Monochromatic products and sums in 2-colorings of N

M Bowen - Advances in Mathematics, 2025 - Elsevier
We show that any 2-coloring of N contains infinitely many monochromatic sets of the form {x,
y, xy, x+ y}, and more generally monochromatic sets of the form {xi,∏ xi,∑ xi: i≤ n} for any …

On zero-sum spanning trees and zero-sum connectivity

Y Caro, A Hansberg, J Lauri, C Zarb - arXiv preprint arXiv:2007.08240, 2020 - arxiv.org
We consider $2 $-colourings $ f: E (G)\rightarrow\{-1, 1\} $ of the edges of a graph $ G $ with
colours $-1$ and $1 $ in $\mathbb {Z} $. A subgraph $ H $ of $ G $ is said to be a zero-sum …

Graphs isomorphisms under edge-replacements and the family of amoebas

Y Caro, A Hansberg, A Montejano - arXiv preprint arXiv:2007.11769, 2020 - arxiv.org
This paper offers a systematic study of a family of graphs called amoebas. Amoebas recently
emerged from the study of forced patterns in $2 $-colorings of the edges of the complete …

Zero-Sum Over and the Story of

Y Caro, A Hansberg, A Montejano - Graphs and Combinatorics, 2019 - Springer
We prove the following results solving a problem raised by Caro and Yuster (Graphs Comb
32: 49–63, 2016). For a positive integer m ≥ 2 m≥ 2, m ≠ 4 m≠ 4, there are infinitely many …

Turán theorems for unavoidable patterns

A Girão, B Narayanan - Mathematical Proceedings of the Cambridge …, 2022 - cambridge.org
We prove Turán-type theorems for two related Ramsey problems raised by Bollobás and by
Fox and Sudakov. First, for t≥ 3, we show that any two-colouring of the complete graph on n …

Colored unavoidable patterns and balanceable graphs

M Bowen, A Hansberg, A Montejano… - arXiv preprint arXiv …, 2019 - arxiv.org
We study a Tur\'an-type problem on edge-colored complete graphs. We show that for any $ r
$ and $ t $, any sufficiently large $ r $-edge-colored complete graph on $ n $ vertices with …

On the balanceability of some graph classes

A Dailly, A Hansberg, D Ventura - Discrete Applied Mathematics, 2021 - Elsevier
Given a graph G, a 2-coloring of the edges of K n is said to contain a balanced copy of G if
we can find a copy of G such that half of its edges are in each color class. If, for every …

Ramsey numbers upon vertex deletion

Y Wigderson - Journal of Graph Theory, 2024 - Wiley Online Library
Given a graph GG, its Ramsey number r (G) r(G) is the minimum NN so that every two‐
coloring of E (KN) E(K_N) contains a monochromatic copy of G G. It was conjectured by …

[HTML][HTML] Two Ramsey problems in blowups of graphs

A Girão, R Hancock - European Journal of Combinatorics, 2024 - Elsevier
Given graphs G and H, we say G→ r H if every r-colouring of the edges of G contains a
monochromatic copy of H. Let H [t] denote the t-blowup of H. The blowup Ramsey number B …

The evolution of unavoidable bi-chromatic patterns and extremal cases of balanceability

Y Caro, A Hansberg, A Montejano - arXiv preprint arXiv:2204.04269, 2022 - arxiv.org
We study the color patterns that, for $ n $ sufficiently large, are unavoidable in $2 $-colorings
of the edges of a complete graph $ K_n $ with respect to $\min\{e (R), e (B)\} $, where $ e (R) …