Por Gonçalo Oliveira (Duke University - E.U.A.).

Por Javier Alcaide (Mestrado em Matemática da FCUL).

Björn Gohla
GFM, Universidade de Lisboa

Abstract: Lattice models arise in physics as discrete approximations of quantum field theories (QFT). Topological quantum field theories (TQFT) on the other hand by definition are QFTs, that can be defined on smooth or topological space-times, as opposed to the usual pseudo-Riemannian space-times required by QFTs. Interesting TQFTs can be defined as lattice models, giving exactly solvable models in 2 dimensions for example.

Sean Lawton
George Mason University - U.S.A.

Abstract: In this talk we will first discuss a general procedure for compactifying G-character varieties of discrete groups, where G is a semisimple algebraic group of adjoint type over an algebraically closed field. We will then discuss various properties of this compactification in special cases of the discrete group. This work is in collaboration with Dan Ramras and Indranil Biswas.

Leonor Godinho
Dep. Matemática - Instituto Superior Técnico

Miguel Abreu
Dep. Matemática - Instituto Superior Técnico

Abstract: In this talk I will prove that the mean Euler characteristic of a Gorenstein toric contact manifold is equal to half the normalized volume of the corresponding toric diagram. I will also give some immediate applications of this result. This is joint work with Leonardo Macarini.

This seminar is supported by National Funding from FCT - Fundação para a Ciência e a Tecnologia, under the project: UID/MAT/04561/2013.

Björn Gohla
Group of Mathematical Physics of the University of Lisbon

Daniel Barlet
Univ. Nancy

Luisa Fiorot
Universidade de Pádua

Por Rui Pacheco (CMAF-CIO / Universidade da Beira Interior).

This is a joint work with Pedro Morais.

Acknowledgments: This work was supported by CMA-UBI through the project UID/MAT/00212/2013.

Seminário financiado por Fundos Nacionais através da FCT - Fundação para a Ciência e a Tecnologia no âmbito do projeto UID/MAT/04561/2013.