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We apply the Dual Ramsey Theorem of Graham and Rothschild to prove the Ramsey property for classes of finite Boolean algebras with distinguished ideals. This allows us to compute the universal minimal flow of the group of automorphisms of…

Dynamical Systems · Mathematics 2013-01-17 Dana Bartošová

We prove a theorem ensuring that the compositions of certain Ramsey families are still Ramsey. As an application, we show that in any finite coloring of $\mathbb{N}$ there is an infinite set $A$ and an as large as desired finite set $B$…

Combinatorics · Mathematics 2022-11-22 Matt Bowen

We use the model theoretic notion of coheir to give short proofs of old and new theorems in Ramsey Theory. As an illustration we start from Ramsey's theorem itself. Then we prove Hindman's theorem and the Hales-Jewett theorem. Finally, we…

Combinatorics · Mathematics 2025-10-29 Eugenio Colla , Domenico Zambella

In this paper, we will develop a significantly more general notion of classical Ramsey numbers (extending most other graph-theoretic generalizations) and make some preliminary characterizations of these new Ramsey numbers using simple…

Combinatorics · Mathematics 2025-02-07 Bryce Alan Christopherson

We apply a recent duality theorem for tangles in abstract separation systems to derive tangle-type duality theorems for width-parameters in graphs and matroids. We further derive a duality theorem for the existence of clusters in large data…

Combinatorics · Mathematics 2020-01-24 Reinhard Diestel , Sang-il Oum

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

As a result of 33 intercontinental Zoom calls, we characterise big Ramsey degrees of the generic partial order. This is an infinitary extension of the well known fact that finite partial orders endowed with linear extensions form a Ramsey…

Ramsey theory for words over a finite alphabet was unified in the work of Carlson and Furstenberg-Katznelson. Carlson, in the same work, outlined a method to extend the theory for words over an infinite alphabet, but subject to a fixed…

Combinatorics · Mathematics 2010-11-03 Vassiliki Farmaki , Andreas Koutsogiannis

Wei's celebrated Duality Theorem is generalized in several ways, expressed as duality theorems for linear codes over division rings and, more generally, duality theorems for matroids. These results are further generalized, resulting in two…

Information Theory · Computer Science 2009-10-13 Thomas Britz , Bård Heiseldel , Trygve Johnsen , Dillon Mayhew , Keisuke Shiromoto

Let $r(G_1, G_2)$ be the Ramsey number of the two graphs $G_1$ and $G_2$. For $n_1\ge n_2\ge 1$ let $S(n_1,n_2)$ be the double star given by $V(S(n_1,n_2))=\{v_0,v_1,\ldots,v_{n_1},w_0,w_1,\ldots,w_{n_2}\}$ and…

Combinatorics · Mathematics 2023-02-17 Zhi-Hong Sun

We show that there exists a constant $c>0$ such that every $n$-vertex tree $T$ with $\Delta(T)\le cn$ has Ramsey number $R(T)=\max\{t_1+2t_2,2t_1\}-1$, where $t_1\ge t_2$ are the sizes of the bipartition classes of $T$. This improves an…

Combinatorics · Mathematics 2025-09-10 Richard Montgomery , Matías Pavez-Signé , Jun Yan

Ramsey theory is a central and active branch of combinatorics. Although Ramsey numbers for graphs have been extensively investigated since Ramsey's work in the 1930s, there is still an exponential gap between the best known lower and upper…

Combinatorics · Mathematics 2025-01-03 António Girão , Gal Kronenberg , Alex Scott

In 2012 M. Soki\'c proved that the class of all finite permutations has the Ramsey property. Using different strategies the same result was then reproved in 2013 by J. B\"ottcher and J. Foniok, in 2014 by M. Bodirsky and in 2015 yet another…

Combinatorics · Mathematics 2017-10-31 Dragan Masulovic

In this note we study and obtain factorization theorems for colorings of matrices and Grassmannians over $\mathbb{R}$ and ${\mathbb{C}}$, which can be considered metric versions of the Dual Ramsey Theorem for Boolean matrices and of the…

Combinatorics · Mathematics 2019-10-02 Dana Bartošová , Jordi Lopez-Abad , Martino Lupini , Brice Mbombo

Ramsey theory is an active research area in combinatorics whose central theme is the emergence of order in large disordered structures, with Ramsey numbers marking the threshold at which this order first appears. For generalized Ramsey…

Quantum Physics · Physics 2016-08-30 Mani Ranjbar , William G. Macready , Lane Clark , Frank Gaitan

This work continues to investigate the link between differentially private (DP) and online learning. Alon, Livni, Malliaris, and Moran (2019) showed that for binary concept classes, DP learnability of a given class implies that it has a…

Machine Learning · Computer Science 2024-08-15 Simone Fioravanti , Steve Hanneke , Shay Moran , Hilla Schefler , Iska Tsubari

For a graph $G$, we write $G\rightarrow \big(K_{r+1},\mathcal{T}(n,D)\big)$ if every blue-red colouring of the edges of $G$ contains either a blue copy of $K_{r+1}$, or a red copy of each tree with $n$ edges and maximum degree at most $D$.…

Combinatorics · Mathematics 2021-04-06 Pedro Araújo , Luiz Moreira , Matías Pavez-Signé

Milliken's tree theorem is a deep result in combinatorics that generalizes a vast number of other results in the subject, most notably Ramsey's theorem and its many variants and consequences. Motivated by a question of Dobrinen, we initiate…

An algebraic formalism, developped with V. Glaser and R. Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized…

High Energy Physics - Theory · Physics 2016-04-27 Henri Epstein

We apply the Ramsey theory to the analysis of geometrical properties of closed contours. Consider a set of six points placed on a closed contour. The straight lines connecting these points are y_ik (x)={\alpha}_ik x+\b{eta}_ik (i,k=1...6),…

Dynamical Systems · Mathematics 2022-12-21 Nir Shvalb , Mark Frenkel , Shraga Shoval , Edward Bormashenko