Paths to Quantum Field Theory 2024

22 Jul 2024, 08:00 → 27 Jul 2024, 11:30 Europe/Sarajevo

Three Physicists amphitheatre (University of Sarajevo - Faculty of Science)

Registrations are now closed. If you would like to participate in the workshop, please get in touch with Tin Sulejmanpasic at tin.sulejmanpasic (at) durham (dot) ac (dot) uk.

The workshop is designed to bring together a small number of expert speakers across the fields related to quantum field theory, including high-energy, nuclear and condensed matter physics, applying a range of techniques from numerical to theoretical and hybrid approaches.  The number of formal talks will be quite limited.  A typical day will consist of either two talks, with 2-hour slots available to to speakers to use as they wish, or one 2-hour talk and three 30-minute talks.  The idea of the longer talks is to enable the speakers to give a thorough introduction to a broad audience and to encourage questions and discussions during the talks. The 30-minute talks allow for several speakers to briefly introduce the participants to exciting recent developments. Crucially, between all talks there will be sufficiently long breaks which will allow more in-depth discussions. Finally, we hope that a number of junior researchers will join as participants in discussing and posing insightful questions.

The workshop will take place in Sarajevo, Bosnia and Herzegovina from July 22 to July 27th in 2024.

All talks will take place at the University of Sarajevo - Faculty of Science.

We aim to fund the accommodations of all participants. In limited cases we will aim to support travel expenses for the participants. If you have questions please contact the organizers using the contact link below.

Confirmed speakers:

Lukasz Fidkowski

Sungwoo Hong

Emilie Huffman

Theodore Jacobson

Adam Nahum

Emily Nardoni

Shu-Heng Shao

 

This is the fourth workshop in an annual series of "Paths to Quantum Field Theory" workshops. The earlier workshops were held in 2021, 2022, and 2023.

Link to the YouTube channel: https://m.youtube.com/@DUMathSc?cbrd=1&pli=1

Link to previous workshops

2023: https://indico.cern.ch/event/1251480/

2022: https://indico.cern.ch/event/1162387/

2021: https://indico.cern.ch/event/1038599/

 

Travel to Sarajevo:

 

Travel by air:

The closest airport is Sarajevo international airport. You can take a taxi or public transportation bus from the airport to your accommodation in Sarajevo. 

 

You may also travel to Tuzla International airport (by Wizz air, Lumiwings), but Tuzla-Sarajevo bus ride takes about 2,5 hours.

 

Tourism in Sarajevo:

Sarajevo offers terrific historical and natural attractions. Consult the webpage https://sarajevo.travel/en  for further information.

Organizers

Mohamed Anber
Aleksey Cherman
Iñaki Garcia-Etxebarria
Azra Gazibegović-Busuladžić
Nabil Iqbal
Zohar Komargodski
Maxim Metlitski
Tin Sulejmanpasic
David Tong
Mithat Ünsal

 

Monday 22 July

09:00 → 09:30 Registration/Welcome

09:30 → 11:30 Adam Nahum: Replica field theory approaches to entanglement transitions

11:30 → 14:30 Lunch and Discussion

14:30 → 16:30 Theodore Jacobson: Gauging C on the Lattice

We will discuss general aspects of charge conjugation symmetry in Euclidean lattice field theories including its dynamical gauging. As an application, we construct O(2) gauge theory on the lattice using a non-abelian generalization of the Villain formulation. This lattice discretization preserves a myriad of generalized global symmetries of the continuum theory, and we describe how to construct the associated symmetry operators and discuss their implications and associated selection rules.

Tuesday 23 July

09:00 → 09:30 Coffee and Discussion

09:30 → 11:30 Lukasz Fidkowski: Symmetry Protected Topological Phases and Quantum Cellular Automata

11:30 → 14:00 Lunch and Discussion

14:00 → 14:30 Rajath Radhakrishnan: Anomaly matching for bosonic and fermionic 1-form symmetries

I will describe some special properties of (non-invertible) 1-form symmetries of 2+1d QFTs implemented by bosonic and fermionic topological line operators. I will give a complete classification of such symmetries. I will use this classification to study RG flows preserving such symmetries.

14:30 → 15:00 Discussion/Break

15:00 → 15:30 Hersh Singh: Fermionic anomalies on the lattice and generalized Ginsparg-Wilson relations

15:30 → 16:00 Discussion/Break

16:00 → 16:30 Guilherme Delfino: Gauging finite modulated symmetries in 1+1D

Modulated symmetries, which naturally arise in multipole-conserving theories, are characterized by a non-trivial interplay between space and internal symmetry groups. These symmetries lead to ultraviolet/infrared (UV/IR) mixing and impose constraints on the system's dynamics. In this talk, we explore the gauging of finite Abelian modulated symmetries in 1+1 dimensions, investigate the symmetries of the dual theories, and identify the emergence of non-invertible mirror symmetries.

Wednesday 24 July

09:00 → 09:30 Coffee/Discussion

09:30 → 11:30 Emilie Huffman: Conformally Symmetric Views from a Fuzzy Sphere

11:30 → 15:00 Lunch / discussion

15:00 → 17:00 Sungwoo Hong: Non-invertible Naturalness

We will discuss non-invertible chiral symmetries in the Standard Model and its motivated extensions. These newly found generalized symmetries include non-invertible lepton number, non-invertible Peccei-Quinn symmetry, and non-invertible axion shift symmetries. They provide new ways to think about naturalness questions in particle physics. We will discuss new solutions to the strong-CP problem, smallness of neutrino mass, and axion domain wall problem.

Thursday 25 July

09:00 → 09:30 Coffee/Discussion

09:30 → 11:30 Emily Nardoni: Dimensionally Reducing Generalized Symmetries from 4d

11:30 → 14:30 Lunch/Discussion

14:30 → 15:00 Arkya Chatterjee: Self-dual criticality in Z_{k ≥ 4} gauge theory with matter

We study the putative multicritical point in 2+1D Z_k gauge theory where the Higgs and confinement transitions meet. The e-m duality symmetry at this critical point forces anyons with nontrivial braiding to close their gaps simultaneously, giving rise to a critical theory that mixes strong interactions with mutual statistics. An effective U(1) × U(1) gauge theory with a mutual Chern-Simons term at level k is proposed to describe the vicinity of the multicritical point for k ≥ 4. We argue analytically that monopoles are irrelevant in the IR CFT, indicating the emergence of U(1) (0-form) global symmetries, and compute the scaling dimensions of the leading duality-symmetric and anti-symmetric operators. This is based on work in collaboration with Zhengyan Darius Shi [arXiv:2407.07941].

15:00 → 15:30 Discussion/Break

15:30 → 16:00 Alessandro Podo: Positivity and analyticity without Lorentz invariance

I will describe the analytic structure and positivity properties of the perturbative S-matrix of a class of relativistic superfluids. Motivated by this I will then discuss non-perturbative analyticity properties of correlators of relativistic QFTs in non-trivial backgrounds, including finite density and curved spacetime.

16:00 → 16:30 Discussion/Break

16:30 → 17:00 Saranesh Prembabu: Exotic Transitions in Boundary Conformal Field Theory

Decades of research have revealed a deep understanding of topological quantum matter with protected edge modes. In this talk I discuss how even richer boundary physics emerges when tuning between topological phases of matter whose respective edge modes are incompatible, a hitherto unexplored regime. In a minimal case study I consider a 1+1D gapless theory (moreover, a “gapless SPT”) representing a phase transition from one nontrivial SPT phase to another. Using boundary CFT techniques I reveal how its edge modes display a non-Landau boundary critical transition constituting a 0+1D version of the exotic phenomenon of deconfined quantum criticality with an emergent symmetry relating boundary and bulk.

Friday 26 July

09:00 → 09:30 Coffee/Discussion

09:30 → 11:30 Shu-Heng Shao: Tensor networks for non-invertible symmetries

We will discuss the tensor network presentation for exact non-invertible symmetries of various lattice models, ranging from the Ising model to discrete lattice gauge theories.

11:30 → 14:30 Lunch/Discussion

14:30 → 15:00 Salvatore Pace: Topological holography and spacetime symmetry

Topological holography is a powerful framework in which the symmetries of a d-dimensional quantum many-body system are separated from its dynamics using a d+1 dimensional topological field theory (TFT) called the Symmetry TFT (SymTFT). Thus far, research on topological holography has focused on internal (generalized) symmetries. In this talk, I will discuss a proposal towards incorporating spacetime symmetries into the topological holography picture by having the SymTFT be a topological order enriched by spacetime symmetry (i.e., a nontrivial SET). As a demonstration, I will discuss this proposal and its applications in the context of Lieb-Schultz-Mattis anomalies and (non-invertible) dipole symmetries that occur in simple 1+1D quantum spin chains.

15:00 → 15:30 Discussion/Break

15:30 → 16:00 Ryan Lanzetta: Bootstrapping the magnetic line defect of the 3d Ising CFT

I will present conformal bootstrap calculations aimed at the magnetic "pinning field" line defect of the 3d Ising CFT, including bounds on its defect g-function, the scaling dimensions of various defect-changing operators, and OPE coefficients. By including the endpoints of this defect as external operators in our bootstrap setup, together with known bulk operators, we are able to use standard numerical bootstrap techniques to obtain the bounds. An interesting physical result that follows from our bounds is that stable spontaneous symmetry breaking is forbidden in the non-simple defect obtained by taking the direct sum over the sign of the pinning field perturbation.

16:00 → 16:30 Discussion/Break

16:30 → 17:00 Sandip Maiti: A qubit regularization of asymptotic freedom at the BKT transition without fine-tuning

We will discuss a novel regularization of the asymptotically
free massive continuum QFT that emerges at the BKT transition through a
hard core loop-gas model, discussing the advantages this model compared to
traditional regularizations.