English
Related papers

Related papers: Sunflowers and Ramsey problems for restricted inte…

200 papers

Let $K_m^{(3)}$ denote the complete $3$-uniform hypergraph on $m$ vertices and $S_n^{(3)}$ the $3$-uniform hypergraph on $n+1$ vertices consisting of all $\binom{n}{2}$ edges incident to a given vertex. Whereas many hypergraph Ramsey…

Combinatorics · Mathematics 2022-10-10 David Conlon , Jacob Fox , Xiaoyu He , Dhruv Mubayi , Andrew Suk , Jacques Verstraete

Until recently, techniques for obtaining lower bounds for kernelization were one of the most sought after tools in the field of parameterized complexity. Now, after a strong influx of techniques, we are in the fortunate situation of having…

Data Structures and Algorithms · Computer Science 2015-03-19 Stefan Kratsch

For a (possibly infinite) fixed family of graphs F, we say that a graph G overlays F on a hypergraph H if V(H) is equal to V(G) and the subgraph of G induced by every hyperedge of H contains some member of F as a spanning subgraph.While it…

Data Structures and Algorithms · Computer Science 2017-03-16 Nathann Cohen , Frédéric Havet , Dorian Mazauric , Ignasi Sau , Rémi Watrigant

The discrete cube $\{0,1\}^d$ is a fundamental combinatorial structure. A subcube of $\{0,1\}^d$ is a subset of $2^k$ of its points formed by fixing $k$ coordinates and allowing the remaining $d-k$ to vary freely. The subcube structure of…

Combinatorics · Mathematics 2011-10-20 J. Robert Johnson , Klas Markström

A major theme in arithmetic combinatorics is proving multiple recurrence results on semigroups (such as Szemer\'edi's theorem) and this can often be done using methods of ergodic Ramsey theory. What usually lies at the heart of such proofs…

Logic · Mathematics 2017-04-18 Anush Tserunyan

Ramsey's theorem states that for any coloring of the n-element subsets of N with finitely many colors, there is an infinite set H such that all n-element subsets of H have the same color. The strength of consequences of Ramsey's theorem has…

Logic · Mathematics 2024-12-09 Ludovic Patey

Robust sunflowers are a generalization of combinatorial sunflowers that have applications in monotone circuit complexity, DNF sparsification, randomness extractors, and recent advances on the Erd\H{o}s-Rado sunflower conjecture. The recent…

Computational Complexity · Computer Science 2022-08-08 Bruno Pasqualotto Cavalar , Mrinal Kumar , Benjamin Rossman

We prove that hypergraphs defined by low-degree polynomial inequalities contain large homogeneous subsets. Formally, let $H$ be an $r$-uniform hypergraph on $N$ vertices that is semialgebraic of constant description complexity, and each…

Combinatorics · Mathematics 2026-02-23 Azem Adibelli , István Tomon

We obtain the asymptotic behaviour of the longest increasing/non-decreasing subsequences in a random uniform multiset permutation in which each element in {1,...,n} occurs k times, where k may depend on n. This generalizes the famous…

Combinatorics · Mathematics 2025-04-08 Lucas Gerin

A set of vertices in a hypergraph is called an independent set if no hyperedge is completely contained inside the set. Given a hypergraph, computing its largest size independent set is an NP-hard problem. In this work, we study the…

Data Structures and Algorithms · Computer Science 2021-04-05 Yash Khanna , Anand Louis , Rameesh Paul

Ramsey Theory deals with avoiding certain patterns. When constructing an instance that avoids one pattern, it is observed that other patterns emerge. For example, repetition emerges when avoiding arithmetic progression (Van der Waerden…

Discrete Mathematics · Computer Science 2020-12-24 Zhenjun Liu , Leroy Chew , Marijn Heule

In this paper, we construct explicit families of polynomials $P \in \mathbb{F}_q[x_1,\dots,x_n]$ with large root sets which have restricted intersections with affine lines. We use these sets to make substantial progress on a number of…

Combinatorics · Mathematics 2026-02-12 Jakob Führer , Vladislav Taranchuk

We say that a family of $k$-subsets of an $n$-element set is intersecting if any two of its sets intersect. In this paper we study properties and structure of large intersecting families. We prove a conclusive version of Frankl's theorem on…

Combinatorics · Mathematics 2018-10-03 Andrey Kupavskii

The $q$-color Ramsey number of a $k$-uniform hypergraph $H$ is the minimum integer $N$ such that any $q$-coloring of the complete $k$-uniform hypergraph on $N$ vertices contains a monochromatic copy of $H$. The study of these numbers is one…

Combinatorics · Mathematics 2023-08-22 Domagoj Bradač , Jacob Fox , Benny Sudakov

Given a vector $\alpha = (\alpha_1, \ldots, \alpha_k) \in \mathbb{F}_2^k$, we say a collection of subsets $\mathcal{F}$ satisfies $\alpha$-intersection pattern modulo $2$ if all $i$-wise intersections consisting of $i$ distinct sets from…

Combinatorics · Mathematics 2025-03-27 Griffin Johnston , Jason O'Neill

We study a finite-field analogue of the Erd\H{o}s distinct distances problem under the Hamming metric. For a set \(S\subseteq \mathbb{F}_q^n\) let $\Delta(S)$ denote the set of Hamming distances determined by \(S\). We prove the lower bound…

Combinatorics · Mathematics 2025-10-14 Nataly Brukhim , Ariel Bruner , Orit E. Raz

A theorem of Matou\v{s}ek asserts that for any $k \ge 2$, any set system whose shatter function is $o(n^k)$ enjoys a fractional Helly theorem of order $k$: in the $k$-wise intersection hypergraph, positive density implies a linear-size…

Computational Geometry · Computer Science 2026-03-25 Sergey Avvakumov , Marguerite Bin , Xavier Goaoc

We present equivalent formulations for concepts related to set families for which every subfamily with empty intersection has a bounded sub-collection with empty intersection. Hereby, we summarize the progress on the related questions about…

Combinatorics · Mathematics 2022-10-31 Stijn Cambie , Nika Salia

Building on recent work of Mattheus and Verstra\"ete, we establish a general connection between Ramsey numbers of the form $r(F,t)$ for $F$ a fixed graph and a variant of the Zarankiewicz problem asking for the maximum number of 1s in an…

Combinatorics · Mathematics 2024-04-25 David Conlon , Sam Mattheus , Dhruv Mubayi , Jacques Verstraëte

We provide a systematic study on the possibility of supersymmetry (SUSY) for one dimensional quantum mechanical systems consisting of a pair of lines $\R$ or intervals [-l, l] each having a point singularity. We consider the most general…

High Energy Physics - Theory · Physics 2010-12-01 Takashi Uchino , Izumi Tsutsui