Understand
Non-gaussianity in the microwave background radiation is bound to play a key role in giving us clues about the physics of the very early universe.
- However, the associated calculations, at second and even third order in perturbation theory, tend to be complicated to the point of obscuring simple underlying physical processes.
- In this note, we present a simple analytic procedure for approximating the non-linearity parameters f_{NL} and g_{NL} for cyclic models in which the cosmological perturbations are generated via the entropic mechanism.
- Our approach is quick, physically transparent and agrees well with the results of numerical calculations.
Reading the bibliography…