Dipartimento di Matematica -UTV-

Date	Type	Start	End	Room	Speaker	From	Title
28/05/26	Seminario	16:00	17:00	1201 Dal Passo	Jacob Kewarth	University of Toronto	Seminario di Sistemi Dinamici Maximizing Core Entropy Abstract Core Entropy is a function aimed at measuring the complexity of the iterations of post critically finite polynomials. In this talk we first recall the basic notions of polynomial dynamics: Julia sets, Hubbard Trees, and Core Entropy, and then we explore the core entropy as a function on the parameter space of polynomials. We then introduce new techniques to understand the maxima of core entropy.
27/05/26	Colloquium	14:30	15:30		Alessandro Carlotto	Università di Trento	Colloquium di Dipartimento The latest on the generic regularity problem for minimal subvarieties Abstract It is well-known that submanifolds of least area for a fixed boundary (Plateau problem) or in a fixed homology class (homological Plateau problem) shall not be smoothly embedded in general, but rather exhibit a singular set (as first noted by Simons and then justified by Bombieri-De Giorgi-Giusti half a century ago). The first singular example(s) of minimizers were in fact extremely rigid: cones with an isolated singularity at the origin. As it is now clear, the occurrence of singularities is an intriguing and partly elusive pathology that may be imputable to diverse causes, ranging from topological obstructions (related e.g. to pioneering work by Thom) to basic complex-analytic phenomena. But how wild may the singular set possibly be, and how frequently will it be observable as one varies the boundary in question or, respectively, the background metric? Over the past five years we have witnessed striking advances on both fronts. In this lecture I will present the general state of the art and my contributions to the latter question(s), known as the generic regularity problem, as well as some surprising geometric applications. Based on joint works with Yangyang Li and Zhihan Wang. NB: This talk is part of the activity of the MUR Excellence Department Project MATH@TOV CUP E83C23000330006
25/05/26	Seminario	14:30	15:30	1101 D'Antoni	Anargyros Dogkas	University of Pisa	DocTorV seminar: Hamiltonian Perturbation Theory in Celestial Mechanics Abstract Perturbation theory is the construction of local quasi-integrals through the composition of a series of canonical or near-identity transformations, called perturbation steps. It has been, historically, the fundamental analytical method for the study of nearly integrable Hamiltonian systems, as it allows the study of the local behavior in an otherwise complex dynamical setting, as well as the construction of local analytical solutions, and the study of the effective stability of the trajectories in the associated phase space. Naturally, the construction of such quasi-integrals is a non-convergent process , with the rate of non-convergence heavily depending from the domain that is considered. In celestial mechanics, the domains of fast divergence are called resonances. In their vicinity, stable and unstable manifolds are formed, splitting the phase space into rotation regions, foliated with KAM rotational tori, libration regions, which contain secondary tori, and chaotic domains, where the tori have broken down. In the non resonant domain, quasi-integrals allow the study of the secular dynamics of celestial bodies, their classification into groups of common origin, and the study of their stability . In contrast, resonant regions (Dogkas & Guido 2026) restrict the applicability domain of such methods. Nevertheless, effective stability estimates can be found in their vicinity (Celletti, Dogkas, et al. 2026), when an optimized selection of the associated parameters is considered, while quasi-integrals can still be defined in the libration regions, deep inside the resonant domain (Dogkas & Vartolomei 2026). N.B.: This series of talks is part of the activity of the MIUR Excellence Department Project Mat-Mod@TOV (CUP E83C23000330006).
22/05/26	Seminario	16:00	17:00	1201 Dal Passo	Olivier SCHIFFMANN	CNRS - Paris Saclay	Algebra & Representation Theory Seminar (ARTS) - joint session with the Topology Seminar - "Khovanov-Lauda-Rouquier type algebras for the projective line" N.B.: this talk is part of the activity of the MIUR Excellence Department Project Mat-Mod@TOV (CUP E83C23000330006) Abstract   The Khovanov-Lauda-Rouquier (KLR) algebras associated to quivers have been used to categorify positive halves of quantum enveloping algebras of Kac-Moody algebras. Suitable quotients of these algebras, the cyclotomic KLR algebras, categorize highest weight integrable re-presentations, and also lead to interesting knot and link invariants. In this talk, we will present some work which goes towards an analogous theory in which the quiver gets replaced by a smooth projective curve (the case of the projective line is already interesting). <br> This is joint work with Fang Yang. <br>     <em><small><small> <strong><u>N.B.</u>:</strong> this talk is part of the activity of the MIUR Excellence Department Project MatMod@TOV (CUP E83C23000330006) </small></small></em>
22/05/26	Seminario	14:30	15:30	1201 Dal Passo	Xujia CHEN	ISTA, Wien	Algebra & Representation Theory Seminar (ARTS) - joint session with the Topology Seminar - "A product operation on disk fiber bundles and its relation to the Lie bracket in graph homology" N.B.: this talk is part of the activity of the MIUR Excellence Department Project Mat-Mod@TOV (CUP E83C23000330006) Abstract In this talk we will be concerned with smooth, framed fiber bundles whose fibers are the standard d-dimensional disk, trivialized along the boundary. "Kontsevich's characteristic classes" are invariants defined for these bundles: given such a bundle π : E ⟶ B , we can associate to it a collection of cohomology classes in H^(B). On the other hand, there is a "bracket operation" for these bundles defined by Sander Kupers: namely, given two such bundles π₁ and π₂ as input, we can output a "bracket bundle" [π₁, π₂]. I will talk about this bracket bundle construction and a formula relating the Kontsevich's class of [π₁, π₂] with those of π₁ and π₂ . The main input of the proof is a generalization of the Fulton-MacPherson configuration spaces. This is joint work with Robin Koytcheff and Sander Kupers. N.B.:* this talk is part of the activity of the MIUR Excellence Department Project MatMod@TOV (CUP E83C23000330006)
21/05/26	Seminario	14:15	15:45	1201 Dal Passo	Junsheng Zhang	New York University Courant	Geometry Seminar Weak transcendental base-point freeness and diameter lower bounds for the Kähler-Ricci flow Abstract We prove a weaker version of the transcendental base-point-freeness conjecture using techniques from the relative minimal model program (MMP). As an application, we establish a lower bound for the diameter in the case of finite-time singularities of the Kähler-Ricci flow.
20/05/26	Seminario	14:00	15:00	1201 Dal Passo	Lothar Reichel	Kent State University	Randomized iterative methods for inverse problems Abstract Randomized methods can be applied to speed up the computation of the singular value decomposition of a large matrix of low rank. They also can be used to accelerate the convergence of Krylov subspace methods for the solution of certain linear systems of equations. This talk discusses several approaches to apply randomized methods to the solution of large-scale linear systems of equations that arise when solving linear inverse problems. These kind of problems appear when one seeks to determine the cause of an observed effect. This talk is part of the activity of the MUR Excellence Department Project MatMod@TOV.
19/05/26	Seminario	14:30	15:30	1201 Dal Passo	Lun Guo	South-Central Minzu University, Wuhan	Seminario di Equazioni Differenziali Standing waves for Hartree system with Hardy-Littlewood-Sobolev critical exponent Abstract In this talk, I will give some recent results on the Hartree system with Hardy-Littlewood-Sobolev critical exponent. Under some technical conditions on potentials, we investigate the existence and multiplicity of standing waves by using variational method combined with Brouwer degree theory and Ljusternik-Schnirelmann theory. NB: This talk is part of the activity of the MUR Excellence Department Project MATH@TOV CUP E83C23000330006
19/05/26	Seminario	14:30	15:30	2001	Daniele Angella	Università di Firenze	Seminario di Analisi e Geometria Complessa Some problems concerning canonical metrics in Hermitian non-Kähler geometry Abstract We investigate several possible notions of "canonical'' metrics that naturally arise in Hermitian non-Kähler geometry. In particular, we study an analogue of the Yamabe problem in the non-Kähler setting, concerning the existence of Hermitian metrics with constant scalar curvature with respect to the Chern connection. We also develop a moment map interpretation of the Chern scalar curvature in the locally conformally Kähler setting. Another tool for highlighting ''canonical structures'' is the Chern–Ricci flow. The long-time behavior of its solutions is expected to reflect the underlying complex structure, and we present some evidence of this in the case of compact complex surfaces. This talk is based on joint work with Simone Calamai, Mauricio Corrêa, Francesco Pediconi, Cristiano Spotti, Valentino Tosatti, and Oluwagbenga Joshua Windare.
19/05/26	Seminario	14:30	16:00	1101 D'Antoni	Xavier Roulleau	Université d'Angers	Geometry Seminar Point and line arrangements: moduli spaces and operator actions Abstract Point and line arrangements in the plane arise in various contexts, including topology (Zariski pairs), algebra (freeness), and combinatorics. Notably, Hirzebruch utilized these configurations to construct specific ball-quotient surfaces. In this talk, I will introduce operators acting on these arrangements and their corresponding parameter spaces. We shall see how certain elliptic modular surfaces and modular curves can be recovered as parameter spaces of point arrangements under the action of these operators. *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