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While there has been significant progress on algorithmic aspects of the Lov\'{a}sz Local Lemma (LLL) in recent years, a noteworthy exception is when the LLL is used in the context of random permutations. The breakthrough algorithm of Moser…

Data Structures and Algorithms · Computer Science 2023-10-13 David G. Harris , Aravind Srinivasan

We obtain new lower and upper bounds for the maximum multiplicity of some weighted and, respectively, non-weighted common geometric graphs drawn on n points in the plane in general position (with no three points collinear): perfect…

Discrete Mathematics · Computer Science 2011-09-27 Adrian Dumitrescu , André Schulz , Adam Sheffer , Csaba D. Tóth

Given a partial Steiner triple system (STS) of order $n$, what is the order of the smallest complete STS it can be embedded into? The study of this question goes back more than 40 years. In this paper we answer it for relatively sparse…

Combinatorics · Mathematics 2019-07-30 Rajko Nenadov , Benny Sudakov , Adam Zsolt Wagner

A Latin tableau of shape $\lambda$ and type $\mu$ is a Young diagram of shape $\lambda$ in which each box contains a single positive integer, with no repeated integers in any row or column, and the $i$th most common integer appearing…

Combinatorics · Mathematics 2024-08-09 Timothy Y. Chow , Mark G. Tiefenbruck

A hypergraph is \textit{bipartite with bipartition $(A, B)$} if every edge has exactly one vertex in $A$, and a matching in such a hypergraph is \textit{$A$-perfect} if it saturates every vertex in $A$. We prove an upper bound on the number…

Combinatorics · Mathematics 2026-05-21 Tantan Dai , Alexander Divoux , Tom Kelly

There exists a bijection between the set of Latin squares of order $n$ and the set of feasible solutions of the 3-dimensional planar assignment problem ($3PAP_n$). In this paper, we prove that, given a Latin square isotopism $\Theta$, we…

Combinatorics · Mathematics 2011-05-06 R. M. Falcón , J. Martín-Morales

An order-preserving square in a string is a fragment of the form $uv$ where $u\neq v$ and $u$ is order-isomorphic to $v$. We show that a string $w$ of length $n$ over an alphabet of size $\sigma$ contains $\mathcal{O}(\sigma n)$…

Data Structures and Algorithms · Computer Science 2023-02-03 Paweł Gawrychowski , Samah Ghazawi , Gad M. Landau

The online square detection problem is to detect the first occurrence of a square in a string whose characters are provided as input one at a time. Recall that a square is a string that is a concatenation of two identical strings. In this…

Data Structures and Algorithms · Computer Science 2014-11-10 Dmitry Kosolobov

We show the existence of a large family of representations supported by the orbit closure of the determinant. However, the validity of our result is based on the validity of the celebrated `Latin Square Conjecture' due to Alon-Tarsi or more…

Representation Theory · Mathematics 2019-02-20 Shrawan Kumar

We refine a uniform algebraic approach for deriving upper bounds on reset thresholds of synchronizing automata. We express the condition that an automaton is synchronizing in terms of linear algebra, and obtain upper bounds for the reset…

Formal Languages and Automata Theory · Computer Science 2015-12-21 Mikhail Berlinkov , Marek Szykuła

Given a line arrangement $\cal A$ with $n$ lines, we show that there exists a path of length $n^2/3 - O(n)$ in the dual graph of $\cal A$ formed by its faces. This bound is tight up to lower order terms. For the bicolored version, we…

Combinatorics · Mathematics 2015-06-12 Udo Hoffmann , Linda Kleist , Tillmann Miltzow

The Bruhat order on permutation matrices extends to alternating sign matrices via corner-sum matrices, where the order is given by entrywise domination. A classical result of Lascoux and Sch\"utzenberger states that alternating sign…

Combinatorics · Mathematics 2026-05-26 Angela Carnevale , Cian O'Brien

We prove that with high probability over the choice of a random graph $G$ from the Erd\H{o}s-R\'enyi distribution $G(n,1/2)$, a natural $n^{O(\varepsilon^2 \log n)}$-time, degree $O(\varepsilon^2 \log n)$ sum-of-squares semidefinite program…

Computational Complexity · Computer Science 2021-05-18 Pravesh K. Kothari , Peter Manohar

We consider the problem of constructing Latin cubes subject to the condition that some symbols may not appear in certain cells. We prove that there is a constant $\gamma > 0$ such that if $n=2^k$ and $A$ is $3$-dimensional $n\times n\times…

Combinatorics · Mathematics 2018-09-10 Carl Johan Casselgren , Klas Markström , Lan Anh Pham

Let lambda_s(n) denote the maximum length of a Davenport-Schinzel sequence of order s on n symbols. For s=3 it is known that lambda_3(n) = Theta(n alpha(n)) (Hart and Sharir, 1986). For general s>=4 there are almost-tight upper and lower…

Discrete Mathematics · Computer Science 2013-03-25 Gabriel Nivasch

The chromatic number of a latin square $L$, denoted $\chi(L)$, is the minimum number of partial transversals needed to cover all of its cells. It has been conjectured that every latin square satisfies $\chi(L) \leq |L|+2$. If true, this…

Combinatorics · Mathematics 2019-05-17 Luis Goddyn , Kevin Halasz , E. S. Mahmoodian

In this paper we study collections of mutually nearly orthogonal Latin squares ($\text{MNOLS}$), which come from a modification of the orthogonal condition for mutually orthogonal Latin squares. In particular, we find the maximum $\mu$ such…

Combinatorics · Mathematics 2018-11-06 F. Demirkale , D. M. Donovan , J. I. Kokkala , T. G. Marbach

An alternating sign matrix, or ASM, is a $(0, \pm 1)$-matrix where the nonzero entries in each row and column alternate in sign. We generalize this notion to hypermatrices: an $n\times n\times n$ hypermatrix $A=[a_{ijk}]$ is an {\em…

Combinatorics · Mathematics 2017-04-26 Richard A. Brualdi , Geir Dahl

We study a classical iterative algorithm for balancing matrices in the $L_\infty$ norm via a scaling transformation. This algorithm, which goes back to Osborne and Parlett \& Reinsch in the 1960s, is implemented as a standard preconditioner…

Data Structures and Algorithms · Computer Science 2015-06-16 Leonard J. Schulman , Alistair Sinclair

In 1975, Erd\H{o}s and Sauer asked to estimate, for any constant $r$, the maximum number of edges an $n$-vertex graph can have without containing an $r$-regular subgraph. In a recent breakthrough, Janzer and Sudakov proved that any…

Combinatorics · Mathematics 2025-11-27 Debsoumya Chakraborti , Oliver Janzer , Abhishek Methuku , Richard Montgomery