Triangle Seminars
Tuesday, 8 Oct 2013
TBA
Lionel Mason
(Oxford)
Wednesday, 9 Oct 2013
Higher Spin correlators
Alday Fernando
(Oxford)
Abstract:
I will discuss the three-point correlator of two protected scalar operators and one higher spin twist-two operator in N = 4 SYM, in the limit of large spin. This structure constant can be extracted from the OPE of the four-point correlator of protected scalar operators. Based on the OPE structure, symmetry arguments and intuition from the available perturbative results, it is possible to predict the structure constant at all loops in perturbation theory. Furthermore, this allows also to propose an expression for the all loops four-point correlator in a particular limit.
I will discuss the three-point correlator of two protected scalar operators and one higher spin twist-two operator in N = 4 SYM, in the limit of large spin. This structure constant can be extracted from the OPE of the four-point correlator of protected scalar operators. Based on the OPE structure, symmetry arguments and intuition from the available perturbative results, it is possible to predict the structure constant at all loops in perturbation theory. Furthermore, this allows also to propose an expression for the all loops four-point correlator in a particular limit.
Posted by: KCL
An Update on Moonshine
Miranda Cheng
(Paris VI)
Abstract:
In 2010, Eguchi–Ooguri–Tachikawa observed an unexpected relation between K3 elliptic genus and the sporadic group M24. In this talk I'll briefly review the recent developments on the topic of moonshine. In particular I will describe a more general relation between mock modular forms and finite groups, using Niemeier lattices as the starting point and including the M24 observation as a special case. I will also discuss various approaches in attempting to understand these mysterious relations, focusing on the study of compactification of heterotic strings on K3 surfaces. This talk will be based on joint work with Duncan–Harvey and with Dong–Harrison–Kachru–Whalen–Wrase.
In 2010, Eguchi–Ooguri–Tachikawa observed an unexpected relation between K3 elliptic genus and the sporadic group M24. In this talk I'll briefly review the recent developments on the topic of moonshine. In particular I will describe a more general relation between mock modular forms and finite groups, using Niemeier lattices as the starting point and including the M24 observation as a special case. I will also discuss various approaches in attempting to understand these mysterious relations, focusing on the study of compactification of heterotic strings on K3 surfaces. This talk will be based on joint work with Duncan–Harvey and with Dong–Harrison–Kachru–Whalen–Wrase.
Posted by: KCL
Friday, 11 Oct 2013
Lifshitz as a deformation of Anti-de Sitter
Yegor Korovin
(UvA and Southampton)
Abstract:
We consider holography for Lifshitz spacetimes with dynamical exponent z=1+epsilon^2, where epsilon is small. Тhe holographically dual field theory is a specific deformation of the relativistic CFT, corresponding to the z=1 theory. We set up the holographic dictionary for Einstein-Proca models and explain how renormalization turns the relativistic conformal invariance into non-relativistic Lifshitz invariance with dynamical exponent z=1+epsilon^2. Using only QFT arguments we show that a particular class of deformations of CFTs generically leads to Lifshitz scaling invariance and we provide examples of such deformations. An analytic Lifshitz black brane up to second order in ε is constructed. Relation to some top-down construction will be discussed. Based on 1304.7776 and 1306.3344.
We consider holography for Lifshitz spacetimes with dynamical exponent z=1+epsilon^2, where epsilon is small. Тhe holographically dual field theory is a specific deformation of the relativistic CFT, corresponding to the z=1 theory. We set up the holographic dictionary for Einstein-Proca models and explain how renormalization turns the relativistic conformal invariance into non-relativistic Lifshitz invariance with dynamical exponent z=1+epsilon^2. Using only QFT arguments we show that a particular class of deformations of CFTs generically leads to Lifshitz scaling invariance and we provide examples of such deformations. An analytic Lifshitz black brane up to second order in ε is constructed. Relation to some top-down construction will be discussed. Based on 1304.7776 and 1306.3344.
Posted by: IC