A Simplified Formalism for Computing Growth Rates for Perturbations in Standard Cosmology
Abstract
We present a simplified formalism for computing growth rates for perturbations within standard
cosmology. We show that converting the perturbation evolution equations into ordinary differen1ia1
equations in terms of D-functions, related to the growth functions, not only simplifies fie
equations, but also eliminates the commonly encountered complex problem of computing initial
conditions in cosmological studies, avoiding making any assumptions - as is usually done - when
setting up initial conditions for the perturbations.