Holographic Brownian dynamics of a heavy particle in a boosted thermal plasma background

Abstract: In this work, we have performed a detailed holographic analysis of the stochastic dynamics of a heavy quark propagating through a strongly coupled plasma moving with a constant velocity along a fixed spatial direction. To model this scenario within the framework of the AdS/CFT correspondence, we consider a boosted AdS black brane geometry in the bulk. The boost corresponds to the uniform motion of the plasma on the boundary field theory side. The presence of this boost introduces a preferred direction, leading to an anisotropic environment in which the behavior of the quark differs depending on its direction of motion. Consequently, we examine two distinct cases, namely, quark motion parallel to the direction of the boost and motion perpendicular to it. In this work we have computed the diffusion coefficient for both along the boost and perpendicular to the boost directions. We have obtained the diffusion coefficient by following the two different approaches in both the cases. These complementary approaches yield consistent results, thereby reinforcing the reliability of the computations carried out. Additionally, we derive and verify the fluctuation-dissipation relation within this anisotropic setup, confirming its validity in both longitudinal and transverse channels. Our findings provide deeper insight into the non-equilibrium transport properties of strongly coupled plasma and further elucidate the holographic description of Brownian motion in anisotropic backgrounds. Then we have moved on to proving the fluctuation dissipation theorem in this context. Finally, we proceed to holographcally compute the Butterfly velocity by using the entanglement wedge subregion duality and express the diffusion coefficients in terms of the chaotic observables.