### Conveners

#### Beyond Einstein's Gravity

- Salvatore Capozziello (Università di Napoli "Federico II")

I will review recent non-trivial tests of the AdS/CFT correspondence which provides a dual description of the 4D quantum gravity in terms of 3D Chern-Simons-matter superconformal field theories. After a general discussion, I will focus on BPS Wilson loops that represent one of the best playgrounds to match exact field theory results with dual gravity predictions.

We construct a new class of extension of General Relativity starting from the idea that the coupling between spacetime and matter is the key to understand dark phenomenology. We then focus on one of the simplest examples of such a class of theories which contains only one additional parameter dubbed "MEMe model". We show that this theory is able to offer a unified framework for dark energy and...

We present a simple quantum description of black holes and the late Universe in which the effective Schwarzschild-de Sitter spacetime geometry emerges from a coherent state of background gravitons. Once localised baryonic matter is added consistently, such quantum states are shown to describe regular black holes and to contain the necessary components to describe MoND phenomenology at galactic...

An exact form of the stress-energy tensor in quantum field theory (QFT) with a local equilibrium statistical operator would be a crucial ingredient of the semiclassical Einstein equation, with non-trivial quantum corrections to the equation of state. While a solution in a curved background is still unknown, much can be learned from solving related problems in flat space-time. In this talk, I...

We propose a model where, in the Einstein equations, the right-hand side is modified by the addition of a term proportional to the symmetrized partial contraction of the Ricci tensor with the energy-momentum tensor. Bearing in mind the existence of a natural length scale given by the Planck length, dimensional analysis shows that such a term yields a correction linear in hbar to the classical...

Spontaneous symmetry breaking is a transversal concept in modern physics, being pivotal for our understanding of mass generation in particle physics, topological defects formation in cosmology and the appearance of condensed phases of matter. I will discuss some recent results about the way symmetry breaking occurs for systems embedded in a curved background, when curvature acts as an...

We investigate the interplay between gravity and the quantum coherence present in the state of a pulse of light propagating in curved spacetime. We first introduce an operational way to distinguish between the overall shift in the pulse wavepacket and its genuine deformation after propagation.

We then apply our technique to quantum states of photons that are coherent in the frequency degree...

We study how self gravitation of quantum systems affects the quantum coherence present in their state. Spatial superpositions of static, large, heavy systems tend to rapidly lose coherence, whereas light or massless particles are unaffected. Furthermore, large and heavy objects also rapidly localize into a single classical position. The ratio of the characteristic size of the system and its...