Inflationary gravitational wave background as a tail effect

Autor:	Jokela, Niko, Kajantie, K., Laine, M., Nurmi, Sami, Sarkkinen, Miika
Rok vydání:	2023
Předmět:	General Relativity and Quantum Cosmology Astrophysics - Cosmology and Nongalactic Astrophysics High Energy Physics - Phenomenology
Druh dokumentu:	Working Paper
Popis:	The free propagator of a massless mode in an expanding universe can be written as a sum of two terms, a lightcone and a tail part. The latter describes a subluminal (time-like) signal. We show that the inflationary gravitational wave background, influencing cosmic microwave background polarization, and routinely used for constraining inflationary models through the so-called $r$ ratio, originates exclusively from the tail part. Comment: 8 pages
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2303.17985 Zobrazit plný text záznamu View this record from Arxiv