scholarly journals Are stellar-mass binary black hole mergers isotropically distributed?

2020 ◽  
Vol 501 (1) ◽  
pp. 970-977
Author(s):  
Richard Stiskalek ◽  
John Veitch ◽  
Chris Messenger
Keyword(s):  
Black Hole ◽  
Probability Distribution ◽  
Cosmological Model ◽  
Bayesian Model ◽  
Bayes Factor ◽  
Selection Function ◽  
Anisotropic Model ◽  
Isotropic Model ◽  
Binary Black Hole ◽  
The Universe

ABSTRACT The Advanced LIGO and Advanced Virgo gravitational wave detectors have detected a population of binary black hole mergers in their first two observing runs. For each of these events, we have been able to associate a potential sky location region represented as a probability distribution on the sky. Thus, at this point we may begin to ask the question of whether this distribution agrees with the isotropic model of the Universe, or if there is any evidence of anisotropy. We perform Bayesian model selection between an isotropic and a simple anisotropic model, taking into account the anisotropic selection function caused by the underlying antenna patterns and sensitivity of the interferometers over the sidereal day. We find an inconclusive Bayes factor of 1.3: 1, suggesting that the data from the first two observing runs are insufficient to pick a preferred model. However, the first detections were mostly poorly localized in the sky (before the Advanced Virgo joined the network), spanning large portions of the sky and hampering detection of potential anisotropy. It will be appropriate to repeat this analysis with events from the recent third LIGO observational run and a more sophisticated cosmological model.

scholarly journals GENESIS AND BLACK HOLE UNIVERSE: THE SECOND DAY

2020 ◽  
Vol 4 (7) ◽  
pp. 5-19
Author(s):  
Tianxi ZHANG ◽  
Keyword(s):  
Black Hole ◽  
Cosmological Model ◽  
Big Bang ◽  
Universe Model ◽  
Event Horizons ◽  
Space And Time ◽  
Entire Universe ◽  
The Creation ◽  
Book Of Genesis ◽  
The Universe

The biblical cosmology is apparently neither consistent with objections of the universe nor able to be fully addressed, described, and understood by the standard big bang cosmological model. Recently, the author has found that his newly well-developed black hole universe model does not have to reject or exclude the creation of the entire universe, the infinite grand universe, and can further provide an innovative interpretation of the book of Genesis. In Paper-I, the author has fully addressed the first day of Genesis according to the black hole universe model. In this paper (as Paper-II), he will further interpret the second day of Genesis. God created the entire universe with matter and light, space and time, forces and motion in the first day, while in the second day God structured the entire universe by separating the matter and space with layers and further formed our finite black hole universe. From the infinite entire universe to our finite black hole universe, there are infinite layers, whose boundaries are called as event horizons in physics or vaults in the book of Genesis. This effort attempts to bridge the gap between Genesis and observations of the universe and to bring a better understanding and wider acceptance to the Genesis.

On the Origin of Four Pi in Physics

2016 ◽  
pp. 3994-4013
Author(s):  
Aaron Hanken
Keyword(s):  
Black Hole ◽  
Surface Area ◽  
Single Particles ◽  
Pythagorean Triples ◽  
Free Particles ◽  
Close Relationship ◽  
Dimensional Parameters ◽  
Gaussian Surface ◽  
Planck Energy ◽  
The Universe

We find the highest symmetry between the fields intrinsic to free particles (free particles having only mass, charge and spin), and show these fields symmetries and their close relationship to force and entropy. The Boltzmann Constant is equal to the natural entropy, in that it is The Planck Energy over The Planck Temperature. This completes a needed symmetry in The Bekenstein-Hawking Entropy. Upon substitution of Planck Units into The Schwarzschild Radius, we find that the mass and radius of any black hole define both the gravitational constant and the natural force. We find that the Gaussian Surface area about a particle is equal to the surface area of an equally massed black hole if we define the gravitational field of that particle to be the quotient of The Planck Force and the particles mass. By these simple substitutions we find that gravity is quantized in units of surface entropy. We also find Pythagorean Triples are resting within the dimensional parameters of Special Relativity, and show this to be the dimensional aspects of single particles observing one another, coupled with the intrinsic Hubble nature of the universe.

Black Hole Universe: a grand cosmic recycler and Big Bang generator?

2019 ◽  
Author(s):  
Matheus Pereira Lobo
Keyword(s):  
Black Hole ◽  
Big Bang ◽  
Subsequent Increase ◽  
Expansion Of The Universe ◽  
The Universe

We propose the discussion of a highly speculative idea for the scenario where black hole collisions and their subsequent increase in sizes exceed the expansion of the universe.

Cosmological spacetimes

2018 ◽  
Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan
Keyword(s):  
Cosmological Model ◽  
Large Scale ◽  
Cosmic Time ◽  
De Sitter ◽  
Matter Distribution ◽  
Observable Universe ◽  
Cosmological Principle ◽  
Riemannian Spacetime ◽  
The Universe ◽  
Copernican Principle

This chapter provides a few examples of representations of the universe on a large scale—a first step in constructing a cosmological model. It first discusses the Copernican principle, which is an approximation/hypothesis about the matter distribution in the observable universe. The chapter then turns to the cosmological principle—a hypothesis about the geometry of the Riemannian spacetime representing the universe, which is assumed to be foliated by 3-spaces labeled by a cosmic time t which are homogeneous and isotropic, that is, ‘maximally symmetric’. After a discussion on maximally symmetric space, this chapter considers spacetimes with homogenous and isotropic sections. Finally, this chapter discusses Milne and de Sitter spacetimes.

scholarly journals Mixed fluid cosmological model in f(R, T) gravity

2020 ◽  
Vol 98 (11) ◽  
pp. 1015-1022 ◽  
Author(s):  
Parbati Sahoo ◽  
Barkha Taori ◽  
K.L. Mahanta
Keyword(s):  
Cosmological Model ◽  
Bianchi Type ◽  
Type I ◽  
Time Varying ◽  
Eos Parameter ◽  
Barotropic Fluid ◽  
Rotationally Symmetric ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Mixed Fluid

We construct a locally rotationally symmetric (LRS) Bianchi type-I cosmological model in f(R, T) theory of gravity when the source of gravitation is a mixture of barotropic fluid and dark energy (DE) by employing a time-varying deceleration parameter. We observe through the behavior of the state finder parameters (r, s) that our model begins from the Einstein static era and goes to ΛCDM era. The equation of state (EOS) parameter (ωd) for DE varies from the phantom (ω < –1) phase to quintessence (ω > –1) phase, which is consistent with observational results. It is found that the discussed model can reproduce the current accelerating phase of the expansion of the universe.

scholarly journals Optimization of model independent gravitational wave search for binary black hole mergers using machine learning

2021 ◽  
Vol 104 (2) ◽  
Author(s):  
T. Mishra ◽  
B. O’Brien ◽  
V. Gayathri ◽  
M. Szczepańczyk ◽  
S. Bhaumik ◽  
...  
Keyword(s):  
Machine Learning ◽  
Black Hole ◽  
Gravitational Wave ◽  
Binary Black Hole ◽  
Model Independent

scholarly journals Binary black hole spectroscopy: A no-hair test of GW190814 and GW190412

2020 ◽  
Vol 102 (12) ◽  
Author(s):  
Collin D. Capano ◽  
Alexander H. Nitz
Keyword(s):  
Black Hole ◽  
Binary Black Hole

scholarly journals Binary black hole mergers from LIGO/Virgo O1 and O2: Population inference combining confident and marginal events

2020 ◽  
Vol 102 (12) ◽  
Author(s):  
Javier Roulet ◽  
Tejaswi Venumadhav ◽  
Barak Zackay ◽  
Liang Dai ◽  
Matias Zaldarriaga
Keyword(s):  
Black Hole ◽  
Binary Black Hole ◽  
Population Inference
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