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A latin square of order $n$ is an $n\times n$ array of $n$ symbols in which each symbol occurs exactly once in each row and column. A transversal of such a square is a set of $n$ entries such that no two entries share the same row, column…

Combinatorics · Mathematics 2015-10-27 Ian M. Wanless

In a recent paper, Roland Bacher conjectured three identities concerning Stern's sequence and its twist. In this paper we prove Bacher's conjectures. Possibly of independent interest, we also give a way to compute the Stern value (or…

Number Theory · Mathematics 2010-10-19 Michael Coons

We present two related conjectures, arising in work on i-matchings in random r-regular bipartite graphs. The conjectures themselves are easily stated and involve only basic properties of convergent power series. One formulation involves…

Combinatorics · Mathematics 2020-02-11 Paul Federbush

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

Ryser's Conjecture states that any $r$-partite $r$-uniform hypergraph has a vertex cover of size at most $r - 1$ times the size of the largest matching. For $r = 2$, the conjecture is simply K\"onig's Theorem and every bipartite graph is a…

Combinatorics · Mathematics 2016-06-21 Penny Haxell , Lothar Narins , Tibor Szabó

Ryser's Conjecture states that for any $r$-partite $r$-uniform hypergraph the vertex cover number is at most $r-1$ times the matching number. This conjecture is only known to be true for $r\leq 3$. For intersecting hypergraphs, Ryser's…

Combinatorics · Mathematics 2014-09-18 Ahmad Abu-Khazneh , Alexey Pokrovskiy

In the preprint of 1993 the author formulated some conjectures on monotonicity of ratios for exponential series remainders. They are equivalent to conjectures on monotonicity of a ratio of Kummer hypergeometric functions and presumably not…

Classical Analysis and ODEs · Mathematics 2015-01-13 S. M. Sitnik

In this paper we investigate three unsolved conjectures in geometric combinatorics, namely Falconer's distance set conjecture, the dimension of Furstenburg sets, and Erdos's ring conjecture. We formulate natural $\delta$-discretized…

Classical Analysis and ODEs · Mathematics 2007-05-23 Nets Hawk Katz , Terence Tao

This article, showing that almost all objects in the title are asymmetric, is re-typed from a manuscript I wrote somewhere around 1980 (after the papers of Bang and Friedland on the permanent conjecture but before those of Egorychev and…

Combinatorics · Mathematics 2015-07-09 Peter J. Cameron

The conjecture of Masser-Oesterl\'e, popularly known as $abc$-conjecture have many consequences. We use an explicit version due to Baker to solve a number of conjectures.

Number Theory · Mathematics 2011-12-13 Shanta Laishram , T. N. Shorey

In a very celebrated paper A. Connes has formulated a conjecture which is now one of the most important open problem in Operator Algebras. This importance comes from the works of many mathematicians who have found some unexpected equivalent…

Operator Algebras · Mathematics 2010-03-11 Valerio Capraro

In a latin square of order $n$, a near transversal is a collection of $n-1$ cells which intersects each row, column, and symbol class at most once. A longstanding conjecture of Brualdi, Ryser, and Stein asserts that every latin square…

Combinatorics · Mathematics 2019-08-13 Luis Goddyn , Kevin Halasz

In 1975 Lov\'{a}sz conjectured that every $r$-partite, $r$-uniform hypergraph contains $r-1$ vertices whose deletion reduces the matching number. If true, this statement would imply a well-known conjecture of Ryser from 1971, which states…

Combinatorics · Mathematics 2025-06-12 Alexander Clow , Penny Haxell , Bojan Mohar

We establish Schmutz Schaller's conjecture that the hexagonal lattice is `better' than the square lattice. Schmutz Schaller (Bulletin of the AMS 35 (1998), p. 201), motivated by considerations from hyperbolic geometry, conjectured that in…

Number Theory · Mathematics 2007-05-23 Pieter Moree , Herman J. J. te Riele

A well-known special case of a conjecture attributed to Ryser states that k-partite intersecting hypergraphs have transversals of at most k-1 vertices. An equivalent form was formulated by Gy\'arf\'as: if the edges of a complete graph K are…

Combinatorics · Mathematics 2016-04-12 András Gyárfás , Zoltán Király

This survey contains a recollection of results, problems and conversations which go back to the early years of Representation Theory and Tilting Theory.

Representation Theory · Mathematics 2014-01-10 Gabriella D'Este

We address an old (1977) conjecture of a subset of the authors (a variant of Ryser's conjecture): in every r-coloring of the edges of a biclique [A,B] (complete bipartite graph), the vertex set can be covered by the vertices of at most 2r-2…

Combinatorics · Mathematics 2013-01-01 G. Chen , S. Fujita , A. Gyarfas , J. Lehel , A. Toth

In preparing the paper "Some extensions of Hilbert-Kunz multiplicity", we had occasion to perform an intricate set of computations pertaining to a single illustrative example. In the end, we have decided not to include the computations in…

Commutative Algebra · Mathematics 2016-05-09 Neil Epstein , Yongwei Yao

We offer a reader-friendly introduction to the attracting edge problem (also known as the "triangle conjecture") and its most general current solution of Limic and Tarr\`es (2007). Little original research is reported; rather this article…

Probability · Mathematics 2008-05-20 V. Limic , P. Tarres

A rainbow matching for (not necessarily distinct) sets F_1,...,F_k of hypergraph edges is a matching consisting of k edges, one from each F_i. The aim of the paper is twofold - to put order in the multitude of conjectures that relate to…

Combinatorics · Mathematics 2013-05-28 Ron Aharoni , Pierre Charbit , David Howard