Where will Einstein fail? Lessons for gravity and cosmology
Abstract
Einstein's theory of General Relativity is the benchmark example for empirical success and mathematical elegance in theoretical physics. However, in spite of being the most successfully tested theory in physics, there are strong theoretical and observational arguments for why General Relativity should fail. It is not a question of if, but rather a question of where and when! I start by recounting the tremendous success in observational cosmology over the past three decades, that has led to the era of precision cosmology. I will then summarize the pathologies in Einstein's theory of gravity, as the cornerstone of standard cosmological model. Attempts to address these pathologies are either inspired by mathematical elegance, or empirical falsifiability. Here, I provide different arguments for why a falsifiable solution should violate Lorentz symmetry, or revive ``gravitational aether''. Deviations from Einstein's gravity are then expected in: 1) cosmological matterradiation transition, 2) neutron stars, 3) gravitomagnetic effect, 4) astrophysical black holes, and their potential connection to dark energy, and 5) early Universe, where the predictions are ranked by their degree of robustness and falsifiability.
 Publication:

Bulletin of the Astronomical Society of India
 Pub Date:
 March 2012
 DOI:
 10.48550/arXiv.1203.3827
 arXiv:
 arXiv:1203.3827
 Bibcode:
 2012BASI...40....1A
 Keywords:

 cosmology: theory;
 gravitation;
 dark energy;
 neutron stars;
 black hole physics;
 early Universe;
 Astrophysics  Cosmology and Extragalactic Astrophysics;
 Astrophysics  High Energy Astrophysical Phenomena;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 20 pages, 3 figures, Based on the Professor M.K. Vainu Bappu gold medal award (2008) lecture given at IUCAA, Pune on 2011 October 15, To appear in the 2012 March issue of the Bulletin of the Astronomical Society of India