Triangle Seminars
Monday, 2 Nov 2020
Global symmetry, Euclidean gravity, and the black hole information problem
Daniel Harlow
(MIT)
Abstract:
Part of the London Black Hole Information Paradox Journal Club (for Zoom link, please subscribe here: https://forms.gle/wLYi4A72tEUwuzGK6)
Part of the London Black Hole Information Paradox Journal Club (for Zoom link, please subscribe here: https://forms.gle/wLYi4A72tEUwuzGK6)
Posted by: andrea
Tuesday, 3 Nov 2020
Dark Energy and String Theory
Susha Parameswaran
(University of Liverpool)
Abstract:
I will give a (biased) review on the main current ideas to explain the fundamental nature of Dark Energy using string theory. The possibility of a de Sitter vacuum in string theory, corresponding to a cosmological constant with w=-1, has proven difficult to achieve, leading to the conjecture that such vacua might lie in the String Theory Swampland. Other interesting string candidates include axion or runaway quintessence. I will in particular discuss the Thermal Dark Energy proposal. Here finite temperature effects in a light hidden sector hold a hidden scalar away from the minimum of its zero-temperature potential, leading to an effective cosmological constant, consistently with the Swampland Conjectures and with potentially observable consequences.
[please email a.held@imperial.ac.uk for zoom link or password]
I will give a (biased) review on the main current ideas to explain the fundamental nature of Dark Energy using string theory. The possibility of a de Sitter vacuum in string theory, corresponding to a cosmological constant with w=-1, has proven difficult to achieve, leading to the conjecture that such vacua might lie in the String Theory Swampland. Other interesting string candidates include axion or runaway quintessence. I will in particular discuss the Thermal Dark Energy proposal. Here finite temperature effects in a light hidden sector hold a hidden scalar away from the minimum of its zero-temperature potential, leading to an effective cosmological constant, consistently with the Swampland Conjectures and with potentially observable consequences.
[please email a.held@imperial.ac.uk for zoom link or password]
Posted by: IC
Wednesday, 4 Nov 2020
Type-B Anomalies on the Higgs Branch
📍 London
Elli Pomoni
(DESY)
Abstract:
In this talk we will study type-B conformal anomalies associated with
1/2-BPS Coulomb-branch operators in 4D N=2 SCFTs. We will derive the
conditions under which these anomalies can match across the conformal
phase and the Higgs phase, and explicitly see them at work in concrete
examples of both matching and non-matching. On the one hand matching
leads to a new class of data on the Higgs branch of 4D N=2 SCFTs that
are exactly computable. On the other, non-matching imposes novel
restrictions on the holonomy of the conformal manifold.
[For the Zoom link, please email to: alejandro.cabo_bizet@kcl.ac.uk ]
In this talk we will study type-B conformal anomalies associated with
1/2-BPS Coulomb-branch operators in 4D N=2 SCFTs. We will derive the
conditions under which these anomalies can match across the conformal
phase and the Higgs phase, and explicitly see them at work in concrete
examples of both matching and non-matching. On the one hand matching
leads to a new class of data on the Higgs branch of 4D N=2 SCFTs that
are exactly computable. On the other, non-matching imposes novel
restrictions on the holonomy of the conformal manifold.
[For the Zoom link, please email to: alejandro.cabo_bizet@kcl.ac.uk ]
Posted by: andrea
Thursday, 5 Nov 2020
Stringy resurgence: modular graph functions and Poincare series
Daniele Dorigoni
(Durham University)
Abstract:
Zoom link: Please email Silvia Nagy (s.nagyATqmul.ac.uk) or Jungwook Kim (jung-wook.kimATqmul.ac.uk) for the zoom link.
Abstract:In string theory SL(2,Z) invariant functions, such as modular graph functions or coefficient functions of higher derivative corrections, are ubiquitous. Using a representation in terms of Poincaré series we can combine different methods for asymptotic expansions and obtain the complete perturbative and non-perturbative expansion. In the case of the higher derivative corrections, these terms have an interpretation in terms of perturbative string loop effects and pairs of instantons/anti-instantons.
There will also be a pre-seminar for the students which will begin at 2:30 pm.
Zoom link: Please email Silvia Nagy (s.nagyATqmul.ac.uk) or Jungwook Kim (jung-wook.kimATqmul.ac.uk) for the zoom link.
Abstract:In string theory SL(2,Z) invariant functions, such as modular graph functions or coefficient functions of higher derivative corrections, are ubiquitous. Using a representation in terms of Poincaré series we can combine different methods for asymptotic expansions and obtain the complete perturbative and non-perturbative expansion. In the case of the higher derivative corrections, these terms have an interpretation in terms of perturbative string loop effects and pairs of instantons/anti-instantons.
There will also be a pre-seminar for the students which will begin at 2:30 pm.
Posted by: QMW
Non-planar N=4 SYM: from integrability to quantum chaos
Tristan McLoughlin
(Trinity College Dublin)
Abstract:
In this talk we will consider the spectrum of anomalous dimensions in N=4 super-Yang-Mills and related theories. We will first discuss the emergence of quantum chaos as one goes from infinite to finite N and how the perturbative spectrum is described by GOE random matrix theory. We will then describe how the integrability of the planar-limit can be used to rewrite the computation of the leading 1/N corrections to the one-loop anomalous dimensions in terms of scalar products of off-shell Bethe states or, alternatively, hexagon-like functions.–– Part of London Integrability Journal Club. If you are a new participant, please register filling the form at integrability-london.weebly.com. The link will be emailed.
In this talk we will consider the spectrum of anomalous dimensions in N=4 super-Yang-Mills and related theories. We will first discuss the emergence of quantum chaos as one goes from infinite to finite N and how the perturbative spectrum is described by GOE random matrix theory. We will then describe how the integrability of the planar-limit can be used to rewrite the computation of the leading 1/N corrections to the one-loop anomalous dimensions in terms of scalar products of off-shell Bethe states or, alternatively, hexagon-like functions.–– Part of London Integrability Journal Club. If you are a new participant, please register filling the form at integrability-london.weebly.com. The link will be emailed.
Posted by: andrea