par Mironov, Sergey S.A.;Rubakov, Valéry V.A.;Ramazanov, Sabir
Référence Journal of Cosmology and Astroparticle Physics, 2014, 4, 015
Publication Publié, 2014
Référence Journal of Cosmology and Astroparticle Physics, 2014, 4, 015
Publication Publié, 2014
Article révisé par les pairs
Résumé : | We consider a non-inflationary early Universe scenario in which relevant scalar perturbations get frozen out at some point, but then are defrosted and follow a long nearly Minkowskian evolution before the hot era. This intermediate stage leaves specific imprint on the CMB 3-point function, largely independent of details of microscopic physics. In particular, the CMB bispectrum undergoes oscillations in the multipole l space with roughly constant amplitude. The latter is in contrast to the oscillatory bispectrum enhanced in the flattened triangle limit, as predicted by inflation with non-Bunch-Davies vacuum. Given this and other peculiar features of the bispectrum, stringent constraints imposed by the Planck data may not apply. The CMB 3-point function is suppressed by the inverse duration squared of the Minkowskian evolution, but can be of observable size for relatively short intermediate Minkowskian stage. © 2014 IOP Publishing Ltd and Sissa Medialab srl. |