Skip to main content

Links condivisione social

PhD Colloquium: Lorenzo Bianchini

Data visualizzata da utente finale
14 March 2024 at 4pm
Paragrafo
Measuring the mass of the W boson: a quest for precision
Image
Lorenzo Bianchini

Since its first observation in the early eighties, the W boson has always found a place in the research program of high-energy colliders. Within the Standard Model (SM) of particle physics, the W boson mass can be predicted from a few observables which have been now measured with high precision: comparing the SM prediction to a sufficiently accurate measurement of the W mass thus provides a consistency test of the model. However, the SM prediction could be broken by quantum corrections induced by new unknown fields, which would actually turn the consistency test into indirect evidence of new physics.


Unfortunately, a precise measurement of the W boson mass at colliders is also extremely challenging for a wealth of reasons, as it is also possibly implied by the neat tension between the two most-precise measurements to date. The CMS experiment at the LHC is now in the process of delivering a new measurement of the W mass. This will come as the result of an impressive amount of work done by researchers (and students!) who have been carefully ticking off all the items on a long task list over the past years. In this talk, a concise overview of the state of the art will be given, focusing on the challenges posed by the quest for precision at the LHC and on some of the solutions that have been worked out along the way.

Sede evento
Seminar Room A101
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

PhD Colloquium: Fabio Caccioli (UCL)

Data visualizzata da utente finale
15 February 2024 at 4pm
Paragrafo
Statistical Mechanics Applications to Financial Risk Management
Image
Fabio Caccioli

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.

Sede evento
A101
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

Seminar by Thomas Jennewein (University of Waterloo)

Data visualizzata da utente finale
28 February 2024, at 3 pm
Paragrafo
LONG-DISTANCE QUANTUM COMMUNICATIONS – HOW FUNDAMENTAL SCIENCE TESTS LEAD TO SATELLITE-BASED QUANTUM NETWORKS
Image
Foto relatore
Document
Sede evento
PhD Room
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

Seminar by Yafet Sanchez Sanchez (U. di Genova)

Data visualizzata da utente finale
31 January 2024, at 2:30pm
Paragrafo
Quantum Field Theory in Non-Smooth Spacetimes

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.

Sede evento
Seminar Room A109
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

PhD Colloquium: Iacopo Carusotto (INO-CNR BEC Center and Università di Trento)

Data visualizzata da utente finale
18 January 2024 at 4pm
Paragrafo
Quantum simulation of gravitational problems using quantum fluids of atoms and of light
Image
Foto relatore

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.

Sede evento
Physics Department, Room A101
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

Seminar by Stefano Galanda (U. di Genoa)

Data visualizzata da utente finale
Friday 26 January 2024 at 2:30pm
Paragrafo
Secular growths and their relation to equilibrium states in perturbative QFT

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.

Sede evento
Seminar Room A109
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

Seminar by Giacomo Guarnieri (U. of Pavia)

Data visualizzata da utente finale
Wednesday 10 January 2024 at 4pm
Paragrafo
Thermodynamics of Precision in Open Quantum Systems: My Past and Ongoing Scientific Journey

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.

Sede evento
Seminar Room A102
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

PhD Colloquium: Pietro Faccioli (U. Milano Bicocca)

Data visualizzata da utente finale
14 December 2023 at 4pm
Paragrafo
All-atom computer simulations empower a new paradigm in drug discovery
Image
Pietro Faccioli

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.

Sede evento
Seminar Room A101
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

PhD Colloquium: Nicole D'Hose (Paris-Saclay)

Data visualizzata da utente finale
16 November 2023 at 5pm
Paragrafo
Recent insights into Proton Structure
Image
Nicole D'Hose

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.

Sede evento
Seminar Room A101
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-

PhD Colloquium: Katherine Blundell (U. of Oxford)

Data visualizzata da utente finale
12 October 2023 at 4pm
Paragrafo
Our Galaxy: close encounters in turbulent times
Image
Katherine Blundell

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.

Sede evento
Aula Volta, Palazzo Centrale
Data inizio evento
Data fine evento
Periodo pubblicazione in HP
-