In heavy-ion collisions at ultra-relativistic energies, nuclear matter is subject to extreme conditions of temperature and density. A crossover happens, and nuclear matter transits into an almost perfect liquid that exhibits properties similar to those of a quantum fluid, the Quark Gluon Plasma (QGP). In a manner similar to the Rutherford experiment, where alpha particles were short-range probes of the atom, revealing the existence of the nucleus, we use energetic quarks and gluons as high-resolution probes of the QGP to study its microscopic structure. I will discuss the status and main open questions of the field.

Non-equilibrium statistical mechanics has seen some impressive developments in the last three decades, since the ground-breaking formulation of the transient and steady entropic Fluctuation Relations (FR) in the early nineties. The extension of these results to the quantum setting has turned out to be surprisingly challenging and it is still an ongoing sort. Kurchan and Hal Tasaki's seminal works (2000) showed quantum formulation of the transient version of FR is possible by introducing the two-time measurement framework. In this talk, we present some results in a recent series of papers, where we attempt to introduce a quantum equivalent of steady entropic functional and compare it to the transient version for open quantum system. In order to deal with the thermodynamic limit and to have general results, we use methods of C*- algebras and modular theory.

We will consider idealised direct projective measurement on the reservoirs. We show in particular that the direct measurement has an invasive role, leading to dramatic consequences about stability with respect to the initial state. Therefore it is natural to consider experimentally accessible indirect measurement through coupling with an ancilla. In this context, a parallel with the classical case is restored, but we can prove robustness of the protocol with respect to the first measurement time.

Joint work with T. Benoist, L. Bruneau, V. Jaksic, C.A. Pillet.

Illuminare la mente (Enlighting Mind) è un progetto del Dipartimento di Fisica e Astronomia dell’Università di Firenze, in collaborazione con il CNR-Istituto Nazionale di Ottica, che dal 2022 propone un’esposizione permanente ospitata negli spazi del Dipartimento. Il progetto utilizza illusioni ottiche (vedi l’immagine, esempio di bistabilità percettiva) e opere di optical art contemporanea per incuriosire e stimolare la riflessione sui meccanismi dell’ottica e della percezione visiva.
Nel seminario, attraverso esempi ottici e percettivi e facendo riferimento a risultati della letteratura scientifica sulla percezione umana, si mostrerà come le illusioni ottiche non siano errori del sistema visivo, ma una manifestazione del suo funzionamento efficiente. Il cervello privilegia interpretazioni rapide ed efficaci del mondo visivo piuttosto che una rappresentazione fisicamente accurata. La percezione visiva ne emerge come un processo evolutivo, dando luogo a una visione stabile e affidabile, ottimizzata ai fini della selezione naturale.
Prima del seminario – a partire dale ore 15 – e al termine dello stesso sarà inoltre presentata una selezione di installazioni dimostrative e interattive, attraverso le quali il pubblico potrà esplorare direttamente alcuni fenomeni ottici e percettivi.

In the setting of the wave equation on asymptotically anti-de Sitter spacetimes, it is possible to define an operator which maps Dirichlet data of solutions to corresponding Neumann data at the conformal boundary. The Dirichlet-to-Neumann map (or the boundary-to-boundary propagator) is conjectured to determine the bulk metric up to trivial transformations. In this talk I will report on recent progress on this question, based on the proof that the Dirichlet-to-Neumann map is a fractional power for the boundary metric in a suitable sense. In particular I will discuss the case of Einstein AdS spaces in which case we can prove stronger statements (joint work with Alberto Enciso and Gunther Uhlmann).

This seminar will review recent advances in the development of efficient tree tensor network algorithms and their applications to quantum simulation, benchmarking, and theoretical interpretation [1,2].
In particular, results on two- and three-dimensional systems will be presented, both in and out of equilibrium, including scattering processes and induced false vacuum decay in the two-dimensional quantum Ising model [3]. It will further highlights the use of tree tensor network methods beyond traditional quantum simulation, such as addressing hard classical combinatorial problems through mappings to many-body quantum Hamiltonians, optimizing quantum compilation tasks, integer factorization and enabling quantum equational reasoning [4].
 

[1] Introduction to Tensor Network Methods, Simone Montangero Springer International Publishing
[2] Scattering and induced false vacuum decay in the two-dimensional quantum Ising model, Luka
Pavešić, Marco Di Liberto, Simone Montangero
arXiv:2509.02702
[3] Quantum algorithms for equational reasoning, Davide Rattacaso, Daniel Jaschke, Marco Ballarin, Ilaria Siloi, Simone Montenegro
arXiv:2508.21122
[4] Quantum inspired factorization up to 100-bit RSA number in polynomial time
Marco Tesoro, Ilaria Siloi, Daniel Jaschke, Giuseppe Magnifico, Simone Montangero
arXiv:2410.16355