Fundamental Physics with Pulsars around Sagittarius A${}^{\star }$

Abstract

Searching for radio pulsars orbiting around the Galactic centre black hole (BH), Sagittarius A${}^{\star }$ (Sgr A${}^{\star }$), represents a holy grail goal for large-area radio telescopes, in particular for the Square Kilometre Array. Follow-up timing observation of such a PSR-Sgr A${}^{\star }$ binary system with an orbital period $\lesssim O(1\mathrm{year})$ will bring forward a handful of new tests on different aspects of fundamental physics that are barely accessible with other means. However, mass perturbation in the Galactic centre harms the gravitational cleanness of PSR-Sgr A${}^{\star }$ systems. In order to flexibly account for perturbations, a numerical pulsar timing model is gradually being built, which can be used to probe the spacetime around Sgr A${}^{\star }$ BH and study the nature of dark matter.

4 pages, 1 figure