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For primordial black holes (PBH) to be the dark matter in single-field inflation, the slow-roll approximation must be violated by at least ${\cal O}(1)$ in order to enhance the curvature power spectrum within the required number of efolds…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-08 Hayato Motohashi , Wayne Hu

Primordial black holes (PBHs) cannot be produced abundantly enough to be the dark matter in canonical single-field inflation under slow roll. This conclusion is robust to local non-Gaussian correlations between long- and short-wavelength…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Samuel Passaglia , Wayne Hu , Hayato Motohashi

We study inflation in a recently proposed gravitational effective field theory describing the trace anomaly. The theory requires an additional scalar which is massless in the early universe. This scalar -- referenced as an anomalyon --…

High Energy Physics - Theory · Physics 2025-03-17 Gregory Gabadadze , David N. Spergel , Giorgi Tukhashvili

In this work, we investigate the generation of primordial black holes (PBHs) within the framework of single-field inflationary models and their compatibility with the cosmological history of the Universe. Our results suggest that, depending…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-30 Sasha Allegrini , Loris Del Grosso , Antonio J. Iovino , Alfredo Urbano

Recent numerical evidence suggests that a mass spectrum of primordial black holes (PBHs) is produced as a consequence of near critical gravitational collapse. Assuming that these holes formed from the initial density perturbations seeded by…

Astrophysics · Physics 2016-08-25 Graham D. Kribs , Adam K. Leibovich , I. Z. Rothstein

We study the dynamics of a spectator Higgs field which stochastically evolves during inflation onto near-critical trajectories on the edge of a runaway instability. We show that its fluctuations do not produce primordial black holes (PBHs)…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-24 Samuel Passaglia , Wayne Hu , Hayato Motohashi

Primordial Black Holes (PBHs) might have formed in the early Universe as a consequence of the collapse of density fluctuations with an amplitude above a critical value $\delta_{c}$: the formation threshold. Although for a…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-12 J. L. G. Sobrinho , P. Augusto , A. L. Gonçalves

Primordial black holes (PBHs) are theoretical black holes which may be formed during the radiation dominant era and, basically, caused by the gravitational collapse of radiational overdensities. It has been well known that in the context of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-26 Yuichiro Tada , Shuichiro Yokoyama

We study Primordial Black Holes (PBHs) formed by the collapse of rare primordial fluctuations during an early period of Matter Domination. The collapse threshold strongly depends on the shape of the peaks, decreasing as they become flatter…

General Relativity and Quantum Cosmology · Physics 2026-03-26 Ehsan Ebrahimian , Ali Akbar Abolhasani , Mehrdad Mirbabayi

As potential candidates of dark matter, primordial black holes (PBHs) are within the core scopes of various astronomical observations. In light of the explosive development of gravitational wave (GW) and radio astronomy, we thoroughly…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-23 Yi-Fu Cai , Chao Chen , Xi Tong , Dong-Gang Wang , Sheng-Feng Yan

We investigate the production of primordial black holes and their contribution to the presently observed dark matter in a dilaton two-field extension of Starobinsky's quadratic $f(R)$ model of inflation. The model features a multi-field…

High Energy Physics - Theory · Physics 2021-04-28 Anirudh Gundhi , Sergei V. Ketov , Christian F. Steinwachs

We propose a unified framework where the totality of dark matter (DM), the baryon asymmetry of the universe, and a detectable stochastic gravitational wave (GW) background originate from ultra-slow-roll (USR) inflation. The drastic…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-13 Shyam Balaji

Primordial black holes (PBHs) can form in the early Universe via the collapse of large density perturbations. There are tight constraints on the abundance of PBHs formed due to their gravitational effects and the consequences of their…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-30 Amandeep S. Josan , Anne M. Green , Karim A. Malik

Recently we have proposed a novel method to probe primordial gravitational waves from upper bounds on the abundance of primordial black holes (PBHs). When the amplitude of primordial tensor perturbations generated in the early Universe is…

General Relativity and Quantum Cosmology · Physics 2016-08-18 Tomohiro Nakama , Teruaki Suyama

We study the formation of primordial black holes (PBH) with ultra-slow-roll inflation when stochastic effects are important. We use the $\Delta N$ formalism and simplify the stochastic equations with an analytical constant-roll…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-19 Sami Raatikainen , Syksy Rasanen , Eemeli Tomberg

Scalar field with generalized kinetic interactions metamorphoses depending on its field value, ranging from cosmological constant to stiff matter. We show that such a scalar field can give rise to temporal enhancement of the curvature…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-20 Teruaki Suyama , Yi-Peng Wu , Jun'ichi Yokoyama

Post-inflationary reheating phase is usually said to be solely governed by the decay of coherently oscillating inflaton into radiation. In this submission, we explore a new avenue toward reheating through the evaporation of primordial black…

High Energy Physics - Phenomenology · Physics 2023-05-19 Md Riajul Haque , Essodjolo Kpatcha , Debaprasad Maity , Yann Mambrini

We investigate the formation of large peaks in the inflationary curvature power spectrum from double-well potentials. In such scenarios, the initial CMB spectrum is created at large field values. Subsequently, the inflaton will cross one of…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-06 Alexandros Karam , Niko Koivunen , Eemeli Tomberg , Antonio Racioppi , Hardi Veermäe

While there exist various candidates, the identification of dark matter remains unresolved. Recently it was argued that the generalized uncertainty principle (GUP) may prevent a black hole from evaporating completely, and as a result there…

Astrophysics · Physics 2009-11-10 Pisin Chen

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
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