par Mironov, Sergey S.A.;Rubakov, Valéry V.A.;Ramazanov, Sabir
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.