Speaker
Mr
Carlos Alberto Sierra Ordoñez
(UIS)
Description
The standard slow-roll conditions maintain the Hubble parameter almost constant, leaving place to the primordial inflationary epoch. Through the separate-universe assumption, these conditions could be "extended" to its local form allowing the use of the moment transport equations methodology. The aim of this investigation is to standardize a procedure that allows us to calculate the non-gaussianity parameter $f_{NL}$ related to a cosmological model, using the moment transport equations and some adequate gauge transformations. The motivation of this study relies on the difficulty at obtaining the non-gaussianity parameters of cosmological models by means of the $\delta N$ formalism, since there does not exist a standard analytic procedure to obtain the derivatives of the amount of expansion or number of e-folds $N$. To overtake this difficulty, the application of the extended slow-roll condition allows us to use of the moment transport equations, so that the evolution of the $n-point$ correlators of the perturbations of the inflaton fields is obtained. The latter is complemented, in the framework of this methodology, with the ease of obtaining the derivatives of $N$ through a proper gauge transformation.
Primary author
Mr
Carlos Alberto Sierra Ordoñez
(UIS)
Co-author
Dr
Yeinzon Rodriguez
(UIS-UAN)
