Joe O'Leary (EOS Space Systems Pty. Ltd.; University of South Australia)

Colloquium: General relativistic and post-Newtonian dynamics for near-Earth objects and solar system bodies

Remotely Hosted

Abstract

The general theory of relativity is the currently accepted framework for the description of gravitational physics, and is experimentally verified across a plethora of domains. Given the highly non-linear nature of the Einstein field equations of gravitation, approximation methods are often employed for the description of realistic astrophysical systems. The so-called post-Newtonian approximation is a tool utilised by modern relativists to obtain approximate solutions to the Einstein field equations and is heavily exploited in fields such as geodesy and astrophysics.

In this talk, we present topics from three distinct areas of Einstein’s general theory of relativity. The first part of this talk investigates arguably the most well-known area of Einstein’s theory of gravitation: the spherically symmetric Schwarzschild solution. Using non-traditional dynamical and physical assumptions, we present a derivation of an alternative spherically symmetric solution which avoids the coordinate singularity associated with the Schwarzschild spacetime. The second part of this talk is an exploration of fundamental post-Newtonian dynamical quantities associated with test particles in local geocentric and solar-system barycentric reference frames. The final part of this talk suggests a novel framework to compute general relativistic spacecraft orbits by accounting for non-gravitational perturbations with highly accurate data from on-board accelerometers.