose k+1 }-{d+1-s \choose k+1 } \] $k$-faces. We prove this conjecture and also…

Combinatorics · Mathematics 2020-04-21 Lei Xue

Steinhaus proved that given a~positive integer $n$, one may find a circle surrounding exactly $n$ points of the integer lattice. This statement has been recently extended to Hilbert spaces by Zwole\'{n}ski, who replaced the integer lattice…

Functional Analysis · Mathematics 2016-10-26 Tomasz Kania , Tomasz Kochanek

Yanni Chen extended the classical Beurling-Helson-Lowdenslager Theorem for Hardy spaces on the unit circle $\mathbb{T}$ defined in terms of continuous gauge norms on $L^{\infty}$ that dominate $\Vert\cdot\Vert_{1}$. We extend Chen's result…

Functional Analysis · Mathematics 2016-11-03 Haihui Fan , Don Hadwin , Wenjing Liu

A celebrated result in convex geometry is Gr\"unbaum's inequality, which quantifies how much volume of a convex body can be cut off by a hyperplane passing through its barycenter. In this work, we establish a series of sharp Gr\"unbaum-type…

Functional Analysis · Mathematics 2025-07-17 Matthieu Fradelizi , Dylan Langharst , Jiaqian Liu , Francisco Marín Sola , Shengyu Tang

A recent conjecture by I. Ra\c{s}a asserts that the sum of the squared Bernstein basis polynomials is a convex function in $[0,1]$. This conjecture turns out to be equivalent to a certain upper pointwise estimate of the ratio…

Classical Analysis and ODEs · Mathematics 2014-02-27 Geno Nikolov

For $d\geq 2$ and any norm on $\mathbb R^d$, we prove that there exists a set of $n$ points that spans at least $(\tfrac d2-o(1))n\log_2n$ unit distances under this norm for every $n$. This matches the upper bound recently proved by Alon,…

Combinatorics · Mathematics 2025-10-03 Josef Greilhuber , Carl Schildkraut , Jonathan Tidor

Additive combinatorics asks for lower bounds on sumsets and restricted sumsets over finite fields. Central examples are the Cauchy-Davenport theorem and the Erd\H{o}s-Heilbronn conjecture. In this note, we develop Das's linear algebraic…

Combinatorics · Mathematics 2026-05-20 Guanzhong Yang

We study some properties of the randomized series and their applications to the geometric structure of Banach spaces. For $n\ge 2$ and $1<p<\infty$, it is shown that $\ell_\infty^n$ is representable in a Banach space $X$ if and only if it…

Functional Analysis · Mathematics 2007-06-27 Han Ju Lee

In this paper, we establish a suitable version of the Hahn-Banach theorem within the framework of Colombeau spaces, a class of spaces used to model generalized functions. Our approach addresses the case where maps are defined…

Functional Analysis · Mathematics 2024-10-14 Djamel eddine Kebiche , Paolo Giordano

We present a proof of the Harbourne-Hirschowitz conjecture for linear systems with base points of multiplicity seven or less. This proof uses a well-known degeneration of the projective plane, as well as a combinatorial technique that…

Algebraic Geometry · Mathematics 2009-02-14 Stephanie Yang

Prompted by results of Guardo, Van Tuyl and the second author for lines in projective 3 space, we develop asymptotic upper bounds for the least degree of a homogeneous form vanishing to order at least m on a union of disjoint r dimensional…

Algebraic Geometry · Mathematics 2016-04-12 Marcin Dumnicki , Brian Harbourne , Tomasz Szemberg , Halszka Tutaj-Gasińska

In this paper, we study the conjecture of Gardner and Zvavitch from \cite{GZ}, which suggests that the standard Gaussian measure $\gamma$ enjoys $\frac{1}{n}$-concavity with respect to the Minkowski addition of \textbf{symmetric} convex…

Analysis of PDEs · Mathematics 2019-09-19 Alexander V. Kolesnikov , Galyna V. Livshyts

We prove existence of wide types in a continuous theory expanding a Banach space, and density of minimal wide types among stable types in such a theory. We show that every minimal wide stable type is "generically" isometric to an l_2 space.…

Logic · Mathematics 2019-08-20 Saharon Shelah , Alexander Usvyatsov

The universal limit theorem is a central result in rough path theory, which has been proved for: (i) rough paths with roughness $\frac{1}{3}< \alpha \leq \frac{1}{2}$; (ii) geometric rough paths with roughness $0< \alpha \leq 1$; (iii)…

Probability · Mathematics 2025-06-18 Xing Gao , Nannan Li , Dominique Manchon

We extend the $\lambda$-theory of operator spaces given by Defant and Wiesner (2014), that generalizes the notion of the projective, Haagerup and Schur tensor norm for operator spaces to matrix ordered spaces and Banach $*$-algebras. Given…

Operator Algebras · Mathematics 2017-10-11 Preeti Luthra , Ajay Kumar , Vandana Rajpal

A celebrated conjecture due to De Giorgi states that any bounded solution of the equation $\Delta u + (1-u^2) u = 0 \hbox{in} \R^N $ with $\pp_{y_N}u >0$ must be such that its level sets $\{u=\la\}$ are all hyperplanes, {\em \bf at least}…

Analysis of PDEs · Mathematics 2009-03-27 Manuel del Pino , Mike Kowalczyk , Juncheng Wei

The main goal of the paper is to provide a quantitative lower bound greater than $1$ for the relative projection constant $\lambda(Y, X)$, where $X$ is a subspace of $\ell_{2p}^m$ space and $Y \subset X$ is an arbitrary hyperplane. As a…

Functional Analysis · Mathematics 2017-10-02 Tomasz Kobos

We obtain a gradient estimate for the Gauss maps from complete spacelike constant mean curvature hypersurfaces in Minkowski space into the hyperbolic space. As applications, we prove a Bernstein theorem which says that if the image of the…

dg-ga · Mathematics 2008-02-03 Huai-Dong Cao , Ying Shen , Shunhui Zhu

G\"ahler ([4],[5]) introduced and investigated the notion of 2-metric spaces and 2-normed spaces in sixties. These concepts are inspired by the notion of area in two dimensional Euclidean space. In this paper, we choose a fundamentally…

Classical Analysis and ODEs · Mathematics 2018-09-26 Kamran Alam Khan

Kippenhahn discovered a real algebraic plane curve whose convex hull is the numerical range of a matrix. The correctness of this theorem was called into question when Chien and Nakazato found an example where the spatial analogue fails.…

Algebraic Geometry · Mathematics 2017-05-03 Stephan Weis