Ciclo di Conferenze dei corsi di Laurea in Fisica del Dipartimento di Matematica e Fisica
Comitato organizzatore: D. Meloni, F. La Franca, L. Lupi, S. Lauro, S. Mari, F. Paolucci
Edizione 2023
Alessandro Ercoli
Liceo Scientifico Statale “P. Ruffini” – Viterbo
Termodinamica e teoria microscopica: una proposta didattica
Link identifier #identifier__188848-1Locandina – 17 gennaio 2023 ore 15:00 Aula B
Verrà presentata una proposta didattica con l’obiettivo di illustrare la fisica elegante, organica e coerente contenuta nella Termodinamica, mediante un percorso didattico, accessibile alle scuole superiori, che assegna alla descrizione microscopica dei sistemi fisici un ruolo costantemente privilegiato. Questo approccio consente di arrivare ad una comprensione semplice e allo stesso tempo approfondita delle leggi della Termodinamica, la cui generalità è così vasta da consentirne l’applicazione ai più diversi sistemi fisici, dai semplici gas ai buchi neri, fino ad arrivare a caratterizzare l’evoluzione dell’intero Universo.
Leone Cavicchia
Fondazione CMCC – Centro Euro-Mediterraneo sui Cambiamenti Climatici
AI-enhanced prediction of weather and climate extremes
Link identifier #identifier__109336-2Locandina – 7 febbraio 2023 ore 14:30 Aula B
Despite major advances in the development of numerical Earth system models and the increase of available computer power, the prediction of extreme events at (sub)seasonal and longer time scales remains challenging. In a recent development, machine learning techniques are used to improve the accuracy of predictions. In those applications, large observational datasets are exploited to train algorithms to detect connections between the extreme events and their large-scale drivers. In this talk, I will first review the state of the art of numerical climate predictions systems and their limitations. I will then show through selected examples how AI techniques can be exploited to increase the skill of climate predictions.
Daniele Coslovich
Dipartimento di Fisica, Università di Trieste
The glass transition problem: challenges and breakthroughs
Link identifier #identifier__29555-3Locandina – 7 marzo 2023 ore 14:30 Aula G
Glasses are amorphous solids produced by cooling a liquid fast enough to avoid crystallization. Mankind has manufactured them since thousands of years and yet we still lack a fundamental understanding of how and why they form. Over the last decades, a handful of competing theoretical scenarios have emerged, but none of them provides a fully satisfactory description of glass formation. In this seminar, I will give an overview of some of the long-standing open problems around the glass transition and show how recent breakthroughs in particle-based simulations are shedding new light on them. I will conclude with a critical discussion on the growing role of machine learning algorithms in this field and in physics.
Francesco Ursini
Dipartimento di Matematica e Fisica, Roma Tre
X-ray polarimetry of active galactic nuclei with IXPE
Link identifier #identifier__2215-4Locandina – 18 aprile 2023 ore 14:30 Aula C
Active galactic nuclei (AGN), the most luminous persistent objects in the sky, are powered by accretion discs onto supermassive black holes in the centers of galaxies. The study of their X-ray emission via spectroscopy gives us information on key physical parameters, such as the temperature of the hot corona of electrons located in the innermost region of the accretion flow. However, the geometry of the hot corona is currently poorly known, and so it is its physical origin. Furthermore, the large-scale environment of AGN is rich of gas and dust, thought to be distributed in a toroidal structure surrounding the accretion disc and reflecting the primary X-rays from the AGN. X-ray polarimetry, being very sensitive to geometry, allows us to directly constrain the shape of the hot corona and the geometry of the reflecting torus. This is now possible thanks to the Imaging X-ray Polarimetry Explorer (IXPE), a NASA/ASI mission operative since December 2021. In this talk, I will review the first IXPE results on radio-quiet AGN, which provide a significant advancement in the physical understanding of these objects.
Laura Inno e Alessandra Rotundi
Dipartimento di Scienze e Tecnologie, Università degli Studi di Napoli “Parthenope”
The Italian contribution to advances in cometary science through dedicated space missions
Link identifier #identifier__177680-5Locandina – 18 maggio 2023 ore 15:30 Aula B
Comets are the only observable reservoir of the pristine remnants of the Solar System, enclosing fundamental imprints of the formation and evolution of the protoplanetary disk. In order to better understand their nature, many space missions have targeted comets over the past decades, including the NASA/Stardust probe and the most recent ESA mission, Rosetta. They all visited short period comets, with well-defined orbits that makes planning ahead of time but whose surfaces are strongly altered by evolution processes (cometary activity, space weathering). Visiting a relatively more pristine object motivated the recently selected the multi-spacecraft ESA mission Comet Interceptor (CI) comprising a primary platform and two small probes that will flyby at three different closest approach distances of the targeted comet. In fact, CI target will be a dynamically new comet from the Oort cloud approaching the Sun for the first time or possibly an interstellar object, to be discovered even after the spacecraft launch (~2029). After launch, CI will be delivered to the Sun-Earth Lagrange Point L2, where it will reside until directed to the target. Such a challenging mission will be feasible thanks to the Legacy Survey of Space and Time (LSST) that will be carried out by the Vera C. Rubin Observatory, in Chile. LSST is expected to identify thousands of new comets and several interstellar objects per year. In this talk, we will summarize the most relevant discoveries from space mission to Comets characterized by a remarkable Italian contribution: NASA/Stardust, ESA/Rosetta and ESA/Comet Interceptor, together with the ongoing work to prepare for its target identification within the LSST framework.
Paolo Ventura
INAF – Osservatorio Astronomico di Roma
The study of evolved stars as dust manufacturers under the JWST perspective
Link identifier #identifier__187596-6Locandina – 6 giugno 2023 ore 14:30 Aula C
Stars evolving through the Asymptotic Giant Branch (AGB) are generally recognized as the most efficient stellar dust manufacturers, owing to the thermodynamic conditions of their winds, extremely favourable to condensation of gaseous molecules into solid particles. In this contribution we present a review of the results obtained by modelling dust formation in the winds of AGB stars, the applications of these results to the characterization of evolved stellar populations in the Milky Way and nearby galaxies, and the possibilities offered by the launch of the James Webb Space Telescope.
Sebastian E. Lauro
Dipartimento di Matematica e Fisica Università Roma Tre
Exploring planets, moons and small bodies with radar sounder
Link identifier #identifier__43409-7Locandina – 3 ottobre 2023 Aula C
Radar sounder has become one of the most suitable geophysical instruments to explore planets and moons, given the very dry and/or cold conditions of their shallow crusts, which favour the penetration of radio waves at great depths. It can work remotely on board spacecrafts or rovers without the need for direct contact between the antennas and soil. Planetary subsurface radar was tested beyond Earth during the Apollo 17 mission using the Apollo Lunar Sounder Experiment (ALSE), based on a decade of development and testing of radio echo sounding (RES) in Earth polar regions. After the golden age of lunar exploration, radar technology for terrestrial applications grew rapidly. It was only in the 1990s that the planetary community acquired a renewed interest in subsurface radar sounders, with particular focus on using them to search for liquid water on Mars. In this talk, I will summarise the most relevant radar discoveries from space mission to planetary bodies (Mars, the Moon, etc) with a special attention to the detection of liquid water under the Martian South Pole using MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding), launched in 2003 on board the ESA Mars Express.
Roberta Sparvoli
Università di Roma Tor Vergata e INFN
Studio di precursori sismici e perturbazioni ionosferiche con la missione italo/cinese CSES
Link identifier #identifier__81887-8Locandina – 5 dicembre 2023 ore 14:30 Aula 108
La missione spaziale italo/cinese CSES (China Seismo Electromagnetic Satellite) nasce con lo scopo di identificare precursori sismici di tipo elettromagnetico, ionosferico e magnetosferico studiando possibili correlazioni spazio temporali con l’avvento di terremoti di grande intensità. Inoltre, è una potente sentinella per fenomeni di Space Weather in magnetosfera. Il programma italiano vede coinvolte l’ASI, l’INFN, l’INAF, l’INGV, il CNR e molte università italiane. La missione prevede la messa in orbita di una costellazione di satelliti in orbita LEO, recanti a bordo vari rilevatori di campo elettrico, magnetico, di plasma e di particelle cosmiche. Il lancio del satellite CSES-01 è avvenuto il 2 febbraio 2018; la missione CSES-02 partirà invece a Dicembre 2024. In questo seminario illustrerò gli obiettivi scientifici della missione, i rivelatori a bordo di CSES, i risultati raggiunti con il volo di CSES-01 e le aspettative legate alla seconda missione.