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The Astrophysics of Nanohertz Gravitational Waves

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arxiv 1811.08826 v4 pith:XA7V5Y6U submitted 2018-11-15 astro-ph.HE astro-ph.GAgr-qc

The Astrophysics of Nanohertz Gravitational Waves

classification astro-ph.HE astro-ph.GAgr-qc
keywords ptasnanohertzquestionstimingarticlebandgravitationalunderstanding
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
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Pulsar timing array (PTA) collaborations in North America, Australia, and Europe, have been exploiting the exquisite timing precision of millisecond pulsars over decades of observations to search for correlated timing deviations induced by gravitational waves (GWs). PTAs are sensitive to the frequency band ranging just below 1 nanohertz to a few tens of microhertz. The discovery space of this band is potentially rich with populations of inspiraling supermassive black-holes binaries, decaying cosmic string networks, relic post-inflation GWs, and even non-GW imprints of axionic dark matter. This article aims to provide an understanding of the exciting open science questions in cosmology, galaxy evolution, and fundamental physics that will be addressed by the detection and study of GWs through PTAs. The focus of the article is on providing an understanding of the mechanisms by which PTAs can address specific questions in these fields, and to outline some of the subtleties and difficulties in each case. The material included is weighted most heavily towards the questions which we expect will be answered in the near-term with PTAs; however, we have made efforts to include most currently anticipated applications of nanohertz GWs.

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Forward citations

Cited by 15 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

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    astro-ph.CO 2026-05 unverdicted novelty 6.0

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    PTA statistical tests cannot distinguish Gaussian and non-Gaussian GWB amplitude distributions in a model-agnostic way after decorrelation.

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