3 papers
math.QA2025
A non-semisimple Kitaev lattice model
Sebastian Halbig, Ulrich Krähmer
The construction of the topologically protected code space of Kitaev's model for fault-tolerant quantum computation is extended from complex semisimple to arbitrary finite-dimensio…
math.CT2025
Duplicial functors, descent categories and generalized Hopf modules
Ivan Bartulović, John Boiquaye, Ulrich Krähmer
Böhm and Ştefan have expressed cyclic homology as an invariant that assigns homology groups to right and left coalgebras respect…
math.CT2022
Cyclic duality for slice and orbit 2-categories
John Boiquaye, Philipp Joram, Ulrich Krähmer
The self-duality of the paracyclic category is extended to a certain class of homotopy categories of (2,1)-categories. These generalise the orbit category of a group and are associ…