Dear all,

I would like to announce the following talk at the IPMU Mathematics-String theory seminar.

Speaker: Hyun Kyu Kim	(KIAS)

Date: Wed, Oct 15, 2014, 16:00 - 17:30

Place: Kavli IPMU, Seminar Room B


Title: 

Central extensions of the Ptolemy-Thompson group T from quantization
of universal Teichmüller space

Abstract : 

Quantization of the Teichmuller space of a Riemann surface
yields projective representations of the mapping class group of the
surface, and hence central extensions of it. Quantization of universal
Teichmuller space yields central extensions of the Ptolemy-Thompson group,
which is a discrete universal analog of mapping class groups, and which is
isomorphic to Richard Thompson's group T. Meanwhile, the braided
Ptolemy-Thompson groups are extensions of T by the infinite braid group,
and by abelianizing the infinite braid group one obtains central extensions
of T. We show that these central extensions are isomorphic to the ones
coming from quantum Teichmuller theory. In particular, we notice a
discrepancy between the Kashaev quantization and the Chekhov-Fock
quantization. In this talk, no knowledge on the subject is assumed, as I
will start from a brief introduction to quantum Teichmuller theory. A
relation to Liouville conformal field theory will also be mentioned.

reference : arXiv:1211.4300



-----------------------------

Todor Eliseev Milanov
Assistant Professor
Kavli IPMU,  Japan

todor.milanov at ipmu.jp