Celestial Holography Summer School 2024

Session

Lightning Talks

LT

Jul 24, 2024, 3:15 PM

PI/1-100 - Theatre (Perimeter Institute for Theoretical Physics)

26. Asymptotic symmetries for logarithmic soft theorems

Sangmin Choi (University of Amsterdam)

7/24/24, 3:15 PM

Lightning Talks

In the last few years, a remarkable link has been established between the soft theorems and asymptotic symmetries of quantum field theories: soft theorems are Ward identities of the asymptotic symmetry generators. In particular, the tree-level subleading soft theorems are the Ward identities of the subleading asymptotic symmetries of the theory, for instance divergent gauge transformation in...

28. Quantum Corrections to the Thermodynamics of Cold Black Holes

Ahmed Sheta

7/24/24, 3:20 PM

Lightning Talks

I will review an old puzzle related to the breakdown of the semiclassical description of the thermodynamics of very cold (ultraspinning) black holes. Then, I will discuss recent work where we resolved this puzzle by properly accounting for quantum corrections arising from graviton loops, which dominate the low-temperature thermodynamics.

31. Celestial Chiral Algebras of self-dual Black Holes

Simon Heuveline (University of Cambridge)

7/24/24, 3:25 PM

Lightning Talks

This talk is based on work in progress with Giuseppe Bogna. We consider the twistor description of classical self-dual Einstein gravity in the presence of a cosmological constant and a defect operator wrapping a certain $\mathbb{CP}^1$. The backreaction of this defect deforms the flat twistor space to that of quaternionic Taub-NUT space, a certain self-dual limit of a family of Kerr Taub-NUT...

36. A Celestial Dual for MHV Amplitudes

Mr Walker Melton (Harvard University)

7/24/24, 3:30 PM

Lightning Talks

We show that a 2D CFT consisting of a central charge c Liouville theory, a chiral level one, rank N Kac-Moody algebra and a weight −3/2 free fermion holographically generates 4D MHV leaf amplitudes associated to a single hyperbolic slice of flat space. Celestial amplitudes arise in a large-N and semiclassical large-c limit, according to the holographic dictionary, as a...

37. Collinear singularities from a double cover of twistor space

Seraphim Hsieh Jarov (Perimeter Institute)

7/24/24, 3:35 PM

Lightning Talks

Based on an idea of Kevin Costello, I will show how to construct a double cover of the twistor space of $\mathbb{R}^4$, $X = \pi^*(\mathcal{O}(1)\oplus\mathcal{O}(1))\to\Sigma$ where $\Sigma$ is an (hyper)elliptic curve. I then discuss how holomorphic theories such as BF and Chern-Simons theory on $X$ descend to theories on ordinary twistor space. Once on twistor space, compactifying along the...

40. The Bulk Model of Dissipative Dynamics On Lie Group

Mr Afshin Besharat (McMaster University and Perimeter Institute)

7/24/24, 3:40 PM

Lightning Talks

47. Higher-Spin Charges in Gravity

Nicolas Cresto (Perimeter Institute)

7/24/24, 3:45 PM

Lightning Talks

I will describe shortly what the higher-spin charges are and why they are relevant from a holographic point of view. Besides, I will emphasize the recent result according to which they are realized as Noether charges in a non-linear regime.

43. beta deformation in twistor space

Mr Eggon Viana (ICTP-SAIFR)

Lightning Talks

In this work, we find the beta deformation states in the context of twistor string theory. For that, we make cohomological computations in the topological B-model defined on the projective space $\mathbb{CP}^{3|4}$. We identify the beta deformation states as elements of the BRST cohomology. We find that by first defining the beta deformation states as states leaving in a specific...