相关论文: Probing the Dark Ages with the Square Kilometer Ar…

The cosmic reionization era, which includes formation of the first stars, galaxies, and AGN, is now one of the most active frontiers of cosmological research. We review briefly our current understanding of the early structure formation, and…

Prior to the epoch of full reionization, the intergalactic medium and gravitationally collapsed systems will be detectable in 21-cm radiation. Physical mechanisms that would produce a 21-cm signature are discussed. These include Lya…

We explore the possibility of detecting HI 21cm absorption by the neutral intergalactic medium (IGM) toward very high redshift radio sources, and by gas associated with the first collapsed structures, using the Square Kilometer Array at low…

Within the next few years, the Square Kilometer Array (SKA) or one of its pathfinders will hopefully provide a detection of the 21-cm signal fluctuations from the Epoch of Reionization (EoR). Then, the main goal will be to accurately…

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…

We investigate how precisely we can determine the nature of dark energy such as the equation of state (EoS) and its time dependence by using future observations of 21 cm fluctuations at the epoch of reionization (6.8 <~ z <~ 10) such as…

An extremely large void and a cosmic texture are two possible explanations for the cold spot seen in the cosmic microwave background. We investigate how well these two hypotheses can be tested with weak lensing of 21-cm fluctuations from…

Over the next few years the new radio telescopes, such as the Low Frequency Array (LOFAR) will greatly enhance our knowledge of the active history of the Universe. Large-area surveys with these new telescopes will no longer be dominated by…

We discuss the detection of redshifted line and continuum emission at radio wavelengths using a Square Kilometer Array (SKA), specifically from low-excitation rotational molecular line transitions of CO and HCN (molecular lines), the…

Studying the cosmic dawn and the epoch of reionization through the redshifted 21 cm line are among the major science goals of the SKA1. Their significance lies in the fact that they are closely related to the very first stars in the…

This thesis investigates the Epoch of Cosmic Reionization (EoR), a key period in the early Universe when the first luminous sources formed and their radiation transformed the intergalactic medium (IGM) from neutral to ionized. Understanding…

Tests of general relativity (GR) are still in their infancy on cosmological scales, but forthcoming experiments promise to greatly improve their precision over a wide range of distance scales and redshifts. One such experiment, the Square…

Recent observations have set the first constraints on the epoch of reionization (EoR), corresponding to the formation epoch of the first luminous objects. Studies of Gunn-Peterson (GP) absorption, and related phenomena, suggest a…

During the Epoch of reionisation, the intergalactic medium is reionised by the UV radiation from the first generation of stars and galaxies. One tracer of the process is the 21 cm line of hydrogen that will be observed by the Square…

The Square Kilometre Array is conceived as a telescope which will both test fundamental physical laws and transform our current picture of the Universe. However, the scientific challenges outlined in this book are today's problems--will…

The ionisation structure of the Intergalactic Medium (IGM) during reionisation is sensitive to the unknown galaxy formation physics that prevailed at that time. This structure introduces non-Gaussian statistics into the redshifted 21 cm…

This lecture briefly reviews the major recent advances in radio astronomy made possible by ultra-deep surveys, reaching microJansky flux density levels. A giant step forward in many fields, including the study of the evolution of the cosmic…

The Epoch of Reionisation (EoR) is the period within which the neutral universe transitioned to an ionised one. This period remains unobserved using low-frequency radio interferometers which target the 21 cm signal of neutral hydrogen…

The Hydrogen Epoch of Reionization Array (HERA) is a staged experiment to measure 21 cm emission from the primordial intergalactic medium (IGM) throughout cosmic reionization ($z=6-12$), and to explore earlier epochs of our Cosmic Dawn…

The local intensity of the 21 cm signal emitted during the Epoch of Reionization that will be mapped by the SKA is modulated by the amount of neutral hydrogen. Consequently, understanding the process of reionization of the intergalactic…