# On the homotopy type of a simplicial complex

## Speaker:

Pedro V. Silva (FCUP - CMUP)

## Date:

Friday, 8 November, 2013 - 15:30

## Venue:

Room FC1006, DMat-FCUP

The problem of determining the homotopy type of a simplicial complex is very much simplified if the complex happens to be shellable. This means that there exists an enumeration of the facets of a particularly favourable type. But when is a simplicial complex shellable? In general, there is no...

# Exponential families, Kähler geometry and quantum mechanics

## Speaker:

Mathieu Molitor (University of Bahia, Salvador)

## Date:

Friday, 13 September, 2013 - 14:30

## Venue:

Anfiteatro 0.29

Exponential families are a particular class of statistical manifolds which are important in statistical inference, and which appear very frequently in statistics. For example, the set of normal distributions, with mean $\mu$ and deviation $\sigma$ forms a 2-dimensional exponential family.
...

# Lower bounds on Gromov width of coadjoint orbits through the Gelfand-Tsetlin pattern.

## Speaker:

Milena Pabiniak (IST, Lisbon)

## Date:

Friday, 12 July, 2013 - 14:30

## Venue:

M003, DMat-FCUP

Gromov width of a symplectic manifold M is a supremum of capacities of balls that can be symplectically embedded into M. The definition was motivated by the Gromov's Non-Squeezing Theorem which says that maps preserving symplectic structure form a proper subset of volume preserving maps.
...

# Monopoles in Higher Dimensions

## Speaker:

Gonçalo Oliveira (Imperial College)

## Date:

Wednesday, 24 April, 2013 - 13:30

## Venue:

M006, DMat-FCUP

The Monopole (Bogomolnyi) equations are Geometric PDE in 3 dimensions that admit generalizations to Higher dimensional manifolds with special structures on them. Calabi Yau and G_2 manifolds are the main candidates for interesting solutions to these equations. There are several conjectural...

# Two periodic orbits on the standard three-sphere

## Speaker:

Leonardo Macarini

## Date:

Friday, 5 April, 2013 - 13:30

## Venue:

sala 0.03

We show that the Reeb flow of every contact form on the tight three-sphere has at least two geometrically distinct periodic orbits. This result was obtained recently by Cristofaro-Gardiner and Hutchings using embedded contact homology but our approach instead is based on cylindrical contact...

# (Non-)Displaceable Lagrangian Tori

## Speaker:

Miguel Abreu (IST)

## Date:

Friday, 8 February, 2013 - 15:40

## Venue:

sala 0.03

Rigidity of Lagrangian intersections play a fundamental role in symplectic geometry and topology. In this talk, after a general introduction, I will address a natural Lagrangian intersection problem in the context of toric symplectic manifolds: displaceability of torus orbits. The emphasis will...

# Symmetric powers of tautological bundles on Hilbert schemes of points on a surface

## Speaker:

Luca Scala (PUC-Rio)

## Date:

Friday, 25 January, 2013 - 15:40

sala 0.03

# Relações em Diff(C,0) e topologia de folhas na vizinhança de curvas invariantes

## Speaker:

Helena Reis (FEP & CMUP)

## Date:

Friday, 1 February, 2013 - 14:30

## Venue:

Sala M031. Será servido café depois da palestra (15h30-16h00).

Uma equação diferencial complexa é localmente dada por um campo de vectores da forma F(x,y)d/dx+G(x,y)d/dy, x,y∈C. Alternativamente essa equação pode ser pensada como uma folheação holomorfa singular definida localmente pela 1-forma F(x,y)dy−G(x,y)dx. Nesta palestra consideraremos o...

# On periodic orbits in complex planar billiards

## Speaker:

Alexey Glutsyuk (ENS-Lyon)

## Date:

Friday, 14 December, 2012 - 15:30

## Venue:

sala 0.31

A conjecture of Victor Ivrii (1980) says that in every billiard with smooth boundary the set of periodic orbits has measure zero. This conjecture is closely related to a conjecture of Hermann Weyl (1911) from the spectral theory. The particular case of Ivrii’s conjecture for triangular orbits was...

# Symplectic invariants and dynamics

## Speaker:

José Basto Gonçalves

## Date:

Friday, 7 December, 2012 - 14:30

## Venue:

sala 0.31

I will present some recent results on symplectic invariants concerning the possibility of embedding a given set in another one, discussing their relevance for conservative dynamics.