Lagrangian theory of structure formation in relativistic cosmology. V. Irrotational fluids (2018)
Abstract
We extend the general relativistic Lagrangian perturbation theory, recently developed for the formation of cosmic structures in a dust continuum, to the case of model universes containing a single fluid with a single–valued analytic equation of state. Using a coframe–based perturbation approach, we investigate evolution equations for structure formation in pressure–supported irrotational fluids that generate their rest–frame spacetime foliation. We provide master equations to first order for the evolution of the trace and traceless parts of barotropic perturbations that evolve in the perturbed space, where the latter describes the propagation of gravitational waves in the fluid. We illustrate the trace evolution for a linear equation of state and for a model equation of state describing isotropic velocity dispersion, and we discuss differences to the dust matter model, to the Newtonian case, and to standard perturbation approaches.
ANZSRC Fields of Research
49  Mathematical sciences::4902  Mathematical physics::490204  Mathematical aspects of general relativity51  Physical sciences::5101  Astronomical sciences::510105  General relativity and gravitational waves
02  Physical Sciences::0203  Classical Physics::020303  Fluid Physics
49  Mathematical sciences::4901  Applied mathematics::490109  Theoretical and applied mechanics
51  Physical sciences::5101  Astronomical sciences::510103  Cosmology and extragalactic astronomy
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