We study the almost Gorenstein property in the sense of Goto et al for the class of normal semigroup rings. The graded version is related to the existence of what we call Ulrich elements for the semigroup. …
Eventi
Amenable open covers of aspherical spaces – Kevin Li (University of Southampton, UK)
Amenable groups are small from a large scale geometric point of view. If a space can be covered by few subsets with amenable fundamental group, there are strong vanishing results for several invariants…