This seminar aims to report on an ongoing project to develop Quantum Field Theory (QFT) in the context of non-smooth spacetimes. The motivation for studying such geometries stems from their appearance in many astrophysical models and generic solutions to Einstein´s Equation. I will introduce the key mathematical modifications required to adapt QFT to these geometries.

In this Colloquium, the state of the art and the new perspectives in the theoretical and experimental work on the quantum simulation of gravitational problems using condensed matter and optical systems, the so-called analog models of gravity, will be discussed.
It will start with a pedagogical presentation of the general concept of analog mode and a review of milestone theoretical and experimental works on Hawking emission of phonons from acoustic horizons in trans-sonic flows of ultracold atoms.
It will then proceed with an outline of a joint theoretical-experimental effort that is on-going at the BEC Center on false vacuum decay processes: I will present experimental evidence of the decay of an extended metastable state via the nucleation of spatially localised bubbles in a two-component atomic superfluid and I will highlight its connection to open questions in quantum field theory and cosmology.
The seminar will conclude with a presentation of on-going theoretical work on analog Hawking emission processes in quantum fluids of light and the promising perspectives for its experimental observation. In particular, an unexpected interplay between Hawking emission and the quasi-normal modes of the black hole will be discussed, as well as its anticipated consequences on the zero-point fluctuations of the gravitational field around astrophysical black holes.

In the perturbative treatment of interacting quantum field theories, if the interaction Lagrangian changes adiabatically in time, secular growths may appear in the truncated perturbative series also when the Lagrangian has returned to be constant. If this happens, the perturbative approach does not furnish reliable results. In this talk we show that these effects are avoided for a QFT on Minkowski spacetime, if the interaction Lagrangian is spatially compact and for a large family of background states. In particular, this family of background states for which secular growths are absent is characterized and for equilibrium states the possibility of removing the spacetime cutoff in connection with the thermalisation process is further presented. The content of the talk is based on a joint work together with Nicola Pinamonti and Leonardo Sangaletti.

In this talk I will describe my past, present and prospective research in the relatively newborn, and highly interdisciplinary, field of Quantum Thermodynamics. I will start by giving a bird’s eye overview of the main results that I have obtained in the past few years that range from open quantum systems to quantum information, from thermoelectric devices to single photons, all broadly aimed at characterising the impact of quantum mechanics onto the dynamics of energy and other related observable quantities.

I will then zoom in and present recent results obtained within the newborn, and rapidly growing, field of Thermodynamics of Precision. This area tackles the problem of identifying the minimum cost, in terms of thermodynamic resources such as heat and work, needed to achieve a desired precision during a generic operation done on a quantum system. Here I will present both theoretical results that provide this ultimate cost for genuinely quantum close-to-equilibrium processes and a trapped-ion experiment proving their measurability.

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.