Inflation, braneworlds and quintessence

Abstract

Inflationary cosmology is developed in the second Randall-Sundrum braneworld scenario, where the accelerated expansion arises through potentials that are too steep to drive inflation in conventional cosmology. A relationship between the scalar and tensor perturbation spectra is derived that is independent of both the inflaton potential and the brane tension. It is found that a single field with an inverse power law potential can act as both the inflaton and the quintessence field for suitable values of the brane tension.

5 Dark Matter and Dark Energy

“…This gives rise to the intriguing possibility that both inflation and quintessence may be sourced by one and the same scalar field. Termed 'quintessential inflation', these models have been examined in [142,53,85,169,116,66,106,57,185,178,177]. An example of quintessential inflation is shown in figure 8.…”

Consistency relations and degeneracies in (non)commutative patch inflation

“…This problem arose for the first time when the degeneracy of the 4D and RS lowest-SR-order tensor index was discovered [1,2]; several works then showed that this degeneracy is most likely incidental (e.g. [3] and references therein).…”

Curvaton hypothesis and theηproblem of quintessential inflation, with and without branes

“…However, here it should be pointed out that T * is overestimated above because we have considered an instantaneous transition between inflation and kination. In reality this transition takes some time so that t * is somewhat larger and, therefore, T * turns out about an order of magnitude smaller that the estimate of (24) [15]. This will be taken into account when we apply the BBN constraint below.…”

“…Moreover, mild quintessential tails, e.g. of the inverse power-law type [15], make it hard to satisfy coincidence. Furthermore, quintessential tails steeper than exponential have disastrous attractors [13], which, not only do they diminish ρ φ faster than ρ B , but are also reached very soon after the end of inflation and, therefore, cannot lead to late-time acceleration.…”