Leonhard Euler stands among the most influential mathematicians in history. One of his earliest and most remarkable achievements, which helped establish his reputation, was the evaluation of the infinite series of the reciprocals of the squares: 1 + 1/4 + 1/9 + 1/16 + ... now recognized as a p-series with p=2. In this presentation, we will explore Euler’s original proof of this celebrated result and examine how he extended his methods to determine the values of other p-series.

We introduce the dynamical commensurator group for a generalized odometer action, that is for minimal equicontinuous group actions on Cantor sets. We show there is a map from the pointed mapping class group of a solenoidal manifold (ie a weak solenoid) to a dynamical commensurator group, and give conditions for when this map is either surjective or an isomorphism. Odden proved that this map is an isomorphism for the mapping class of the universal hyperbolic solenoid; Bering and Studenmund proved that the mapping class group of a universal solenoid over a compact K(G,1) manifold maps onto the commensurator group of G. We extend the results of both of these papers to arbitrary solenoidal manifolds. This work is joint with Olga Lukina.

Newelski introduced tools from topological dynamics into model theory to generalize the notion of a generic type from stable group theory to arbitrary first-order theories. He adapted Ellis’s theory to the definable setting and introduced what is now known as the Ellis Group Conjecture, which relates the Ellis group of the space of types concentrating on a definable group G, viewed as a G-flow, to the maximal compact quotient of G, a model-theoretic invariant, under suitable tameness assumptions. The conjecture has been established for definably amenable groups in NIP theories by Chernikov and Simon. In this talk, we will outline the conjecture’s motivation, introduce the key concepts surrounding it, and discuss possible directions for further research.

Precision medicine is the future of drug development, and subgroup identification plays a critical role in achieving the goal. In this presentation, we propose a powerful end-to-end solution squant (available on CRAN) that explores a sequence of quantitative objectives. The method converts the original study to an artificial 1:1 randomized trial, and features a flexible objective function, a stable signature with good interpretability, and an embedded false discovery rate (FDR) control. We demonstrate its performance through simulation and provide a real data example.