Prossimi seminari del Dipartimento di Matematica

tra circa 13 ore
Lunedì
09 dicembre
Paola D'Aquino
Seminario di algebra e geometria, logica
ore 14:00
presso Seminario II
I will introduce the main algebraic and model theoretic properties of the rings M/nM where M is a model of Peano Arithmetic. I will explain the role played by the classical result due to Feferman and Vaught in this analysis.
Martedì
10 dicembre
Linear degenerations of the flag variety arise as natural generalizations of the complete flag variety, and their geometric properties frequently reveal intriguing combinatorial patterns. In the first part of this talk, I will introduce these objects and discuss how the celebrated Schubert cells decomposition of the complete flag variety can be generalized in this context. Moreover, I will introduce basic notions about quiver representation theory and discuss how linear degenerations can be described as varieties of representations of equioriented quivers of type A. In the second part, I will provide an overview of their geometric properties and outline the main open problems in this interesting research area. Finally, I will present some very recent general results about the smoothness and irreducibility of these varieties.
Martedì
10 dicembre
Elena Issoglio
nell'ambito della serie: STOCHASTICS AND APPLICATIONS
Seminario di analisi matematica, probabilità
ore 14:00
presso Aula E2 di Informatica
TBA
Martedì
10 dicembre
Tiziano De Angelis
nell'ambito della serie: STOCHASTICS AND APPLICATIONS
Seminario di finanza matematica, probabilità
ore 15:00
presso Aula E2 di Informatica
TBA
Giovedì
12 dicembre
In classical algorithms, tools such as the overlap gap property and free energy barrier are used to provide lower bounds for algorithms that are local, stable, or low-degree. In this talk, we review quantum algorithms for Gibbs sampling and show that they face analogous obstructions due to a general quantum bottleneck lemma. When applied to Metropolis-like algorithms and classical Hamiltonians, our result reproduces classical slow mixing arguments. Unlike previous techniques to bound mixing times of quantum Gibbs samplers, however, our bottleneck lemma provides bounds for non-commuting Hamiltonians. We apply it to systems such as random classical CSPs, quantum code Hamiltonians, and the transverse field Ising model. Key to our work are two notions of distance, which we use to measure the locality of quantum samplers and to construct the bottleneck.
Giovedì
12 dicembre
Taro Sano
Seminario di algebra e geometria
ore 11:15
presso Aula Enriques
I will give an introduction to complete intersections in weighted projective spaces. I will present the construction and their basic properties with examples. If time permits, I will also mention some results obtained in joint work with Luca Tasin.
Giovedì
12 dicembre
Umberto Zannier
nel ciclo di seminari: MATEMATICI NELLA STORIA
Seminario di algebra e geometria, interdisciplinare, storia della matematica
ore 15:00
presso Aula Pincherle
seminario on line •
Venerdì
13 dicembre
Taro Sano
Seminario di algebra e geometria
ore 11:15
presso Aula Seminario VIII piano
This is the second part of a minicourse. I will give an introduction to complete intersections in weighted projective spaces. I will present the construction and their basic properties with examples. If time permits, I will also mention some results obtained in joint work with Luca Tasin.
A classical tool in the study of real closed fields are the fields K((G)) of generalized power series (i.e., formal sums with well-ordered support) with coefficients in a field K of characteristic 0 and exponents in an ordered abelian group G. We generalize previous results about irreducible elements and unique factorization in the subring K((G≤0)).
Venerdì
13 dicembre
We describe the irreducible components of the Hilbert scheme of d points on affine space for d=9, 10. The main techniques we use are the variety of commuting matrices and analyzing loci of local algebras with a specific Hilbert function. As the main consequence, we establish the equality of cactus Grassmann and the secant Grassmann variety in the corresponding cases. This is a joint project with Hanieh Keneshlou and Klemen Sivic.
Lunedì
16 dicembre
This seminar presents two recent works focused on sparse signal recovery and inverse problems. The first part introduces the truncated Huber penalty, a non-convex penalty function designed for robust signal recovery. We explore its application in constrained and unconstrained models, proving theoretical properties of the optimal solutions. An efficient algorithm based on the block coordinate descent method is also discussed, along with applications in signal and image processing. The second part covers a generalized Tikhonov regularization framework with spatially varying weights estimated via a neural network. This end-to-end approach integrates adaptive parameter estimation, improving detail preservation.
Lunedì
16 dicembre
Francesco Paolo Gallinaro
Seminario di algebra e geometria, logica
ore 14:00
presso Seminario I
A valued difference field is a field equipped with a valuation and an automorphism which preserves the valuation ring setwise. In this talk I will discuss various results on these objects, concerning the existence of a section of the valuation compatible with the automorphism and of extensions of the valuation to difference fields extension, the solvability of amalgamation problems of valued difference fields, and the classification of the theory of valued difference fields in the sense of positive model theory. This is joint work with Jan Dobrowolski and Rosario Mennuni.
Martedì
17 dicembre
Dario Ascari
nell'ambito della serie: SEMINARIO DI ALGEBRA E GEOMETRIA
Seminario di algebra e geometria
ore 11:00
presso - Aula Da Stabilire -
18/12/2024
20/12/2024
Conference
ASK Conference 2024: Interaction Between Different Areas of Mathematical Analysis and Probability
da mercoledì 18 dicembre 2024 a venerdì 20 dicembre 2024
First workshop of the ASK group for young researchers in analysis and probability.
Giovedì
19 dicembre
Michele Bailetti
Seminario di algebra e geometria, logica
ore 16:00
presso Seminario I
In the classification of first-order theories, many "dividing lines" have been defined in order to understand the complexity and the behavior of some classes of theories. These classes are usually defined by forbidding some specific configurations of definable subsets. Patterns (of consistency and inconsistency) are essentially descriptions of abstract configurations of sets and hence can give a general framework to study dividing lines. In this talk, we describe this general framework and we introduce a notion of maximal complexity, first defined by Shelah, by requesting the presence of all the exhibitable patterns of definable sets. Weakening this notion, we define Positive Maximality and the PM_k hierarchy, and describe some results about them.
Venerdì
20 dicembre
Linus Richter
Seminario di algebra e geometria, interdisciplinare, logica, teoria delle categorie
ore 14:00
presso Seminario II
I will talk about the relationship between computability theory, the complexity of sets of reals, and set-theoretical axioms. Using all these, I will prove a ZFC consistency result in fractal geometry, which shows that the Hausdorff dimension of “simple" sets can behave badly under projections.
Giovedì
09 gennaio
Angelina Zheng
Seminario di algebra e geometria
ore 11:00
presso - Aula Da Stabilire -
Giovedì
09 gennaio
Ivan Di Liberti
Seminario di algebra e geometria, logica, teoria delle categorie
ore 14:00
presso Seminario I
Inspired by a recent characterisation of coherent topoi as a class of Kan injectives, we provide a tentative definition of fragment of geometric logic. We treat them as mathematical objects, and study them from the point of view of Lindstrom-type theorems.
Venerdì
10 gennaio
Tamas Katay
Seminario di algebra e geometria, logica
ore 14:00
presso Seminario II
Group operations on a fixed countably infinite universe form a Polish space G. Thus we can view group properties as isomorphism-invariant subsets of G, and it makes sense to ask: what properties are generic (in the sense of Baire category)? In my talk, I will address this question and if time permits, I may also say a few words about generic properties of compact groups.
15/01/2025
17/01/2025
Conference
Varietà italiane olomorfe simplettiche
da mercoledì 15 gennaio 2025 a venerdì 17 gennaio 2025
sede di via Tombesi, dall’Ova, 55 - Ravenna, Aula 1.0
Giovedì
16 gennaio
Luigi Ambrosio
nel ciclo di seminari: MATEMATICI NELLA STORIA
Seminario di analisi matematica, storia della matematica
ore 16:00
presso - Aula Da Stabilire -
seminario on line •
Venerdì
17 gennaio
Pietro Freni
Seminario di algebra e geometria, logica
ore 16:00
presso Seminario II
Lunedì
20 gennaio
Lorenzo Luperi Baglini
Seminario di logica
ore 14:00
presso Seminario II
We introduce the concept of Ramsey pairs, and show how they can be prove several infinitary results in combinatorics.
Martedì
28 gennaio
Laura Pertusi
TBA
nell'ambito della serie: SEMINARIO DI ALGEBRA E GEOMETRIA
Seminario di algebra e geometria
ore 11:00
presso Aula Bombelli
TBA
Mercoledì
29 gennaio
Philippe Ellia
nel ciclo di seminari: MATEMATICI NELLA STORIA
Seminario di algebra e geometria, analisi numerica, storia della matematica
ore 16:00
presso Aula Pincherle
seminario on line •
Giovedì
30 gennaio
The classical Plateau problem asks which surface in three-dimensional space spans the least area among all the surfaces with boundary given by an assigned curve S. This problem has many variants and generalizations, along with (partial) answers, and has inspired numerous new ideas and techniques. In this talk, we will briefly introduce the problem in both its classical and modern contexts, and then we will focus on a specific vectorial (planar) type of the Plateau problem. - Given a curve S in the plane, we can ask which diffeomorphism T of the disk D maps the boundary of D to S and spans the least area, computed as the integral of the Jacobian of T, among competitors with the same boundary condition. For simply connected curves, the answer is provided by the Riemann map, and the minimal area achieved is the Lebesgue measure of the region enclosed by S. For more complex curves, possibly self-intersecting, new analysis is required. I will present a recent result in this sense, obtained in collaboration with Prof. Riccardo Scala from the University of Siena, where the value of the minimum area is computed with an explicit formula that depends on the topology of S.
Martedì
04 febbraio
Carlo Gasparetto
Seminario di analisi matematica
ore 17:00
presso Aula Pincherle
seminario on line • collegamento al meeting
Allard’s theorem roughly states that a minimal surface, that is close enough to a plane, coincides with the graph of a smooth function which enjoys suitable a priori estimates. In this talk we will show how one can prove this result by exploiting viscosity technique and a weighted monotonicity formula. -Seminario per il ciclo ASK -
Giovedì
06 febbraio
Alessandro Verra
nel ciclo di seminari: MATEMATICI NELLA STORIA
Seminario di algebra e geometria, storia della matematica
ore 16:00
presso Aula Cremona
seminario on line •
La conferenza intende approfondire la figura, storica e scienti ca, del grande geometra Jakob Steiner alla luce del suo viaggio in Italia, svoltosi nel 1843-44. Uno degli episodi salienti del viaggio è la scoperta della superficie che prese poi il nome di superficie romana di Steiner. Esso si inserisce in un più ampio episodio, con tutte le caratteristiche di un Grand Tour, che vedrrà, in Italia con Steiner, altri matematici di primissimo piano, residenti a Berlino o comunque collegati all'odierna Humboldt Universitaet di tale città. Sarà proprio Alexander von Humboldt a spendersi per rendere possibile tale impresa a Steiner ed ai suoi compagni di viaggio: Carl Borchardt, Johann P. G. Lejeune Dirichlet, Carl Gustav Jacobi e Ludwig Schlaefli. Su di essa diversi spunti di informazione e descrizione verranno presentati, al fine di metterne a fuoco i diversi aspetti storici, geometrici e culturali, negli anni che precedevano la nascita, con Luigi Cremona e diversi altri, della Scuola geometrica italiana.
Martedì
11 febbraio
Luca Pol
nell'ambito della serie: SEMINARIO DI ALGEBRA E GEOMETRIA
Seminario di algebra e geometria
ore 11:00
presso - Aula Da Stabilire -
Mercoledì
19 febbraio
Claudia Ceci
TBA
nell'ambito della serie: STOCHASTICS AND APPLICATIONS
Seminario di finanza matematica, probabilità
ore 11:00
presso - Aula Da Stabilire -
seminario on line •
I will discuss the existence of a solution to the logarithmic Schrödinger equation in a bounded convex domain, with the property that log u is concave. Since the reaction is sign-changing and non-monotone, the classical techniques to attack the problem fail. We instead rely on a continuity argument for the approximating Lane-Emden problems based on the heuristic argument. We will discuss the optimality of the result, exhibiting for any α > 0 a solution such that u^a is not concave. This is a joint work with M. Squassina and M. Gallo.
Martedì
25 febbraio
Claudio Agostini
Seminario di algebra e geometria, logica
ore 14:00
presso Seminario II
Given a realcompact space X, we denote by Exp(X) the smallest infinite cardinal κ such that X is homeomorphic to a closed subspace of Rκ. In this talk, we analyze the realcompactness number of countable spaces. We will show that, for every cardinal κ, there exists a countable crowded space X such that Exp(X) = κ if and only if p ≤ κ ≤ c. On the other hand, we show that a scattered space of weight κ has pseudocharacter at most κ in any compactification. This will allow us to calculate Exp(X) for an arbitrary (that is, not necessarily crowded) countable space. This is a joint work with Andrea Medini and Lyubomyr Zdomskyy.
Mercoledì
19 marzo
Luciano Campi
TBA
nell'ambito della serie: STOCHASTICS AND APPLICATIONS
Seminario di finanza matematica, probabilità
ore 11:00
presso - Aula Da Stabilire -
seminario on line •
Venerdì
28 marzo
Given a measured groupoid G, together with Filippo Sarti, we defined a cohomology theory which generalizes the measurable bounded cohomology of a locally compact group. In the particular case of a groupoid associated to a measure preserving action, our cohomology boils down to the usual bounded cohomology of the group with twisted coefficients. We will discuss the possible applications of this result to orbit equivalence. 
TBA
Mercoledì
18 giugno
Giuseppina Guatteri
TBA
nell'ambito della serie: STOCHASTICS AND APPLICATIONS
Seminario di probabilità
ore 11:00
presso - Aula Da Stabilire -
seminario on line •