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Related papers: New Bounds for the Integer Carath\'{e}odory Rank

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Umbilics are points of a surface embedded in three space where normal curvatures are independent of direction. The (in)famous Carath\'{e}odory Conjecture states that a compact simply connected embedded surface has at least two umbilic…

Differential Geometry · Mathematics 2025-02-04 John Guckenheimaer

We present a new approach of proving certain Carath\'{e}odory-type theorems using the Perron-Frobenius Theorem, a classical result in matrix theory describing the largest eigenvalue of a matrix with positive entries. One of the problems…

Metric Geometry · Mathematics 2021-12-28 Márton Naszódi , Alexandr Polyanskii

We prove that the density of any covering single-insertion code $C\subseteq X^r$ over the $n$-symbol alphabet $X$ cannot be smaller than $1/r+\delta_r$ for some positive real $\delta_r$ not depending on $n$. This improves the volume lower…

Combinatorics · Mathematics 2025-05-27 Oleg Pikhurko , Oleg Verbitsky , Maksim Zhukovskii

We give improved lower bounds for binary $3$-query locally correctable codes (3-LCCs) $C \colon \{0,1\}^k \rightarrow \{0,1\}^n$. Specifically, we prove: (1) If $C$ is a linear design 3-LCC, then $n \geq 2^{(1 - o(1))\sqrt{k} }$. A design…

Computational Complexity · Computer Science 2024-10-29 Pravesh K. Kothari , Peter Manohar

We introduce a new method for computing bounds on the independence number and fractional chromatic number of classes of graphs with local constraints, and apply this method in various scenarios. We establish a formula that generates a…

Combinatorics · Mathematics 2021-07-26 François Pirot , Jean-Sébastien Sereni

We derive general formula for the fourth coefficient of the functions belonging to the Carath\'{e}odory class involving the parameters lying in the open unit disk. Further, we obtain sharp upper bounds of initial inverse coefficients for…

Complex Variables · Mathematics 2020-10-08 Priyanka Goel , S. Sivaprasad Kumar

We give a deterministic nearly-linear time algorithm for approximating any point inside a convex polytope with a sparse convex combination of the polytope's vertices. Our result provides a constructive proof for the Approximate…

Data Structures and Algorithms · Computer Science 2015-12-31 Vahab Mirrokni , Renato Paes Leme , Adrian Vladu , Sam Chiu-wai Wong

Let $C_1,\dots,C_{d+1}\subset \mathbb{R}^d$ be $d+1$ point sets, each containing the origin in its convex hull. We call these sets color classes, and we call a sequence $p_1, \dots, p_{d+1}$ with $p_i \in C_i$, for $i = 1, \dots, d+1$, a…

Computational Geometry · Computer Science 2018-08-31 Wolfgang Mulzer , Yannik Stein

This paper studies the cardinality of codes correcting insertions and deletions. We give improved upper and lower bounds on code size. Our upper bound is obtained by utilizing the asymmetric property of list decoding for insertions and…

Information Theory · Computer Science 2023-12-14 Kenji Yasunaga

The structure of maximal faces of the cone of completely positive matrices is still not well understood in higher dimensions, mainly due to the lack of a general characterization of extreme exposed rays of the copositive cone beyond small…

Optimization and Control · Mathematics 2026-03-11 O. I. Kostyukova , T. V. Tchemisova

The Universal Coding of Integers~(UCI) is suitable for discrete memoryless sources with unknown probability distributions and infinitely countable alphabet sizes. A UCI is a class of prefix codes for which the ratio of the average codeword…

Information Theory · Computer Science 2026-05-15 Wei Yan , Yunghsiang S. Han

Identifying and locating-dominating codes have been widely studied in circulant graphs of type $C_n(1,2, \ldots, r)$, which can also be viewed as power graphs of cycles. Recently, Ghebleh and Niepel (2013) considered identification and…

Combinatorics · Mathematics 2023-06-22 Ville Junnila , Tero Laihonen , Gabrielle Paris

We outline some ongoing work related to a conjecture of Reed \cite{reed97} on $\omega$, $\Delta$, and $\chi$. We conjecture that the complement of a counterexample $G$ to Reed's conjecture has connectivity on the order of $\log(|G|)$. We…

Combinatorics · Mathematics 2007-05-23 landon rabern

In entropy coding, universal coding of integers~(UCI) is a binary universal prefix code, such that the ratio of the expected codeword length to $\max\{1, H(P)\}$ is less than or equal to a constant expansion factor $K_{\mathcal{C}}$ for any…

Information Theory · Computer Science 2021-09-21 Wei Yan , Sian-Jheng Lin

We give an improvement of the Carath\'eodory theorem for strong convexity (ball convexity) in $\mathbb R^n$, reducing the Carath\'eodory number to $n$ in several cases; and show that the Carath\'eodory number cannot be smaller than $n$ for…

Metric Geometry · Mathematics 2022-02-03 Vuong Bui , Roman Karasev

In this paper we give sufficient conditions for a compactum in $\mathbb R^n$ to have Carath\'{e}odory number less than $n+1$, generalizing an old result of Fenchel. Then we prove the corresponding versions of the colorful Carath\'{e}odory…

Metric Geometry · Mathematics 2012-12-27 Imre Barany , Roman Karasev

It is proved that for infinitely many positive integers n, there exists a circulant graph of order n whose Weisfeiler-Leman dimension is at least c\sqrt{log n} for some positive constant c not depending on n.

Combinatorics · Mathematics 2025-12-16 Yulai Wu , Qing Ren , Ilia Ponomarenko

Let $r_k(n)$ denote the maximum cardinality of a set $A \subset \{1,2, \dots, n \}$ such that $A$ does not contain a $k$-term arithmetic progression. In this paper, we give a method of constructing such a set and prove the lower bound…

Combinatorics · Mathematics 2017-11-21 Vladislav Taranchuk

Let $X$ be a compact metric space, let $A$ be a unital AH algebra with large matrix sizes, and let $B$ be a stably finite unital C*-algebra. Then we give a lower bound for the radius of comparison of $C(X) \otimes B$ and prove that the…

Operator Algebras · Mathematics 2020-04-08 Mohammad B. Asadi , M. Ali Asadi-Vasfi

The purpose of this note is to use the scaling principle to study the boundary behaviour of some conformal invariants on planar domains. The focus is on the Aumann--Carath\'{e}odory rigidity constant, the higher order curvatures of the…

Complex Variables · Mathematics 2019-04-16 Amar Deep Sarkar , Kaushal Verma