16-20 April 2018
Institut Henri Poincaré
Europe/Paris timezone

Inflation meets dark energy: $\alpha$-attractor quintessential inflation in the era of Euclid

Not scheduled
15m
Amphithéâtre Darboux (ground floor, on the right) (Institut Henri Poincaré)

Amphithéâtre Darboux (ground floor, on the right)

Institut Henri Poincaré

11 Rue Pierre et Marie Curie, 75005 Paris
TWG talk

Speaker

Yashar Akrami (Lorentz Institute for Theoretical Physics, Leiden University)

Description

Over the last few years, a large family of cosmological attractor models has been discovered, which can successfully match the latest inflation-related observational data. Many of these models can also describe a small cosmological constant $\Lambda$. In this talk, I will present a recently discovered class of $\alpha$-attractor models with dynamical dark energy, including the cosmological constant $\Lambda$ as a free parameter. Predominantly, the models with $\Lambda > 0$ converge to the asymptotic regime with the equation of state $w=-1$. However, there are some models with $w\neq -1$, which are compatible with the current observations. In the simplest models with $\Lambda = 0$, one has the tensor to scalar ratio $r=\frac{12\alpha}{N^2}$ and the asymptotic equation of state $w=-1+\frac{2}{9\alpha}$. For example, in the seven disk M-theory related model with $\alpha = 7/3$ one finds $r \sim 10^{-2}$ and the asymptotic equation of state is $w \sim -0.9$. Future observations, including large-scale structure surveys such as Euclid as well as B-mode detectors will test these, as well as more general models that I will present in this talk. I will also discuss gravitational reheating in models of quintessential inflation and argue that its investigation may be interesting from the point of view of inflationary cosmology. Such models require a much greater number of $e$-folds, and therefore predict a spectral index $n_{s}$ that can exceed the value in more conventional models by about $0.006$. This suggests a way to distinguish the conventional inflationary models from the models of quintessential inflation, even if they predict $w = -1$.

Primary author

Yashar Akrami (Lorentz Institute for Theoretical Physics, Leiden University)

Presentation Materials

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