2 papers
math.GR2024
Snakes can be fooled into thinking they live in a tree
Laurent Bartholdi, Ville Salo
We construct a finitely generated group which is not virtually free, yet has decidable snake tiling problem. This shows that either a long-standing conjecture by Ballier and Stein…
math.DS2024
Shifts on the lamplighter group
Laurent Bartholdi, Ville Salo
We prove that the lamplighter group admits strongly aperiodic SFTs, has undecidable tiling problem, and the entropies of its SFTs are exactly the upper semicomputable nonnegative r…