A novel way of constraining the $α$-attractor chaotic inflation through Planck data [CL]

http://arxiv.org/abs/2106.02920


Defining a scale of $k$-modes of the quantum fluctuations during inflation through the dynamical horizon crossing condition $k = aH$ we go from the physical $t$ variable to $k$ variable and solve the equations of cosmological perturbations self consistently, with chaotic $\alpha$-attractor type potentials. This enables us to study the behaviour of $n_{s}$, $r$, $n_{h}$ and $N$ in the $k$-space. Comparison of our results in the low-$k$ regime with the Planck data puts constraints on the values of the $\alpha$ parameter through microscopic calculations. Both for the $E$-model and the $T$-model potentials, low values of $\alpha$ are experimentally favoured. For the $E$-model ($T$-model) the values of $\alpha<5$ ($\alpha<10$) are consistent with the Planck-2018 data in the $n_{s}$-$r$ plane at $95\%$ CL. The relevance of this study in the context of large scale structure of the universe is pointed out.

Read this paper on arXiv…

A. Sarkar, C. Sarkar and B. Ghosh
Tue, 8 Jun 21
62/86

Comments: 21 pages, 14 figures