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A Latin square of order $n$ is an $n$ by $n$ grid filled using $n$ symbols so that each symbol appears exactly once in each row and column. A transversal in a Latin square is a collection of cells which share no symbol, row or column. The…

Combinatorics · Mathematics 2023-10-31 Richard Montgomery

In 1975, Stein made a wide generalisation of the Ryser-Brualdi-Stein conjecture on transversals in Latin squares, conjecturing that every equi-$n$-square (an $n\times n$ array filled with $n$ symbols where each symbol appears exactly $n$…

Combinatorics · Mathematics 2024-12-11 Debsoumya Chakraborti , Micha Christoph , Zach Hunter , Richard Montgomery , Teo Petrov

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

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

We prove that for $n \in \mathbb N$ and an absolute constant $C$, if $p \geq C\log^2 n / n$ and $L_{i,j} \subseteq [n]$ is a random subset of $[n]$ where each $k\in [n]$ is included in $L_{i,j}$ independently with probability $p$ for each…

Combinatorics · Mathematics 2023-03-28 Dong Yeap Kang , Tom Kelly , Daniela Kühn , Abhishek Methuku , Deryk Osthus

A Latin square of order $n$ is an $n\times n$ matrix in which each row and column contains each of $n$ symbols exactly once. For $\epsilon>0$, we show that with high probability a uniformly random Latin square of order $n$ has no proper…

Combinatorics · Mathematics 2024-05-08 Michael J. Gill , Adam Mammoliti , Ian M. Wanless

We prove that, for all even $n\geq10$, there exists a latin square of order $n$ with at least one transversal, yet all transversals coincide on $ \big\lfloor n/6 \big\rfloor$ entries. These latin squares have at least $ 19 n^2/36 + O(n)$…

Combinatorics · Mathematics 2024-12-18 Afsane Ghafari , Ian M. Wanless

Let $L$ be an order-$n$ Latin square. For $X, Y, Z \subseteq \{1, ... ,n\}$, let $L(X, Y. Z)$ be the number of triples $i\in X, j\in Y, k\in Z$ such that $L(i,j) = k$. We conjecture that asymptotically almost every Latin square satisfies…

Combinatorics · Mathematics 2016-07-26 Nathan Linial , Zur Luria

A Latin array is a matrix of symbols in which no symbol occurs more than once within a row or within a column. A diagonal of an $n\times n$ array is a selection of $n$ cells taken from different rows and columns of the array. The weight of…

Combinatorics · Mathematics 2021-08-17 Darcy Best , Kyle Pula , Ian M. Wanless

A transversal in an $n \times n$ latin square is a collection of $n$ entries not repeating any row, column, or symbol. Kwan showed that almost every $n \times n$ latin square has $\bigl((1 + o(1)) n / e^2\bigr)^n$ transversals as $n \to…

Combinatorics · Mathematics 2023-05-24 Sean Eberhard , Freddie Manners , Rudi Mrazović

A partial transversal $T$ of a Latin square $L$ is a set of entries of $L$ in which each row, column and symbol is represented at most once. A partial transversal is maximal if it is not contained in a larger partial transversal. Any…

Combinatorics · Mathematics 2021-03-02 Anthony B. Evans , Adam Mammoliti , Ian Wanless

Gy\'{a}rf\'{a}s and S\'{a}rk\"{o}zy conjectured that every $n\times n$ Latin square has a `cycle-free' partial transversal of size $n-2$. We confirm this conjecture in a strong sense for almost all Latin squares, by showing that as $n…

Combinatorics · Mathematics 2022-04-12 Stephen Gould , Tom Kelly

We are seeking a sufficient condition that forces a transversal in a generalized Latin square. A generalized Latin square of order $n$ is equivalent to a proper edge-coloring of $K_{n,n}$. A transversal corresponds to a multicolored perfect…

Combinatorics · Mathematics 2017-01-31 János Barát , Zoltán Lóránt Nagy

We prove a general result on completing objects similar to Latin rectangles in which the number of occurrences of each symbol is prescribed, each cell contains multiple symbols, and no cell contains repeated symbols. This generalizes…

Combinatorics · Mathematics 2025-09-16 Amin Bahmanian

A critical set in an $n \times n$ array is a set $C$ of given entries, such that there exists a unique extension of $C$ to an $n\times n$ Latin square and no proper subset of $C$ has this property. For a Latin square $L$, $\scs{L}$ denotes…

Combinatorics · Mathematics 2007-05-23 Mahya Ghandehari , Hamed Hatami , Ebadollah S. Mahmoodian

An array is row-Latin if no symbol is repeated within any row. An array is Latin if it and its transpose are both row-Latin. A transversal in an $n\times n$ array is a selection of $n$ different symbols from different rows and different…

Combinatorics · Mathematics 2018-01-10 Darcy Best , Kevin Hendrey , Ian M. Wanless , Tim E. Wilson , David R. Wood

Let $T(n)$ denote the maximal number of transversals in an order-$n$ Latin square. Improving on the bounds obtained by McKay et al., Taranenko recently proved that $T(n) \leq \left((1+o(1))\frac{n}{e^2}\right)^{n}$, and conjectured that…

Combinatorics · Mathematics 2015-06-03 Roman Glebov , Zur Luria

We introduce a notion of parity for transversals, and use it to show that in Latin squares of order $2 \bmod 4$, the number of transversals is a multiple of 4. We also demonstrate a number of relationships (mostly congruences modulo 4)…

Combinatorics · Mathematics 2020-04-30 Darcy Best , Ian M. Wanless

Let $L$ be an $n\times n$ array whose top left $r\times r$ subarray is filled with $k$ different symbols, each occurring at most once in each row and at most once in each column. We establish necessary and sufficient conditions that ensure…

Combinatorics · Mathematics 2025-09-16 Amin Bahmanian , A. J. W. Hilton

The logarithm of the maximum number of transversals over all latin squares of order $n$ is greater than $\frac{n}{6}(\ln n+ O(1))$.

Combinatorics · Mathematics 2018-11-01 Vladimir N. Potapov
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