Triangle Seminars

Week of 31 Oct 2022 - 6 Nov 2022

Tuesday, 1 Nov 2022

LonTI: Lectures on the duality between the Sine-Gordon and the Thirring model
Alessandro Torrielli (University of Surrey)
Venue: Other · Room: LIMS, Royal Institution · Time: 10:30 · Type: Regular Seminar
Abstract:
We will describe the duality between two integrable systems: the 2D Sine-Gordon model and the 2D Thirring model. We will spend some time describing the classical and quantum Sine-Gordon model, in particular its spectrum, S-matrices and underlying quantum-group symmetry. We will then present the duality with the Thirring model as originally stated by Coleman and refined in subsequent literature. All the basic elements will be provided without relying on too many pre-requisites beyond standard graduate-level quantum field theory. The notes comprise a series of exercises.
Posted by: lonti
Pure supergravity and the conformal bootstrap
Shai Chester (Jefferson Physical Laboratory, Harvard University)
Venue: IC · Room: H503 · Time: 13:30 · Type: Regular Seminar
Abstract:
We consider graviton scattering in maximal supergravity on Anti-de Sitter space (AdS) in d+1 dimensions for d=3,4,and 6 with no extra compact spacetime factor. Holography suggests that this theory is dual to an exotic maximally supersymmetric conformal field theory (CFT) in d dimensions whose only light single trace operator is the stress tensor. This contrasts with more standard cases like Type IIB string theory on AdS_5x S^5 dual to N=4 Super-Yang-Mills, where the CFT has light single trace operators for each Kaluza-Klein mode on S^5. We compute the 1-loop correction to the pure AdS_{d+1} theory in a small Planck length expansion, which is dual to the large central charge expansion in the CFT. We find that this correction saturates the most general non-perturbative conformal bootstrap bounds on this correlator in the large central charge regime for d=3,4,6. After imposing theory-specific constraints from localization in d=3,4, the bootstrap constraints strengthen and are then saturated by the string/M-theory dual CFT data.
Posted by: IC
Skyrmions: Colloquium + Book Launch
Nick Manton (Cambridge University)
Venue: Other · Room: LIMS, Royal Institution · Time: 14:00 · Type: Colloquium
Abstract:
https://lims.ac.uk/event/skyrme-theory-at-60/

Prof. Nick Manton, FRS, will give a colloquium on Skyrmions, followed by book launch and reception, celebrating his latest book on the subject, in the historic Faraday Suites of the London Institute for Mathematical Sciences (LIMS).

Schedule
2 - 3 Colloquium
3 - 3:30 Introduction by Prof. Yang-Hui He, Fellow of LIMS
3:30 - 5 Book launch + Reception: Prof. Manton

Address: LIMS, Royal Institution, 21 Albemarle St., Mayfair.
Posted by: oxford

Wednesday, 2 Nov 2022

Symmetry TFT and Non-invertible Symmetries (seminar cancelled)
Sakura Schafer-Nameki (University of Oxford)
Venue: IC · Room: H503 · Time: 13:30 · Type: Regular Seminar
Abstract:
The seminar has been cancelled.
Posted by: IC2
Double holography and Page curves in Type IIB
📍 London
Christoph Uhlemann (Oxford)
Venue: KCL · Room: K0.16 · Time: 13:45 · Type: Regular Seminar

Friday, 4 Nov 2022

Chern-Simons Gravity and Neutrino Self-Interactions
Cyril Creque-Sarbinowski (Center for Computational Astrophysics at the Flatiron Institute)
Venue: IC · Room: Blackett 1004 · Time: 12:00 · Type: Exceptional Seminar
Abstract:
Dynamical Chern-Simons gravity (dCS) is a four-dimensional parity-violating extension of general relativity. Current models predict the effect of this extension to be negligible due to large decay constants f close to the scale of grand unified theories. Here, we present a construction of dCS allowing for much smaller decay constants, ranging from sub-eV to Planck scales. Specifically, we show that if there exists a fermion species with strong self-interactions, the short-wavelength fermion modes form a bound state. This bound state can then undergo dynamical symmetry breaking and the resulting pseudoscalar develops Yukawa interactions with the remaining long-wavelength fermion modes. Due to this new interaction, loop corrections with gravitons then realize a linear coupling between the pseudoscalar and the gravitational Chern-Simons term. The strength of this coupling is set by the Yukawa coupling constant divided by the fermion mass. Therefore, since self-interacting fermions with small masses are ideal, we identify neutrinos as promising candidates. For example, if a neutrino has a mass mν ≲meV and the Yukawa coupling is order unity, the dCS decay constant can be as small as f∼10^3mν ≲eV. We discuss other potential choices for fermions.
Posted by: IC

Week of 31 Oct 2022 - 6 Nov 2022