Our next cosmology seminar takes place on **Friday 15th** of November,
seminar **room E349** at **2pm**. The speaker is **Jibril Ben Achour**
from the Yukawa Institute (Kyoto, Japan).

At 14:00, room E349, Jibril Ben Achour (Yukawa Institute, Kyoto), will be talking about

### FLRW cosmology as a conformally invariant field theory in 1D

*Over the last decades, conformal field theory (CFT) technics have
played an important role in black hole physics, due to the discovery
of unexpected conformal symmetries in the near horizon of black
hole. Using these technics, crucial features of black hole physics,
among which their spectroscopy, quasi-normal modes, as well as their
state counting have been reproduced using CFT technics. So far, the
possible existence of similar hidden conformal symmetry in
cosmological spacetimes have been much less investigated. In this
talk, I will show that the simplest cosmological model, consisting in
the homogeneous and isotropic Einstein-Scalar system, enjoys a
surprising hidden conformal symmetry. I will present in detail this
new structure, the associated Noether’s charge as well as the CVH
algebra which encodes this conformal symmetry at the hamiltonian
level. Then, I will explain how this cosmological system can be
mapped to the well known conformal mechanics developed by de Alfaro,
Fubini and Furlan, and which provides the simplest example of a
classically conformal field theory in 1d. This conformal structure
extends beyond this simple homogeneous and isotropic setting. I will
briefly discuss the inclusion of a cosmological constant,
anisotropies, self-interacting potential for the scalar field, as well
as work in progress on the fully inhomogeneous Einstein-Scalar system.
Finally, I will discuss the consequences of this new conformal
structure at the quantum level. A major outcome is the possibility to
apply the conformal bootstrap program to quantize the theory. Just as
quantum conformal mechanics, I will show that despite the lack of a
conformally invariant group state, it is possible to find an operator
which reproduces the standard form of the CFT two points function in
quantum cosmology. I will discuss the cosmological interpretation of
this operator and the vacuum state which are used to construct this
correlator. In the end, this provides a first step to bootstrap
quantum cosmology using this new conformal symmetry.*

Based on: arXiv:1909.13390