相关论文: Exploring the cosmic dawn and epoch of reionizatio…
The recent EDGES measurements of the global 21-cm signal from the cosmic dawn suggest that the kinetic temperature of the inter-galactic medium (IGM) might be significantly lower compared to its expected value. The colder IGM directly…
Observations of the hydrogen hyperfine transition through the 21 cm line near the end of the cosmic dark ages provide unique opportunities to probe new physics. In this work, we investigate the potential of the sky-averaged 21 cm signal to…
The sky-averaged (global) 21-cm signal is a powerful probe of the intergalactic medium (IGM) prior to the completion of reionization. However, it has so far been unclear that even in the best case scenario, in which the signal is accurately…
The Dark Age is the period between the time when the cosmic microwave background was emitted and the time when the evolution of structure in the universe led to the gravitational collapse of objects in which the first stars were formed. The…
The Dark Ages, probed by the redshifted 21-cm signal, is the ideal epoch for a new rigorous test of the standard LCDM cosmological model. Divergences from that model would indicate new physics, such as dark matter decay (heating) or…
In addition to being a probe of Cosmic Dawn and Epoch of Reionization astrophysics, the 21cm line at $z>6$ is also a powerful way to constrain cosmology. Its power derives from several unique capabilities. First, the 21cm line is sensitive…
The process of heating and reionization of the Universe at high redshift links small scale structures/galaxy formation and large scale inter-galactic medium properties. Even if the first one is difficult to observe, an observation window is…
Observations of the redshifted 21 cm line from neutral hydrogen will open a new window on the early Universe. By influencing the thermal and ionization history of the intergalactic medium (IGM), annihilating dark matter (DM) can leave a…
The Epoch of Reionization (EoR) is the epoch in which hydrogen in the Universe reionize after the "Dark Ages". This is the second of two major phase transitions that hydrogen in the Universe underwent, the first phase being the…
We discuss the prospects for ``tomography'' of the intergalactic medium (IGM) at high redshifts using the 21 cm transition of neutral hydrogen. Existing observational constraints on the epoch of reionization imply a complex ionization…
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…
We highlight recent progress in the sophistication and diversification of cosmic dawn and reionization simulations. The application of these modeling tools to current observations has allowed us narrow down the timing of reionization, which…
The Cosmic Dawn and Epoch of Reionisation, during which collapsed structures produce the first ionising photons and proceed to reionise the intergalactic medium, span a large range in redshift (z~30-6) and time (t_{age} ~ 0.1-1.0~Gyr).…
After recombination the cosmic gas was left in a cold and neutral state. However, as the first stars and black holes formed within early galactic systems, their UV and X-ray radiation induced a gradual phase transition of the intergalactic…
The epoch of reionization (EoR) corresponds to a 'cosmic phase transition', when the neutral intergalactic medium (IGM) becomes ionized by the first stars and/or AGN. While the discoveries of Gunn-Peterson (GP) absorption troughs in the…
The first light from stars and quasars ended the ``dark ages'' of the universe and led to the reionization of hydrogen by redshift 7. Current observations are at the threshold of probing this epoch. The study of high-redshift sources is…
The birth of the first luminous sources and the ensuing epoch of reionization are best studied via the redshifted 21-cm emission line, the signature of the first two imprinting the last. In this work we present a fully-Bayesian method,…
One of the last unexplored windows to the cosmos, the Dark Ages and Cosmic Dawn, can be opened using a simple low frequency radio telescope from the stable, quiet lunar farside to measure the Global 21-cm spectrum. This frontier remains an…
Details of various unknown physical processes during the cosmic dawn and the epoch of reionization can be extracted from observations of the redshifted 21-cm signal. These observations, however, will be affected by the evolution of the…
The universe would have been completely dark between the epoch of recombination and the development of the first non-linear structure. But at redshifts beyond 5 -- perhaps even beyond 20 -- stars formed within `subgalaxies' and created the…