In the Beginning: The First Sources of Light and the Reionization of the Universe
- R. Barkana, A. Loeb
- Physics
- 24 October 2000
Fuzzy cold dark matter: the wave properties of ultralight particles.
- W. Hu, R. Barkana, A. Gruzinov
- PhysicsPhysical Review Letters
- 7 August 2000
These problems might be solved, and the virtues of CDM models retained, even without postulating ad hoc dark matter particle or field interactions, if the dark matter is composed of ultralight scalar particles initially in a (cold) Bose-Einstein condensate, similar to axion dark matter models.
A Method for Separating the Physics from the Astrophysics of High-Redshift 21 Centimeter Fluctuations
- R. Barkana, A. Loeb
- Physics
- 23 September 2004
Fluctuations in the 21 cm brightness from cosmic hydrogen at redshifts z ≳ 6 have their source in the primordial density perturbations from inflation, as well as the radiation from galaxies. We…
Possible interaction between baryons and dark-matter particles revealed by the first stars
- R. Barkana
- PhysicsNature
- 28 February 2018
The analysis indicates that the spatial fluctuations of the 21-centimetre signal at cosmic dawn could be an order of magnitude larger than previously expected and that the dark-matter particle is no heavier than several proton masses, well below the commonly predicted mass of weakly interacting massive particles.
Cold and Fuzzy Dark Matter
- Wayne Hu, R. Barkana, A. Gruzinov
- Physics
- 24 March 2000
Cold dark matter (CDM) models predict small-scale structure in excess of observations of the cores and abundance of dwarf galaxies. These problems might be solved, and the virtues of CDM models…
The observable signature of late heating of the Universe during cosmic reionization
- A. Fialkov, R. Barkana, E. Visbal
- PhysicsNature
- 5 February 2014
It is shown that the hard spectra of X-ray binaries make such heating ineffective, resulting in a delayed and spatially uniform heating that modifies the 21-centimetre signature of reionization.
Detecting the Earliest Galaxies through Two New Sources of 21 Centimeter Fluctuations
- R. Barkana, A. Loeb
- Physics
- 5 October 2004
The first galaxies that formed at a redshift z ~ 20-30 emitted continuum photons with energies between the Lyα and Lyman limit wavelengths of hydrogen, to which the neutral universe was transparent…
Unusually Large Fluctuations in the Statistics of Galaxy Formation at High Redshift
- R. Barkana, A. Loeb
- Physics
- 14 October 2003
We show that various milestones of high-redshift galaxy formation, such as the formation of the first stars or the complete reionization of the intergalactic medium, occurred at different times in…
The Reionization of the Universe by the First Stars and Quasars
- A. Loeb, R. Barkana
- Physics
- 23 October 2000
▪ Abstract The formation of the first stars and quasars marks the transformation of the universe from its smooth initial state to its clumpy current state. In popular cosmological models, the first…
Charting the parameter space of the global 21-cm signal
- Aviad Cohen, A. Fialkov, R. Barkana, M. Lotem
- Physics
- 8 September 2016
The early star-forming Universe is still poorly constrained, with the properties of high-redshift stars, the first heating sources, and reionization highly uncertain. This leaves observers planning…
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