Inflationary gravitational wave background as a tail effect
Autor: | Jokela, Niko, Kajantie, K., Laine, M., Nurmi, Sami, Sarkkinen, Miika |
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Rok vydání: | 2023 |
Předmět: | |
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 |
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