In his seminal classification paper from 1976, Connes remarked that every separable tracial von Neumann algebra ought to be embeddable into an ultrapower of the hyperfinite type II_1 factor, or, in other words, be approximable by matrices. Over the following decades, the Connes Embedding Problem (CEP) remained unsolved, but many interesting and deep reformulations were discovered. Prominently, Kirchberg proved in his famous 1991 Inventiones paper that CEP is equivalent to several questions concerning C*-algebras and their tensor product, including his QWEP conjecture. He also showed that CEP holds if and only if there is a unique C*-norm of the tensor product of two copies of the full group C*-algebra of the free group. The latter was shown (by several authors) to be equivalent to Tsirelson’s conjecture about quantum correlations. CEP also relates to the open problems in group theory if all infinite discrete groups are sofic. Recently, Ji-Natarajan-Vidick-Wright-Yuen announced a negative solution to Tsirelson’s conjecture, and hence also a negative answer to CEP by proving that two complexity classes are the same

I am going to discuss a certain characterization of Birkhoff Billiards inside discs which is related to the expansion of the formal Lazutkin conjugacy at the boundary. Based on the joint work with Jacopo De Simoi, Andrew Gad and Marco Poon.
Note: This talk is part of the activity of the MIUR Department of Excellence Project MatMod@TOV (2023–2027).

Finite Element Exterior Calculus (FEEC) is a powerful framework for developing stable discretizations of partial differential equations, providing a systematic approach to problems in computational electromagnetism and fluid mechanics. This talk explores recent developments in isogeometric versions of FEEC, with a special focus on structure-preserving discretizations for geometries with polar singularities. We will first discuss the construction of hierarchically-refined polar-spline spaces. We will then demonstrate how they form a discrete de Rham complex and provide a mathematically sound foundation for adaptive structure-preserving simulations on polar geometries. The talk is part of the activity of the MUR Excellence Department Project MatMod@TOV (CUP E83C23000330006).

Finding smooth interpolations between probability measures is a problem of broad interest, with natural applications, e.g., in biology (trajectory inference) and computer graphics (image interpolation). In this talk, I will discuss a model in which such interpolations are obtained by minimizing an action functional of the acceleration. This minimization defines a discrepancy between measures that -- in analogy with Wasserstein distances from optimal transport theory -- admits an equivalent fluid-dynamical formulation and induces a Riemannian-like geometry on the space of measures. These results suggest possible applications to kinetic PDEs. This talk is based on arXiv:2502.15665, in collaboration with G. Brigati (ISTA) and J. Maas (ISTA), and ongoing work with G. Brigati (ISTA), G. Carlier (CEREMADE, Paris Dauphine-PSL), and J. Dolbeault (CEREMADE, Paris Dauphine University-PSL).
NB: This talk is part of the activity of the MUR Excellence Department Project MATH@TOV CUP E83C23000330006

In recent years, the analysis of topologically ordered ground states of 2d quantum lattice systems in the thermodynamic limit has been developed to provide a rigorous invariant of gapped phases. The methodology is based on the approach of Doplicher, Haag, and Roberts in the context of algebraic quantum field theory, and derives a braided C*-tensor category which represents the anyonic excitations above the ground state and the fusion and braiding among them.

I will report on a joint work with S. Coughlan, R. Pardini and S. Rollenske. The investigation of (minimal) surfaces of general type with low invariants and their moduli spaces started with the work of Castelnuovo and Enriques and during the last decades of the 20th century many authors continued studying these surfaces. Nowadays Gieseker's moduli space of canonical models of surfaces of general type with K^2 and χ fixed is known to admit a modular compactification, namely the KSBA moduli space, obtained considering stable surfaces. The structure of such moduli space is not completely known and studying stable surfaces with low invariants is a starting point to see concrete examples and studying its properties. The aim of this talk is to give a description of the KSBA moduli space of stable surfaces with K^2=1 and χ=3, showing different ways to construct boundary components. After an overview of the know components, I will focus on the case of 2-Gorenstein surfaces, (with particular attention to the surfaces obtained by gluing two irreducible surfaces) and to the case of normal surfaces having rational singularities.
Note: This talk is part of the activity of the MIUR Department of Excellence Project MatMod@TOV (2023-2027) and the PRIN 2022 Moduli Spaces and Birational Geometry and Prin PNRR 2022 Mathematical Primitives for Post Quantum Digital Signatures

There are classical results showing that if a negatively closed manifold has its horospheres of constant mean curvature then it is locally symmetric. Here we shall present a rigidity result involving the intrinsic Riemannian structure of these horospheres. More precisely if one of them is flat than the closed manifold is locally real hyperbolic. Several questions arose from the approach that we will discuss, in particular concerning replacing the hypothesis on the curvature by the assumption that there is no conjugate points. This is based on a joint work with G. Courtois and S. Hersonsky.

Cercherò di dare un’idea di alcuni dei risultati contenuti nel preprint ArXiv 2508.05105.
Note: This talk is part of the activity of the MIUR Department of Excellence Project MatMod@TOV (2023-2027) and the PRIN 2022 Moduli Spaces and Birational Geometry and Prin PNRR 2022 Mathematical Primitives for Post Quantum Digital Signatures

We give necessary and sufficient conditions for the connectedness of some degeneracy loci. In the special case of Ulrich bundles, these degeneracy loci are called Ulrich subvarieties and we will see that they are always connected with a few exceptions. Joint work with V. Buttinelli and R. Vacca.
Note: This talk is part of the activity of the MIUR Department of Excellence Project MatMod@TOV (2023-2027) and the PRIN 2022 Moduli Spaces and Birational Geometry and Prin PNRR 2022 Mathematical Primitives for Post Quantum Digital Signatures

Le superoscillazioni sono un fenomeno che nasce dalla teoria dei misuramenti deboli di Aharonov ma che trovano inaspettate applicazioni in microscopia (superrisoluzione) ed in teoria dei numeri. Da un punto di vista matematico danno origine ad un fenomeno, detto supershift, che imita il comportamento delle funzioni analitiche. La precisa relazione tra queste due nozioni è più complessa di quanto ci si possa aspettare. In questo seminario darò le nozioni di base sulle funzioni superoscillanti e discuterò brevemente le loro applicazioni alla microscopia e alla teoria dei numeri. Concluderò discutendo la nozione di supershift e la sua relazione con il concetto di analiticità.
NB: This talk is part of the activity of the MUR Excellence Department Project MATH@TOV CUP E83C23000330006