Year: 1994
Type: article
Abstract: We explore constraints on the spectral index $n$ of density fluctuations and the neutrino energy density fraction ${\ensuremath{\Omega}}_{\ensuremath{\nu}}$ from observations of large scale structure. The best fits imply $n\ensuremath{\approx}1$ and ${\ensuremath{\Omega}}_{\ensuremath{\nu}}\ensuremath{\approx}0.1\ensuremath{-}0.3$, for Hubble constants 40-60 km ${\mathrm{s}}^{\ensuremath{-}1}$ ${\mathrm{Mpc}}^{\ensuremath{-}1}$. We present a new class of inflationary models based on realistic supersymmetric grand unified theories (GUTs) which do not have the usual "fine tuning" problems. The amplitude of primordial density fluctuations is found to be $\ensuremath{\propto}{(\frac{{M}_{X}}{{M}_{P}})}^{2}$, where ${M}_{X}$ (${M}_{P}$) denote the GUT (Planck) scale. The spectral index $n=0.98$, in excellent agreement with the observations.
Source: Physical Review Letters
Authors: G. Dvali, Q. Shafi, R. Schaefer
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: U.S. Department of Energy
OpenAlex ID: W2100305395