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We state the Ramsey property of classes of ordered structures with closures and given local properties. This generalises many old and new results: the Ne\v{s}et\v{r}il-R\"{o}dl Theorem, the author's Ramsey lift of bowtie-free graphs as well…

Combinatorics · Mathematics 2017-06-07 Jan Hubička , Jaroslav Nešetřil

In this paper we disprove three conjectures from [M. Dehmer, F. Emmert-Streib, Y. Shi, Interrelations of graph distance measures based on topological indices, PLoS ONE 9 (2014) e94985] on graph distance measures based on topological indices…

Combinatorics · Mathematics 2016-08-09 Aleksandar Ilic , Milovan Ilic

A {\em tree cover} of a metric space $(X,d)$ is a collection of trees, so that every pair $x,y\in X$ has a low distortion path in one of the trees. If it has the stronger property that every point $x\in X$ has a single tree with low…

Data Structures and Algorithms · Computer Science 2019-05-21 Yair Bartal , Nova Fandina , Ofer Neiman

In this note we consider a Ramsey type result for partially ordered sets. In particular, we give an alternative short proof of a theorem for a posets with multiple linear extensions recently obtained by Solecki and Zhao.

Combinatorics · Mathematics 2016-08-19 Andrii Arman , Vojtěch Rödl

Merge trees, contour trees, and Reeb graphs are graph-based topological descriptors that capture topological changes of (sub)level sets of scalar fields. Comparing scalar fields using their topological descriptors has many applications in…

Computational Geometry · Computer Science 2023-06-05 Fangfei Lan , Salman Parsa , Bei Wang

We present an extension of the duality theorem, previously defined by S. Catani et al. on the one-loop level, to higher loop orders. The duality theorem provides a relation between loop integrals and tree-level phase-space integrals. Here,…

High Energy Physics - Phenomenology · Physics 2010-12-13 Isabella Bierenbaum

One proves a far-reaching upper bound for the degree of a generically finite rational map between projective varieties over a base field of arbitrary characteristic. The bound is expressed as a product of certain degrees that appear…

Commutative Algebra · Mathematics 2021-01-29 M. Chardin , S. H. Hassanzadeh , A. Simis

A path $v_1,v_2,\ldots,v_m$ in a graph $G$ is $degree$-$monotone$ if $deg(v_1) \leq deg(v_2) \leq \cdots \leq deg(v_m)$ where $deg(v_i)$ is the degree of $v_i$ in $G$. Longest degree-monotone paths have been studied in several recent…

Combinatorics · Mathematics 2015-03-30 Yair Caro , Raphael Yuster , Christina Zarb

We extend two well-known results in Ramsey theory from from $K_n$ to arbitrary $n$-chromatic graphs. The first is a note of Erd\H os and Rado stating that in every 2-coloring of the edges of $K_n$ there is a monochromatic tree on $n$…

Combinatorics · Mathematics 2015-06-16 Arie Bialostocki , Andras Gyarfas

Packing graphs is a combinatorial problem where several given graphs are being mapped into a common host graph such that every edge is used at most once. In the planar tree packing problem we are given two trees T1 and T2 on n vertices and…

Computational Geometry · Computer Science 2016-03-28 Markus Geyer , Michael Hoffmann , Michael Kaufmann , Vincent Kusters , Csaba D. Tóth

In this paper, we study uniform rooted plane trees with given degree sequence. We show, under some natural hypotheses on the degree sequence, that these trees converge toward the so-called Inhomogeneous Continuum Random Tree after…

Probability · Mathematics 2025-11-24 Gabriel Berzunza Ojeda , Cecilia Holmgren , Paul Thévenin

A Ramsey-like theorem is a statement of the form ``For every 2-coloring of $[\mathbb{N}]^2$, there exists an infinite set~$H \subseteq \mathbb{N}$ such that $[H]^2$ avoids some pattern''. We prove that none of these statements are…

Logic · Mathematics 2026-05-12 Ahmed Mimouni , Ludovic Patey

The class of finite distributive lattices, as many other classes of structures in everyday use, does not have the Ramsey property. It is quite common, though, that after expanding the structures with appropriatelly chosen linear orders the…

Combinatorics · Mathematics 2015-11-25 Dragan Masulovic , Nebojsa Mudrinski

We resolve the Ramsey problem for $\{x,y,z:x+y=p(z)\}$ for all polynomials $p$ over $\mathbb{Z}$. In particular, we characterise all polynomials that are $2$-Ramsey, that is, those $p(z)$ such that any $2$-colouring of $\mathbb{N}$ contains…

Number Theory · Mathematics 2023-01-10 Hong Liu , Péter Pál Pach , Csaba Sándor

At the beginning of 1950's Erd\H os and Rado suggested the investigation of the Ramsey-type results where the number of colors is not finite. This marked the birth of the so-called canonizing Ramsey theory. In 1985 Pr\"omel and Voigt made…

Combinatorics · Mathematics 2017-12-08 Dragan Masulovic

We complete a 40-year old program on the computability-theoretic analysis of Ramsey's theorem, starting with Jockusch in 1972, and improving a result of Chong, Slaman and Yang in 2014. Given a set $X$, let $[X]^n$ be the collection of all…

Logic · Mathematics 2019-12-03 Benoit Monin , Ludovic Patey

We obtain a double exponential bound in Brauer's generalisation of van der Waerden's theorem, which concerns progressions with the same colour as their common difference. Such a result has been obtained independently and in much greater…

Combinatorics · Mathematics 2020-01-06 Jonathan Chapman , Sean Prendiville

Given a finite group $G$ and its representation $\rho$, the corresponding McKay graph is a graph $\Gamma(G,\rho)$ whose vertices are the irreducible representations of $G$; the number of edges between two vertices $\pi,\tau$ of…

Representation Theory · Mathematics 2022-08-02 Avraham Aizenbud , Inna Entova-Aizenbud

Hindman's theorem says that every finite coloring of the natural numbers has a monochromatic set of finite sums. Ramsey algebras are structures that satisfy an analogue of Hindman's Theorem. This paper introduces Ramsey algebras and…

Combinatorics · Mathematics 2016-08-04 Wen Chean Teh

This paper investigates big Ramsey degrees of unrestricted relational structures in (possibly) infinite languages. Despite significant progress in the study of big Ramsey degrees, the big Ramsey degrees of many classes of structures with…