3 papers
math.GR2025
On cardinalities whose arithmetical properties determine the structure of solutions of the Yang--Baxter equation
Maria Ferrara, Marco Trombetti, Cindy Tsang
The aim of this paper is to provide purely arithmetical characterisations of those natural numbers for which every non-degenerate set-theoretic solution of cardinality of t…
math.GR2025
Skew Braces from a model-theoretic point of view 1
Maria Ferrara, Marco Trombetti, Moreno Invitti +1
Skew braces are one of the main algebraic tools controlling the structure of a non-degenerate bijective set-theoretic solution of the Yang-Baxter equation. The aim of this paper is…
math.LO2022
A note on the series' of ordinal numbers
Marco Trombetti
The aim of this short note is to provide a proof to a statement of Sierpiński concerning the number of possible sums of a series (of type ) of arbitrary ordinal numbers…