Primordial black holes from a curvaton scenario with strongly non-Gaussian perturbations

Gow, Andrew; Miranda, Tays; Nurmi, Sami

doi:10.1088/1475-7516/2023/11/006

Cited by 7 publications

(3 citation statements)

References 97 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[123], with implications for PBH formation analyzed in refs. [58,102,129]. As we will see, the standard curvaton model with only a quadratic potential cannot produce sufficient non-Gaussianity to generate a non-negligible abundance of SMBHs without violating spectral distortions constraints.…”

Section: Jcap04(2024)021mentioning

confidence: 82%

“…15 In figure 3, we show the shape of this class of probability distributions for various choices of n. As expected, we see that smaller n gives rise to heavier tails. This raises the question of how small n must be in order to efficiently form primordial SMBHs while keeping the 13 As noted in [102], large curvature perturbations in models with heavy-tailed distributions are often type II.…”

Section: Jcap04(2024)021 4 Departures From Gaussianitymentioning

confidence: 99%

See 1 more Smart Citation

Supermassive primordial black holes from inflation

Hooper,

Ireland,

Krnjaic

et al. 2024

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

There is controversy surrounding the origin and evolution of our universe's largest supermassive black holes (SMBHs). In this study, we consider the possibility that some of these black holes formed from the direct collapse of primordial density perturbations. Since the mass of a primordial black hole is limited by the size of the cosmological horizon at the time of collapse, these SMBHs must form rather late, and are naively in conflict with constraints from CMB spectral distortions. These limits can be avoided, however, if the distribution of primordial curvature perturbations is highly non-Gaussian. After quantifying the departure from Gaussianity needed to evade these bounds, we explore a model of multi-field inflation — a non-minimal, self-interacting curvaton model — which has all the necessary ingredients to yield such dramatic non-Gaussianities. We leave the detailed model building and numerics to a future study, however, as our goal is to highlight the challenges associated with forming SMBHs from direct collapse and to identify features that a successful model would need to have. This study is particularly timely in light of recent observations of high-redshift massive galaxy candidates by the James Webb Space Telescope as well as evidence from the NANOGrav experiment for a stochastic gravitational wave background consistent with SMBH mergers.

show abstract

Section: Jcap04(2024)021mentioning

confidence: 82%

Section: Jcap04(2024)021 4 Departures From Gaussianitymentioning

confidence: 99%

Supermassive primordial black holes from inflation

Hooper,

Ireland,

Krnjaic

et al. 2024

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

show abstract

“…Furthermore, mechanisms involving a spectator field have been extensively explored as promising alternatives to mitigate the fine-tuning required for PBH production [77][78][79][80][81][82][83][84]. Although the spectator field does not drive inflation, it evolves independently and significantly influences the formation of structures and phenomena, including PBHs.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms for Producing Primordial Black Holes from Inflationary Models beyond Fine-Tuning

Stamou

2024

Universe

View full text Add to dashboard Cite

In this study, we present an analysis of the fine-tuning required in various inflationary models in order to explain the production of Primordial Black Holes (PBHs). We specifically examine the degree of fine-tuning necessary in two prominent single-field inflationary models: those with an inflection point and those with step-like features in the potential. Our findings indicate that models with step-like features generally require less fine-tuning compared to those with an inflection point, making them more viable for consistent PBH production. An interesting outcome of these models is that, in addition to improved fine-tuning, they may also predict low-frequency signals that can be detected by pulsar timing array (PTA) collaborations. Additionally, we extend our analysis to multifield inflationary models to assess whether the integration of additional fields can further alleviate the fine-tuning demands. The study also explores the role of a spectator field and its impact on the fine-tuning process. Our results indicate that although mechanisms involving a spectator field can circumvent the issue of fine-tuning parameters for PBH production, both multifield models and models with step-like features present promising alternatives. While fine-tuning involves multiple considerations, our primary objective is to evaluate various inflationary models to identify the one that most naturally explains the formation of PBHs. Hence, this study introduces a novel approach by categorizing existing PBH mechanisms, paving the way for subsequent research to prioritize models that minimize the need for extensive fine-tuning.

show abstract

Realisation of the ultra-slow roll phase in Galileon inflation and PBH overproduction

Choudhury,

Karde,

Panda

et al. 2024

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

We demonstrate the explicit realisation of the ultra-slow roll phase in the framework of the effective field theory of single-field Galileon inflation. The pulsar timing array (PTA) collaboration hints at the scalar-induced gravity waves (SIGW) from the early universe as an explanation for the origin of the observed signal, which, however, leads to an enhancement in the amplitude of the scalar power spectrum giving rise to the overproduction of primordial black holes (PBHs). In the setup under consideration, we examine the generation of SIGW consistent with PTA (NANOGrav15 and EPTA) data, in addition to which we also consider the impact from QCD crossover at the nHz frequencies and address the PBH overproduction issue assuming linear approximations for the over-density without incorporating non-Gaussian effects from the comoving curvature perturbation. The framework is shown to give rise to SIGWs well consistent with the PTA signal with comfortable PBH abundance, 10-3 ≲ fPBH < 1, of near solar-mass black holes.

show abstract

Primordial black holes from a curvaton scenario with strongly non-Gaussian perturbations

Cited by 7 publications

References 97 publications

Supermassive primordial black holes from inflation

Supermassive primordial black holes from inflation

Mechanisms for Producing Primordial Black Holes from Inflationary Models beyond Fine-Tuning

Realisation of the ultra-slow roll phase in Galileon inflation and PBH overproduction

Contact Info

Product

Resources

About