2024/10/12 by Ved Kenjale, Tina Kahniashvili, Kenjale, Ved +1 · 1 citation
Computer Science · Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Distributed and Parallel Computing Systems #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Physics - Phenomenology (hep-ph) #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2410.09658
openalex publication_date 2024/10/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Several pulsar timing array (PTA) missions have reported convincing evidence of a stochastic gravitational wave background within their latest datasets. This background could originate from an astrophysical source, though there are multiple possibilities for its origin to be cosmological. Focusing on the NANOGrav signal, which was in good agreement with other PTAs, we evaluate the possibility of an inflationary source for the background. However, we'll consider a time-dependent minimal theory of massive gravity instead of standard general relativity for our analysis. We find that an inflationary interpretation will require a strongly blue spectrum, characterized by nT = 1.8 ± 0.54, while Big Bang Nucleosynthesis limits will require a low reheating scale of Trh ≃ 4000 GeV. Though these constraints make it difficult for inflation to be the source of the NANOGrav signal, we find that the massive gravity model allows for a greater reheating temperature than standard general relativity, making an inflationary interpretation slightly less cumbersome.