English
Related papers

Related papers: Computational lower limits on small Ramsey numbers

200 papers

We describe here how the recent Wagner's approach for applying reinforcement learning to construct examples in graph theory can be used in the search for critical graphs for small Ramsey numbers. We illustrate this application by providing…

Combinatorics · Mathematics 2024-04-01 Mohammad Ghebleh , Salem Al-Yakoob , Ali Kanso , Dragan Stevanović

In this note we establish a Ramsey-type result for certain subsets of the $n$-dimensional cube. This can then be applied to obtain reasonable bounds on various related structures, such as (partial) Hales-Jewett lines for alphabets of sized…

Combinatorics · Mathematics 2008-07-11 Ron Graham , Jozsef Solymosi

This paper sets out the results of a range of searches for linear and cyclic graph colourings with specific Ramsey properties. The new graphs comprise mainly 'template graphs' which can be used in a construction described by the current…

Combinatorics · Mathematics 2022-09-20 Fred Rowley

In this work, we give several new upper and lower bounds on Ramsey numbers for books and wheels, including a tight upper bound establishing $R(W_5, W_7) = 15$, matching upper and lower bounds giving $R(W_5, W_9) = 18$, $R(B_2, B_8) = 21$,…

Combinatorics · Mathematics 2026-02-17 Bernard Lidický , Gwen McKinley , Florian Pfender , Steven Van Overberghe

In this article we present an algorithm to compute bounds on the marginals of a graphical model. For several small clusters of nodes upper and lower bounds on the marginal values are computed independently of the rest of the network. The…

Artificial Intelligence · Computer Science 2011-06-27 B. Kappen , M. Leisink

Using appropriate notation systems for proofs, cut-reduction can often be rendered feasible on these notations, and explicit bounds can be given. Developing a suitable notation system for Bounded Arithmetic, and applying these bounds, all…

Logic in Computer Science · Computer Science 2007-12-11 Klaus Aehlig , Arnold Beckmann

The question of what can be computed, and how efficiently, are at the core of computer science. Not surprisingly, in distributed systems and networking research, an equally fundamental question is what can be computed in a…

Distributed, Parallel, and Cluster Computing · Computer Science 2016-04-01 Fabian Kuhn , Thomas Moscibroda , Roger Wattenhofer

This survey on graphs of large girth consists of two parts. The first deals with some aspects of algebraic and extremal graph theory loosely related to the Moore bound. Our point of departure for the second, Ramsey theoretic, part are some…

Combinatorics · Mathematics 2024-03-21 Christian Reiher

Let $R(H_1,H_2)$ denote the Ramsey number for the graphs $H_1, H_2$, and let $J_k$ be $K_k{-}e$. We present algorithms which enumerate all circulant and block-circulant Ramsey graphs for different types of graphs, thereby obtaining several…

Combinatorics · Mathematics 2021-07-12 Jan Goedgebeur , Steven Van Overberghe

The Ramsey number is of vital importance in Ramsey's theorem. This paper proposed a novel methodology for constructing Ramsey graphs about R(3,10), which uses Artificial Bee Colony optimization(ABC) to raise the lower bound of Ramsey number…

Artificial Intelligence · Computer Science 2015-12-09 Wei-Hao Mao , Fei Gao , Yi-Jin Dong , Wen-Ming Li

Using computational techniques we derive six new upper bounds on the classical two-color Ramsey numbers: R(3,10) <= 42, R(3,11) <= 50, R(3,13) <= 68, R(3,14) <= 77, R(3,15) <= 87, and R(3,16) <= 98. All of them are improvements by one over…

Combinatorics · Mathematics 2013-03-21 Jan Goedgebeur , Stanisław P. Radziszowski

This list presents problems in the Reverse Mathematics of infinitary Ramsey theory which I find interesting but do not personally have the techniques to solve. The intent is to enlist the help of those working in Reverse Mathematics to take…

Logic · Mathematics 2018-08-31 Natasha Dobrinen

We present deterministic techniques for computing upper and lower bounds on marginal probabilities in sigmoid and noisy-OR networks. These techniques become useful when the size of the network (or clique size) precludes exact computations.…

Artificial Intelligence · Computer Science 2013-02-18 Tommi S. Jaakkola , Michael I. Jordan

In this article we show the rough outline of a computer algorithm to generate lower bounds on the exponential function of (in principle) arbitrary precision. We implemented this to generate all necessary analytic terms for the Boltzmann…

Numerical Analysis · Computer Science 2013-01-07 Martijn Leisink , Hilbert Kappen

The diameter of a graph is among its most basic parameters. Since a few years, it moreover became a key issue to compute it for massive graphs in the context of complex network analysis. However, known algorithms, including the ones…

Data Structures and Algorithms · Computer Science 2009-09-30 Clemence Magnien , Matthieu Latapy , Michel Habib

In this paper we define new numbers called the Neo-Ramsay numbers. We show that these numbers are in fact equal to the Ramsay numbers. Neo-Ramsey numbers are easy to compute and for finding them it is not necessary to check all possible…

General Mathematics · Mathematics 2007-05-23 Dhananjay P. Mehendale

The problem of constructing explicit functions which cannot be approximated by low degree polynomials has been extensively studied in computational complexity, motivated by applications in circuit lower bounds, pseudo-randomness,…

Computational Complexity · Computer Science 2014-12-16 Abhishek Bhowmick , Shachar Lovett

This article provides new lower bounds for both Schur and weak Schur numbers by exploiting a "template"-based approach. The concept of "template" is also generalized to weak Schur numbers. Finding new templates leads to explicit partitions…

Combinatorics · Mathematics 2022-04-05 Romain Ageron , Paul Casteras , Thibaut Pellerin , Yann Portella , Arpad Rimmel , Joanna Tomasik

The Ramsey number $R(C_4,K_m)$ is the smallest $n$ such that any graph on $n$ vertices contains a cycle of length four or an independent set of order $m$. With the help of computer algorithms we obtain the exact values of the Ramsey numbers…

Combinatorics · Mathematics 2013-10-14 Ivan Livinsky , Alexander Lange , Stanisław Radziszowski

We prove some results on the border of Ramsey theory (finite partition calculus) and model theory. Also a beginning of classification theory of finite models in undertaken.

Logic · Mathematics 2016-09-06 Doug Ensley , Rami Grossberg