Gravity as the breakdown of conformal invariance
Abstract
We propose that at the beginning of the universe gravity existed in a limbo either because it was switched off or because it was only conformally coupled to all particles. This picture can be reverse-engineered from the requirement that the cosmological perturbations be (nearly) scale-invariant without the need for inflation. It also finds support in recent results in quantum gravity suggesting that spacetime becomes two-dimensional at super-Planckian energies. We advocate a novel top-down approach to cosmology based on the idea that gravity and the Big Bang Universe are relics from the mechanism responsible for breaking the fundamental conformal invariance. Such a mechanism should leave clear signatures in departures from scale-invariance in the primordial power spectrum and the level of gravity waves generated.
Keywords
Cite
@article{arxiv.1505.04649,
title = {Gravity as the breakdown of conformal invariance},
author = {Giovanni Amelino-Camelia and Michele Arzano and Giulia Gubitosi and Joao Magueijo},
journal= {arXiv preprint arXiv:1505.04649},
year = {2015}
}
Comments
Awarded Second Prize in the Gravity Research Foundation 2015 Awards for Essays on Gravitation