Noncommutative Geometry

Speaker: Asghar Ghorbanpour (Western)

"Quantum dynamical systems I: Geodesic flow in NCG"

Time: 14:30

Room: MC 107

This talk is an introduction to the classical dynamical systems and the way it can be generalized to the quantum setting. We shall start with a Hamiltonian on the phase space and show that how the flow can be lifted on the observables after quantization. The Heisenberg equation can be obtained from its classical counterpart, i.e. Hamilton's equations. It is a well known fact that the geodesic flow of a Riemannian manifold $M$ is the flow of the Hamiltonian given by $H(q,p)=g_q(p,p)/2$. This can be generalized to spectral triples. We also show that for a finitely summable (even) spectral triple $(A,H,D)$ the analogue of the geodesic flow on the bounded operators of H, is given by $$F_t(T)=e^{it|D|}T e^{-it|D|}.$$ Finally I shall recall Egorov's theorem.

This is the first talk in a series of talks on "quantum dynamical systems and their properties" which will be jointly delivered by Ali Fathi and Asghar Ghorbanpour.

Geometry and Topology

Speaker: Marcy Robertson (UWO)

"Schematic Homotopy Types of Operads"

Time: 15:30

Room: MC 108

The rational homotopy type $X_{\mathbb{Q}}$ of an arbitrary space $X$ has pro-nilpotent homotopy type. As a consequence, pro-algebraic homotopy invariants of the space $X$ are not accessible through the space $X_{\mathbb{Q}}$. In order to develop a substitute of rational homotopy theory for non-nilpotent spaces Toen introduced the notion of a pointed schematic homotopy type over a field $\mathbb{k}$, $(X\times k)^{sch}.$

In his recent study of the pro-nilpotent Grothendieck-Teichmuller group via operads, Fresse makes use of the rational homotopy type of the little $2$-disks operad $E_2$. As a first step in the extension of Fresse's program to the pro-algebraic case we discuss the existence of a schematization of the little $2$-disks operad.

Homotopy Theory

Speaker: Martin Frankland (Western)

"Relation between completion and localization"

Time: 14:30

Room: MC 108

Noncommutative Geometry

Speaker: Mitsuru Wilson (Western)

"Formal Deformation Theory of Poisson Manifolds"

Time: 14:30

Room: MC 107

Pioneer works in formal deformation theory goes back to the late 60's, where a noncommutative space from a classical algebra of smooth functions was constructed. In his '98 paper Kontsevich proved the existence of a deformation called star products, on $C^\infty(M)$ where the product is understood to be a formal power series in one variable, on a Poisson manifold. In this talk I will define and derive an explicit formula on $\mathbb{R}^n$ of the star product. Furthermore I will explain Kontsevich's proof inasmuch elementary words as possible.

Algebra Seminar

Speaker: Tom Baird (Memorial University)

"Moduli spaces of vector bundles over a real curve"

Time: 14:30

Room: MC 108

In a seminal paper in 1983, Atiyah and Bott calculated the Betti numbers of the moduli space of holomorphic bundles over a complex curve using Morse theory of the Yang-Mills functional. In this talk, I will explain how to adapt the Atiyah-Bott method to calculate Z/2-Betti numbers of the moduli space of real/quaternionic vector bundles over a real curve. I will also report on work in progress on calculating rational Betti numbers.