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We use direct $N$-body calculations to investigate the impact of primordial mass segregation on the size scale and mass-loss rate of star clusters in a galactic tidal field. We run a set of simulations of clusters with varying degrees of…

Astrophysics of Galaxies · Physics 2015-06-22 Hosein Haghi , Seyed Mohammad Hoseini-Rad , Akram Hasani Zonoozi , Andreas H. W. Kuepper

In this letter, combining peak theory and the numerical analysis of gravitational collapse in the radiation dominated era, we show that the abundance of primordial blacks holes, generated by an enhancement in the inflationary power…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-16 Cristiano Germani , Ilia Musco

This work considers the idea of massive black holes being the constituents of the Galactic dark matter halo. It constrains the maximum black hole mass to $\mbh \sil 5 \times 10^4 \msun$ by examining their influence on the population of…

Astrophysics · Physics 2015-06-24 Ralf Klessen , Andreas Burkert

The perturbations in the early universe are generated as a result of the interplay between quantum field theory and gravitation. Since these primordial perturbations lead to the anisotropies in the cosmic microwave background and eventually…

General Relativity and Quantum Cosmology · Physics 2021-07-29 D. Jaffino Stargen , V. Sreenath , L. Sriramkumar

Small distortions in the images of Einstein rings or giant arcs offer the exciting prospect of detecting dark matter haloes or subhaloes of mass below $10^9$M$_{\odot}$, most of which are too small to have made a visible galaxy. A very…

Astrophysics of Galaxies · Physics 2018-08-29 Qiuhan He , Ran Li , Sungsoon Lim , Carlos S. Frenk , Shaun Cole , Eric W. Peng , Qiao Wang

Many cosmological phenomena lead to the production of primordial black holes in the early Universe. These phenomena often create a population of black holes with extended mass and spin distributions. As these black holes evaporate via…

High Energy Physics - Phenomenology · Physics 2025-01-10 Andrew Cheek , Lucien Heurtier , Yuber F. Perez-Gonzalez , Jessica Turner

In this review, we describe our current understanding of cluster formation: from the general picture of collapse from initial density fluctuations in an expanding Universe to detailed simulations of cluster formation including the effects…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Andrey Kravtsov , Stefano Borgani

We consider the effect of quantum diffusion on the dynamics of the inflaton during a period of ultra-slow-roll inflation. We extend the stochastic-$\delta\mathcal{N}$ formalism to the ultra-slow-roll regime and show how this system can be…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-11 Chris Pattison , Vincent Vennin , David Wands , Hooshyar Assadullahi

Atomic cooling haloes with virial temperatures $\rm T_{vir} \geq 10^{4}$ K are the most plausible sites for the formation of the first galaxies and the first intermediate mass black holes. It is therefore important to assess whether one can…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 M. A. Latif , D. R. G. Schleicher , W. Schmidt , J. Niemeyer

Primordial black holes may arise through ultra slow-roll inflation. In this work we study a toy model of ultra slow-roll inflation with a shallow dip. The ultra slow-roll stage enhances the curvature perturbations and thus the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-02 Bao-Min Gu , Fu-Wen Shu , Ke Yang

High-redshift quasars ($z\gtrsim6$), powered by black holes (BHs) with large inferred masses, imply rapid BH growth in the early Universe. The most extreme examples have inferred masses of $\sim \! 10^9\,$M$_\odot$ at $z = 7.5$ and $\sim \!…

Astrophysics of Galaxies · Physics 2023-11-09 Jake S. Bennett , Debora Sijacki , Tiago Costa , Nicolas Laporte , Callum Witten

N-body simulations and analytical calculations of the gravitational collapse in an expanding universe predict that halos should form with a diverging inner density profile, the cusp. There are some observational indications that the dark…

Astrophysics · Physics 2009-11-06 Amr El-Zant , Isaac Shlosman , Yehuda Hoffman

We consider the presence and evolution of primordial density perturbations in a cosmological model based on a simple ansatz which captures -- by providing a set of effective gravitational field equations -- the strength of the enhanced…

General Relativity and Quantum Cosmology · Physics 2014-11-21 N. C. Tsamis , R. P. Woodard

Primordial black hole (PBH) mergers have been proposed as an explanation for the gravitational wave events detected by the LIGO collaboration. Such PBHs may be formed in the early Universe as a result of the collapse of extremely rare…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-20 Tomohiro Nakama , Joseph Silk , Marc Kamionkowski

Primordial black holes (PBHs) whose masses are in $\sim[10^{-15}M_\odot,10^{-11}M_{\odot}]$ have been extensively studied as a candidate of whole dark matter (DM). One of the probes to test such a PBH-DM scenario is scalar-induced…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Katsuya T. Abe , Ryoto Inui , Yuichiro Tada , Shuichiro Yokoyama

In this paper, we show how the structure of the landscape potential of the primordial Universe may be probed through the properties of the primordial density perturbations responsible for the origin of the cosmic microwave background…

High Energy Physics - Theory · Physics 2019-09-25 Xingang Chen , Gonzalo A. Palma , Walter Riquelme , Bruno Scheihing Hitschfeld , Spyros Sypsas

In this article we provide a new closed relationship between cosmic abundance of primordial gravitational waves and primordial blackholes originated from initial inflationary perturbations for inflection-point models of inflation where…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-19 Sayantan Choudhury , Anupam Mazumdar

The non-Gaussian distribution of primordial perturbations has the potential to reveal the physical processes at work in the very early Universe. Local models provide a well-defined class of non-Gaussian distributions that arise naturally…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 David Wands

The conservation law for the angular momentum in curved spacetime, consistent with relativistic quantum mechanics, requires that the antisymmetric part of the affine connection (torsion tensor) is a variable in the principle of least…

General Relativity and Quantum Cosmology · Physics 2026-05-28 Nikodem Popławski

When density fluctuations collapse gravitationally out of the expanding cosmological background universe to form galaxies, the secondary energy release which results can affect their subsequent evolution profoundly. We focus here on the…

Astrophysics · Physics 2007-05-23 Hugo Martel , Paul R. Shapiro
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