Role of the magnetic fields on the evolution and dynamics of Rayleigh-Taylor instability

The magnetic Rayleigh Taylor instability (MRTI) is ubiquitous in a wide range of astrophysical and laboratory systems. However, the evolution and the dynamics of MRTI is not fully understood. Magnetic fields play a crucial role in the instability dynamics of these systems. Towards understanding the interplay between gravity and magnetic forces on the evolution of instability, we study MRTI under simplified setting using analytical and numerical techniques. Our study shows that the imposed magnetic field hinders the self-similarity of MRTI evolution. However, when sufficiently evolved, MRTI converges towards self-similar behaviour with the same temporal scaling as the HD instability. The study revealed various physical processes, like energy dissipation (ED), kinetic and magnetic energy partition, anisotropy that determine the non-linear growth of instability across a wide range of magnetic field strengths. A particularly interesting finding is the drastic increase in energy dissipation with marginal increase in field strength, with magnetic ED thrice the kinetic ED for all field strengths. To understand this surprising behaviour, we investigate the potential role of magnetic reconnection. Thus, the current study presents a comprehensive understanding on the influence of magnetic fields on the evolution and growth of non-linear MRTI, and the impact of magnetic reconnection on MRTI dynamics. The unspecialized configuration meant the results are applicable in a wide range of practical systems.