Notiziario Scientifico
a cura del Dipartimento di Matematica Guido Castelnuovo, Sapienza Università di Roma
Settimana dal 27-09-2021 al 03-10-2021
Martedì 28 settembre 2021
Ore 14:30, D'Antoni, Dipartimento di matematica, Universita' di Roma Tor Vergata
Seminari di Geometria
Rick Miranda (Colorado State University)
Moduli spaces for rational elliptic surfaces (of index 1 and 2)
Elliptic surfaces form an important class of surfaces both from the theoretical perspective (appearing in the classification of surfaces) and the practical perspective (they are fascinating to study, individually and as a class, and are amenable to many particular computations). Elliptic surfaces that are also rational are a special sub-class. The first example is to take a general pencil of plane cubics (with 9 base points) and blow up the base points to obtain an elliptic fibration; these are so-called Jacobian surfaces, since they have a section (the final exceptional curve of the sequence of blowups). Moduli spaces for rational elliptic surfaces with a section were constructed by the speaker, and further studied by Heckman and Looijenga. In general, there may not be a section, but a similar description is possible: all rational elliptic surfaces are obtained by taking a pencil of curves of degree 3k with 9 base points, each of multiplicity k. There will always be the k-fold cubic curve through the 9 points as a member, and the resulting blowup produces a rational elliptic surface with a multiple fiber of multiplicity m (called the index of the fibration). A. Zanardini has recently computed the GIT stability of such pencils for m=2; in joint work with her we have constructed a moduli space for them via toric constructions. I will try to tell this story in this lecture.
Per informazioni, rivolgersi a: onorati@mat.uniroma2.it
Martedì 28 settembre 2021
Ore 15:00, Il seminario avrà luogo presso il Dipartimento di Matematica e Fisica Lungotevere Dante - Aula M1. Oppure cliccare sul seguente link, Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre
Seminario di Teoria dei Numeri
Giovanni Rosso (Concordia University)
Specialness for non-archimedean varieties
Since the fundamental work of Faltings on Mordell's conjecture, many conjectures have been made concerning the problems of when rational points of a variety over a number field are (potentially) Zariski dense. Varieties whose rational points are (potentially) Zariski dense are called special, and Campana characterised these varieties as the ones that (loosely speaking) don’t admit fibrations to varieties of general type. Conjecturally, this is equivalent to the fact that complex analytification of the variety is Brody-special; that is, it admits a dense entire curve. Inspired by the notion of Brody-special, in a joint work with Jackson Morrow, we introduced the notion of $K$-analytically special varieties over an algebraically closed non archimedean field $K$. In this presentation, I shall explain this definition and prove several results ($K$-analytically special sub-varieties of semi-abelian varieties are translate of semi-abelian varieties; $K$-analytically special varieties don't dominate pseudo-$K$-analytically Brody hyperbolic variety) that support the fact that our notion is the right one to test specialness in $p$-adic analytic geometry.
Mercoledì 29 settembre 2021
Ore 14:00, Sala di Consiglio, Dipartimento di Matematica, Sapienza Università di Roma
seminario di Algebra e Geometria
Nicolas Tholozan (DMA - CNRS)
Equidistribution of Noether-Lefschetz loci
Let \(V\to B\) be a holomorphic family of smooth complex projective and polarized varieties. The Noether-Lefschetz locus of \(B\) is the set of points \(x\) where the Picard rank jumps, i.e. where \(H_2(V_x)\) has exceptional integral classes of type \((1,1)\). I will explain that, when \(B\) has the correct dimension, the Noether-Lefschetz locus “equidistributes” toward a smooth volume form given by a characteristic class of the Hodge bundle. The proof uses homogeneous dynamics and reduces to a study of the invariant cohomology of period domains. This is a joint work with Salim Tayou.
Per informazioni, rivolgersi a: diverio@mat.uniroma1.it
Giovedì 30 settembre 2021
Ore 14:30, Sala di Consiglio - https://meet.google.com/ads-dekx-bgm, Dipartimento di Matematica, Sapienza Università di Roma
Seminario P(n)
Alessandro Goffi (Università di Padova)
Recent regularity results for viscous Hamilton-Jacobi equations
In this talk I will discuss some recent developments on the regularity of solutions of viscous Hamilton-Jacobi equations, addressing the so-called problem of maximal L^p-regularity both for stationary and time-dependent models. In particular, I will focus on two approaches based, respectively, on a refinement of the Bernstein method and duality. Applications to Mean Field Games systems will also be discussed. The results answer positively to a conjecture raised some years ago by P.-L. Lions. The talk will be based on a series of works in collaboration with M. Cirant (Padova).
Per informazioni, rivolgersi a: galise@mat.uniroma1.it
Giovedì 30 settembre 2021
Ore 9:00, Sala del Chiostro, Facoltà di Ingegneria Civile e Industriale, Sapienza Università di Roma
Workshop internazionale
RAM3 "Recent Advances in the Mechanics and Mathematics of Materials"
Nei giorni 30 Settembre e 1 Ottobre 2021, il Dipartimento di Ingegneria Strutturale e Geotecnica ospiterà la terza edizione del Workshop per giovani ricercatori RAM3 "Recent Advances in the Mechanics and Mathematics of Materials". Durante il workshop si terranno 4 keynote lectures della durata di 1h dei Proff. Adriana Garroni (Sapienza), Davide Bigoni (Università di Trento), John Maddocks (EPFL) e Paul Steinmann (University of Erlangen-Nuremberg), insieme a 15 lectures di giovani ricercatori provenienti da tutta Europa. L'evento si svolgerà nella Sala del Chiostro della facoltà di Ingegneria e sarà esclusivamente in presenza. Informazioni sull'evento sono disponibili sul sito: https://sites.google.com/a/uniroma1.it/ram3/
Per informazioni, rivolgersi a: ram3@uniroma1.it
Le comunicazioni relative a seminari da includere in questo notiziario devono pervenire esclusivamente
mediante apposita form da compilare online, entro le ore 24 del giovedì precedente la settimana
interessata. Le comunicazioni pervenute in ritardo saranno ignorate.
Per informazioni, rivolgersi all'indirizzo di posta elettronica
seminari@mat.uniroma1.it.
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