Speaker
Description
This thesis explores a Lorentz-violating modification of gravity through the inclusion of a massive Kalb-Ramond (KR) field coupled nonminimally to curvature. Motivated by the need to probe gravitational dynamics in ultra-low acceleration regimes where General Relativity and Newtonian gravity may be incomplete, we develop a post-Newtonian framework to study wide binary systems as natural testbeds for such deviations. Starting from a modified action that incorporates the KR field mass, self-interactions, and Lorentz-violating background terms, we derive the coupled Einstein-Kalb-Ramond field equations. We adopt a static, spherically symmetric configuration and implement a numerical scheme to solve for the gravitational potential Φ(r) and the KR field components b01(r) and b23(r) in the presence of a double-peaked Gaussian matter distribution mimicking a wide binary system. The resulting potential deviates from the Newtonian 1/r form and admits a modified profile with a Yukawa-like decay, characterized by an exponential suppression at large distances. This numerically derived potential reflects the impact of the KR field and Lorentz-violating interactions on gravitational dynamics in the weak-field, long-range regime. The analysis provides a self-consistent demonstration of how antisymmetric tensor fields can generate observable modifications to the gravitational potential without invoking dark matter.