The dynamics of billiards has been studied in great detail when the reflection law is the specular one, i.e., when the angle of reflection equals the angle of incidence. In this talk, I will be concerned with polygonal billiards with a contracting…
Eventi
Cohomological Hall algebras – Francesco Sala (Università di Pisa)
The present talk is a gentle introduction to the theory of cohomological Hall algebras and their relevance in the study of the topology of moduli spaces, such as the Hilbert schemes of points on a smooth surface.…
The Beauville-Voisin conjecture for $\mathsf{Hilb}(K3)$ and the Virasoro algebra – Andrei Negut (MIT)
We give a geometric representation theory proof of a mild version of the Beauville-Voisin Conjecture for Hilbert schemes of $K3$ surfaces, namely the injectivity of the cycle map restricted to the subring of Chow generated by tautological classes.…
Dynamical Systems Stemming from a Family of Multi-dimensional Continued Fraction Algorithms – Thomas Garrity (Williams College)
The underlying dynamics behind classical continued fractions has been heavily studied. Attempts to generalize the many properties of continued fractions fall under the rubric of “multi-dimensional continued fractions.” As continued fractions can be…
Flanders’ theorem for many matrices under commutativity assumptions – Fernando De Terán (Universidad Carlos III de Madrid)
Given two matrices $A \in C^{m \times n}$ and $B \in C^{n \times m}$ , it is known [1] that theJordan canonical form of AB and BA can only differ in the sizes of theJordan blocks associated with the eigenvalue zero, and the difference in thesize of…
Contact structures on lens spaces and their Stein fillings – Edoardo Fossati (SNS)
Everything has been said about Stein fillings of lens spaces when they are endowed with their standard (tight) contact structure. Nevertheless, lens spaces support many more tight structures, that are all classified, but for which a complete list of…
3-varietà e rivestimenti ramificati – Simone Cappellini (Università di Pisa)
Titolo: 3-VARIETÀ E RIVESTIMENTI RAMIFICATI Abstract: Lo studio delle 3-varietà è fortemente collegato alla Teoria dei Nodi. In questo seminario ne mostreremo un esempio che passa attraverso lo studio dei rivestimenti ramificati della 3-sfera,…
A deterministic particle approach to aggregation diffusion models and application to opinion dynamics. – Emanuela Radici (Università degli Studi dell’Aquila)
We describe the one dimensional dynamics of a biological population influenced by the presence of a nonlocal attractive potential and a diffusive term, under the constraint that no overcrowding can occur. This setting can be expressed by a class of…
A quantitative Obata theorem via localization – Daniele Semola (Scuola Normale Superiore )
Obata’s theorem characterizes the equality case in the spectral gap inequality for N dimensional Riemannian manifolds with Ricci curvature bounded below by N-1. In this talk I will present an approach to the quantitative study of the shape of…
Triangulated categories of log-motives over a field – Federico Binda (Università di Milano Statale)
In this talk, I will give an overview of the construction of a triangulated category of motives for log smooth log schemes over a field $k$, based on the notion of finite log correspondence, in analogy to Voevodsky’s $\mathsf{DM}(k)$. The affine…