Seminari/Colloquia
Pagina 3 di 33
| Data | Tipo | Inizio | Fine | Room | Speaker | Provenienza | Titolo |
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| 15/04/26 | Seminario | 16:00 | 17:00 | 1201 | Boris Bolvig Kjær | Univ. of Copenhagen |
Computing the category of superselection sectors of 2d lattice spin systems Note:This talk is part of the activity of the MUR Excellence Department Project MatMod@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.
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| 14/04/26 | Seminario | 14:30 | 16:00 | 1101 | Marco Franciosi | Università di Pisa |
Stable surfaces with K^2=1 and χ=3
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 |
| 14/04/26 | Seminario | 14:00 | 15:00 | 1103 | Gérard Besson | CNRS-Grenoble |
On the intrinsic geometry of horospheres in negative curvature
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.
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| 07/04/26 | Seminario | 14:30 | 16:00 | 1101 | Corrado De Concini | Università di Roma La Sapienza |
Applicazioni della coomologia quantistica a problemi di razionalità secondo Katzarkov, Kontsevich, Pantev, Yu
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 |
| 31/03/26 | Seminario | 14:30 | 16:00 | 1101 | Angelo Felice Lopez | Università di Roma Tre |
On the connectedness of some degeneracy loci and of Ulrich subvarieties
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 |
| 27/03/26 | Seminario | 14:30 | 15:30 | 2001 | Rafael Martinez Vergara | University of Barcelona |
The emergence of nonsmooth bifurcations in quasiperiodically forced systems
This presentation explores the emergence of Strange Non-Chaotic Attractors (SNAs) within quasiperiodically forced dynamical systems. We examine two distinct methodologies to rigorously prove the existence of these unique mathematical structures, focusing on recent results. In this work, we analyse a two-parameter family of quasiperiodically forced maps acting on the cylinder. We establish the existence of a continuous bifurcation curve, along which the system undergoes a nonsmooth period-doubling bifurcation. Furthermore, we demonstrate that at this critical parameter value, the closure of the associated attractor possesses a positive two-dimensional Lebesgue measure. We characterize the resulting fractalization by the divergence of the Lipschitz constant of the attracting invariant curve.
N.B.: This talk is part of the
activity of the MIUR Excellence Department Project Mat-Mod@TOV (CUP E83C23000330006).
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| 27/03/26 | Seminario | 15:30 | 16:30 | 2001 | Rafael Martinez Vergara | University of Barcelona |
DocTorV Seminars-
The emergence of nonsmooth bifurcations in quasiperiodically forced systems
This presentation explores the emergence of Strange Non-Chaotic Attractors (SNAs) within quasiperiodically forced dynamical systems. We examine two distinct methodologies to rigorously prove the existence of these unique mathematical structures, focusing on recent results. In this work, we analyse a two-parameter family of quasiperiodically forced maps acting on the cylinder. We establish the existence of a continuous bifurcation curve, along which the system undergoes a nonsmooth period-doubling bifurcation. Furthermore, we demonstrate that at this critical parameter value, the closure of the associated attractor possesses a positive two-dimensional Lebesgue measure. We characterize the resulting fractalization by the divergence of the Lipschitz constant of the attracting invariant curve.
N.B.: This talk is part of the
activity of the MIUR Excellence Department Project Mat-Mod@TOV (CUP E83C23000330006).
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| 24/03/26 | Seminario | 14:30 | 15:30 | 1201 | Daniele Struppa | Chapman University |
Superoscillazioni: un ponta tra fisica, analisi e teoria dei numeri
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 |
| 24/03/26 | Seminario | 14:30 | 16:00 | 1101 | Riccardo Salvati Manni | Università di Roma La Sapienza |
Slope of Siegel modular forms
I will study the Kodaira dimension of $A_6$, i.e., the moduli space of principally polarized Abelian $g$-folds, and of $X_g^n$, i.e., the space of Kuga $n$-fold varieties on these spaces. I will then use the results on the slope of Siegel modular forms to determine the Kodaira dimension for all Kuga varieties and $A_g (g
eq 6)$. I will report the results for the case $g=6$. If I have time, I will report the results on the moving slope of $A_g$. These results were obtained in collaboration with: Dittmann, Scheithauer, Poon, Sankaran, Grushevsky, Ibukiyama, and Mondello.
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 |
| 20/03/26 | Seminario | 14:30 | 15:30 | 1201 |
"Utilising Meta Kazhdan-Lusztig Combinatorics" N.B.: this talk is part of the activity of the MIUR Excellence Department Project MatMod@TOV (CUP E83C23000330006)
Parabolic Kazhdan-Lusztig polynomials are ubiquitous across representation theory, geometry, and Lie theory. This raises two questions: can the (often strictly combinatorial) methods used to compute them be enriched to shed light on algebraic and geometric structures? Furthermore, if two a priori distinct structures are governed by the same polynomials, does this imply a deeper equivalence? <br>
In this talk, we address these questions for parabolic Kazhdan-Lusztig polynomials of type (<em>D<sub>n</sub></em> , <em>A</em><sub><em>n</em>-1</sub>) . By enriching the combinatorial methods to calculate these polynomials, we give a new presentation of the structure for the basic algebra of the anti-spherical Hecke category of isotropic Grassmannians. We then use this enriched structure to prove that it is isomorphic to the type <em>D</em> Khovanov arc algebra.
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<em> <strong><u>N.B.</u>:</strong> this talk is part of the activity of the MIUR Excellence Department Project MatMod@TOV (CUP E83C23000330006) </em>
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