Simona Boyadzhiyska

activity

20192025

collaborators

5 papers

math.CO2025

Odd-Ramsey numbers of Hamilton cycles

Simona Boyadzhiyska, Shagnik Das, Thomas Lesgourgues +1

The odd-Ramsey number $r_{o dd} (n, H)$ of a graph $H$ , as introduced by Alon in his work on graph-codes, is the minimum number of colours needed to edge-colour $K_{n}$ so that ev…

math.CO2025

Ramsey numbers for 1-degenerate 3-graphs

Peter Allen, Simona Boyadzhiyska, Matías Pavez-Signé

We construct a 3-uniform 1-degenerate hypergraph on $n$ vertices whose 2-colour Ramsey number is $Ω (n^{3/2} / lo g n)$ . This shows that all remaining open cases of the hyperg…

math.CO2023

Covering grids with multiplicity

Anurag Bishnoi, Simona Boyadzhiyska, Shagnik Das +1

Given a finite grid in $R^{2}$ , how many lines are needed to cover all but one point at least $k$ times? Problems of this nature have been studied for decades, with a genera…

math.CO2021

Subspace coverings with multiplicities

Anurag Bishnoi, Simona Boyadzhiyska, Shagnik Das +1

We study the problem of determining the minimum number $f (n, k, d)$ of affine subspaces of codimension $d$ that are required to cover all points of $\mathbb{F}_2^n\setminus \{\vec{0}…

math.CO2019

Enumerating extensions of mutually orthogonal Latin squares

Simona Boyadzhiyska, Shagnik Das, Tibor Szabó

Two $n \times n$ Latin squares $L_{1}, L_{2}$ are said to be orthogonal if, for every ordered pair $(x, y)$ of symbols, there are coordinates $(i, j)$ such that $L_{1} (i, j) = x$ and $L_2(i…