10 papers
Particle number density fluctuations and pressure effects on structure formation
D. R. Matravers, J. Triginer
We provide a covariant and gauge-invariant approach to the question of how a first order pressure can be incorporated self-consistently in a cosmological scenario. The approximatio…
Stress effects in structure formation
Roy Maartens, Josep Triginer, David Matravers
Residual velocity dispersion in cold dark matter induces stresses which lead to effects that are absent in the idealized dust model. A previous Newtonian analysis showed how this a…
Backreaction effects of dissipation in neutrino decoupling
Roy Maartens, Josep Triginer
Dissipative effects during neutrino decoupling in the early universe create a small backreaction on the Hubble rate, and lead to a small rise in temperature and entropy. We use a s…
Exact solutions of Einstein's equations with ideal gas sources
Roberto A. Sussman, Josep Triginer
We derive a new class of exact solutions characterized by the Szekeres-Szafron metrics (of class I), admitting in general no isometries. The source is a fluid with viscosity but ze…
Acoustic oscillations and viscosity
Roy Maartens, Josep Triginer
Using a simple thermo-hydrodynamic model that respects relativistic causality, we revisit the analysis of qualitative features of acoustic oscillations in the photon-baryon fluid.…
Density perturbations with relativistic thermodynamics
Roy Maartens, Josep Triginer
We investigate cosmological density perturbations in a covariant and gauge-invariant formalism, incorporating relativistic causal thermodynamics to give a self-consistent descripti…