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The Cosmological Constant and Dark Energy
- P. Peebles, Bharat Ratra
- Physics
- 16 July 2002
Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda: nowadays the concept is termed dark energy or…
Cosmology with a Time Variable Cosmological Constant
- P. Peebles, Bharat Ratra
- Physics
- 1 February 1988
Description d'une cosmologie basee sur une constante cosmologique Λ decroissante avec le temps quand l'energie potentielle du champ scalaire φ possede une queue en loi de puissance V∼φ − α pour φ…
Cosmological 'seed' magnetic field from inflation
- Bharat Ratra
- Physics
- 1 October 1991
We extend the canonical exponential potential scalar field inflation modified hot big bang model by adding an inflation epoch coupling, between the scalar field Φ responsible for inflation and an…
HUBBLE PARAMETER MEASUREMENT CONSTRAINTS ON THE COSMOLOGICAL DECELERATION-ACCELERATION TRANSITION REDSHIFT
- O. Farooq, Bharat Ratra
- Physics
- 22 January 2013
We compile a list of 28 independent measurements of the Hubble parameter between redshifts 0.07 ≤ z ≤ 2.3 and use this to place constraints on model parameters of constant and time-evolving dark…
Median Statistics and the Hubble Constant
- Gang Chen, Bharat Ratra
- Physics
- 26 May 2011
ABSTRACT.Following Gott et al., we use Huchra’s final compilation of 553 measurements of the Hubble constant (H0H0) to estimate median statistical constraints on H0H0. Our median statistical analysis…
Median Statistics Estimate of the Distance to the Galactic Center
- Tia Camarillo, Varun Mathur, T. Mitchell, Bharat Ratra
- Physics
- 3 August 2017
We show that error distributions of a compilation of 28 recent independent measurements of the distance from the Sun to the Galactic center, $R_{0}$, are wider than a standard Gaussian and best fit…
Cosmic Microwave Background Anisotropy in COBE DMR-normalized Open and Flat-Λ Cold Dark Matter Cosmogonies
- Bharat Ratra, N. Sugiyama, A. Banday, K. Gorski
- Physics
- 20 May 1997
We compute the cosmic microwave background (CMB) anisotropy in open and flat-Λ cold dark matter (CDM) cosmogonies which are normalized to the two-year DMR sky maps. Presently available CMB data are…
Hubble Parameter and Baryon Acoustic Oscillation Measurement Constraints on the Hubble Constant, the Deviation from the Spatially Flat ΛCDM Model, the Deceleration–Acceleration Transition Redshift,…
- Hai-Bo Yu, Bharat Ratra, Fayin Wang
- Physics
- 9 November 2017
We compile a complete collection of reliable Hubble parameter H(z) data to redshift z ≤ 2.36 and use them with the Gaussian Process method to determine continuous H(z) functions for various data…
Median Statistics, H0, and the Accelerating Universe
- J. Gott, M. Vogeley, Silviu Podariu, Bharat Ratra
- Physics
- 7 June 2000
We develop median statistics that provide powerful alternatives to χ2 likelihood methods and require fewer assumptions about the data. Application to astronomical data demonstrates that median…
Large-scale structure in COBE-normalized cold dark matter cosmogonies
- S. Cole, D. Weinberg, C. Frenk, Bharat Ratra
- Physics
- 10 February 1997
We study the clustering of the mass distribution in COBE-normalized open and flat CDM models using large N-body simulations. With an age of the universe of 14 Gyr (12 Gyr) for the flat (open) models…
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