Triangle Seminars
Tuesday, 20 Apr 2021
(please note that the time of this semiar has been moved to 15:30)
Cliff Burgess
(McMaster University and Perimeter Institute for Theoretical Physics)
Abstract:
(please note that the time of this semiar has been moved to 15:30)
(please note that the time of this semiar has been moved to 15:30)
Posted by: IC
EFTs, Gravity and Clues from the UV
Clifford Burgess
(Perimeter Institute for Theoretical Physics and McMaster University)
Abstract:
Everyone seems to have strong opinions these days about what UV completions to gravity can tell us about lower-energy physics. Perceived difficulties finding inflationary solutions to string theory in particular have prompted re-examination of the utility of EFT methods, such as through the swampland trans-Planckian conjectures. This talk provides a curmudgeonly assessment of some of these proposals together with my own opinion about the likely low-energy take-aways of attempts to embed cosmology into string theory. If there is time I will describe some aspects of gravitation EFTs that really do seem to deviate from the standard Wilsonian picture.
[please note the unusual time]
[please email a.held@imperial.ac.uk for zoom link or password]
Everyone seems to have strong opinions these days about what UV completions to gravity can tell us about lower-energy physics. Perceived difficulties finding inflationary solutions to string theory in particular have prompted re-examination of the utility of EFT methods, such as through the swampland trans-Planckian conjectures. This talk provides a curmudgeonly assessment of some of these proposals together with my own opinion about the likely low-energy take-aways of attempts to embed cosmology into string theory. If there is time I will describe some aspects of gravitation EFTs that really do seem to deviate from the standard Wilsonian picture.
[please note the unusual time]
[please email a.held@imperial.ac.uk for zoom link or password]
Posted by: IC
Wednesday, 21 Apr 2021
Current operators in integrable models: Review of recent results
📍 London
Balazs Pozsgay
(Eotvos Lorand U., Budapest, Inst. Theor. Phys.)
Abstract:
We review the recent progress regarding current operators in integrable models, focusing especially on integrable spin chains. These operators describe the flow of the conserved charges, and they are important for the construction of Generalized Hydrodynamics. They are also connected to long range deformations and TTbar-like deformations of the spin chains, and also to the theory of factorized correlation functions. We argue that these operators are very special, because their mean values can be computed relatively easily even in nested spin chains. This is rather unique because mean values in nested models are rather difficult to compute for generic operators. We review these various connections and also show how to construct current operators using the Quantum Inverse Scattering Approach, the canonical framework developed by the Leningrad school.
[please email alejandro.cabo_bizet@kcl.ac.uk for the zoom link]
We review the recent progress regarding current operators in integrable models, focusing especially on integrable spin chains. These operators describe the flow of the conserved charges, and they are important for the construction of Generalized Hydrodynamics. They are also connected to long range deformations and TTbar-like deformations of the spin chains, and also to the theory of factorized correlation functions. We argue that these operators are very special, because their mean values can be computed relatively easily even in nested spin chains. This is rather unique because mean values in nested models are rather difficult to compute for generic operators. We review these various connections and also show how to construct current operators using the Quantum Inverse Scattering Approach, the canonical framework developed by the Leningrad school.
[please email alejandro.cabo_bizet@kcl.ac.uk for the zoom link]
Posted by: andrea
Thursday, 22 Apr 2021
Boundary-bulk relations in conformal/topological field theories
Liang Kong
(Shenzhen Institute of Quantum Science and Engineering, SUSTech)
Abstract:
[There will be a pre-seminar for students starting at 13:30. For zoom link please email s.nagyATqmul.ac.uk]
The relation between the physics of the bulk and that of a boundary plays an important role in quantum field theories, quantum gravity and condensed matter physics. In this talk, I will review a manifestation of this relation that can be summarized as a short statement: "the bulk is the center of a boundary". I will explain the meaning of "center" and provide a formal proof of this statement (arXiv:1702.00673). By including higher codimensional domain walls between boundaries, the boundary-bulk relation can be formulated mathematically as a higher functor. In lower dimensional cases, it becomes precise mathematical theorems. In the end, I will discuss the significances of this relation in the study of topological orders and topological phase transitions.
[There will be a pre-seminar for students starting at 13:30. For zoom link please email s.nagyATqmul.ac.uk]
The relation between the physics of the bulk and that of a boundary plays an important role in quantum field theories, quantum gravity and condensed matter physics. In this talk, I will review a manifestation of this relation that can be summarized as a short statement: "the bulk is the center of a boundary". I will explain the meaning of "center" and provide a formal proof of this statement (arXiv:1702.00673). By including higher codimensional domain walls between boundaries, the boundary-bulk relation can be formulated mathematically as a higher functor. In lower dimensional cases, it becomes precise mathematical theorems. In the end, I will discuss the significances of this relation in the study of topological orders and topological phase transitions.
Posted by: QMW
Lattice nonlinear Schroedinger equation: history and open problems.
Vladimir Korepin
(YITP Stony Brook)
Abstract:
The model has many names:
Lieb-Liniger, Bose gas with delta interaction and nonlinear Schroedinger. A limiting case is called Tonks-Girardeau. It is solvable by algebraic Bethe ansatz.
We shall use notations of quantum inverse scattering method.
Applications will be mentioned. ––- Part of the London Integrability Journal Club. Please register at integrability-london.weebly.com if you are a new participant. The link will be emailed.
The model has many names:
Lieb-Liniger, Bose gas with delta interaction and nonlinear Schroedinger. A limiting case is called Tonks-Girardeau. It is solvable by algebraic Bethe ansatz.
We shall use notations of quantum inverse scattering method.
Applications will be mentioned. ––- Part of the London Integrability Journal Club. Please register at integrability-london.weebly.com if you are a new participant. The link will be emailed.
Posted by: andrea