Triangle Seminars
Tuesday, 26 May 2020
Constraining Modified Gravity Models with Casimir Force Experiments
Anne-Christine Davis
(University of Cambridge)
Abstract:
Modified gravity models have been developed to try to explain the observed acceleration of the expansion of the Universe. Such models introduce and extra, fifth force, and usually employ a screening mechanism whereby the fifth force is screened in the solar system but unscreened cosmologically. Recent developments in laboratory experiments mean that such theories can now be tested and constrained using existing experiments. In particular innovative Casimir force experiments can be used to constrain such theories. This enables Einstein gravity to be tested on scales not previously explored. ––- Follow the usual link or contact the organisers (Antoine Bourget and Edoardo Vescovi). Student introduction at 13:00.
Modified gravity models have been developed to try to explain the observed acceleration of the expansion of the Universe. Such models introduce and extra, fifth force, and usually employ a screening mechanism whereby the fifth force is screened in the solar system but unscreened cosmologically. Recent developments in laboratory experiments mean that such theories can now be tested and constrained using existing experiments. In particular innovative Casimir force experiments can be used to constrain such theories. This enables Einstein gravity to be tested on scales not previously explored. ––- Follow the usual link or contact the organisers (Antoine Bourget and Edoardo Vescovi). Student introduction at 13:00.
Posted by: IC
Wednesday, 27 May 2020
Higher-derivative supergravity for AdS4 holography
📍 London
Kiril Hristov
(INRNE, Bulgarian Academy of Sciences)
Abstract:
In this talk I discuss some work in progress concerning higher-derivative (HD) terms in 4d supergravity. In particular we'll focus
on the simplest case of 4-derivative terms appearing in minimal gauged
supergravity. This choice minimizes the freedom in the HD terms to two
arbitrary constants, which can be determined by a holographic match. This gives a prediction about the reduction of 11d HD terms on S^7. We then derive holographic predictions for the first subleading terms of various supersymmetric partition functions in their expansion of the gauge group rank, N. Additionally we are able to evaluate the on-shell action for non-BPS solutions in supergravity, allowing us to discuss black hole thermodynamics in the presence of HD terms.
(To request the Zoom link send email with empty text and subject "talk" to alejandro.cabo_bizet@kcl.ac.uk)
In this talk I discuss some work in progress concerning higher-derivative (HD) terms in 4d supergravity. In particular we'll focus
on the simplest case of 4-derivative terms appearing in minimal gauged
supergravity. This choice minimizes the freedom in the HD terms to two
arbitrary constants, which can be determined by a holographic match. This gives a prediction about the reduction of 11d HD terms on S^7. We then derive holographic predictions for the first subleading terms of various supersymmetric partition functions in their expansion of the gauge group rank, N. Additionally we are able to evaluate the on-shell action for non-BPS solutions in supergravity, allowing us to discuss black hole thermodynamics in the presence of HD terms.
(To request the Zoom link send email with empty text and subject "talk" to alejandro.cabo_bizet@kcl.ac.uk)
Posted by: andrea
Thursday, 28 May 2020
From Scattering Amplitudes to Results in General Relativity (email p.agarwal AT qmul.ac.uk for the zoom link)
Emil Bjerrum-Bohr
( Niels Bohr Institute)
Abstract:
Gravity is a fundamental theory of physics, but so weak, that we still know very little about it. A new exciting development is that the Laser Interferometer Gravitational-Wave Observatory (LIGO) can now measure the effects when massive black holes collide in the Universe. This has stimulated many new and interesting studies of gravitational interactions. I will in this talk discuss recent computational advances and discuss how to derive results for observables in general relativity from amplitudes.
Gravity is a fundamental theory of physics, but so weak, that we still know very little about it. A new exciting development is that the Laser Interferometer Gravitational-Wave Observatory (LIGO) can now measure the effects when massive black holes collide in the Universe. This has stimulated many new and interesting studies of gravitational interactions. I will in this talk discuss recent computational advances and discuss how to derive results for observables in general relativity from amplitudes.
Posted by: QMW
Boundary states, overlaps, nesting and bootstrapping AdS/dCFT
Tamas Gombor
(Wigner Research Center, Budapest)
Abstract:
Recently there have been renewed interest and relevant progress in calculating overlaps between periodic multiparticle states and integrable boundary states. They appear in quite distinct parts of theoretical physics including statistical physics and the gauge/string duality.
I will give a summary of known overlap formulas and analyze the connection between selection rules and symmetries. I will introduce a nesting procedure for boundary states which provides the factorizing overlaps for higher rank algebras automatically. This method can be used for the calculation of the asymptotic all-loop 1-point functions in AdS/dCFT. In doing so I will present the solutions of the YBE for the K-matrices with centrally extended su(2|2) symmetry and the generic overlaps of the corresponding boundary states.
Based on 2004.11329
––––––––––––- Part of London Integrability Journal Club. Please register at integrability-london.weebly.com/ for the zoom link
Recently there have been renewed interest and relevant progress in calculating overlaps between periodic multiparticle states and integrable boundary states. They appear in quite distinct parts of theoretical physics including statistical physics and the gauge/string duality.
I will give a summary of known overlap formulas and analyze the connection between selection rules and symmetries. I will introduce a nesting procedure for boundary states which provides the factorizing overlaps for higher rank algebras automatically. This method can be used for the calculation of the asymptotic all-loop 1-point functions in AdS/dCFT. In doing so I will present the solutions of the YBE for the K-matrices with centrally extended su(2|2) symmetry and the generic overlaps of the corresponding boundary states.
Based on 2004.11329
––––––––––––- Part of London Integrability Journal Club. Please register at integrability-london.weebly.com/ for the zoom link
Posted by: andrea