Triangle Seminars
Wednesday, 10 Jun 2026 Today
Conformal collider bootstrap in N=4 SYM
📍 London
Robin Karlsson
(University of Oxford)
Abstract:
Energy correlations characterise the energy flux through detectors at infinity produced in a collision event. In CFTs, these detectors are examples of light-ray operators and, in particular, the stress tensor operator integrated over future null infinity. In N=4 SYM, we combine perturbation theory, holography, integrability, supersymmetric localisation, and modern conformal bootstrap techniques to obtain predictions for such a collider experiment at finite coupling, both at finite number of colours, and in the planar limit. In QCD, the coupling runs with the angle between detectors, and there is a transition from perturbative to non-perturbative QCD. In N=4 SYM, a similar transition occurs when the coupling is varied, which we explore quantitatively. I will describe the physics underlying this observable and some of the methods used, particularly in regimes with analytical control. Based on 2512.10796 and work in progress.
Energy correlations characterise the energy flux through detectors at infinity produced in a collision event. In CFTs, these detectors are examples of light-ray operators and, in particular, the stress tensor operator integrated over future null infinity. In N=4 SYM, we combine perturbation theory, holography, integrability, supersymmetric localisation, and modern conformal bootstrap techniques to obtain predictions for such a collider experiment at finite coupling, both at finite number of colours, and in the planar limit. In QCD, the coupling runs with the angle between detectors, and there is a transition from perturbative to non-perturbative QCD. In N=4 SYM, a similar transition occurs when the coupling is varied, which we explore quantitatively. I will describe the physics underlying this observable and some of the methods used, particularly in regimes with analytical control. Based on 2512.10796 and work in progress.
Posted by: Kiarash Naderi
Thursday, 11 Jun 2026
The EFT of SuperPlanckian Scattering
📍 London
Ira Rothstein
(Carnegie Mellon University)
Abstract:
While quantum gravity is well understood as an effective field theory when all invariants are sub-Planckian, the super-Planckian (Regge) limit still poses open questions which we are just now starting to address. This limit leads a strong coupling problem which forces us to reorganize the calculation via resummations in order to maintain theoretical control. In this talk I will use an recently designed EFT of gravity in this Regge to reveal the structure of the series which must take a very particular form. I will then show how this EFT can be used to calculate higher order loops results using lower order results in conjunction with the rapidity renormalization group. I will also address the question of collinear singularities in this limit which Weinberg famously showed cancel for wide angle scattering.
While quantum gravity is well understood as an effective field theory when all invariants are sub-Planckian, the super-Planckian (Regge) limit still poses open questions which we are just now starting to address. This limit leads a strong coupling problem which forces us to reorganize the calculation via resummations in order to maintain theoretical control. In this talk I will use an recently designed EFT of gravity in this Regge to reveal the structure of the series which must take a very particular form. I will then show how this EFT can be used to calculate higher order loops results using lower order results in conjunction with the rapidity renormalization group. I will also address the question of collinear singularities in this limit which Weinberg famously showed cancel for wide angle scattering.
Posted by: Sebastian Cespedes