Defects, from condensed matter to quantum gravity

Europe/Rome
Castello dei Principi Capano

Castello dei Principi Capano

Pollica (SA), Italy
Description

Defects, from condensed matter to quantum gravity

Quantum field theories are often defined in terms of local operators and their correlation functions. But a much richer set of observables includes probes which are extended in space and time, such as heavy impurities, boundaries or interfaces, and which are referred to collectively as defects. Defects also appear when studying entanglement between subregions of space, and even when modeling the interface between strongly and weakly gravitating regions of spacetime. They are studied by most  communities in theoretical physics: from condensed matter and statistical mechanics to particle physics, holography and quantum information.  Correspondingly, all the available tools in Quantum Field Theory have been applied to this subject: perturbation theory, lattice, conformal bootstrap, holographic methods, supersymmetric localization, and more. The need for transfer of knowledge and collaboration between these communities is pressing. This is the challenge the workshop wants to address, by bringing together some of the world-best experts in their respective research fields.

All of this is to be set against the backdrop of the medieval town of Pollica, in Southwestern Italy (Cilento region). The workshop will take place from the 10th to the 14th of June 2024.

Location: the workshop will take place in the Castello dei Principi Capano, in Pollica (SA).

 

Scientific and organizing committee:

Constantin Bachas (ENS Paris, France)

Lorenzo Bianchi (University of Torino & INFN Torino, Italy)

Shira Chapman (Ben-Gurion University, Israel)

Damian Galante (King's College London, UK)

Marco Meineri (University of Torino & INFN Torino, Italy)

Max Metlitski (Massachusetts Institute of Technology, USA)

Bharathkumar Radhakrishnan (University of Geneva, Switzerland)

 

Sponsored by:

Comune di Pollica

    • 10:00 11:00
      Line defects in CFTs: RG flows, cusps, and applications 1h

      Line defects describe one-dimensional probes of a quantum field theory. Physically interesting examples can be found in different systems, ranging from magnets to gauge theories. In this talk, I will discuss some general properties of line defects, including the monotonicity of the defect renormalization group flow and the structure of the cusp anomalous dimension. I will illustrate the general results by discussing the magnetic line defect in the O(N) CFT. If time permits I will mention additional examples.

      Speaker: Gabriel Cuomo (New York U., CCPP and Princeton U.)
    • 11:00 11:30
      Coffee break 30m
    • 11:30 12:30
      TBA 1h
      Speaker: Carlo Meneghelli (University of Parma)
    • 12:30 14:30
      Lunch 2h
    • 14:30 16:00
      Discussion session
    • 16:00 16:30
      Coffee break 30m
    • 10:00 11:00
      Defects in quantum systems: symmetry, entanglement, and teleportation 1h

      In this talk, I will explore the significant role of defects in various aspects of quantum systems. First, I will discuss how global symmetries can be embedded in topological defects and their connection to symmetry-resolved entanglement. Next, I will examine the influence of conformal junctions on various entanglement measures, highlighting how these insertions can affect quantum correlations. Finally, I will delve into the realm of weak measurements of critical wavefunctions, emphasizing their interplay with defect lines. As a concrete example, I will demonstrate how defects can disrupt a quantum teleportation protocol, preventing Alice from successfully transmitting her state to Bob. Through these discussions, I plan to shed light on the connections between defects and fundamental quantum phenomena.

      Speaker: Sara Murciano (Caltech)
    • 11:00 11:30
      Coffee break 30m
    • 11:30 12:30
      Universal Bounds in interface conformal field theories 1h

      Critical phenomena in the presence of interfaces provide a much richer arena than their more studied cousin of boundary critical phenomena. In this talk, I'll review certain observables that are new and unique in interface conformal field theory and then demonstrate some novel bounds we can derive on these quantities using techniques from holography and quantum information.

      Speaker: Andreas Karch (U. Texas, Austin)
    • 12:30 14:30
      Lunch 2h
    • 14:30 16:00
      Poster session
    • 16:00 16:30
      Coffee break 30m
    • 10:00 11:00
      TBA 1h
      Speaker: Giuseppe Policastro (Ecole Normale Superieure)
    • 11:00 11:30
      Coffee break 30m
    • 11:30 12:30
      TBA 1h
      Speaker: Meng Cheng (Yale University)
    • 12:30 14:30
      Lunch 2h
    • 14:30 17:30
      Free afternoon 3h
    • 10:00 11:00
      Solving conformal defect using the fuzzy sphere regularization 1h

      In this talk, I will introduce our recently proposed fuzzy sphere regularization of 3D CFTs and talk about its application to the conformal defect. Specifically, I will use the pinning field defect of 3D Ising as an example to demonstrate the versatility of fuzzy sphere regularization in the study of defect, including the computation of operator spectrum, bulk-defect OPE and g-function.

      Speaker: Yin-Chen He (Perimeter Institute)
    • 11:00 11:30
      Coffe break 30m
    • 11:30 12:30
      CFT1/QFT2: massless scattering and bulk RG flows 1h

      In this talk we discuss how it is possible to study QFTs in AdS2 (or 2d BCFTs), and in particular their flat space limit, by accurately bootstrapping 1d CFTs.
      We also show how combining crossing with locality allows one not only to reconstruct bulk scattering but also local operators and their correlation functions at all scales, and recover their flat space form.
      We discuss the physical meaning of these results, their limitations, and their relation to bounds on CFT/QFT data.
      Along the way we explain how both the 1d (single correlator) crossing equation and the associated bulk operator reconstruction problem are now essentially solved.

      Speaker: Miguel Paulos (ENS)
    • 12:30 14:30
      Lunch 2h
    • 14:30 16:30
      Discussion session
    • 16:30 17:00
      Coffee break 30m
    • 19:30 21:30
      Conference dinner 2h
    • 10:00 11:00
      TBA 1h
      Speaker: Francesco Parisen Toldin (Aachen University)
    • 11:00 11:30
      Coffee break 30m
    • 11:30 12:30
      Mystery session
    • 12:30 14:30
      Lunch 2h