English
Related papers

Related papers: Fluctuation spatial expansion and observational re…

200 papers

We show that the difference between the theoretically expected and measured by WMAP amplitude of the quadrupole fluctuations of CMB can be related to the impact of the anisotropic curvature of the homogeneous universe dominated by the dark…

Astrophysics · Physics 2008-11-26 M. Demiański , A. G. Doroshkevich

In these notes we prepare the ground for a systematic investigation into the issues of black hole fluctuations and backreaction by discussing the formulation of the problem, commenting on possible advantages and shortcomings of existing…

General Relativity and Quantum Cosmology · Physics 2007-05-23 B. L. Hu , Alpan Raval , Sukanya Sinha

We present a general and unified formulation which can handle the classical evolution and quantum generation processes of the cosmological gravitational wave in a broad class of generalized gravity theories. Applications are made in several…

General Relativity and Quantum Cosmology · Physics 2009-10-30 J. Hwang

It is shown that the Hubble constant can be derived from the standard luminosity function of galaxies as well as from a new luminosity function as deduced from the mass-luminosity relationship for galaxies. An analytical expression for the…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-20 Lorenzo Zaninetti

We consider an addition of the term which is a square of the scalar curvature to the Einstein-Hilbert action. Under this generalized action, we attempt to explain i) the flat rotation curves observed in spiral galaxies, which is usually…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. Kenmoku , E. Kitajima , Y. Okamoto , K. Shigemoto

There is a general agreement that galaxy structures exhibit fractal properties, at least up to some small scale. However the presence of an eventual crossover towards homogenization, as well as the exact value of the fractal dimension, are…

Astrophysics · Physics 2016-08-30 Francesco Sylos Labini

In this work we develop a new propagation model for the Galactic cosmic rays based on the GALPROP code, including contributions from dark matter annihilation. The model predicts compatible Galactic diffuse $\gamma$ ray spectra with EGRET…

Astrophysics · Physics 2008-11-26 Xiao-Jun Bi , Juan Zhang , Qiang Yuan

We investigate the dynamics of the perturbations of the inflaton scalar field oscillating around a minimum of its effective potential in an expanding universe. With the assumption of smallness of the ratio of the Hubble parameter to the…

General Relativity and Quantum Cosmology · Physics 2019-01-30 Vladimir A. Koutvitsky , Eugene M. Maslov

Evolution of galaxies is one of the most actual topics in astrophysics. Among the most important factors determining the evolution are two galactic components which are difficult or even impossible to detect optically: the gaseous disks and…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 R. Kipper , E. Tempel , A. Tamm

Local measurements of the Hubble parameter obtained from the distance ladder at low redshift are in tension with global values inferred from cosmological standard rulers. A key role in the tension is played by the assumptions on the…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-12 Enis Belgacem , Tomislav Prokopec

We use a combination of N-body simulations of the hierarchical clustering of dark matter and semi-analytic modelling of the physics of galaxy formation to probe the relationship between the galaxy distribution and the mass distribution. The…

Astrophysics · Physics 2009-10-31 A. J. Benson , C. M. Baugh , S. Cole , C. S. Frenk , C. G. Lacey

To seek for a possible origin of fractal pattern in nature, we perform a molecular dynamics simulation for a fragmentation of an infinite fcc lattice. The fragmentation is induced by the initial condition of the model that the lattice…

Adaptation and Self-Organizing Systems · Physics 2015-06-26 Shinpei Chikazumi , Akira Iwamoto

A generalization of the multiphase chemical evolution model applied to a wide set of theoretical galaxies is shown. This set of models has been computed by using the so-called Universal Rotation Curve from Persic, Salucci & Steel to…

Astrophysics · Physics 2009-11-07 Mercedes Molla , Angeles I. Diaz

The Hubble law, determined from the distance modulii and redshifts of galaxies, for the past 80 years, has been used as strong evidence for an expanding universe. This claim is reviewed in light of the claimed lack of necessary evidence for…

General Physics · Physics 2011-11-22 John G. Hartnett

Redshift drift is the phenomenon whereby the observed redshift between an emitter and observer comoving with the Hubble flow in an expanding FLRW universe will slowly evolve -- on a timescale comparable to the Hubble time. There are…

General Relativity and Quantum Cosmology · Physics 2022-10-04 Francisco S. N. Lobo , Jose Pedro Mimoso , Matt Visser

Fluctuations play a critical role in cosmology. They are relevant across a range of phenomena from the dynamics of inflation to the formation of structure. In many cases, these fluctuations are coarse grained and follow a Gaussian…

High Energy Physics - Theory · Physics 2023-05-10 Timothy Cohen , Daniel Green , Akhil Premkumar

Modified Newtonian equations for gravitational orbits in the expanding universe indicate that local gravitationally bounded systems like galaxies and planetary systems are unaffected by the expansion of the Universe. This result is derived…

General Relativity and Quantum Cosmology · Physics 2023-02-07 Vaclav Vavrycuk

Proceeding from a homogeneous and isotropic Friedmann universe a conceptional problem concerning light propagation in an expanding universe is brought up. As a possible solution of this problem it is suggested that light waves do not scale…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Peter Huber

A quantum expansion parameter, analogous to the Hubble parameter in cosmology, is defined for a free particle quantum wavefunction. By considering the universe as an initial single Gaussian quantum wavepacket whose mass is that of…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-28 A. D. Ernest

We consider a spacetime with empty Schwarzschild-de Sitter exterior and Schwarzschild-de Sitter interior metric for a spherical fluid with constant density. The fluid interior may be taken to represent a galaxy supercluster, for which the…

General Relativity and Quantum Cosmology · Physics 2010-04-29 David Klein , Peter Collas