The Mathematical Physics Seminar - Semester 2017-2 (01/2017-06/2017)

The seminar is organized by Robert Oeckl and held at the CCM-UNAM in Morelia.

date - time - placespeakertitle
02-01 - 17:00 - Salón 4Albert Much (ICN-UNAM)
X

In this talk we investigate if it is possible to quantize gravity by using techniques from non-commutative geometry. In particular, we investigate if quantization of space-time leads to the quantization of gravity. The investigation is done by using rigorous techniques of deformation quantization.

Quantizing Gravity with Non-commutative geometry
04-05 - 17:00 - Salón 4Albert Much (CCM-UNAM)
X

In this talk we give a very basic introduction to the framework of algebraic quantum field theory. Moreover, we introduce a local quantum field theory as a Morphism between C* Algebras and globally hyperbolic manifolds. This is done by using the framework of category theory.

Algebraic quantum field theory and category theory I [slides]
04-26 - 17:00 - Salón 4Albert Much (CCM-UNAM)
X

In this talk we give a very basic introduction to the framework of algebraic quantum field theory. Moreover, we introduce a local quantum field theory as a Morphism between C* Algebras and globally hyperbolic manifolds. This is done by using the framework of category theory.

Algebraic quantum field theory and category theory II [slides]
05-03 - 17:00 - Salón 4Diego Vidal Cruzprieto (ICN-UNAM) Quantum-corrected Einstein equations for a noncommutative Lie-algebraic spacetime
05-17 - 17:00 - Salón 4Robert Oeckl (CCM-UNAM)
X

The problem of unifying quantum theory and gravity is much deeper than that of "just quantizing gravity". The very notion of measurement becomes problematic in the standard formulation of quantum theory when a fixed classical spacetime background is no longer present. In this informal talk I want to discuss how recent progress on the foundations of quantum theory has led to a much more powerful notion of measurement that is able to address in principle the challenges of quantum gravity. On this occasion, rather than delve into theory I want to highlight concrete examples of how this works. A principal example will be the recent proposal of Rovelli et al. of a bouncing quantum black hole (aka. Planck-star). In particular, it will become clear how the heuristics of Rovelli et al. have to be modified to get a consistent prediction of the tunneling time.

How to predict the tunneling time of a bouncing black hole?
05-24 - 17:00 - Salón 4Suzanne Lanéry (CCM-UNAM)
X

In Hamiltonian mechanics, first class constraints are mostly known as a way to express gauge symmetries, but they can also be used to completely encode the dynamics of a system. The latter can be done in two different ways. One option is to reinterpret the time evolution as a gauge symmetry (aka Hamiltonian constraint), resulting in "timeless" dynamics. The other option, in the spirit of Lagrangian mechanics, is to view the equations of motion within a spacetime region as constraining the values that the dynamical variables can take on the boundary of this region.

In all 3 settings (gauge invariance/timeless dynamics/boundary formulation), quantization will follow essentially the same mathematical recipe, although its physical interpretation will be different. The aim of this talk is to review the mathematical and physical aspects of first class constraints quantization, by working out the simplest example for each setting.

An overview of first class constraints in classical and quantum mechanics
05-31 - 17:00 - Salón 4Noé Barcenas Torres (CCM-UNAM)
X

We will describe some aspects of algebraic topology and noncommutative geometry inspired by the Quantum Hall effect, especifically, versions of twisted K-Theory and K-homology and C*-algebraic methods related to the classification of noncommutative tori.

Mathematics behind the quantum Hall effect
06-28 - 17:00 - Salón 6Suzanne Lanéry (CCM-UNAM)
X

In a previous session (from May 24), I illustrated on an example how quantum transition amplitudes can be seen as emerging from the imposition of suitable first-class constraints. This point of view allows to define quantum amplitudes in a way that only depends on the symplectic structure of the classical theory, and not on some choice of complex structure (aka polarization). I will discuss how this approach can be developed in the case of finite-dimensional linear systems, and show that known formulas for the quantum amplitudes are correctly recovered.

A polarization-independent definition for quantum amplitudes in finite-dimensional linear systems

Last updated 23 June 2017.