Colloquia IGFAE

Quantum chaos and the complexity of time evolution

Abstract: I will describe new ideas relating quantum chaos to the complexity of time evolution.  One approach treats physical time evolution as a quantum computation, and bounds the smallest quantum circuit that can simulate this evolution.  The second approach quantifies how ergodically and rapidly a quantum state explores the accessible part of the system’s Hilbert space.  I will illustrate how these measures separate integrable and chaotic quantum systems by considering examples including particles on group manifolds, spin chains, quantum billiards, and Random Matrix Theory.  I will end by describing an application of these methods to a conjecture that geometrizes complexity in quantum gravity.

Quantum Computing for Particle Physics: beyond theoretical boundaries

Abstract: High‑energy colliders such as the Large Hadron Collider (LHC) at CERN are inherently quantum machines, and so in the spirit of Richard Feynman’s original vision, natural candidates as testbeds for applications of Quantum Computing. Although a fully fledged quantum event generator for collider scattering remains a long‑term goal, there is growing interest in the particle physics community in exploiting recent advances in Quantum Computing.

Promising directions include Quantum Machine Learning for collider data analysis, faster and more precise evaluation of intricate multiloop Feynman integrals, quantum‑enhanced approaches to jet clustering and jet evolution, tracking, parton‑shower simulations, and many other emerging applications. In this colloquium, I will review key Quantum Computing applications in Particle Physics, with emphasis on theoretical predictions at high perturbative orders, and will discuss about future potential developments, particularly in the critical transition from the NISQ era to Fault-Tolerant Quantum Computing.

A tale of many H0

Abstract:

Despite its spectacular success, the standard  model of cosmology, the LCDM model, is ultimately phenomenological: it establishes a robust framework in which some fundamental issues remain unresolved. With observations becoming increasingly precise, it is reasonable to expect that “something\’s gotta give” and that the LCDM model will show some cracks. The Hubble tension — the discrepancy between the value of the Hubble parameter, when inferred as a global parameter of the standard cosmological model, and when measured directly in the late-time Universe from the redshift-to-distance relation — has been looming for a decade and has been studied extensively. Could it be such a crack?  I will give an overview of the status of the Hubble tension and tentatively speculate on why it has persisted thus far.

Biography

Licia Verde is an astrophysicist with interest in cosmology. Her research topics include theoretical cosmology, cosmic microwave background, large-scale structure, galaxy clusters, statistical applications and data analysis. She is also interested in the study of large-scale structure of the Universe and in the analysis of galaxy surveys. She is currently ICREA Professor at the Institut de Ciències del Cosmos at the Universitat de Barcelona (ICCUB)