Joint hep-th seminars with ULB, VUB and KUL

On the 26th of October UMONS will host the joint theoretical high-energy physics seminars organised by the Service de Physique de l’Univers, Champs et Gravitation of UMONS, the Service de Physique Théorique and the Service de Physique Théorique et Mathématique, both of the ULB, the Theoretical Particle Physics Group of the VUB, the High Energy Physics and Relativistic Field Theory group of the KUL and the International Solvay Institutes.

The speakers will be Ricardo Monteiro (Queen Mary University of London) and Ashish Shukla (CPHT Palaiseau):

10h30: Ricardo Monteiro

Celestial chiral algebras, colour-kinematics duality and integrability

We study celestial chiral algebras appearing in celestial holography, using the light-cone gauge formulation of self-dual Yang-Mills theory and self-dual gravity, and explore also their Moyal deformation, which is related to chiral higher-spin theories. The recently discussed w[1+∞] algebra in self-dual gravity arises from the soft expansion of an area-preserving diffeomorphism algebra, which plays the role of the kinematic algebra in the colour-kinematics duality and the double copy relation between the self-dual theories. The W[1+∞] deformation of w[1+∞] arises from a Moyal deformation of self-dual gravity. In all these theories, the chiral structure of the operator-product expansion exhibits the colour-kinematics duality: the implicit `left algebra’ is the self-dual kinematic algebra, while the `right algebra’ provides the structure constants of the operator-product expansion, ensuring its associativity. In a scattering amplitudes version of the Ward conjecture, the left algebra ensures the classical integrability of this type of theories. In particular, it enforces the vanishing of the tree-level amplitudes via the double copy.

12h00: Ashish Shukla

Bounds on gravitational brane couplings and tomography in AdS3 black hole geometries

In the talk, I will discuss AdS3 black hole geometries with an end-of-the-world (ETW) brane embedded in them, cutting off the second asymptotic region of the maximally extended spacetime. I will consider the ETW brane to have possible gravitational dynamics localized on it, the simplest possibility for which is to have JT gravity on the brane. Interestingly, as I will illustrate, bounds on the allowed rate of growth of entanglement in the CFT state dual to this geometry constrain the allowed values for the JT coupling on the brane. Also, by looking at the asymptotic growth of entanglement in the CFT state, one can read-off the brane parameters in the dual geometry, such as its location in the bulk and the value of the JT coupling, as I will elaborate upon in the talk.