3 papers
math.CO2026
A New Lower Bound for the Diagonal Poset Ramsey Numbers
Maria-Romina Ivan, Bernardus A. Wessels
Given two finite posets and , their Ramsey number, denoted by , is defined to be the smallest integer such that any blue/red…
math.GN2025
What is Connectivity?
Jean F. Du Plessis, Zurab Janelidze, Bernardus A. Wessels
In this paper, we explore a taxonomy of connectivity for space-like structures. It is inspired by isolating posets of connected pieces of a space and examining its embedding in the…
math.GM2025
A Primer on Chainmails: Structures for Point-free Connectivity
J. F. Du Plessis, Zurab Janelidze, Bernardus A. Wessels
In point-free topology, one abstracts the poset of open subsets of a topological space, by replacing it with a frame (a complete lattice, where meet distributes over arbitrary join…