專題演講 Seminar

Title

Tensor Non-Gaussianity from Axion-Gauge-Fields Dynamics

Speaker

Dr. Aniket Agrawal (Institute of Astronomy and Astrophysics, Academia Sinica)

URL

https://www.phys.sinica.edu.tw/~heptheory/a_content.php?year=2019&type=Seminar&actid=171

Abstract

I will talk about an inflation model in which a spectator axion field coupled to an SU(2) gauge field produces a large three-point function (bispectrum) of primordial gravitational waves, on scales relevant to cosmic microwave background experiments. The amplitude of the bispectrum at the equilateral configuration is characterized by B_h/P_h² = O(10)×Ω_A^-1, where Ω_A is a fraction of the energy density in the gauge field and P_h is the power spectrum of gravitational waves produced by the gauge field. These gravitational waves are chiral, and can have a scale-independent power spectrum over a large range of wavenumbers, necessitating the measurement of TB and EB cross correlations along with measurement of non-Gaussianity to claim quantum fluctuations of the metric.

Language

演講語言 (Language): in English

Hosted by

吳建宏 研究員
Ng, Kin-Wang / Research Fellow