We consider the spontaneously broken regime of the $O(n)$ vector model in $d=n+1$ space-time dimensions, with boundary conditions enforcing the presence of a topological defect line. Comparing theory and finite size dependence of one-point functions observed in recent numerical simulations [1,2] we argue that the mass of the underlying topological quantum particle becomes infinite for $d\ge...
Out of equilibrium dynamics of integrable systems have been intensively studied in the past 20 years. However, a full characterisation of time evolution of an integrable field theory after a quantum quench is still missing. We investigate processes occurring during relaxation towards a steady state and describe them in terms of analytical properties of matrix elements of operators in the...
Achieving subpercent precision in calculating the hadronic vacuum polarization contribution to the muon $g-2$ is essential to correctly interpret new experimental results. At this level of precision, electromagnetic effects from charged quarks cannot be neglected. Lattice QCD+QED simulations present unique challenges, primarily due to the long-range nature of electromagnetic interactions. Our...
Standard lattice calculations of the glueball spectrum rely on effective mass plots and asymptotic exponential fits of two-point correlators, and involve various numerical challenges.
In this work, we propose an alternative procedure to extract glueball masses, based on the computation of the smeared spectral densities that encode information about the towers of states with given quantum...
Hadronic spectral densities play a pivotal role in particle physics, a primer example being the R-ratio defined from electron-positron scattering into hadrons. To predict them from first principles using Lattice QCD, we face a numerically ill-posed inverse problem, due to the Euclidean signature adopted in practical simulations. Here we review the status of recent numerical approaches to the...
I will review the concept of temporal entropies and their relation to CFTs and the computational cost of performing the simulation of out-of-equilibrium simulations.
The study of entanglement in quantum field theories provides insight into universal properties which are typically challenging to extract by means of more local observables. In the context of strongly coupled gauge theories, entanglement is expected to play a role in understanding many defining phenomena, among which confinement. However, calculations of entanglement-related quantities in...
Normalizing flows allow for independent sampling. For this reason, it is hoped that they can avoid the tunneling problem of local-update MCMC algorithms for multi-modal distributions. In this work, we first point out that the tunneling problem is also present for normalizing flows but is shifted from the sampling to the algorithm's training phase. Specifically, normalizing flows often suffer...
Effective String Theory (EST) is a powerful non-perturbative method used to study confinement in pure gauge theories through the modeling of the interquark potential in terms of vibrating strings. Due to the criticality of EST, an efficient numerical method to simulate such theories is still lacking. However, in the last years a novel class of deep generative algorithms called Normalizing...
In this talk, I will present the advantages of using neural networks that respect symmetries over their non-symmetric counterparts in lattice field theory applications. The concept of equivariance will be explained, together with the reason why it is a sufficient condition for the network to respect the desired symmetry. The benefits of equivariant networks will first be exemplified in the...
In the realm of searches beyond the Standard Model (SM), Yang-Mills theories coupled with adjoint fermions constitute an intriguing possibility. Beyond their relevance in the context of SM extension, studying theories with a different number of dynamical flavors $N_f$ allows access to many distinct physical scenarios, including supersymmetry and conformality. This talk aims to provide a review...
SU($N$) theories present a deconfinement phase transition.
It is well known that the topological properties of the theory, in 3+1 dimensions, are very different in the two phases.
In order to better understand the relation between the topological features of the theory and the deconfinement transition we studied the dependence of the critical temperature $T_c$ on the $\theta$ parameter...
First principle investigations are of fundamental interest for the study of the QCD phase diagram, both in their own right, and in light of experimental measurements from heavy-ion collision experiments, as well as from future observations from gravitational waves. Though not much is known (but much is conjectured) about the phase structure of QCD, a lot of progress has been made in the...
