I seminari di PER2A0P2S6
Venerdì 17 luglio 2026
Ore 11:00 - Aula A
Flavour Changing Neutral Current decays at LHCb
Gabriele Martelli
Flavour Changing Neutral Current (FCNC) decays are among the most sensitive probes of physics beyond the Standard Model (SM). Forbidden at tree level, these processes can only proceed through electroweak loop diagrams, making their branching fractions, angular distributions, and other observables highly responsive to potential contributions from new particles or interactions. These rare transitions can be elegantly described within an effective field theory framework, where short-distance effects are encoded in the Wilson coefficients. Precise measurements of these observables, together with lepton-flavour-universality ratios, therefore provide stringent tests of the SM and powerful constraints on New Physics scenarios. Benefiting from the abundant production of beauty and charm hadrons at the LHC, combined with excellent vertexing, tracking, particle-identification, and trigger capabilities, the LHCb experiment plays a leading role in this sector. This seminar will give an overview of recent FCNC measurements and searches and will discuss their interpretation within the broader flavour-physics programme. Prospects offered by the upgraded detector and the growing Run 3 dataset will also be highlighted.
Giovedì 17 settembre 2026
Ore 15:00 - Aula A
The Cosmic Origin of Heavy Elements: From Neutron Star Mergers to Collapsing White Dwarfs
Tetyana Pitik
Half of the nuclei heavier than iron are thought to be synthesized through rapid neutron-capture (r-process) nucleosynthesis in some of the most extreme environments in the Universe. The discovery of a kilonova accompanying the gravitational-wave event GW170817—the first observed merger of two neutron stars—provided the first direct confirmation that neutron-star mergers are a site of r-process nucleosynthesis. Yet despite the recognition of neutron-star mergers as a key source of r-process material, the astrophysical origin of the heaviest elements remains far from settled, with growing indications that an important piece of the puzzle is still missing.
In this seminar I will review our current understanding of heavy-element production in explosive astrophysical environments, focusing on the physical conditions required for r-process nucleosynthesis and the observational clues that constrain its origin. I will then present recent results identifying accretion-induced collapse (AIC) of white dwarfs as a promising source of heavy nuclei. Using multidimensional general-relativistic magnetohydrodynamic simulations coupled with nucleosynthesis and radiative-transfer calculations, we find that rapidly rotating, strongly magnetized AIC events can eject neutron-rich matter capable of producing heavy r-process nuclei while powering kilonova emission observable at extragalactic distances. I will discuss the implications of these results for the origin of heavy elements, kilonova observations, and the role of white-dwarf collapse in multimessenger astronomy.
Mercoledì 29 aprile 2026
Ore 15:30 - Aula B
Quantum complexity in gravity, quantum field theory and quantum information science
Stefano Baiguera
Quantum complexity quantifies the difficulty of preparing a state or implementing a unitary transformation with limited resources. Applications range from quantum computation to condensed matter physics and quantum gravity. I seek to bridge the approaches of these fields, which define and study complexity using different frameworks and tools. In this talk, I will describe several definitions of complexity, along with their key properties. In quantum information theory, I will focus on complexity growth in random quantum circuits. In quantum many-body systems and quantum field theory (QFT), I will discuss a geometric definition of complexity in terms of geodesics on the unitary group. In dynamical systems, I will explore a definition of complexity in terms of state or operator spreading. I will also outline applications to quantum many-body models, and QFTs including conformal field theories (CFTs). Finally, I will explain the proposed relationship between complexity and gravitational observables within the holographic anti-de Sitter (AdS)/CFT correspondence.
Giovedì 12 marzo 2026
Ore 16:00 - Aula B
To infinity and beyond: the hyperboloidal framework for wave equations
Rodrigo Panosso Macedo
Wave propagation and radiation are common phenomena across many areas of physics, from classical field theory to modern gravitational-wave astronomy. In this talk, I will introduce the mathematical and physical ideas behind the so-called hyperboloidal framework, a concept developed upon Penrose’s seminal work on the “Conformal Treatment of Infinity”. By exploiting spacetime’s causal structures, this framework allows us to treat distant radiation and strong-field regions within a single unified picture, providing a natural way to study waves as they propagate all the way to the infinity far wave zone.
The first part of the talk presents an overview of the conceptual foundations of hyperboloidal methods, emphasizing their geometric intuition and their advantages for analyzing wave behaviour at the wave zone. In the second part, I will illustrate how these ideas have become powerful infrastructure in black-hole perturbation theory and gravitational-wave physics, enabling new insights into phenomena such as black-hole ringdown and radiation from binaries systems. Beyond their role in general relativity, the underlying concepts offer a broader perspective on wave-like systems and may find applications across different areas of physics.
