activity
20192026
most citedUniqueness of the Gibbs measure for the -state anti-ferromagnetic Potts model on the regular tree

5 citations · 20 across the 14 of their papers we have counts for

collaborators

15 papers

math.CO2026

Lean-verified lower bounds for the Shannon capacity of odd cycles

Pjotr Buys, Sven Polak, Jeroen Zuiddam

We give new lower bounds for the Shannon capacities of small odd cycles: , , ,…

math.CO2026

Density of reliability roots of simple graphs in the unit disk

Pjotr Buys

Brown and Colbourn (1992) showed that the complex roots of the reliability polynomial of connected multigraphs are dense in the unit disk and that the closure of the real roots is…

math.CO2025

A group-theoretic approach to Shannon capacity of graphs and a limit theorem from lattice packings

Pjotr Buys, Sven Polak, Jeroen Zuiddam

We develop a group-theoretic approach to the Shannon capacity problem. Using this approach we extend and recover, in a structured and unified manner, various families of previously…

math.CO2025

Triangle-free graphs with the fewest independent sets

Pjotr Buys, Jan van den Heuvel, Ross J. Kang

Given and a positive integer , let be a triangle-free graph on vertices with average degree . With an elegant induction, Shearer (1983) tightened a seminal resu…

math.CO2024

Reconfiguration of Independent Transversals

Pjotr Buys, Ross J. Kang, Kenta Ozeki

Given integers and , suppose there is a graph of maximum degree and a partition of its vertices into blocks of size at least . By a seminal result of Haxel…

math.CO2024

The asymptotic spectrum distance, graph limits, and the Shannon capacity

David de Boer, Pjotr Buys, Jeroen Zuiddam

Determining the Shannon capacity of graphs is a long-standing open problem in information theory, graph theory and combinatorial optimization. Over decades, a wide range of upper a…

math.CO2023

On boundedness of zeros of the independence polynomial of tori

David de Boer, Pjotr Buys, Han Peters +1

We study boundedness of zeros of the independence polynomial of tori for sequences of tori converging to the integer lattice. We prove that zeros are bounded for sequences of balan…

math.CO2023★ 1 cited

Optimal zero-free regions for the independence polynomial of bounded degree hypergraphs

Ferenc Bencs, Pjotr Buys

In this paper we investigate the distribution of zeros of the independence polynomial of hypergraphs of maximum degree . For graphs the largest zero-free disk around zero was de…

math.PR2022★ 2 cited

Uniqueness of the Gibbs measure for the anti-ferromagnetic Potts model on the infinite -regular tree for large

Ferenc Bencs, David de Boer, Pjotr Buys +1

In this paper we prove that for any integer , the anti-ferromagnetic -state Potts model on the infinite -regular tree has a unique Gibbs measure for all edge interac…

math.CO2021★ 3 cited

The limit of the zero locus of the independence polynomial for bounded degree graphs

Ferenc Bencs, Pjotr Buys, Han Peters

The goal of this paper is to accurately describe the maximal zero-free region of the independence polynomial for graphs of bounded degree, for large degree bounds. In previous work…

math.CO2021★ 2 cited

Zeros, chaotic ratios and the computational complexity of approximating the independence polynomial

David de Boer, Pjotr Buys, Lorenzo Guerini +2

The independence polynomial originates in statistical physics as the partition function of the hard-core model. The location of the complex zeros of the polynomial is related to ph…

math.PR2020★ 5 cited

Uniqueness of the Gibbs measure for the -state anti-ferromagnetic Potts model on the regular tree

David de Boer, Pjotr Buys, Guus Regts

We show that the -state anti-ferromagnetic Potts model with interaction parameter on the infinite -regular tree has a unique Gibbs measure if $w\geq 1-\frac{4…

cs.CC2020

Lee-Yang zeros and the complexity of the ferromagnetic Ising model on bounded-degree graphs

Pjotr Buys, Andreas Galanis, Viresh Patel +1

We study the computational complexity of approximating the partition function of the ferromagnetic Ising model with the external field parameter on the unit circle in the compl…

math.DS2019★ 5 cited

Lee-Yang Zeros of the antiferromagnetic Ising Model

Ferenc Bencs, Pjotr Buys, Lorenzo Guerini +1

We investigate the location of zeros for the partition function of the anti-ferromagnetic Ising Model, focusing on the zeros lying on the unit circle. We give a precise characteriz…

math.CO2019★ 2 cited

On the location of roots of the independence polynomial of bounded degree graphs

Pjotr Buys

In [1] Peters and Regts confirmed a conjecture by Sokal by showing that for every there exists a complex neighborhood of the interval $\left[0, \frac{\le…