Prospects of relativistic astrophysics: Viewpoints on the most influential journey

TL;DR

This paper reviews recent developments in relativistic astrophysics and observational cosmology, discussing the theoretical challenges and new observational tests for General Relativity in the context of modern astronomy and physics.

Contribution

It provides a comprehensive overview of the prospects and challenges for testing and refining General Relativity using modern observational techniques and theoretical insights.

Findings

Development of gravitational wave astronomy enables new tests of GR.

Modern telescopes allow exploration of previously uncharted regions of the universe.

Challenges from dark components and cosmological inflation motivate alternative theories.

Abstract

Based on several recent developments in relativistic astrophysics and observational cosmology, this article discusses prospects of (1) theoretical structure of General Relativity (GR) in the new era and (2) submission of GR to new and previously unanticipated tests. It explores the internal theoretical challenges experienced by the theory and challenges produced by it in the otherwise successful journey of 100 years. Gravitational collapse, geometrization of laws of physics, absence of strong field astronomical tests, the dark components of the universe (Cold Dark Matter (CDM) + Cosmological Constant ($\Lambda$ ) or something similar) and cosmological inflation have not only created serious challenges for the theory but also have ignited contemplation for alternatives and attempts for constraining them through observations. The article first explains the nature of the theory and how it was perceived by scientific community a century ago. It then highlights certain perspectives from cosmology and quantum gravity, the ultimate applications of the theory. With the advent of modern observing techniques, the theory has been experiencing tug of war with several tests. Our true journey with the theory has started only recently, thanks to the development of gravitational wave astronomy and extremely large telescopes some of which are and will be dedicated to test the theory by exploring previously uncharted regions of the universe. Incorporating several aspects of observational astronomy and cosmology, gravitational wave research and theoretical physics the article presents the new challenges created by the theory and also their prospects.