English
Related papers

Related papers: A counterexample to Stein's Equi-n-square Conjectu…

200 papers

Fici and Saarela ([2]) conjectured that a binary word of length n contains at least $\lfloor n/4 \rfloor$ abelian squares. We slightly extend this conjecture and show that it holds in some special cases. In all other cases we have the…

Combinatorics · Mathematics 2026-04-28 Szilard Zsolt Fazekas , Adam Mammoliti , Robert Mercas , Jamie Simpson

The \textit{sepr-sequence} of an $n\times n$ real matrix $A$ is $(s_1,\ldots,s_n)$, where $s_k$ is the subset of those signs of $+,-,0$ that appear in the values of the $k\times k$ principal minors of $A$. The $12\times 12$ matrix…

Combinatorics · Mathematics 2019-02-05 Yaroslav Shitov

A $k \times n$ partial Latin rectangle is \textit{$C$-sparse} if the number of nonempty entries in each row and column is at most $C$ and each symbol is used at most $C$ times. We prove that the probability a uniformly random $k \times n$…

Combinatorics · Mathematics 2023-11-10 Alexander Divoux , Tom Kelly , Camille Kennedy , Jasdeep Sidhu

Motivated by the concept of partial words, we introduce an analogous concept of partial permutations. A partial permutation of length n with k holes is a sequence of symbols $\pi = \pi_1\pi_2 ... \pi_n$ in which each of the symbols from the…

Combinatorics · Mathematics 2015-03-17 Anders Claesson , Vit Jelinek , Eva Jelinkova , Sergey Kitaev

The chromatic polynomial $P(G,x)$ of a graph $G$ of order $n$ can be expressed as $\sum\limits_{i=1}^n(-1)^{n-i}a_{i}x^i$, where $a_i$ is interpreted as the number of broken-cycle free spanning subgraphs of $G$ with exactly $i$ components.…

Combinatorics · Mathematics 2020-08-12 Fengming Dong , Jun Ge , Helin Gong , Bo Ning , Zhangdong Ouyang , Eng Guan Tay

In 1958, Hill conjectured that the minimum number of crossings in a drawing of $K_n$ is exactly $Z(n) = \frac{1}{4} \lfloor\frac{n}{2}\rfloor \left\lfloor\frac{n-1}{2}\right\rfloor…

Combinatorics · Mathematics 2015-01-30 Martin Balko , Radoslav Fulek , Jan Kynčl

A run in a string is a maximal periodic substring. For example, the string $\texttt{bananatree}$ contains the runs $\texttt{anana} = (\texttt{an})^{3/2}$ and $\texttt{ee} = \texttt{e}^2$. There are less than $n$ runs in any length-$n$…

Data Structures and Algorithms · Computer Science 2021-02-18 Jonas Ellert , Johannes Fischer

In 1984, Winkler conjectured that every simple Venn diagram with $n$ curves can be extended to a simple Venn diagram with $n+1$ curves. His conjecture is equivalent to the statement that the dual graph of any simple Venn diagram has a…

Combinatorics · Mathematics 2026-01-13 Sofia Brenner , Linda Kleist , Torsten Mütze , Christian Rieck , Francesco Verciani

Hypertrees are linear hypergraphs where every two vertices are connected by a unique path. Elliott and R\"{o}dl conjectured that for any given $\mu>0$, there exists $n_0$ such that the following holds. Every $n$-vertex Steiner triple system…

Combinatorics · Mathematics 2022-08-23 Seonghyuk Im , Jaehoon Kim , Joonkyung Lee , Abhishek Methuku

We establish the existence of an irreducible representation of $A_n$ whose dimension does not occur as the dimension of an irreducible representation of $S_n$, and vice versa. This proves a conjecture by Tong-Viet. The main ingredient in…

Combinatorics · Mathematics 2016-02-09 Korneel Debaene

We investigate a fifty-year-old conjecture of Erd\H{o}s and Graham concerning whether the binomial coefficient ${n \choose k}$ with $1 \leq k \leq \frac{n}{2}$ must always have a divisor $\leq n$ that is ``close'' to $n$: that is, bigger…

Number Theory · Mathematics 2026-05-21 Hung M. Bui , Kyle Pratt , Alexandru Zaharescu

For a positive integer $n$, a graph with at least $n$ vertices is $n$-existentially closed or simply $n$-e.c. if for any set of vertices $S$ of size $n$ and any set $T\subseteq S$, there is a vertex $x\not\in S$ adjacent to each vertex of…

Combinatorics · Mathematics 2024-07-09 Andrea C. Burgess , Robert D. Luther , David A. Pike

Let $r,k,\ell$ be integers such that $0\le\ell\le\binom{k}{r}$. Given a large $r$-uniform hypergraph $G$, we consider the fraction of $k$-vertex subsets which span exactly $\ell$ edges. If $\ell$ is 0 or $\binom{k}{r}$, this fraction can be…

Combinatorics · Mathematics 2025-08-22 Vishesh Jain , Matthew Kwan , Dhruv Mubayi , Tuan Tran

Rudin conjectured that there are never more than c N^(1/2) squares in an arithmetic progression of length N. Motivated by this surprisingly difficult problem we formulate more than twenty conjectures in harmonic analysis, analytic number…

Number Theory · Mathematics 2007-05-23 Javier Cilleruelo , Andrew Granville

In 1933, Borsuk conjectured that any bounded d-dimensional set of nonzero diameter can be broken into d + 1 parts of smaller diameter. This conjecture was disproved for large enough d, though it is true for low dimensional cases. The paper…

Metric Geometry · Mathematics 2010-10-12 Dian Yang

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

The Neggers-Stanley conjecture (also known as the Poset conjecture) asserts that the polynomial counting the linear extensions of a partially ordered set on $\{1,2,...,p\}$ by their number of descents has real zeros only. We provide…

Combinatorics · Mathematics 2012-04-18 Petter Brändén

The main purpose of this note is to give a counterexample to the following conjecture, raised by Florian Frick [\textit{Int. Math. Res. Not. IMRN 2020 (13), 4037-4061 (2020)}]. Conjecture. Let $r\geq 3$ and let $\mathcal{F}$ be a set…

Combinatorics · Mathematics 2022-03-21 Hamid Reza Daneshpajouh

We pose the following conjecture: (*) If A is the union of line segments in R^n, and B is the union of the corresponding full lines then the Hausdorff dimensions of A and B agree. We prove that this conjecture would imply that every…

Metric Geometry · Mathematics 2018-03-12 Tamás Keleti

Khabibullin's conjecture for integral inequalities has two numeric parameters $n$ and $\alpha$ in its statement, $n$ being a positive integer and $\alpha$ being a positive real number. This conjecture is already proved in the case where…

Classical Analysis and ODEs · Mathematics 2011-06-08 Ruslan Sharipov
‹ Prev 1 3 4 5 6 7 10 Next ›