Bridging analytical and numerical methods for quantum field theory

25 Aug 2025, 08:00 → 29 Aug 2025, 19:00 Europe/Rome

Aula Renzo Leonardi (ECT*)

Aleksey Cherman (University of Minnesota), Andreas Athenodorou (The Cyprus Institute, Nicosia/CY & University of Pisa, Pisa/I), Michele Caselle (Università di Torino), Theodore Jacobson (Univ of Maryland-College Park)

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The study of strong-coupling phenomena in quantum field theory has been under particularly intensive study in recent years, with new insights coming from both analytic and numerical innovations.  This one-week meeting will bring together scientists from the analytic and numerical communities for a short but intensive workshop to exchange ideas and strengthen collaborations between researchers using different theoretical approaches, ranging from Monte Carlo methods, insights from generalized symmetries and anomalies, topological phases of matter, tensor networks,  machine learning and other methods. We plan to have a few talks each day with lots of time for informal discussions between the workshop participants.

 

Monday 25 August

08:30 → 09:00 Registration

09:00 → 10:30 Open discussion

10:30 → 11:00 Coffee break

11:00 → 12:00 Open discussion

12:00 → 13:45 Lunch

13:45 → 14:00 Welcome remarks

14:00 → 14:30 The spectrum of open confining strings in the large- limit

Speaker: Alireza Sharifian

Presentation.pdf

14:30 → 15:00 Intrinsic width of the flux tube in 2+1 dimensional Yang-Mills theories

Speaker: Lorenzo Verzichelli

SlidesVerzichelli.pdf

15:00 → 15:30 Coffee break

15:30 → 16:15 Talk

Speaker: Antonio Gonzalez-Arroyo

16:15 → 17:00 Open discussion

Tuesday 26 August

09:00 → 09:45 Non-perturbative physics of (1+1)d gauge theories using symmetric matrix product states

We introduce a novel matrix product operator construction for Hamiltonian lattice gauge theories in $(1+1)$ dimensions. This framework enables the study of strongly coupled phenomena such as bound states, string tension, and vacuum structure. We demonstrate the effectiveness of our method by applying it to the massive Schwinger model and adjoint QCD$_2$

Speaker: Benjamin Sogaard

Sogaard.pdf

09:45 → 10:30 The simplicity of confinement

Motivated by recent literature on the possible existence of a second higher-temperature phase transition in Quantum Chromodynamics (QCD), I revisit the proposal that colour confinement is related to the dynamics of magnetic monopoles using methods derived from Topological Data Analysis, which provide a mathematically rigorous characterisation of topological properties of quantities defined on a lattice. After introducing homology, I shall discuss how this concept can be used to quantitatively analyse the behaviour of monopoles across the deconfinement phase transition. The proposed approach is first demonstrated for Compact U(1) Lattice Gauge Theory, which is known to have a zero-temperature deconfinement phase transition driven by the restoration of the symmetry associated with the conservation of the magnetic charge. For this system, I perform a finite-size scaling analysis of observables capturing the homology of magnetic current loops, showing that the approach reproduces the expected value of the deconfinement critical coupling. Then, I extend this method to SU(3) gauge theory, in which Abelian magnetic monopoles are identified after projection in the Maximal Abelian Gauge. Specifically, I define an observable called "simplicity", which measures the number of topologically non-trivial loops per connected component in a current network. A finite-size scaling of the ensemble-averaged simplicity of Abelian magnetic currents provides the expected value of the critical coupling with an accuracy that is generally higher than that obtained with conventional thermodynamic approaches at comparable statistics, suggesting the relevance of the topological properties of monopole currents for confinement. Finally, preliminary results from a study of simplicity in QCD will be briefly discussed.

Speaker: Biagio Lucini

TDA-blucini.-Trento25.pdf

TDA-blucini.-Trento25.pdf

10:30 → 11:00 Coffee break

11:00 → 11:30 Casimir effect in critical O(N) models with non-equilibrium methods

Speaker: Andrea Bulgarelli

ectstar_talk.pdf

11:30 → 12:00 Three-dimensional U(1) strings beyond effective string theory

Effective string theory provides a successful description of the confining string in non-Abelian gauge theories. On the other hand, U(1) gauge theory in three spacetime dimensions, while confining, displays some peculiar properties (such as the impossibility of holding both the mass and string tension fixed in the continuum limit) which question the applicability of effective string theory to its confining string. In this talk, we report the results of numerical calculations of the ground state energy of the confining string in 3D U(1) gauge theory, and to what extent our results can be described by either effective string theory or alternatives, such as a recent proposal by Aharony, Barel and Sheaffer.

Speaker: Alessandro Mariani

trento_confinement_presentation.pdf

12:00 → 13:30 Lunch

13:30 → 14:15 Aspects of Superconducting Strings

I will examine Abrikosov–Nielsen–Olesen (ANO) vortex strings in variants of Abelian Higgs models. In the large flux limit, the equations governing them simplify, and the resulting giant strings realize two sharply distinct phases. I will explore qualitative features of these strings and identify patterns in their physical properties. I'll also discuss the spectrum of small fluctuations and the associated low energy effective action. I will end by comparing these results to features of confining strings in Yang Mills theory.

Speaker: Amey Gaikwad

14:15 → 15:00 Flux Tubes and Confinement in Lattice QCD

Speaker: Leonardo Cosmai

LCosmai_Trento_Aug2025.pdf

15:00 → 15:30 Coffee break

15:30 → 16:15 Training Neural Networks

Speaker: Luigi Del Debbio

Trento25 (1).pdf

16:15 → 17:00 Open discussion

Wednesday 27 August

09:00 → 09:45 D-branes in large N gauge theories

Speaker: Davide Gaiotto

09:45 → 10:30 Talk

Speaker: Hersch Singh

10:30 → 11:00 Coffee break

11:00 → 11:30 Stochastic Normalizing Flows for lattice gauge theory and defects

Speaker: Elia Cellini

talkECT_EliaCellini.pdf

11:30 → 12:00 Effective string theory on a torus: the 3d Ising interface

Speaker: José Matos

Presentation (1).pdf

12:00 → 13:30 Lunch

13:30 → 14:15 The LLR method in Lattice Gauge Theories

Speaker: Davide Vadacchino

talk_LLR_Vadacchino.pdf

14:15 → 15:00 The Nielsen-Ninomiya theorem versus bosonization

Speaker: Aleksey Cherman

15:00 → 15:30 Coffee break

15:30 → 16:15 Effective strings in QED_3

Speaker: Ofer Aharony

16:15 → 17:00 Open discussion

Thursday 28 August

09:00 → 09:45 Spontaneously Broken Non-Invertible Symmetries in Transverse-Field Ising Qudit Chains

Speaker: Sergej Moroz

09:45 → 10:30 Peculiar phase transitions in three dimensional gauge systems

Speaker: Claudio Bonati

10:30 → 11:00 Coffee break

11:00 → 11:30 The Mass of the Baryon Junction: a lattice computation in dimensions

Speaker: Dario Panfalone

11:30 → 12:00 A new method for measuring high spin glueball states on the lattice

Speaker: Kieran Twaites

12:00 → 13:30 Lunch

13:30 → 14:15 Talk

Speaker: Srimoyee Sen

14:15 → 15:00 Regulated chiral gauge theory and the strong CP problem

Four-dimensional chiral gauge theory can be formulated as the boundary theory on a five-dimensional manifold in a manner that may be realized on a finite lattice. There are interesting features of these theories which defy a purely four-dimensional conception of universality. We find that QCD as embedded in a chiral gauge theory (the Standard Model) when regulated this way appears to suffer neither from a $U(1)_A$ problem nor a strong CP problem, with a central role played by fermion zeromodes localized far away in the fifth dimension. In this way it differs from conventional lattice QCD formulated as a stand-alone theory.

Speaker: David Kaplan

15:00 → 15:30 Coffee break

15:30 → 16:15 Talk

Speaker: Marina Marinkovic

16:15 → 17:00 Open discussion

20:00 → 23:00 WORKSHOP DINNER

Friday 29 August

09:00 → 09:45 Talk

Speaker: Bernardo Zan

09:45 → 10:30 Talk

Speaker: Ling-Xiao Xu (ICTP, Trieste)

10:30 → 11:00 Coffee break

11:00 → 11:45 Yang-Lee Criticality in Various Dimension

Yang-Lee criticality is the simplest non-Hermitian conformal field theory. The model was first reported as a phase transition of Ising model in imaginary longitudinal magnetic field more than half a centry ago. Since then, many qualitative and quantitative properties of YL criticality have been studied, remarkably, including the fact that the model can be described in Landau-Ginzburg scheme with a scalar $i\phi^3$ theory in $D<6$ and the fact that the 2D version is an exactly solvable minimal model. In higher dimensions, the model lacks the same level of understanding as the Ising criticality due to its non-Hermitian nature. We report a new study of 3D YL criticality as a phase transition of Fuzzy Sphere model, which facilitates a direct survey of many quantities such as the spectrum and OPE coefficient to high precision. These quantitative results show a beautiful agreement with conformal symmetry and previous estimates from $(6-\epsilon)$ expansion, high temperature expansion and conformal bootstrap. We also discuss possible approaches in dimensions higher than 3.

Speaker: Yuan Xin

11:45 → 12:30 Center-vortex semiclassics on R2xT2 and large-N adiabatic continuity

When the 4d $SU(N)$ Yang-Mills theory is put on $\mathbb{R}^2\times T^2$ with a nontrivial 't Hooft flux, qualitative features of confinement can be semiclassically described as the gas of center-vortex fractional instantons. We study the condition for the large-$N$ adiabatic continuity via a suitable choice of the $N$-dependent 't Hooft flux from the viewpoint of both $0$-form and $1$-form center symmetry.

Speaker: Yuya Tanizaki

12:30 → 14:00 Lunch

14:00 → 14:45 Talk

Speaker: Masazumi Honda

14:45 → 15:30 Emergent thermalisation in the Schwinger model

Speaker: Adrien Florio

15:30 → 16:00 Coffee break

16:00 → 17:00 Open discussion