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In this study, we investigate the formation of primordial black holes (PBHs) in a scalar field inflationary model coupled to the Gauss-Bonnet (GB) term with fractional power-law potentials. The coupling function enhances the curvature…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-16 Ali Ashrafzadeh , Kayoomars Karami

The production of primordial black hole (PBH) dark matter (DM) and the generation of scalar induced secondary gravitational waves by using the enhancement mechanism with a peak function in the non-canonical kinetic term in natural inflation…

General Relativity and Quantum Cosmology · Physics 2022-05-10 Qing Gao , Yungui Gong , Zhu Yi

Primordial black holes (PBHs) generated by gravitational collapse of large primordial overdensities can be a fraction of the observed dark matter. In this paper, we introduce a mechanism to produce a large peak in the primordial power…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-11 Matteo Braglia , Dhiraj Kumar Hazra , Fabio Finelli , George F. Smoot , L. Sriramkumar , Alexei A. Starobinsky

[Abridged] The primordial scalar power spectrum is well constrained on large scales, primarily by the observations of the anisotropies in the cosmic microwave background (CMB). Over the last few years, it has been recognized that a sharp…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 H. V. Ragavendra , Pankaj Saha , L. Sriramkumar , Joseph Silk

A standard scenario to form primordial black holes in the early universe is based on a phase of ultra-slow-roll in single-field inflation when the amplitude of the short scale modes is enhanced compared to the CMB plateau. Based on general…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-03 Antonio Riotto

The observational data of primordial black holes and scalar-induced gravitational waves can constrain the primordial curvature perturbation at small scales. We parameterize the primordial curvature perturbation by a broken power law form…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-31 Zhu Yi , Qin Fei

Cosmological $\alpha$-attractors stand out as particularly compelling models to describe inflation in the very early universe, naturally meeting tight observational bounds from cosmic microwave background (CMB) experiments. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Laura Iacconi , Hooshyar Assadullahi , Matteo Fasiello , David Wands

We consider the mixed inflaton-curvaton scenario in which quantum fluctuations of the curvaton field during inflation lead to a relatively large curvature perturbation spectrum at small scales. We use the model of chaotic inflation with…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-22 Edgar Bugaev , Peter Klimai

We present new single field inflationary scenarios that produce the critical abundance of primordial black holes as dark matter reconstructing the inflaton potential from an input power spectrum. The method is exact in the slow roll…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-11 Gabriele Autieri , Michele Redi

The primordial black hole (PBH) productions from the inflationary potential with an inflection point usually rely heavily on the fine-tuning of the model parameters. We propose in this work a new kind of the $\alpha$-attractor inflation…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-09 Chengjie Fu , Shao-Jiang Wang

In the curvaton scenario, the curvature perturbation is generated after inflation at the curvaton decay, which may have a prominent non-Gaussian effect. For a model with a non-trivial kinetic term, an enhanced curvature perturbation on a…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-22 Shi Pi , Misao Sasaki

We present a detailed exposition on the prospects of the formation of Primordial Black Holes (PBHs) during Slow Roll (SR) to Ultra Slow Roll (USR) sharp transitions in the framework of single-field inflation. We use an effective field…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-15 Sayantan Choudhury , Sudhakar Panda , M. Sami

As a candidate bound for the Binary Black Hole (BBH) merger events detected by LIGO/Virgo, Primordial Black Holes (PBHs) provide a useful tool to investigate the primordial curvature perturbations on small scales. Using the GWTC-1 to GWTC-3…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-16 Xinpeng Wang , Ying-li Zhang , Rampei Kimura , Masahide Yamaguchi

Within canonical single field inflation models, we provide a method to reverse engineer and reconstruct the inflaton potential from a given power spectrum. This is not only a useful tool to find a potential from observational constraints,…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-18 Mark P. Hertzberg , Masaki Yamada

Inflationary models predicting a scale-dependent large amplification of the density perturbations have recently attracted a lot of attention because the amplified perturbations can seed a sizable amount of primordial black holes (PBHs) and…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Keisuke Inomata , Matteo Braglia , Xingang Chen , Sébastien Renaux-Petel

We discuss the possibility of producing a significant fraction of dark matter in the form of primordial black holes in the context of the pre-big bang inflationary scenario. We take into account, to this purpose, the enhancement of…

General Relativity and Quantum Cosmology · Physics 2020-08-19 P. Conzinu , M. Gasperini , G. Marozzi

Primordial black holes (PBHs) can be both candidates of dark matter and progenitors of binary black holes (BBHs) detected by the LIGO-Virgo-KAGRA collaboration. Since PBHs could form in the very early Universe through the gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 Li-Ming Zheng , Zhengxiang Li , Zu-Cheng Chen , Huan Zhou , Zong-Hong Zhu

We present a single-field string inflationary model which allows for the generation of primordial black holes in the low mass region where they can account for a significant fraction of the dark matter abundance. The potential is typical of…

High Energy Physics - Theory · Physics 2018-07-04 Michele Cicoli , Victor A. Diaz , Francisco G. Pedro

Primordial black holes as dark matter may be generated in single-field models of inflation thanks to the enhancement at small scales of the comoving curvature perturbation. This mechanism requires leaving the slow-roll phase to enter a…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-26 Matteo Biagetti , Gabriele Franciolini , Alex Kehagias , Antonio Riotto

We calculate the primordial black hole (PBH) mass spectrum produced from a collapse of the primordial density fluctuations in the early Universe using, as an input, several theoretical models giving the curvature perturbation power spectra…

Astrophysics · Physics 2009-07-30 Edgar Bugaev , Peter Klimai