School of Mathematical Sciences

Department Colloquium

Schreiber 006, 12:15

Technion

I will start with a short overview of the so-called perturbative invariants of links and 3-manifolds.

Abstract:

While these invariants were intensively studied in the last two decades, many questions, inconsistencies

and problems persist. The reason is that the construction is based on some complicated Feynman integrals

in the perturbative Chern-Simons theory and a lot of technicalities are involved. In the main part of the talk I

will describe an alternative elementary combinatorial construction of these invariants. It involves counting

similar trivalent graphs in a link diagram. This approach immediately extends to invariants of 3-manifolds.

Our construction can be restated in terms of counting certain surfaces ending on a link diagram. The latter

description seem to be a combinatorial counterpart of a so-called "large N duality conjecture" by

Gupakomar-Vafa, relating Chern-Simons theory to open strings.

Coffee will be served at 12:00 before the lecture

at Schreiber building 006