Triangle Seminars
Tuesday, 23 Feb 2021
Gravitational waves from first order phase transitions in the early universe
Mark Hindmarsh
(University of Sussex)
Abstract:
Gravitational waves are expected to be an important probe of physics beyond the Standard Model, through their production at first order phase transitions. I will report on recent work on characterising the gravitational wave power spectrum, and outline some BSM physics which might be probed at the future space-based gravitational wave detector LISA.
[please email a.held@imperial.ac.uk for zoom link or password]
Gravitational waves are expected to be an important probe of physics beyond the Standard Model, through their production at first order phase transitions. I will report on recent work on characterising the gravitational wave power spectrum, and outline some BSM physics which might be probed at the future space-based gravitational wave detector LISA.
[please email a.held@imperial.ac.uk for zoom link or password]
Posted by: IC
Wednesday, 24 Feb 2021
Causal symmetry breaking: from quantum chaos to wormholes
π London
Julian Sonner
(University of Geneva)
Abstract:
Quantum chaotic systems are often defined via the assertion that their spectral statistics coincides with, or is well approximated by, random matrix theory. In this talk I will explain how the universal content of random matrix theory emerges as the consequence of a simple symmetry-breaking principle and its associated Goldstone modes. This approach gives a natural way to identify wormhole-like correlations, even for individual theories, in particular in theories with gravity duals.
I will also discuss how to extend the Goldstone effective-field-theory approach to study operator correlation functions, and explain the relation of the EFT of quantum chaos to the bulk physics of wormhole-like geometries.
[Please email alejandro.cabo_bizet@kcl.ac.uk for the Zoom link]
Quantum chaotic systems are often defined via the assertion that their spectral statistics coincides with, or is well approximated by, random matrix theory. In this talk I will explain how the universal content of random matrix theory emerges as the consequence of a simple symmetry-breaking principle and its associated Goldstone modes. This approach gives a natural way to identify wormhole-like correlations, even for individual theories, in particular in theories with gravity duals.
I will also discuss how to extend the Goldstone effective-field-theory approach to study operator correlation functions, and explain the relation of the EFT of quantum chaos to the bulk physics of wormhole-like geometries.
[Please email alejandro.cabo_bizet@kcl.ac.uk for the Zoom link]
Posted by: andrea
Quantum Field Theory and Beyond
Nathan Seiberg
(IAS)
Abstract:
The first talk will be general, i.e., at a colloquium level. The second talk will be more technical, i.e., at a seminar level. Yet, each of the two talks will be self-contained. For this reason, there will be some overlap between them.
Talk 1: Quantum Field Theory and Beyond
We will review the status of Quantum Field Theory (QFT) and will present it as Γ’β¬Εthe language of physics.Γ’β¬Β Using examples from string theory and condensed matter physics, we will motivate the fact that the standard framework of QFT should be extended. As specific examples, we will review the phenomena of fractons, which do not seem to fit the standard framework of continuum QFT. We will then present recent attempts to incorporate fractons in a slightly generalized version of quantum field theory.
Talk 2: Fractons: going beyond standard QFT
Starting with a lattice system at short distances, its long-distance behavior is captured by a continuum Quantum Field Theory (QFT). This description is universal, i.e., it is independent of most of the details of the microscopic system. Surprisingly, certain recently discovered lattice systems, and in particular models of fractons, seem to violate this general dogma. Motivated by this apparent contradiction, we will present exotic continuum QFTs that describe these systems.
The first talk will be general, i.e., at a colloquium level. The second talk will be more technical, i.e., at a seminar level. Yet, each of the two talks will be self-contained. For this reason, there will be some overlap between them.
Talk 1: Quantum Field Theory and Beyond
We will review the status of Quantum Field Theory (QFT) and will present it as Γ’β¬Εthe language of physics.Γ’β¬Β Using examples from string theory and condensed matter physics, we will motivate the fact that the standard framework of QFT should be extended. As specific examples, we will review the phenomena of fractons, which do not seem to fit the standard framework of continuum QFT. We will then present recent attempts to incorporate fractons in a slightly generalized version of quantum field theory.
Talk 2: Fractons: going beyond standard QFT
Starting with a lattice system at short distances, its long-distance behavior is captured by a continuum Quantum Field Theory (QFT). This description is universal, i.e., it is independent of most of the details of the microscopic system. Surprisingly, certain recently discovered lattice systems, and in particular models of fractons, seem to violate this general dogma. Motivated by this apparent contradiction, we will present exotic continuum QFTs that describe these systems.
Posted by: IC
Thursday, 25 Feb 2021
Energy correlations at conformal collider
Gregory Korchemsky
(IPhT Saclay)
Abstract:
[For zoom link please contact s.nagyATqmul.ac.uk. There will be a pre-seminar for students at 13:30]
The energy-energy correlation (EEC) measures the angular distribution of the energy that flows through two calorimeters separated by some relative angle in the final state created by a source. We present a new approach to computing this observable that exploits the relation between the energy correlations and four-point correlation functions of conserved currents. In the limit of small and large angles, when
EEC describes the correlation between particles belonging, respectively, to the same jet and to
two almost back-to-back jets, we obtain a concise representation
of the EEC in terms of the conformal data of twist-two operators and verify it by comparing with
the results of explicit calculation at next-to-next-to-leading order in maximally supersymmetric
Yang-Mills theory. As a byproduct of our analysis, we predict the maximal weight part of the
analogous QCD expression.
[For zoom link please contact s.nagyATqmul.ac.uk. There will be a pre-seminar for students at 13:30]
The energy-energy correlation (EEC) measures the angular distribution of the energy that flows through two calorimeters separated by some relative angle in the final state created by a source. We present a new approach to computing this observable that exploits the relation between the energy correlations and four-point correlation functions of conserved currents. In the limit of small and large angles, when
EEC describes the correlation between particles belonging, respectively, to the same jet and to
two almost back-to-back jets, we obtain a concise representation
of the EEC in terms of the conformal data of twist-two operators and verify it by comparing with
the results of explicit calculation at next-to-next-to-leading order in maximally supersymmetric
Yang-Mills theory. As a byproduct of our analysis, we predict the maximal weight part of the
analogous QCD expression.
Posted by: QMW
Integrable E-models, 4d Chern-Simons theory and affine Gaudin models
Benoit Vicedo
(University of York)
Abstract:
Two-dimensional integrable field theories are characterised by the existence of infinitely many integrals of motion. Recently, two unifying frameworks for describing such theories have emerged, based on four-dimensional Chern-Simons theory in the presence of surface defects and on Gaudin models associated with affine Kac-Moody algebras. I will explain how these formalisms can be used to construct infinite families of two-dimensional integrable field theories. The latter can all naturally be formulated as so-called E-models, a framework for describing Poisson-Lie T-duality in sigma-models. The talk will be based on the joint work [arXiv:2008.01829] with M. Benini and A. Schenkel and [2011.13809] with S. Lacroix. –– Please register using the form at integrability-london.weebly.com if you are a new participant. The link will be emailed.
Two-dimensional integrable field theories are characterised by the existence of infinitely many integrals of motion. Recently, two unifying frameworks for describing such theories have emerged, based on four-dimensional Chern-Simons theory in the presence of surface defects and on Gaudin models associated with affine Kac-Moody algebras. I will explain how these formalisms can be used to construct infinite families of two-dimensional integrable field theories. The latter can all naturally be formulated as so-called E-models, a framework for describing Poisson-Lie T-duality in sigma-models. The talk will be based on the joint work [arXiv:2008.01829] with M. Benini and A. Schenkel and [2011.13809] with S. Lacroix. –– Please register using the form at integrability-london.weebly.com if you are a new participant. The link will be emailed.
Posted by: andrea