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Related papers: Astrophysical Naturalness

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The Standard Model of cosmology states a surprising composition of the Universe, in which ordinary matter accounts for less than 5%. The remaining 95% are composed of ~70% Dark Energy and ~25% Dark Matter. However, those two components have…

Astrophysics · Physics 2008-11-14 A. Benoit-Lévy , G. Chardin

For the first time, we have a plausible and complete accounting of matter and energy in the Universe. Expressed a fraction of the critical density it goes like this: neutrinos, between 0.3% and 15%; stars, between 0.3% and 0.6%; baryons…

Astrophysics · Physics 2009-10-31 Michael S. Turner

A variation of fundamental constants of physics is proposed in a frame of static universe. It is shown when the velocity of light increases (decreases) the Planck's constant increases (decreases) and mass of bodies decreases (increases).…

Astrophysics · Physics 2007-05-23 V. Jonauskas

Five fundamental scales of mass follow from holographic limitations, a self-similar law for angular momentum and the basic scaling laws for a fractal universe with dimension 2. The five scales correspond to the observable universe,…

General Physics · Physics 2008-05-29 Scott Funkhouser

The matching of our epoch of existence with the approximate equality of dark energy and dark matter energy densities is an apparent further fine-tuning, beyond the already troubling 120 orders of magnitude that separate dark energy from the…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-17 Navin Sivanandam

Our universe has multiple examples of unexplained gravitational losses in black holes and neutron stars. The smallest black holes of about 4 solar masses means the maximum baryon density \rho \approx 10^{17} grams/cm^3. Any collapse of the…

Astrophysics · Physics 2025-05-02 David E. Rosenberg

In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their outstanding macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…

High Energy Astrophysical Phenomena · Physics 2016-09-27 Pierre M. Pizzochero

At present we know nothing about the nature of the dark energy accounting for about 70% of the energy density of the Universe. One possibility is that the dark energy is provided by an extremely light field, the quintessence, rolling down…

High Energy Physics - Phenomenology · Physics 2009-11-07 D. J. H. Chung , L. L. Everett , A. Riotto

We apply the statistical measure of complexity introduced by Lopez-Ruiz, Mancini and Calbet to neutron stars structure. Neutron stars is a classical example where the gravitational field and quantum behavior are combined and produce a…

Solar and Stellar Astrophysics · Physics 2009-10-06 K. Ch. Chatzisavvas , V. P. Psonis , C. P. Panos , Ch. C. Moustakidis

We produce the simple formula for the radius R of a cold body of mass M, (4 pi rho/3)^{1/3} R = I.M^{1/3} / [1+ (M/Mp)^{2/3}], where I is one for white dwarfs with non-relativistic electrons, but depends on the ratio of the total mass to…

Astrophysics · Physics 2007-05-23 D. Lynden-Bell , J. P. O'Dwyer

General properties of neutron stars are briefly reviewed with an emphasis on the indispensability of general relativity in our understanding of these fascinating objects. In Newtonian gravity the pressure within a star merely plays the role…

High Energy Astrophysical Phenomena · Physics 2017-03-02 K. Yavuz Ekşi

In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their amazing macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…

High Energy Astrophysical Phenomena · Physics 2010-01-11 Pierre M. Pizzochero

We describe a MOND-related approach to natural scales of distance and mass, viewing it as a logical step following Planck's modification of the Stoney system of units. The MOND-induced scales are not based on the strength of any physical…

General Physics · Physics 2019-09-16 Piotr Zenczykowski

From a minimum of total energy of celestial bodies, their basic parameters are obtained. The steady-state values of the mass, radius, and temperature of stars and white dwarfs, as well as masses of pulsars are calculated. The luminosity and…

Astrophysics · Physics 2007-05-23 B. V. Vasiliev

The dynamics of our universe is characterised by the density parameters for cosmological constant ($\Omega_V$), nonbaryonic darkmatter($\Omega_{\rm wimp}$), radiation ($\Omega_R$) and baryons ($\Omega_B$). To these parameters -- which…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. Padmanabhan

In the standard cosmological model, the Universe consists mainly of two invisible substances: vacuum energy with constant mass-density rho_v=\Lambda/(8pi G) (where Lambda is a `cosmological constant' originally proposed by Einstein and G is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Matthew G. Walker , Abraham Loeb

Dark energy in the universe is assumed to be vacuum energy. The energy-momentum of vacuum is described by a scale-dependent cosmological constant. The equations of motion imply for the density of matter (dust) the sum of the usual matter…

General Physics · Physics 2008-11-09 Walter Petry

This paper reviews the physics of stars, the type, structure, evolution and stability. Simple thermodynamics and statistical mechanics are used to show the inner working of white dwarf and neutron stars. The major concentration of the paper…

Popular Physics · Physics 2024-03-21 Anuj Chaudhri

The expansion of our Universe is accelerating, due to dark energy. But the nature of dark energy has been a mystery since its discovery at the end of the past century. In Research Highlight https://doi.org/10.1002/ntls.20220003 , Justin…

Instrumentation and Methods for Astrophysics · Physics 2022-03-16 Justin E. Albert , Dmitry Budker , H. R. Sadeghpour

More than sixty years ago Zwicky made the case that the great clusters of galaxies are held together by the gravitational force of unseen (dark) matter. Today, the case is stronger and more precise: Dark, nonbaryonic matter accounts for 30%…

Astrophysics · Physics 2016-11-23 Michael S. Turner