English
Related papers

Related papers: The Brown-Colbourn conjecture on zeros of reliabil…

200 papers

A composition of birational maps given by Laurent polynomials need not be given by Laurent polynomials; however, sometimes---quite unexpectedly---it does. We suggest a unified treatment of this phenomenon, which covers a large class of…

Combinatorics · Mathematics 2025-10-17 Sergey Fomin , Andrei Zelevinsky

Let $G$ be a finite graph with minimum degree $r$. Form a random subgraph $G_p$ of $G$ by taking each edge of $G$ into $G_p$ independently and with probability $p$. We prove that for any constant $\epsilon>0$, if $p=\frac{1+\epsilon}{r}$,…

Combinatorics · Mathematics 2013-06-25 Alan Frieze , Michael Krivelevich

We establish a connection between root multiplicities for Borcherds-Kac-Moody algebras and graph coloring. We show that the generalized chromatic polynomial of the graph associated to a given Borcherds algebra can be used to give a closed…

Combinatorics · Mathematics 2018-07-11 G. Arunkumar , Deniz Kus , R. Venkatesh

We propose a log-concavity conjecture for BPS invariants arising in the enumerative geometry of planar curve singularities, identified with the local Euler obstructions of Severi strata in their versal deformations. We further extend this…

Algebraic Geometry · Mathematics 2026-05-01 Tao Su , Baiting Xie , Chenglong Yu

Jorgensen conjectured that every 6-connected graph with no K_6 minor has a vertex whose deletion makes the graph planar. We prove the conjecture for all sufficiently large graphs.

Combinatorics · Mathematics 2012-03-13 Ken-ichi Kawarabayashi , Serguei Norine , Robin Thomas , Paul Wollan

In this note, the polar decomposition of binary fields of even extension degree is used to reduce the evaluation of the Walsh transform of binomial Boolean functions to that of Gauss sums. In the case of extensions of degree four times an…

Number Theory · Mathematics 2016-08-22 Jean-Pierre Flori

In this paper we prove the generalized Kaplansky conjecture for the Jordan algebras of the type $J_n$ in particular for self adjoint $2\times 2$ matrices over $\R$, over $\C$, $\HH$ and $\Oct$. In fact, we prove that the image of…

Rings and Algebras · Mathematics 2021-11-02 Sergey Malev , Roman Yavich , Roee Shayer

In this paper, we are motivated by the conjectures proposed by C.~Bender \textit{et al.}, \cite{C} in 2024. We have settled the first two conjectures negatively by providing a counter example in \cite{KTJ}, whereas in this paper, we prove…

Combinatorics · Mathematics 2026-04-20 Anagha Khiste , Ganesh Tarte , Vinayak Joshi

A graph $H$ is said to be positive if the homomorphism density $t_H(G)$ is non-negative for all weighted graphs $G$. The positive graph conjecture proposes a characterisation of such graphs, saying that a graph is positive if and only if it…

Combinatorics · Mathematics 2024-04-29 David Conlon , Joonkyung Lee , Leo Versteegen

This is the first of three articles on the Fibered Isomorphism Conjecture of Farrell and Jones for L-theory. We apply the general techniques developed in [15] and [16] to the L-theory case of the conjecture and prove several results. Here…

K-Theory and Homology · Mathematics 2011-03-03 S. K. Roushon

We produce a new, shorter construction of a minor-universal planar graph.

Combinatorics · Mathematics 2023-09-14 George Kontogeorgiou

The aim of this work is to prove a conjecture related to the Combinatorial Invariance Conjecture of Kazhdan-Lusztig polynomials, in the parabolic setting, for lower intervals in every arbitrary Coxeter group. This result improves and…

Combinatorics · Mathematics 2018-07-09 Mario Marietti

We show NP-completeness for several planar variants of the monotone satisfiability problem with bounded variable appearances. With one exception the presented variants have an associated bipartite graph where the vertex degree is bounded by…

Computational Complexity · Computer Science 2016-04-20 Andreas Darmann , Janosch Döcker , Britta Dorn

The first non-obvious case of Hadwiger's Conjecture states that every graph $G$ with chromatic number at least 4 has a $K_4$ minor. We give a new proof that derives the $K_4$ minor from a proper 3-coloring of a subgraph of $G$.

Combinatorics · Mathematics 2023-08-11 Daniel Cooper McDonald

Building on the work of the fourth author in math.AG/9904074, we prove the weak factorization conjecture for birational maps in characteristic zero: a birational map between complete nonsingular varieties over an algebraically closed field…

Algebraic Geometry · Mathematics 2007-05-23 Dan Abramovich , Kalle Karu , Kenji Matsuki , Jarosław Włodarczyk

We construct smooth families of elliptic surface pairs with terminal singularities over a DVR of positive or mixed characteristic $(X,B)\to \mathrm{Spec}R$, such that $P_m(X_k,B_k)>P_m(X_K,B_K)$ for all sufficiently divisible $m>0$. In…

Algebraic Geometry · Mathematics 2022-06-07 Iacopo Brivio

This paper proves that every planar graph $G$ contains a matching $M$ such that the Alon-Tarsi number of $G-M$ is at most $4$. As a consequence, $G-M$ is $4$-paintable, and hence $G$ itself is $1$-defective $4$-paintable. This improves a…

Combinatorics · Mathematics 2018-11-30 Jarosław Grytczuk , Xuding Zhu

The Jones polynomial of an alternating link is a certain specialization of the Tutte polynomial of the (planar) checkerboard graph associated to an alternating projection of the link. The Bollobas-Riordan-Tutte polynomial generalizes the…

Geometric Topology · Mathematics 2008-02-14 Oliver T. Dasbach , David Futer , Efstratia Kalfagianni , Xiao-Song Lin , Neal W. Stoltzfus

A main question in graphical models and causal inference is whether, given a probability distribution $P$ (which is usually an underlying distribution of data), there is a graph (or graphs) to which $P$ is faithful. The main goal of this…

Statistics Theory · Mathematics 2018-01-30 Kayvan Sadeghi

We prove the well-known Brown-Erd\H{o}s-S\'os Conjecture for hypergraphs of large uniformity in the following form: any dense linear $r$-graph $G$ has $k$ edges spanning at most $(r-2)k+3$ vertices, provided the uniformity $r$ of $G$ is…

Combinatorics · Mathematics 2020-07-30 Peter Keevash , Jason Long