4 citations · 16 across the 16 of their papers we have counts for
8 papers · 1 filter
A noncommutative calculus on the cyclic dual of Ext
Niels Kowalzig
We show that if the cochain complex computing Ext groups (in the category of modules over Hopf algebroids) admits a cocyclic structure, then the noncommutative Cartan calculus stru…
Cyclic Gerstenhaber-Schack cohomology
Domenico Fiorenza, Niels Kowalzig
We show that the diagonal complex computing the Gerstenhaber-Schack cohomology of a bialgebra (that is, the cohomology theory governing bialgebra deformations) can be given the str…
Higher brackets on cyclic and negative cyclic (co)homology
Domenico Fiorenza, Niels Kowalzig
The purpose of this article is to embed the string topology bracket developed by Chas-Sullivan and Menichi on negative cyclic cohomology groups as well as the dual bracket found by…
Gerstenhaber and Batalin-Vilkovisky structures on modules over operads
Niels Kowalzig
In this article, we show under what additional ingredients a comp (or opposite) module over an operad with multiplication can be given the structure of a cyclic k-module and how th…
Batalin-Vilkovisky algebra structures on (Co)Tor and Poisson bialgebroids
Niels Kowalzig
In this article, we extend our preceding studies on higher algebraic structures of (co)homology theories defined by a left bialgebroid (U,A). For a braided commutative Yetter-Drinf…
Batalin-Vilkovisky Structures on Ext and Tor
Niels Kowalzig, Ulrich Kraehmer
This article studies the algebraic structure of homology theories defined by a left Hopf algebroid U over a possibly noncommutative base algebra A, such as for example Hochschild,…
Cyclic structures in algebraic (co)homology theories
Niels Kowalzig, Ulrich Kraehmer
This note discusses the cyclic cohomology of a left Hopf algebroid (-Hopf algebra) with coefficients in a right module-left comodule, defined using a straightforward gene…
The cyclic theory of Hopf algebroids
Niels Kowalzig, Hessel Posthuma
We give a systematic description of the cyclic cohomology theory of Hopf algebroids in terms of its associated category of modules. Then we introduce a dual cyclic homology theory…