English
Related papers

Related papers: V/Vmax statistic and Neo-Classic Cosmological Test…

200 papers

In theories in which the cosmological constant Lambda takes a variety of values in different ``subuniverses,'' the probability distribution of its observed values is conditioned by the requirement that there must be someone to measure it.…

Astrophysics · Physics 2009-10-30 Hugo Martel , Paul R. Shapiro , Steven Weinberg

The classical cosmological V/Vm-test is introduced. Use of the differential distribution p(V/Vm) of the V/Vm-variable rather than just the mean <V/Vm> leads directly to the cosmological number density without any need for assumptions about…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-12 Dilip G. Banhatti

We review observational tests for the homogeneity of the Universe on large scales. Redshift and peculiar velocity surveys, radio sources, the X-Ray Background, the Lyman-$\alpha$ forest and the Cosmic Microwave Background are used to set…

Astrophysics · Physics 2007-05-23 Ofer Lahav

The classical cosmological V/Vm-test is introduced and elaborated. Use of the differential distribution p(V/Vm) of the V/Vm-variable rather than just the mean <V/Vm> leads directly to the cosmological number density without any need for…

Cosmology and Nongalactic Astrophysics · Physics 2009-02-09 Dilip G. Banhatti

The value of the cosmological constant arising from a crystalline model for vacuum cosmic space with lattice parameter of the order of the neutron radius [1] has been calculated. The model allows to solve, in an easy way, the problem of the…

We review observational tests for the homogeneity of the Universe on large scales. Redshift and peculiar velocity surveys, radio sources, the X-Ray Background, the Lyman-alpha forest and the Cosmic Microwave Background are used to set…

Astrophysics · Physics 2016-08-30 Ofer Lahav

Using distribution p(V/Vm) of V/Vm rather than just mean <V/Vm> in V/Vm-test leads directly to cosmological number density n(z). Calculation of n(z) from p(V/Vm) is illustrated using best sample (of 76 quasars) available in 1981, when…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-16 Dilip G. Banhatti

The Cosmological Principle states that the Universe is statistically isotropic and homogeneous on large scales. In particular, this implies statistical isotropy in the galaxy distribution, after removal of a dipole anisotropy due to the…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-16 Carlos A. P. Bengaly , Roy Maartens , Nandrianina Randriamiarinarivo , Albert Baloyi

Persistent tensions in the $\Lambda$CDM cosmological model underline the importance of tests of its basic assumptions. One such potential test arises from the fact that the surface of zero expansion around the collapsing object with…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-21 Jan J. Ostrowski , Ismael Delgado Gaspar

We are at a specific period of modern cosmology, during which the large increase of the amount of data leads to the idea that the determination of cosmological parameters has been achieved with a rather good precision. There is a large…

Astrophysics · Physics 2017-08-23 A. Blanchard

Using distribution p(V/Vm) of V/Vm rather than just mean <V/Vm> in V/Vm-test leads directly to cosmological number density n(z). Calculation of n(z) from p(V/Vm) is illustrated using best sample (of 76 quasars) available in 1981, when…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-17 Dilip G. Banhatti

Current and upcoming surveys will measure the cosmological parameters with an extremely high accuracy. The primary goal of these observations is to eliminate some of the currently viable cosmological models created to explain the late time…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Savvas Nesseris , Domenico Sapone

Increasing improvements in the independent determinations of the Hubble constant and the age of the universe now seem to indicate that we need a small non-vanishing cosmological constant to make the two independent observations consistent…

High Energy Physics - Phenomenology · Physics 2009-10-28 Anupam Singh

Cosmological density fields are assumed to be translational and rotational invariant, avoiding any special point or direction, thus satisfying the Copernican Principle. A spatially inhomogeneous matter distribution can be compatible with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Francesco Sylos Labini , Yuri V. Baryshev

The sum of cosmic neutrino masses can be measured cosmologically, as the sub-eV particles behave as `hot' dark matter whose main effect is to suppress the clustering of matter compared to a universe with the same amount of purely cold dark…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-05 Helen Shao , Jahmour J. Givans , Jo Dunkley , Mathew Madhavacheril , Frank Qu , Gerrit Farren , Blake Sherwin

The case for a flat Cold Dark Matter model with a positive cosmological constant $\Lambda$ has been recently strongly advocated by some theoreticians. In this paper we give the observers point of view to the light of the most recent…

Astrophysics · Physics 2007-05-23 B. Fort , Y. Mellier

We discuss the relic density of the lightest of the supersymmetric particles in view of new cosmological data, which favour the concept of an accelerating Universe with a non-vanishing cosmological constant. Recent astrophysical…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. B. Lahanas , D. V. Nanopoulos , V. C. Spanos

A sample of 20 powerful extended radio galaxies with redshifts between zero and two were used to determine constraints on global cosmological parameters. Data for six radio sources were obtained from the VLA archive, analyzed, and combined…

Astrophysics · Physics 2015-06-24 Erick J. Guerra , Ruth A. Daly , Lin Wan

We discuss a new method which is potentially capable of constraining cosmological parameters using observations of giant luminous arcs in rich X-ray clusters of galaxies. The mass profile and the mass normalization of the lenses are…

Astrophysics · Physics 2009-11-10 M. Sereno , G. Longo

A sample of 20 powerful extended radio galaxies with redshifts between zero and two were used to determine constraints on global cosmological parameters. Data for six radio sources were obtained from the VLA archive, analyzed, and combined…

Astrophysics · Physics 2009-10-31 E. J. Guerra , Ruth A. Daly , Lin Wan
‹ Prev 1 2 3 10 Next ›