Constraints on primordial curvature spectrum from primordial black holes and scalar-induced gravitational waves

Zhu, Yanjun; Qin, Fei

doi:10.1140/epjc/s10052-023-11233-3

Cited by 31 publications

(9 citation statements)

References 157 publications

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“…For earlier works on the PBH/SIGW interpretation of the signal in recent PTA data sets, see Vaskonen & Veermäe (2021), De Luca et al (2021), and Kohri & Terada (2021). For earlier Bayesian searches for an SIGW signal in PTA data sets, see Chen et al (2020), Bian et al (2021), Zhao & Wang (2022), Yi & Fei (2023), and Dandoy et al (2023), and for a search in LVK data, see Romero-Rodriguez et al (2022).…”

Section: Model Descriptionmentioning

confidence: 99%

The NANOGrav 15 yr Data Set: Search for Signals from New Physics

Afzal

Agazie

Anumarlapudi

et al. 2023

ApJL

367

137

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The 15 yr pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) shows positive evidence for the presence of a low-frequency gravitational-wave (GW) background. In this paper, we investigate potential cosmological interpretations of this signal, specifically cosmic inflation, scalar-induced GWs, first-order phase transitions, cosmic strings, and domain walls. We find that, with the exception of stable cosmic strings of field theory origin, all these models can reproduce the observed signal. When compared to the standard interpretation in terms of inspiraling supermassive black hole binaries (SMBHBs), many cosmological models seem to provide a better fit resulting in Bayes factors in the range from 10 to 100. However, these results strongly depend on modeling assumptions about the cosmic SMBHB population and, at this stage, should not be regarded as evidence for new physics. Furthermore, we identify excluded parameter regions where the predicted GW signal from cosmological sources significantly exceeds the NANOGrav signal. These parameter constraints are independent of the origin of the NANOGrav signal and illustrate how pulsar timing data provide a new way to constrain the parameter space of these models. Finally, we search for deterministic signals produced by models of ultralight dark matter (ULDM) and dark matter substructures in the Milky Way. We find no evidence for either of these signals and thus report updated constraints on these models. In the case of ULDM, these constraints outperform torsion balance and atomic clock constraints for ULDM coupled to electrons, muons, or gluons.

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Section: Model Descriptionmentioning

confidence: 99%

The NANOGrav 15 yr Data Set: Search for Signals from New Physics

Afzal

Agazie

Anumarlapudi

et al. 2023

ApJL

367

137

View full text Add to dashboard Cite

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“…Such excess has been proposed in many papers, e.g. in the aforementioned works by Di & Gong (2018); Byrnes et al (2019); Braglia et al (2020); Yi & Fei (2023). Notably, this power excess would lead to a copious production of primordial black holes (PBHs) at the radiation-dominated stage, which is sometimes taken by the authors as the motivation to introduce them as cold dark matter candidates.…”

Section: Implications On the 2nd-order Gwb Produced By Primordial Cur...mentioning

confidence: 98%

The International Pulsar Timing Array second data release: Search for an isotropic gravitational wave background

Antoniadis

Arzoumanian

Babak

et al. 2022

Monthly Notices of the Royal Astronomical Society

256

188

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We searched for an isotropic stochastic gravitational wave background in the second data release of the International Pulsar Timing Array, a global collaboration synthesizing decadal-length pulsar-timing campaigns in North America, Europe, and Australia. In our reference search for a power law strain spectrum of the form hc = A(f/1 yr−1)α, we found strong evidence for a spectrally-similar low-frequency stochastic process of amplitude $A = 3.8^{+6.3}_{-2.5}\times 10^{-15}$ and spectral index α = −0.5 ± 0.5, where the uncertainties represqent 95% credible regions, using information from the auto- and cross-correlation terms between the pulsars in the array. For a spectral index of α = −2/3, as expected from a population of inspiralling supermassive black hole binaries, the recovered amplitude is $A = 2.8^{+1.2}_{-0.8}\times 10^{-15}$. Nonetheless, no significant evidence of the Hellings-Downs correlations that would indicate a gravitational-wave origin was found. We also analyzed the constituent data from the individual pulsar timing arrays in a consistent way, and clearly demonstrate that the combined international data set is more sensitive. Furthermore, we demonstrate that this combined data set produces comparable constraints to recent single-array data sets which have more data than the constituent parts of the combination. Future international data releases will deliver increased sensitivity to gravitational wave radiation, and significantly increase the detection probability.

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“…These scalar-induced gravitational waves (SIGWs) have wide frequency distribution and can be detected by pulsar timing arrays (PTA) [115][116][117][118][119] and the space-based GW detectors such as Laser Interferometer Space Antenna (LISA) [120,121], Taiji [122], TianQin [123] and Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) [124] in the future. For example, the stochastic process with a common amplitude and a common spectral slope across pulsars detected by the North American Nanohertz Observatory for Gravitational Wave (NANOGrav) Collaboration [125] and other pulsar timing arrays [126,127] recently may be the SIGWs with nHz frequencies [51,[128][129][130][131][132].…”

Section: Jcap03(2023)048mentioning

confidence: 99%

Primordial black holes and scalar-induced gravitational waves from the generalized Brans-Dicke theory

Zhu

2023

J. Cosmol. Astropart. Phys.

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The power spectrum of the scalar-tensor inflation with a quadratic form Ricci scalar coupling function Ω(ϕ) = 1 - 2ϕ/ϕ c + (1 + δ 2)(ϕ/ϕ c )2 can be enhanced enough to produce primordial black holes and generate scalar-induced gravitational waves. The masses of primordial black holes and the frequencies of scalar-induced gravitational waves are controlled by the parameter ϕ c , and their amplitudes are determined by the parameter δ. Primordial black holes with stellar masses, planetary masses, and masses around 10-12 M ⊙ are produced and their abundances are obtained from the peak theory. The frequencies of the corresponding scalar-induced gravitational waves are around 10-9 Hz, 10-6 Hz, and 10-3 Hz, respectively. The primordial black holes with masses around 10-12 M ⊙ can account for almost all of the dark matter, and the scalar-induced gravitational waves with frequencies around 10-9 Hz can explain the NANOGrav 12.5 yrs signal.

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Constraints on primordial curvature spectrum from primordial black holes and scalar-induced gravitational waves

Cited by 31 publications

References 157 publications

The NANOGrav 15 yr Data Set: Search for Signals from New Physics

The NANOGrav 15 yr Data Set: Search for Signals from New Physics

The International Pulsar Timing Array second data release: Search for an isotropic gravitational wave background

Primordial black holes and scalar-induced gravitational waves from the generalized Brans-Dicke theory

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