Titolo

Il ruolo del fisico nella radiobiologia applicata

Relatore

Leonardo Lonati

Diretta youtube

https://www.youtube.com/@physics-unipv

The seminar will discuss the application of ideas borrowed from statistical mechanics in addressing two problems in finance.
In the first part, we discuss how it is possible to tackle portfolio optimisation using tools borrowed from the physics of disordered systems, and we show that a phase transition takes place when the ratio between the number of assets in the portfolio and the length of the time series used to estimate risk approaches a critical value: When time series become too short compared to the dimension of the portfolio, the in-sample estimated risk vanishes, while the out-of-sample risk remains finite. This leads to a diverging estimation error and large sample to sample fluctuations. The second part of the talk examines the propagation of shocks between financial institutions, an important aspect of systemic risk. Banks interact in a network of interbank exposures, such as interbank loans. If an institution defaults, its creditors will suffer a loss, which may lead some to default in turn, and cause subsequent losses to their creditors, and so on. We will discuss how the problem of modeling cascades of defaults can be understood in terms of the emergence of a giant component of vulnerable nodes in a network of interbank exposures.

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.

Titolo

Introduzione al Machine Learning

Relatori

Ian Postuma, Giacomo Polesello

Diretta youtube

https://www.youtube.com/@physics-unipv