Triangle Seminars
Tuesday, 5 May 2020
Inflation and Geometry
Sebastien Renaux-Petel
(Institut d'Astrophysique de Paris)
Abstract:
Inflation, an era of accelerated expansion of the universe prior to the radiation phase, constitutes the paradigm of primordial cosmology. Within this paradigm, the simplest single-field slow-roll models economically explain all current data. However, the sensitivity of inflation to Planck scale physics, and the fact that ultraviolet completions of inflation invariably involve extra fields coupled to the inflaton, indicate that these models constitute at best a phenomenological description that emerges from a more realistic physical framework.
In this talk, I will describe recent works that aim at understanding the consequences of the presence of several degrees of freedom during inflation. In particular, I will highlight that realistic models are characterized not only by their potentials but also by the internal geometries in which the fields live in, and I will discuss related novel phenomena that have been studied in the past years. ––- Contact the organisers (Antoine Bourget and Edoardo Vescovi) for the link.
Inflation, an era of accelerated expansion of the universe prior to the radiation phase, constitutes the paradigm of primordial cosmology. Within this paradigm, the simplest single-field slow-roll models economically explain all current data. However, the sensitivity of inflation to Planck scale physics, and the fact that ultraviolet completions of inflation invariably involve extra fields coupled to the inflaton, indicate that these models constitute at best a phenomenological description that emerges from a more realistic physical framework.
In this talk, I will describe recent works that aim at understanding the consequences of the presence of several degrees of freedom during inflation. In particular, I will highlight that realistic models are characterized not only by their potentials but also by the internal geometries in which the fields live in, and I will discuss related novel phenomena that have been studied in the past years. ––- Contact the organisers (Antoine Bourget and Edoardo Vescovi) for the link.
Posted by: IC
Wednesday, 6 May 2020
A personal bird eye view of fuzzballs
Rodolfo Russo
(QMUL)
Abstract:
There are indications that "traditional" GR physics at the horizon and usual assumptions of locality cannot provide a consistent description of black holes. The fuzzball paradigm suggests that "traditional" GR physics at the horizon should be relaxed and that string theory provides the right degrees of freedom to have a non-trivial structure at the scale of the horizon. I'll review how this idea has emerged from the analysis of the Strominger-Vafa black hole and its implication for the AdS3/CFT2 duality. For link to the meeting, please email <a href="mailto:damian.galante@kcl.ac.uk">damian.galante@kcl.ac.uk</a>.
There are indications that "traditional" GR physics at the horizon and usual assumptions of locality cannot provide a consistent description of black holes. The fuzzball paradigm suggests that "traditional" GR physics at the horizon should be relaxed and that string theory provides the right degrees of freedom to have a non-trivial structure at the scale of the horizon. I'll review how this idea has emerged from the analysis of the Strominger-Vafa black hole and its implication for the AdS3/CFT2 duality. For link to the meeting, please email <a href="mailto:damian.galante@kcl.ac.uk">damian.galante@kcl.ac.uk</a>.
Posted by: andrea
Thursday, 7 May 2020
Completeness of Bethe equations
Dmytro Volin
(Uppsala University)
Abstract:
We review a proof of bijection between eigenstates of the Bethe algebra and solutions of Bethe equations written as a Wronskian quantisation condition or as QQ-relations on Young diagrams. Furthermore, it is demonstrated that the Bethe algebra is maximal commutative and it has simple spectrum every time it is diagonalisable. The proof covers rational gl(m|n) spin chains in the defining representation with the famous Heisenberg spin chain being a particular subcase. The proof is rigorous (no general position arguments are used). We do not rely on the string hypothesis and moreover we conjecture a precise meaning of Bethe strings as a consequence of the proposed proof.
A short introduction with necessary facts about polynomial rings will be given at the beginning of the talk.
Based on 2004.02865
NOTE: Part of London Integrability Journal Club. Please register at integrability-london.weebly.com to participate.
We review a proof of bijection between eigenstates of the Bethe algebra and solutions of Bethe equations written as a Wronskian quantisation condition or as QQ-relations on Young diagrams. Furthermore, it is demonstrated that the Bethe algebra is maximal commutative and it has simple spectrum every time it is diagonalisable. The proof covers rational gl(m|n) spin chains in the defining representation with the famous Heisenberg spin chain being a particular subcase. The proof is rigorous (no general position arguments are used). We do not rely on the string hypothesis and moreover we conjecture a precise meaning of Bethe strings as a consequence of the proposed proof.
A short introduction with necessary facts about polynomial rings will be given at the beginning of the talk.
Based on 2004.02865
NOTE: Part of London Integrability Journal Club. Please register at integrability-london.weebly.com to participate.
Posted by: andrea
The Precision Frontier in LHC Simulations (please email p.agarwal AT qmul.ac.uk for a link to the zoom meeting)
Frank Krauss
(Durham University)
Abstract:
In my talk, I will introduce concepts relevant for simulation of LHC physics. I will highlight some of the challenges when going to the level of precision necessary to match experimental accuracy.
In my talk, I will introduce concepts relevant for simulation of LHC physics. I will highlight some of the challenges when going to the level of precision necessary to match experimental accuracy.
Posted by: QMW