Results 31 to 40 of about 695,703 (300)

Reionization and Cosmology with 21 cm Fluctuations [PDF]

open access: yes, 2009
Measurement of the spatial distribution of neutral hydrogen via the redshifted 21 cm line promises to revolutionize our knowledge of the epoch of reionization and the first galaxies, and may provide a powerful new tool for observational cosmology from ...
J. Stuart B. Wyithe   +4 more
core   +1 more source

Observational constraints on undulant cosmologies [PDF]

open access: yesJournal of Cosmology and Astroparticle Physics, 2006
19 pages, 12 figures in 19 files, uses iopart.cls, iopart10.clo; added ...
Barenboim, Gabriela   +2 more
openaire   +5 more sources

Space and observers in cosmology [PDF]

open access: yesAstronomy & Astrophysics, 2001
I provide a prescription to define space, at a given moment, for an arbitrary observer in an arbitrary (sufficiently regular) curved space-time. This prescription, based on synchronicity (simultaneity) arguments, defines a foliation of space-time, which corresponds to a family of canonically associated observers.
openaire   +3 more sources

Observational aspects of an inhomogeneous cosmology [PDF]

open access: yesProceedings of VIII International Workshop on the Dark Side of the Universe — PoS(DSU 2012), 2013
One of the biggest mysteries in cosmology is Dark Energy, which is required to explain the accelerated expansion of the universe within the standard model. But maybe one can explain the observations without introducing new physics, by simply taking one step back and re-examining one of the basic concepts of cosmology, homogeneity. In standard cosmology,
Christoph Saulder   +2 more
openaire   +4 more sources

Highly Accreting Supermassive Black Holes as Eddington Standard Candles

open access: yesPhysical Sciences Forum, 2023
Supermassive black holes accreting matter at very high, perhaps even super-Eddington rates appear in the sky as a special class of luminous active galactic nuclei.
Paola Marziani
doaj   +1 more source

Inflationary spectra and observations in loop quantum cosmology [PDF]

open access: yesJ. Phys.: Conf. Ser. 360 (2012) 012027, 2011
We review some recent progress in the extraction of inflationary observables in loop quantum cosmology. Inverse-volume quantum corrections induce a growth of power in the large-scale cosmological spectra and are constrained by observations.
arxiv   +1 more source

Temporal and Spectral Variability of OJ 287 before the April–June 2020 Outburst

open access: yesGalaxies, 2020
We present the results of a temporal and spectral study of the BL Lacertae object OJ 287 in optical, UV, and X-ray bands with observations performed by Swift satellite during September 2019–March 2020.
Nibedita Kalita   +2 more
doaj   +1 more source

Dark Matter and Galaxy Formation: Challenges for the Next Decade [PDF]

open access: yes, 2004
The origin of the galaxies represents an important focus of current cosmological research, both observational and theoretical. Its resolution involves a comprehensive understanding of star formation, galaxy dynamics, the cosmology of the very early ...
Silk, Joseph
core   +3 more sources

Observational Constraints on Cosmological Superstrings [PDF]

open access: yesTheoretical Physics, 2017
From theoretical point of view and not being in contradiction with current observational data, the cosmic strings should have fundamentally different origin and are characterized by wide range of energies. The paper is devoted to search for possible cosmological observational tests on superstring theory, among them to identification of observational ...
O. S. Sazhina, Alfiia I. Mukhaeva
openaire   +2 more sources

Energy Storage and Environmental Justice: A Critical Examination of a Proposed Pumped Hydropower Facility in Goldendale, Washington

open access: yesAntipode, EarlyView., 2023
Abstract Renewable energy sources such as solar and wind produce electricity intermittently, creating challenges in balancing electricity supply and demand for increasingly renewable‐dominated grids. This is driving efforts to increase energy storage infrastructure, such as pumped hydroelectric power storage (pumped storage).
Alida Cantor   +2 more
wiley   +1 more source

Home - About - Disclaimer - Privacy