2 papers
math.CO2020
Planar lattice subsets with minimal vertex boundary
Radhika Gupta, Ivan Levcovitz, Alexander Margolis +1
A subset of vertices of a graph is minimal if, within all subsets of the same size, its vertex boundary is minimal. We give a complete, geometric characterization of minimal sets f…
math.GT2018
Cannon--Thurston maps for CAT(0) groups with isolated flats
Benjamin Beeker, Matthew Cordes, Giles Gardam +2
Mahan Mitra (Mj) proved Cannon--Thurston maps exist for normal hyperbolic subgroups of a hyperbolic group. We prove that Cannon--Thurston maps do not exist for infinite normal hype…