Bollettino settimanale
Settimana 04/04/2022 - 08/04/2022
Seminari
Università di Bologna
Gruppo U.M.I. Prisma
PRobability In Statistics, Mathematics and Applications Seminar
Date: Monday 4th April, 2022
Schedule: 16:00 Rome Time
Where: Webinar, On-line Seminar (see the link below)
Speaker: Enrico Scalas
Title: "Point processes and time change: A fractional non-homogeneous Poisson process and its functional limits"
Abstract: A fractional nonhomogeneous Poisson process was introduced by a time change of the nonhomogeneous Poisson process with the inverse α-stable
subordinator. A similar definition is proposed for the (nonhomogeneous) fractional compound Poisson process. Both finite-dimensional and functional limit theorems are presented for the fractional nonhomogeneous
Poisson process and the fractional compound Poisson process. The results are derived by using martingale methods, regular variation properties and Anscombe’s theorem. Some of the limiting
results are verified in a Monte Carlo simulation.
Referance Papers:
[1] Nikolai Leonenko, Enrico Scalas and Mailan Trinh, The fractional
non-homogeneous Poisson process. Statistics and Probability Letters,
120, 2017, pp. 147-156.
DOI Files: Click here
Arxiv File: Click here
[2] Nikolai Leonenko, Enrico Scalas and Mailan Trinh, Limit theorems for the fractional nonhomogeneous Poisson process, Journal of Applied Probability , 56:1, 2019 , pp. 246 - 264.
DOI Files: Click here
Arxiv File: Click here
This is joint work with Nikolai Leonenko and Mailan Trinh.
Organizing Committee: Administrators (mail to)
Further Info: Click here
Streaming Link (MS Teams): Click here
Università di Bologna
Gruppo U.M.I. Prisma
PRobability In Statistics, Mathematics and Applications Seminar
Date: Monday 4th April, 2022
Schedule: 18:00 Rome Time
Where: Webinar, On-line Seminar (see the link below)
Speaker: Giacomo Ascione
Title: "Spectral methods for time-changed birth-death processes"
Abstract: In this talk we focus on a class of semi-Markov birth-death processes
obtained by means of a time-change of some standard birth-death process.
Precisely, we consider as parent processes the immigration-death process
and the Meixner process, whose stationary distributions are respectively
the Poisson and the Pascal distributions. Exploiting, on one hand, the
properties of the Charlier and Meixner polynomials (in particular, the
self-duality property), while, on the other, characterizing the
eigenfunctions of some non-local operators by means of the Laplace
transform of an inverse subordinator, we are able to explicitly express
the spectral decomposition of the transition probability function of the
aforementioned processes. The latter expression is then used to prove
existence and uniqueness of strong solutions for a class of
time-nonlocal Cauchy problems in a suitable Banach sequence space and
the probabilistic interpretation of such equations as some sort of
non-local backward/forward Kolmogorov equations. Finally, a comparison
with the time-changed diffusion case is carried out by referring to the
spectral decomposition of the probability density function of
time-changed Pearson diffusions. The latter argument hints at the
possibility of applying this kind of spectral methods to a wider range
of problems. This is the result of joint work with Nikolai Leonenko from Cardiff
University and Enrica Pirozzi from University of Naples.
Organizing Committee: Administrators (mail to)
Further Info: Click here
Streaming Link (MS Teams): Click here
Università "Tor Vergata " di Roma
Dipartimento di Matematica
Geometry Seminar
Date: Tuesday 5th April, 2022
Schedule: 14:30 Rome Time
Where: Room 1201 - R. Dal Passo
Speaker: Luca Tasin (Università di Milano)
Title: "Sasaki-Einstein metrics on spheres"
Abstract: I will report on a joint work with Yuchen Liu and Taro Sano in which we construct infinitely many families of Sasaki-Einstein
metrics on odd-dimensional spheres that bound parallelizable manifolds, proving in this way conjectures of Boyer-Galicki-Kollar and Collins-Szekelyhidi.
The construction is based on showing the K-stability of certain Fano weighted orbifold hypersurfaces.
These talks are part of the activity of the MIUR Excellence Department Project MATH@TOV CUP E83C18000100006.
Organizing Committee: Giulio Codogni (mail to) Guido Maria Lido (mail to), Roberto Fringuelli (mail to), Claudio Onorati (mail to).
Further Info: Click here
Streaming Link (MS Teams): Click here
Università Tor Vergata di Roma
Dipartimento di Matematica
Differential Equations Seminar
Date: Tuesday 5th April, 2022
Schedule: 16:00 Rome Time
Where: Room 1201 "R. Dal Passo" and in streaming mode (see the link below)
Speaker: Luca Battaglia (Università Roma Tre)
Title: " Blow-up phenomena for a curvature problem in a disk"
Abstract: We consider the problem of prescribing Gaussian and geodesic curvatures for a conformal metric on the unit disk,
which is equivalent to a Liouville-type PDE with nonlinear Neumann boundary conditions. We build a family of solutions which blow up on the boundary at a critical
point of a functional which is a combination of the curvatures we are prescribing.
The talk is based on joint works with M. Medina and A. Pistoia.
N.B.: This talk is part of the activity of the MIUR Excellence Department Project MATH@TOV CUP E83C18000100006
Organizing Committee: Riccardo Molle (mail to) Alfonso Sorrentino (mail to)
Further Info: Click here
Streaming Link (MS Teams): Click here
Università di Roma Tre
Dipartimento di Matematica
Geometry Seminar
Date: Thursday 7th April, 2022
Schedule: 14:15 Rome Time
Where: Room aula M1 - Dipartimento di Matematica - Roma Tre -
Speaker: Luca Tasin (Università di Milano)
Title: "Sasaki-Einstein metrics on spheres"
Abstract: I will report on a joint work with Yuchen Liu and Taro Sano in which we construct infinitely many families of Sasaki-Einstein metrics on odd-dimensional spheres that bound parallelizable manifolds,
proving in this way conjectures of Boyer-Galicki-Kollar and Collins-Szekelyhidi.
The construction is based on showing the K-stability of certain Fano weighted orbifold hypersurfaces.
Organizing Committee: Amos Turchet (mail to)
Further Info: Click here
Streaming Link (MS Teams): Click here
Università Tor Vergata di Roma
Dipartimento di Matematica
Algebra & Representation Theory Seminar (A.R.T.S.)
Date: Friday 8th April, 2022
Schedule: 14:00 Rome Time
Where: Room 1201 "R. Dal Passo" and in streaming mode (see the link below)
Speaker: Vincenzo Morinelli (Università Tor Vergata di Roma)
Title: "About Lie theory in Algebraic Quantum Field Theory"
Abstract: The relation between the geometric and the algebraic structure in algebraic quantum field theory is an intriguing topic that has been studied through several mathematical areas (Operator algebras, Lie theory, Category theory...). A fundamental concept in Algebraic Quantum Field Theory (AQFT) is the relation between the localization property and the geometry of models. In the recent work with K.-H. Neeb (Univ. Erlangen-Nürnberg) we rephrased and generalized some aspects of this relation by using the language of Lie theory.
We will start the talk introducing fundamental algebraic features of AQFT, in particular the Haag-Kastler axioms and the one particle formalism, and the presenting algebraic construction of the free field due to R.Brunetti, D. Guido and R. Longo. We will explain how this picture can be generalized. Firstly, how to determine some fundamental localization region, called wedge regions, at the Lie theory level and how a general Lie group can support a generalized AQFT. Then we show a classification of the simple Lie algebras supporting abstract wedges in relation with some special wedge configurations. The construction is possible for a large family of Lie groups and provides several new models in a generalized framework. Such a description of AQFT model generalization does not need a supporting manifold even if it is a desirable object. Time permitting, we will comment on recent developments about symmetric manifolds such models.
Based on V. Morinelli and K.-H. Neeb, Covariant homogeneous nets of standard subspaces, Commun. in Math. Phys 386 (1), 305-358 (2021).
Organizing Committee: Fabio Gavarini (mail to) Martina Lanini (mail to)
Further Info: Click here
Streaming Link (MS Teams): Click here
Università Tor Vergata di Roma
Dipartimento di Matematica
Algebra & Representation Theory Seminar (A.R.T.S.)
Date: Friday 8th April, 2022
Schedule: 16:30 Rome Time
Where: Room 1201 "R. Dal Passo" and in streaming mode (see the link below)
Speaker: Paolo PAPI ("Sapienza" Università di Roma)
Title: " Collapsing levels for affine W-algebras"
Abstract: I will discuss some projects in collaboration with D. Adamovic, V. Kac and P. Moseneder-Frajria regarding affine W-algebras.
I will concentrate on the notion of collapsing level for not necessarily minimal W-algebras and I will illustrate some applications to the representation theory of affine algebras and,
if time allows, to our conjectural classification of unitary representations for minimal W-algebras.
Organizing Committee: Fabio Gavarini (mail to) Martina Lanini (mail to)
Further Info: Click here
Streaming Link (MS Teams): Click here
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