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Related papers: On cosmic natural selection

200 papers

The purpose of this paper is to propose an extension to Lee Smolin's hypothesis that our own universe belongs to a population of universes evolving by natural selection. Smolin's hypothesis explains why the parameters of physics possess the…

General Relativity and Quantum Cosmology · Physics 2009-08-31 Gordon McCabe

We investigate the pair creation of noncommutative black holes in a background with positive cosmological constant. As a first step we derive the noncommutative geometry inspired Schwarzschild deSitter solution. By varying the mass and the…

General Relativity and Quantum Cosmology · Physics 2011-09-14 Robert B. Mann , Piero Nicolini

The exact solutions of electrically charged phantom black holes with the cosmological constant are constructed. They are labelled by the mass, the electrical charge, the cosmological constant and the coupling constant between the phantom…

High Energy Physics - Theory · Physics 2007-05-23 C. J. Gao , S. N. Zhang

New and rather controversial observations hint that the fine structure constant \alpha may have been smaller in the early universe, suggesting that some of the fundamental ``constants'' of physics may be dynamical. In a recent paper,…

High Energy Physics - Theory · Physics 2010-04-28 S. Carlip , S. Vaidya

Here it is shown that the variation in the fine structure constant measured by Webb et al. matches the theoretically derived value for the maximum variation in the electronic charge permitted by the Generalized Second Law of Thermodynamics…

Astrophysics · Physics 2007-05-23 Jane H MacGibbon

It is shown that in the instanton approximation the rate of creation of black holes is always enhanced by a factor of the exponential of the black hole entropy relative to the rate of creation of compact matter distributions (stars). This…

General Relativity and Quantum Cosmology · Physics 2009-10-22 J. David Brown

We present a new model for the formation of black holes in cosmological simulations, motivated by the first star formation. Black holes form from high density peaks of primordial gas, and grow via both gas accretion and mergers. Massive…

Astrophysics of Galaxies · Physics 2015-06-19 Philip Taylor , Chiaki Kobayashi

We investigate the pair creation of magnetically charged black holes on a cosmic string in the presence of a background magnetic field. The string may either break or fray to produce a pair of accelerating black holes described by Ernst…

High Energy Physics - Theory · Physics 2021-03-24 Amjad Ashoorioon , Mohammad Bagher Jahani Poshteh

In this paper we follow a new approach for particle creation by a localized strong gravitational field. The approach is based on a definition of the physical vacuum drawn from Heisenberg uncertainty principle. Using the fact that the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. B. Altaie

The mass function of primordial black holes created through the near-critical gravitational collapse is calculated in a manner fairly independent of the statistical distribution of underlying density fluctuation, assuming that it has a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jun'ichi Yokoyama

We address the issue why a cosmological constant (dark energy) possesses a small positive value instead of being zero. Motivated by the cosmic landscape picture, we mimic the dark energy by a scalar field with potential wells and show that…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-06 Claus Kiefer , Friedemann Queisser , Alexei A. Starobinsky

The probability for quantum creation of an inflationary universe with a pair of black holes is computed in a modified gravitational theory. Considering a gravitational action which includes a cosmological constant ($\Lambda$) in addition to…

High Energy Physics - Theory · Physics 2008-11-26 B. C. Paul , Dilip Paul

An artificial scale of observable cosmological constant is dynamically related to its natural bare value due to an installation of relevant coherent state for the inflationary field in a finite volume of early Universe, because of…

General Relativity and Quantum Cosmology · Physics 2014-01-15 V. V. Kiselev

The effective coupling `constants' of physics, especially the cosmological constant, are observed to have highly biophilic values. If this is not a hugely improbable accident, or a consequence of some mysterious logical necessity or of some…

High Energy Physics - Theory · Physics 2011-01-31 Don N. Page

The small or zero cosmological constant, $\Lambda$, probably results from a macroscopic cancellation mechanism of the zero-point energies. However, nearby horizon surfaces any macroscopic mechanism is expected to result in imperfect…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Maurice H. P. M. van Putten

In a recent propposal, the cosmological constant has been considered as as a new thermodynamical variable and its change is related to the radiation produced by black holes. Using this consideration and by modelling the primordial black…

General Relativity and Quantum Cosmology · Physics 2009-06-26 Alexis Larranaga , J. M. Tejeiro

We propose a connection between the butterfly velocity and the complexity growth rate in the context of thermodynamics of black holes where the cosmological constant is interpreted as thermodynamic pressure. According to the Smarr formula…

High Energy Physics - Theory · Physics 2020-07-09 Seyed Ali Hosseini Mansoori , Mohammad M. Qaemmaqami

A C-metric type solution for general relativity with cosmological constant is presented in 2+1 dimensions. It is interpreted as a three-dimensional black hole accelerated by a strut. Positive values of the cosmological constant are…

General Relativity and Quantum Cosmology · Physics 2011-02-22 Marco Astorino

Primordial black holes are considered to be pair created quantum-mechanically during inflation. In the context of General Relativity (GR), it has been shown that the pair creation rate is exponentially decreasing during inflation.…

General Relativity and Quantum Cosmology · Physics 2018-06-27 Konstantinos F. Dialektopoulos , Antonios Nathanail , Athanasios G. Tzikas

According to a variant of the hoop conjecture, if we localize two particles within the Schwarzschild radius corresponding to their center of mass energy, then a black hole will form. Despite a large body of work on the formation of…

General Relativity and Quantum Cosmology · Physics 2018-06-01 Anshul Saini , Dejan Stojkovic