BICEP's acceleration

Abstract

The recent BICEP2 detection of, what is claimed to be primordial $B$-modes, opens up the possibility of constraining not only the energy scale of inflation but also the detailed acceleration history that occurred during inflation. In turn this can be used to determine the shape of the inflaton potential $V(\varphi )$ for the first time - if a single, scalar inflaton is assumed to be driving the acceleration. We carry out a Monte Carlo exploration of inflationary trajectories given the current data. Using this method we obtain a posterior distribution of possible acceleration profiles $\epsilon (N)$ as a function of $e$-fold $N$ and derived posterior distributions of the primordial power spectrum $P(k)$ and potential $V(\varphi )$. We find that the BICEP2 result, in combination with Planck measurements of total intensity Cosmic Microwave Background (CMB) anisotropies, induces a significant feature in the scalar primordial spectrum at scales $k\sim 10^{-3}$ Mpc${}^{-1}$. This is in agreement with a previous detection of a suppression in the scalar power.

10 pages, 6 figures

References in corpus (5)

• Toward an Understanding of Foreground Emission in the BICEP2 Region
• Compatibility of Planck and BICEP2 in the Light of Inflation
• Reconstruction of the primordial power spectra with Planck and BICEP2
• On quantifying and resolving the BICEP2/Planck tension over gravitational waves
• A model-independent fit to Planck and BICEP2 data

Cited by in corpus (1)

• The History of Inflation from Microwave Background Polarimetry and Laser Interferometry