Eur. Phys. J. C (2014) 74: 2943
https://doi.org/10.1140/epjc/s10052-014-2943-y

Regular Article - Theoretical Physics

Study of inflationary generalized cosmic Chaplygin gas for standard and tachyon scalar fields

Department of Mathematics, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan

^* e-mail: msharif.math@pu.edu.pk

Received: 13 February 2014
Accepted: 8 June 2014
Published online: 5 July 2014

Abstract

We consider an inflationary universe model in the context of the generalized cosmic Chaplygin gas by taking the matter field as standard and tachyon scalar fields. We evaluate the corresponding scalar fields and scalar potentials during the intermediate and logamediate inflationary regimes by modifying the first Friedmann equation. In each case, we evaluate the number of e-folds, scalar as well as tensor power spectra, scalar spectral index, and the important observational parameter, the tensor–scalar ratio in terms of inflation. The graphical behavior of this parameter shows that the model remains incompatible with WMAP7 and Planck observational data in each case.