2 papers
math.GR2026
Piecewise isometry groups of Euclidean tessellations
Robert Bieri, Alex Feingold, Daniel Studenmund
Given a tessellation of Euclidean or hyperbolic space, the piecewise isometry group is the group whose elements are given by cutting space into finitely many tessellated convex sub…
math.RT2024
Decompositions of hyperbolic Kac-Moody algebras with respect to imaginary root groups
Alex J. Feingold, Axel Kleinschmidt, Hermann Nicolai
We propose a novel way to define imaginary root subgroups associated with (timelike) imaginary roots of hyperbolic Kac-Moody algebras. Using in an essential way the theory of unita…