56 citations · 71 across the 4 of their papers we have counts for
10 papers
Deformations of Lie brackets: cohomological aspects
M. Crainic, I. Moerdijk
We introduce a new cohomology for Lie algebroids, and prove that it provides a differential graded Lie algebra which ``controls'' deformations of the structure bracket of the algeb…
Families of Hopf algebras of trees and pre-Lie algebras
Pepijn van der Laan, Ieke Moerdijk
Using methods from math-ph/9907010, we study families of Hopf algebra structures on coloured trees.
Introduction to the language of stacks and gerbes
Ieke Moerdijk
This is an introduction to gerbes for topologists, with emphasis on non-abelian cohomology.
The renormalisation bialgebra and operads
Pepijn van der Laan, Ieke Moerdijk
In a recent preprint, Brouder and Schmitt give a careful construction of a `renormalisation' Hopf algebra out of an arbitrary bialgebra. In this note, we point out that this is a s…
Orbifolds as Groupoids: an Introduction
Ieke Moerdijk
This is a survey paper based on my talk at the Workshop on Orbifolds and String Theory, the goal of which was to explain the role of groupoids and their classifying spaces as a fou…
On the Classification of Regular Groupoids
I. Moerdijk
We observe that any regular Lie groupoid G over an manifold M fits into an extension of a foliation groupoid E by a bundle of connected Lie groups K. If $\FF$ is th…