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Open Mic

Come listen to or contribute a minitalk (no longer than 15 minutes). Anything (as long as it vaguely relates tomathematics and is reasonably accessible) goes!

MC 5479

(Refreshments will start at 16:30)

Faisal Romshoo, University of Waterloo

Deformations of calibrations

We will look at a criterion for unobstructedness for calibrations and see when the corresponding moduli spacesform smooth manifolds, following the approach by Goto in https://arxiv.org/abs/math/0112197

MC 5403

Rahim Moosa, University of Waterloo

Definable groups in CCM

I will survey what is known about the structure of definable groups in both the standard and nonstandard models of CCM.

MC 5479

William Dan, University of Waterloo

A Characterization of Random, Left C.E. Reals

An immediate property of the halting probability of a prefix-free machine is that it is a left c.e. real. An easycorollary of the Kraft-Chaitin theorem is that the converse is true: any left c.e. real is the halting probability ofsome prefix-free machine. The most common example of a random real is Chaitin's omega, the haltingprobability of a universal prefix-free machine. In fact, it is a random left c.e. real. It is natural then to ask if theconverse holds in this case as well: that any random left c.e. real is the halting probability of some universalprefix-free machine. As it turns out, this is the case, and in this talk I will explain the concept used to solve thisquestion, Solovay reducibility, then prove the theorems demonstrating the converse. This talk follows sections9.1 and 9.2 of the Downey and Hirschfeldt book.

MC 5403

Catherine St-Pierre, University of Waterloo

Why does the Spec functor not extend to non-commutative rings?

The functor Spec, which assigns to a commutative ring its prime spectrum, plays a central role in algebraicgeometry. A natural question is whether this construction can be extended in a meaningful way tononcommutative rings. In this talk, we discuss the obstruction to the extension of the functor Spec to non-commutative rings presented by Manuel L. Reyes, showing that any functor extending Spec and satisfyingreasonable compatibility conditions must collapse on certain noncommutative rings, such as matrix algebras$M_3(\mathbb C)$.

MC 5417

Jules Ribolzi, University of Waterloo

Nonstandard models of CCM

We start to consider elementary extensions of the standard model.

MC 5479

Yash Singh, University of Waterloo

Buildings of reductive groups.

We study an algebraic construction of the spherical building of the reductive group due to Halpern-Leistner and a connection between this construction and the classification of toric vector bundles by Kiaveh-Manon.

MC 5403

Tommaso Pacini, University of Torino

Kahler techniques beyond Kahler geometry: the case of pluripotential theory

Classical pluripotential theory was introduced into complex analysis in the 1940's, as an analogue of the theory of convex functions. In the early 2000's, Harvey and Lawson showed that both pluripotential theory and many of its analytic applications make sense in a much broader setting.

Starting with the work of Calabi in the 1950's, however, it has become clear that pluripotential theory is central also to Kahler geometry. In particular, it is closely related to the cohomology of Kahler manifolds via Hodge theory and the ddbar lemma, and it provides one of the main ingredients in proving the existence of canonical metrics.

Work in progress, joint with A. Raffero, shows how parts of this "second life" of pluripotential theory extend to other geometries, hinting towards new research directions in the field of calibrated geometry and manifolds with special holonomy.

The goal of this talk will be to present a non-technical overview of some of these topics, aimed at non-specialists.

MC 5501

Jules Ribolzi, University of Waterloo

Meromorphic groups

We continue the proof that definable groups in CCM are meromorphic.

MC 5479

Aareyan manzoor, University of Waterloo

1 bounded entropy, strong convergence and peterson thom conjecture

I will introduce 1 bounded entropy and show connections to strong convergence. We will discuss how this was used to resolve the peterson thom conjecture, which says that every amenable and diffuse subalgebra of free group factors are contained in a unique maximal amenable subalgebra.

MC 5479