Bollettino settimanale
Settimana 30/01/2022 - 03/02/2022
Seminari
Università degli Studi Roma Tor Vergata
Dipartimento di Matematica
Joint Seminar on Differential Equations and Complex Analysis
Date: Tuesday 31 January 2023,
Schedule: 16:00 - Rome Time
Where: Conference Room 1201 - "R. Dal Passo"
Title: " The harmonic measure for random walks on cocompact Fuchsian groups "
Speaker: Giulio Tiozzo (Toronto)
Abstract: We consider random walks on groups of isometries of the hyperbolic plane,
known as Fuchsian groups. It is well-known since Furstenberg that such random walks converge to the boundary at infinity,
and the probability to reach a given subset of the boundary defines a hitting, or harmonic, measure on the circle.
It has been a long-standing question whether this harmonic measure is absolutely continuous with respect to the Lebesgue measure.
Conjecturally, this is never the case for random walks on cocompact, discrete groups. In the talk, based on joint work with
Petr Kosenko, we settle the conjecture for nearest neighbour random walks on hyperelliptic groups.
In fact, we show that the dimension of the harmonic measure for such walks is strictly less than one.
This is also related to an inequality between entropy and drift.
Organizing Committee:
Riccardo Molle (mail to contact)
Alfonso Sorrentino (mail to contact)
Leandro Arosio (mail to contact)
Further Info and Program:
Click here for Differential Equations Web page and
Click here for Complex Analysis Web page
Streaming Link (MS Teams): This seminar will be held in person
Università degli Studi di Roma "Tor Vergata"
Dipartimento di Matematica
Geometry Seminar
Date: 31th of January 2023
Schedule: 14:30 Rome Time
Where: Conference Room 1201 "Roberta Dal Passo"
Speaker: Stefano Trapani ( Università degli Studi di Roma "Tor Vergata" )
Title: " Varietà debolmente Kahler iperboliche "
Abstract: Racconterò un lavoro in collaborazione con Simone Diverio, Francesco Bei e Philippe Eyssidieux.
Nel 1991 Michael Gromov ha introdotto la nozione di varietà Kahler iperbolica, una varietà Kahler iperbolica é una varietà complessa compatta $X$ dotata di una forma di Kahler \omega tale che il pull back \tilde{omega} di omega sul rivestimento universale sia esatta con una primitiva limitata rispetto allo stesso tilde omega.
Gromov prova molte proprietà delle varietà Kahler iperboliche studiando la teoria spettrale dell operatore di Laplace. In particolare prova che X é di tipo generale e che non esistono mappe olomorfe non costanti da C in X (cioé X é Kobayashi iperbolica).
In questo lavoro generalizziamo la nozione di varietà Kahler iperbolica ammettendo una classe di coomologia omega che sia big e ne f e non necessariamente Kahler.
Questa nozione é piú adatta allo studio birazionale di X. Noi Proviamo che tali varietà sono di tipo generale, che per tali varietà la congettura di Green- Greeffith é vera (cioé tutte le mappe olomorfe da C ad X hanno immagine contenuta in una fissata sottovarietà propria) e che tutte le sottovarietà
(anche singolari) di varietà Kahler iperboliche sono di tipo generale. Cercherò di esporre varie tecniche usate per passare da classi Kahler a classi big e ne f come la teoria spettrale, il luogo non Kahler di una classe big, le correnti di Ahlfors e le equazioni di Monge Ampere complesse.
Organizing Committee:
Codogni Giulio (Contact Mail)
Lido Guido Maria ( Contact Mail)
Onorati Claudio ( Contact Mail)
Further Information: Click here for geometry webpage
NOTE: For more information contact: Onorati Claudio Click here for mail
Streaming Link (MS Teams): This seminar will be held in person
Università degli Studi di Roma "Tor Vergata"
Dipartimento di Matematica
Algebra and Representation Theory Seminar
Date: Friday, February 3rd, 2023
Schedule: 14:30 Rome Time
Where: Conference Room 1201 “Roberta Dal Passo”
Speaker: Lorenzo VECCHI (Università di Bologna)
Title: "Categorical valuative invariants of matroids"
Abstract: Matroids are combinatorial objects that abstract the notion of linear independence and can be used to describe several structures such as, for example, vector spaces and graphs. Informa-tion on matroids can be encoded in several polynomial invariants, the most famous one being the characteristic polynomial; some of these polynomials can also be upgraded to graded vector spaces via abelian categorification or, when the matroid has a non-trivial group of symmetries, to graded virtual representations. Moreover, to each matroid, one can associate a polytope that belongs to the more general class of generalized permutahedra; a matroid invariant is called valuative if it behaves well under subdivi-sions of matroid polytopes. After introducing matroids and their invariants, the goal of the talk is to formulate the new notion of categorical valuativity and give some examples. This is based on a joint ongoing project with Dane Miyata and Nicholas Proudfoot.
Organizing Committee:
Fabio Gavarini (mail to)
Martina Lanini (mail to)
Further Info: Click here
Streaming Link (MS Teams): This seminar will be held in person
Università degli Studi di Roma "Tor Vergata"
Dipartimento di Matematica
Algebra and Representation Theory Seminar
Date: Friday, February 3rd, 2023
Schedule: 16:00 Rome Time
Where: Conference Room 1201 “Roberta Dal Passo”
Speaker: Francesco ESPOSITO (Università di Padova)
Title: " Cohomology of quiver Grassmannians and Motzkin combinatorics "
Abstract: Quiver Grassmannians are projective algebraic varieties generalizing ordinary Grass-mannians and flag varieties. The cohomology of quiver Grassmannians of particular type has appli-cations to the geometric interpretation of various algebraic objects such as quantized universal enveloping algebras and cluster algebras. The variation in the cohomology of families of quiver Grassmannians of equioriented type A has been studied by Lanini-Strickland and Fang-Reineke. In this talk, I relate on joint work with Cerulli Irelli-Fang-Fourier and Cerulli Irelli-Marietti, in which we prove an upper semicontinuity statement for the cohomology of quiver Grassmannians of type A and we study the relation with Motzkin combinatorics found in work of Fang-Reineke.
Organizing Committee:
Fabio Gavarini (mail to)
Martina Lanini (mail to)
Further Info: Click here
Streaming Link (MS Teams): This seminar will be held in person
Eventi
Università degli Studi di Roma "Tor Vergata"
Dipartimento di Matematica
Corso di Dottorato
Reading course on Birational Geometry
Period: 2023.10.01 - 2023.06.06
Schedule:
| Day | Time and Room |
|---|---|
| 2023.10.01 | h:14:30/15:30 Conference Room 1103 "F.DE Blasi" |
| 2023.17.01 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.24.01 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.31.01 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.17.02 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.07.02 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.14.02 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.21.02 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.28.02 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.07.03 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.14.03 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.21.03 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.28.03 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.04.04 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.11.04 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.18.04 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.02.05 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.09.05 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.16.05 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.23.05 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.30.05 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |
| 2023.06.06 | h: 11:00/13:00 Conference Room 1103 "F.DE Blasi" |