Inflationary Universe in Higher Derivative Induced Gravity

TL;DR

This paper investigates how higher derivative terms in induced gravity models affect the stability of inflationary solutions and the resulting cosmological implications, including the emergence of a non-zero cosmological constant after inflation.

Contribution

It analyzes the stability conditions of inflationary solutions in higher derivative induced gravity models and explores their implications for early universe cosmology.

Findings

Higher derivative terms can destabilize inflationary solutions without additional constraints.

Models tend to develop a non-zero cosmological constant post-inflation.

Certain models have specific implications for the early universe dynamics.

Abstract

In an induced-gravity model, the stability condition of an inflationary slow-rollover solution is shown to be $\phi_0 \partial_{\phi_0}V(\phi_0)=4V(\phi_0)$. The presence of higher derivative terms will, however, act against the stability of this expanding solution unless further constraints on the field parameters are imposed. We find that these models will acquire a non-vanishing cosmological constant at the end of inflation. Some models are analyzed for their implication to the early universe.