Speaker
Description
We investigate the local gravitational instability of self-gravitating, rotating thin astrofluidic disks within the fourth order gravity (FOG) framework [1], [2]. The analysis is performed in the weak-field non-relativistic regime. This consideration is well motivated as the dynamical timescales associated with the disk instabilities are much longer than the relativistic ones. In this regime, the evolution of the structure formation mechanism is consistently captured by the hydrodynamic equations coupled and enclosed with the FOG-modified gravitational Poisson equation. By incorporating higher-order corrections to the self-gravitational potential, we derive a modified dispersion relation using the tight-winding (local) approximation. Consequently, we also obtain the associated generalized FOG-modified Toomre stability criterion for the astrofluidic disks. The resulting modified criterion reveals that the stability of the fluidic disk is significantly altered by the free length parameter (L), introduced by the FOG theory. It potentially shifts the threshold value of the Toomre parameter, leading to observable differences in triggering structure formation compared to the Newtonian predictions.
