Year: 1993
Type: article
Abstract: We investigate models of `intermediate' inflation, where the scale factor $a(t)$ grows as $a(t)=\mathrm{exp}(A{t}^{f})$, $0<f<1$, $A$ constant. These solutions arise as exact analytic solutions for a given class of potentials for the inflaton $\ensuremath{\varphi}$. For a simpler class of potentials falling off as a power of $\ensuremath{\varphi}$ they arise as slow-roll solutions, and in particular they include, for $f=\frac{2}{3}$, the class of potentials which give the Harrison-Zel'dovich spectrum. The perturbation spectral index $n$ can be greater than unity on astrophysical scales. It is also possible to generate substantial gravitational waves while keeping the scalar spectrum close to scale invariance; this latter possibility performs well when confronted with most observational data.
Authors: John D. Barrow, Andrew R. Liddle
Institution: University of Sussex
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: Leverhulme Trust, Royal Society
OpenAlex ID: W2156577875