90 citations · 146 across the 8 of their papers we have counts for
8 papers
On the Rozansky-Witten weight systems
Justin Roberts, Simon Willerton
Ideas of Rozansky and Witten, as developed by Kapranov, show that a complex symplectic manifold X gives rise to Vassiliev weight systems. In this paper we study these weight system…
Unusual formulae for the Euler characteristic
Justin Roberts
Everyone knows that the Euler characteristic of a combinatorial manifold is given by the alternating sum of its numbers of simplices. It is shown that there are other linear combin…
Asymptotics and 6j-symbols
Justin Roberts
Recent interest in the Kashaev-Murakami-Murakami hyperbolic volume conjecture has made it seem important to be able to understand the asymptotic behaviour of certain special functi…
Rozansky-Witten theory
Justin Roberts
Rozansky and Witten proposed in 1996 a family of new three-dimensional topological quantum field theories, indexed by compact (or asymptotically flat) hyperkaehler manifolds. As a…
Generalisations of Rozansky-Witten invariants
Justin Roberts, Justin Sawon
We survey briefly the definition of the Rozansky-Witten invariants, and review their relevance to the study of compact hyperkahler manifolds. We consider how various generalisation…
Irreducibility of some quantum representations of mapping class groups
Justin Roberts
The SU(2) TQFT representation of the mapping class group of a closed surface of genus g, at a root of unity of prime order, is shown to be irreducible. Some examples of reducible r…