Physics-based computer simulations can provide microscopic insight into fundamental biomolecular processes, but are limited by their huge computational load. Our team has developed algorithms that exploit some mathematical methods of theoretical physics to overcome some of these issues, making it possible for the first time to microscopically reconstruct the folding mechanisms of biologically relevant proteins with an atomic level of resolution. This technology led us to develop a new paradigm for drug discovery named Pharmacological Protein Inactivation by Folding Intermediate Targeting (PPI-FIT), which is based on finding small molecules that trigger protein degradation by hindering the folding process. For example, using PPI-FIT we found small molecules that can selectively modulate the cellular expression of the human prion protein, which is involved in neurodegenerative diseases for which conventional methods have been largely ineffective. We then planned an experiment in the International Space Station executed in August 2023 that aims at developing the technology to exploit microgravity conditions to obtain crystals partially folded proteins in complex with one of the small molecules we discovered using PPI-FIT.

In the last part of this talk, how integrating emerging computational technologies (AI and quantum computers) may help us enlarge the range of applicability of molecular simulations will be discussed, and this could potentially suggest new therapeutic strategies.

The proton is one of three building blocks of the atom. Since the 1960s, we have known that a proton consists of three quarks. However, researchers now have a much more differentiated picture of this familiar particle. Lepton scattering on nucleon is a very nice tool to reveal the structure of the nucleon. In the past elastic scattering and deep inelastic scattering have provided fundamental observables to determine nucleon size or momentum of quarks and gluons inside the nucleon. Nowadays high-energy exclusive experiments are still more challenging aiming to describe more precisely quarks and gluons to measure energy, angular momentum and pressure inside the nucleon. Exclusive reaction means that the final state with the emission for example of a single photon or a meson, is clearly identified. This requires the detection of all the particles in the event with high precision. We will review exclusive experiments, which have been realised in the world so far and why a new electron-ion collider (EIC) of high energy, high luminosity equipped with a hermetic detector of high resolution can help to achieve this goal. We will describe the first extraction of the pressure inside the nucleon which has been published in 2018. The pressure distribution inside the nucleon indicated that the central value is of the same order as that of neutron stars.This result opens a nice avenue and the experimental method is so demanding that it is worth pursuing the effort at EIC.

Our Galaxy is a dynamic place, teeming with interactions, close encounters and explosions. In this seminar, the speaker will describe how transient signals of these activities may be detected, measured and understood, and how remarkable structures have emerged from turbulent times. It will be defined and discussed spectroscopy and illustrate what a powerful tool in the toolkit it is to explore dynamic behaviour in the Galaxy, both in terms of extreme orbital paths as well as explosions and ejections. The Global Jet Watch will be introduced, which is the means by which “time-lapse” spectroscopy can be obtained for various research endeavours, and show how these elucidate particle acceleration in relativistic jets, jet launch from nova explosions, circumbinary orbiting matter and star-star interactions during their “flypast” at their periastron.

In order to study physical effects of quantum fields on curved spacetimes, one needs appropriate Hadamard states to describe the fields. In this talk, we present a rigorous construction, including the proof of the Hadamard property, of the Unruh state for the free scalar field on slowly rotating Kerr-de Sitter spacetimes. We demonstrate how this state can be used to compute the stress-energy tensor of the quantum field and present numerical results for the stress-tensor at the inner horizon.

Parametrizing TMD parton densities and fragmentation functions in ways that consistently match their large transverse momentum behavior in standard collinear factorization has remained notoriously difficult. We show how the problem is solved in a recently introduced set of steps for combining perturbative and nonperturbative transverse momentum in TMD factorization. Called a “bottom-up" approach in a previous article, here we call it a \hadron structure oriented" (HSO) approach to emphasize its focus on preserving a connection to the TMD parton model interpretation. We show that the associated consistency constraints improve considerably the agreement between parametrizations of TMD functions and their large-k_T behavior, as calculated in collinear factorization. The procedure discussed herein will be important for guiding future extractions of TMD parton densities and fragmentation functions and for testing TMD factorization and universality. We illustrate the procedure with an application to semi-inclusive deep inelastic scattering (SIDIS) structure functions at an input scale Q₀, and we show that there is improved consistency between different methods of calculating at moderate transverse momentum. We end with a discussion of plans for future phenomenological applications.

Dopo la scoperta della materia oscura ed energia oscura sappiamo che tutto ciò che l'umanità ha studiato finora nel cielo è solo il 5%. In questi ultimi anni sono stati effettuati con successo due importanti esperimenti, Borexino e Planck. Il primo, scoprendo il meccanismo che produce l’energia solare, ci ha permesso di capire come e perché il Sole e le altre stelle brillano. Il secondo è riuscito a captare la radiazione che si è liberata nell'universo primordiale, circa 14 miliardi di anni fa, e a creare un'immagine dell'Universo neonato che mostra i semi gravitazionali dai quali si sono formate le galassie, le stelle e i pianeti che osserviamo nell'universo presente. I relatori Gianpaolo Bellini e Marco Bersanelli ci aiuteranno a percorrere il viaggio di queste importanti scoperte.

Over the past decade or more, there has been a great deal of interest in the mechanical, electronic and optical properties of graphene. The interest in the optical properties of graphene stems largely from two key features of the electronic band structure: it is gapless and the dispersion is linear near the Dirac points where the two bands touch. Both of these features can be uniquely accessed using terahertz radiation, because, under the right conditions, it can strongly drive both interband and intraband transitions. In this talk, I will describe the formalism and computational results of our density-matrix approach to modelling the nonlinear terahertz response of graphene, including various scattering mechanisms. As I will show, in undoped graphene, a very large nonlinearity can arise due to the interplay between the intraband and interband transitions. I will finish by showing how a parallel-plate waveguide configuration containing graphene could be used to generate the third harmonic of a 2 terahertz incident field with a power conversion efficiency of up to 20%. If time allows, I will also discuss our recent results on the effects of impurities and strain on third harmonic generation in graphene.

Come per qualsiasi sistema dinamico, la modellizzazione del clima consiste nella risoluzione delle equazioni differenziali che lo governano, a partire dalle condizioni iniziali e tenendo conto delle condizioni al contorno e del forzante del sistema. Il modello climatico restituisce quindi, istante per istante, lo stato delle variabili climatiche essenziali (ECV) che descrivono la dinamica dell’atmosfera e dell’oceano, tipicamente temperatura, pressione, umidità e velocità del vento. A seconda dell’orizzonte temporale della simulazione, lo stato del sistema è influenzato maggiormente dalle condizioni iniziali (per es. alla scala meteorologica), dalle condizioni al contorno (es. alla scala stagionale) o dal forzante (es. alla scala decennale e multidecennale). In questo seminario saranno presentate le caratteristiche principali del sistema climatico e delle equazioni che lo governano, e come i modelli climatici possano essere utilizzati per produrre l’informazione (ovvero i dati) sullo stato fisico del sistema su diversi orizzonti temporali.

Titolo
Particelle elementari e interazioni fondamentali.

Relatori
E.Budassi, C.Del Pio, A.Gurgone

The 2022 Nobel prize in Physics has acknowledged the fundamental role of Bell’s theorem in physics. It is well understood that the experimental demonstration of the theorem implies the existence of quantum correlations, often known as nonlocal, that cannot be described by classical theories, in which measurement outcomes are predetermined.

In recent years, Bell nonlocal correlations have also acquired the status of information resource, as they are crucial for the construction of quantum information protocols in the device-independent scenario, where no modelling of the devices is assumed in the implementation. Because of this absence of modelling, device-independent protocols offer the strongest form of security attainable in quantum theory.

This seminar provides an introduction to all these concepts, going from quantum foundations to quantum information science and back. The main concepts and tools in the device-independent formalism are explained, together with an overview of the main results and remaining challenges.