2014/12/28 by E. Yusofi, M. Mohsenzadeh · 2 citations
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology #Cosmology and Gravitation Theories #De Sitter space #De Sitter universe #Inflation (cosmology) #Inflaton #Noncommutative and Quantum Gravity Theories #Nonlinear system #Scale factor (cosmology) #Spacetime #Universe #gr-qc #hep-th #math-ph #math.MP
paper · pdf · doi:10.1142/s0217732315500418
published as Modern Physics Letters A Vol. 30, No. 9 (2015) 1550041 (8 pages) · 7 pages, no figures, accepted for publication in Modern Physics Letters A, 2014
arxiv created 2014/12/28 · openalex publication_date 2015/02/27 · openalex created_date 2016/06/24 · arxiv updated 2018/04/06 · openalex updated_date 2026/08/05
We present some features of early universe cosmology in terms of Hankel functions index (ν). Actually, the recent data from observational cosmology indicate that our universe was nearly de Sitter spacetime in the early times which results in an approximate scale-invariant spectrum. This imposes some constrains on index ν [E. Yusofi and M. Mohsenzadeh, JHEP 09, 020 (2014)]. These constrains stimulate us to use general solution of inflaton field equation for [Formula: see text]. To obtain the general solution for the inflationary background, we use asymptotic expansion of Hankel functions up to nonlinear order of [Formula: see text]. We consider the nonlinear modes as the fundamental modes for early universe during the inflation. In this paper, we obtain the general form of the inflationary modes, scale factor expansion, equation of state and some nonlinear corrections of power spectrum in terms of index ν. These results are general and in quasi-de Sitter and de Sitter limit confirm the conventional results.