Results 31 to 40 of about 4,402,515 (251)

A Bias-free Cosmological Analysis with Quasars Alleviating H 0 Tension

The Astrophysical Journal Supplement Series, 2023
Cosmological models and their parameters are widely debated because of theoretical and observational mismatches of the standard cosmological model, especially the current discrepancy between the value of the Hubble constant, H _0 , obtained by Type Ia ...
Aleksander Łukasz Lenart, Giada Bargiacchi, Maria Giovanna Dainotti, Shigehiro Nagataki, Salvatore Capozziello   +4 more
doaj   +1 more source

Conserved cosmological perturbations. [PDF]

, 2003
A conserved cosmological perturbation is associated with each quantity whose local evolution is determined entirely by the local expansion of the Universe.
David H. Lyth, Lyth, D., Wands, David, David Wands, Lyth, David H.   +4 more
core   +1 more source

The Cosmological Parameter: Constant or Dynamical

Journal of Physics: Conference Series, 2020
After providing a brief history of the cosmological constant, some early cosmological models are discussed. The most popular current cosmological model is the ΛCDM model, but there are several problems associated with this model, e.g., the cosmological constant problem and fine tuning.
Beesham, Aroonkumar, Tiwari, Rakesh Kumar   +1 more
openaire   +1 more source

Cosmological constraints from the clustering of the Sloan Digital Sky Survey DR7 luminous red galaxies [PDF]

, 2009
We present the power spectrum of the reconstructed halo density field derived from a sample of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) Seventh Data Release (DR7).
Weinberg, D. H., Gunn, James E., Gott, J. Richard, York, D. G., Spergel, David N., Bahcall, Neta A., Knapp, Gillian R., McKay, T. A., Meiksin, A., Schlegel, D. J., Tegmark, M., Szalay, Alexander S., Zeljko, Ivezic, Percival, Will J., Lupton, Robert H., Kron, R. G., Pope, A. C., Frieman, Joshua A., York, Donald G., Meiksin, Avery, Tegmark, Max Erik, Szalay, A. S., Fukugita, M., Mckay, Timothy A., Schneider, D. P., Vogeley, M. S., Fukugita, Masataka, Zehavi, Idit, Verde, L., Reid, B. A., Gott, J. R., Vogeley, Michael S., Schlegel, David J., Weinberg, David H., Spergel, D. N., Strauss, M. A., Nichol, Robert C., Budavari, Tamas, Stoughton, Christopher, Ivezić, Željko, Ivezic, Z., Frieman, J. A., Stoughton, C., Bahcall, N. A., Nichol, R. C., Skibba, Ramin A., Knapp, G. R., Eisenstein, D. J., Schneider, Donald P., Percival, W. J., Eisenstein, Daniel J., Strauss, Michael A., Reid, Beth A., Pope, Adrian C., Stoughton, Chris, Zehavi, I., Tegmark, Max, Lupton, R. H., Skibba, Raman A., Budavari, T., Verde, Licia, Skibba, R. A., Kron, Richard G., Gunn, J. E.   +63 more
core   +1 more source

DIRECTIONAL DEPENDENCE OF ΛCDM COSMOLOGICAL PARAMETERS [PDF]

The Astrophysical Journal, 2013
6 pages, 7 figures, published in ...
Axelsson, M., Fantaye, Y., Hansen, F. K., Banday, A. J., Eriksen, H. K., Gorski, K. M.   +5 more
openaire   +3 more sources

Investigating Cosmological Models and the Hubble Tension Using Localized Fast Radio Bursts

The Astrophysical Journal, 2023
We use the dispersion measure (DM) and redshift measurements of 24 localized fast radio bursts (FRBs) to compare cosmological models and investigate the Hubble tension.
Jun-Jie Wei, Fulvio Melia
doaj   +1 more source

STATEFINDER PARAMETERS FOR FIVE-DIMENSIONAL COSMOLOGY [PDF]

Modern Physics Letters A, 2008
We study the statefinder parameter in the five-dimensional big bounce model, and apply it to differentiate the attractor solutions of quintessence and phantom field. It is found that the evolving trajectories of these two attractor solutions in the statefinder parameters plane are quite different, and that are different from the statefinder ...
Chang, Baorong, Liu, Hongya, Xu, Lixin, Zhang, Chengwu   +3 more
openaire   +3 more sources

Cosmographic constraints from late-time probes including fast radio bursts

Astronomy & Astrophysics
Context. Late-time astrophysical probes offer a powerful way to investigate the expansion history of the Universe. Among these probes, fast radio bursts (FRBs) are millisecond-duration astrophysical transients whose extragalactic origin makes them a ...
Sales Lázaro L., de Farias Klecio E. L., Queiroz Amilcar R., Santos Joao R. L., Batista Rafael A., Oliveira Ana R. M., Santana Lucas F., Wuensche Carlos A., Villela Thyrso, Vieira Jordany   +9 more
doaj   +1 more source

PROBING FOR THE COSMOLOGICAL PARAMETERS WITH PLANCK MEASUREMENT [PDF]

International Journal of Modern Physics D, 2008
In this paper we investigate the constraints on the cosmological parameters, especially the equation of state of dynamical dark energy w DE , the inflationary parameters ns, αs and r, the total neutrino mass ∑ mν and the curvature of the universe ΩK, using the simulated data of future Planck measurement. First, we determine the cosmological parameters
Xia, Jun-Qing, Li, Hong, Zhao, Gong-Bo, Zhang, Xinmin   +3 more
openaire   +2 more sources

COSMOLOGICAL PARAMETERS: FASHION AND FACTS [PDF]

New Worlds in Astroparticle Physics, 2003
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 consensus around the so-called concordance model.
openaire   +2 more sources