Following the paper “ Preperiodic points and unlikely intersection” by Baker and DeMarco.

Partially based on the paper "The Markoff Group of Transformations in Prime and Composite Moduli" by Meiri and Puder.

I'll tell a couple of anecdotes related to imaginary quadratic fields
(e.g. primes in the sequence n^2+n+41), and then open a new story --
local CFT and the explicit construction of K^ab due to Lubin-Tate.

This will be a research talk. The abstract is below:
A group G is stable in permutations if every almost-action of G on a finite set is close to some actual action. Part of the interest in this notion comes from the observation that a non-residually finite stable group cannot be sofic. 
I will show that surface groups are stable in a flexible sense, that is if one is allowed to "add a few extra points" to the action. This is the first non-trivial stability result for a non-amenable group. 

I will give an introduction to sheaves and microlocal sheaves, as pioneered by Kashiwara-Schapira. The goal will be to explain recent work with Shende establishing that microlocal sheaves on a Weinstein manifold are a symplectic invariant.

Abstract. We consider families of holomorphic maps defined on subsets of the complex plane,

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Following the paper “ Preperiodic points and unlikely intersection” by Baker and DeMarco.

We'll talk about explicit class field theory of imaginary quadratic fields

Abstract: Any birational geometer would agree that the best algorithm
for resolution of singularities should run by defining a simple invariant of
the singularity and iteratively blowing up its maximality locus.
The only problem is that already the famous example of Whitney umbrella
shows that this is impossible, and all methods following Hironaka had
to use some history and resulted in more complicated algorithms.
Nevertheless, in a recent work with Abramovich and Wlodarczyk we did

Abstract:
Paul L\'evy's classical arcsine law states that the occupation time ratio of one-dimensional Brownian motion for the positive side is arcsine-distributed. The arcsine law has been generalized to a variety of classes of stochastic processes and dynamical systems.

Title: An intrinsic characterization of cofree representations of reductive groups

Abstract.
The realization of m.p automorphisms as transfer on the space of the
paths on the graded graphs allows to use new kind of encoding
of one-sided Bernoulli shift.
I will start with simple example how to realize Bernoulli shift in
the locally finite space (graph) $\prod_n {1,2,\dots n}$ (triangle
compact.)
Much more complicated example connected to old papers by
S.Kerov-Vershik and recent by Romik-Sniady in which one-sided
Bernoulli shift is
realized as Schutzenberger transfer on the space of infinite Young

Abstract: A Markov chain over a finite state space is said to exhibit the total variation cutoff phenomenon if, starting from some Dirac measure, the total variation distance to the stationary distribution drops abruptly from near maximal to near zero. It is conjectured that simple random walks on the family of $k$-regular, transitive graphs with a two sided $\epsilon$ spectral gap exhibit total variation cutoff (for any fixed $k$ and $\epsilon). This is known to be true only in a small number of cases.