相关论文: Recovering 21cm Monopole Signals Without Smoothnes…

The search for a particle dark matter signal in terms of radiation produced by dark matter annihilation or decay has to cope with the extreme faintness of the predicted signal and the presence of masking astrophysical backgrounds. It has…

We use an integral representation for nonthermal radiation, which is bounded from below and above, to describe the spectrum of the cosmic microwave background (CMB). The upper bound is given by the Rayleigh-Jeans law with a temperature…

This paper proposes a new approach to separate the $\mu$ spectral distortions of the cosmic microwave background from foregrounds with poorly defined spectral shapes. The idea is based on finding the optimal response to the observed signal.…

The polarization of the Cosmic Microwave Background (CMB)is a powerful observational tool at hand for modern cosmology. It allows to break the degeneracy of fundamental cosmological parameters one cannot obtain using only anisotropy data…

The cosmic microwave background (CMB) has been a treasure trove for cosmology. Over the next decade, current and planned CMB experiments are expected to exhaust nearly all primary CMB information. To further constrain cosmological models,…

Departures of the energy spectrum of the cosmic microwave background (CMB) from a perfect blackbody probe a fundamental property of the universe -- its thermal history. Current upper limits, dating back some 25 years, limit such spectral…

We study the constraints on primordial magnetic fields (PMFs) in light of the global 21-cm signal observed during the dark ages. Primordial magnetic fields can heat the intergalactic medium (IGM) via magnetohydrodynamic effects. We…

The extraction of the sky-averaged 21 cm signal from Cosmic Dawn and the Epoch of Reionization faces significant challenges. The bright and anisotropic Galactic foreground, which is 4 - 5 orders of magnitude brighter than the 21 cm signal,…

The ability to subtract foreground contamination from low-frequency observations is crucial to reveal the underlying 21 cm signal. The traditional line-of-sight methods can deal with the removal of diffuse emission and unresolved point…

Hydrogen 21-cm Line Intensity Mapping offers the unique opportunity to access the Dark Ages and trace the formation and evolution of the large scale structure of the Universe prior to star and galaxy formation. In this work we investigate…

The Cosmic Microwave Background provides our most ancient image of the Universe and our best tool for studying its early evolution. Theories of high energy physics predict the formation of various types of topological defects in the very…

In the first paper of this series, we proposed a novel method to probe large-scale intergalactic magnetic fields during the cosmic Dark Ages, using 21-cm tomography. This method relies on the effect of spin alignment of hydrogen atoms in a…

The spectral distortion of the cosmic microwave background blackbody spectrum in a radially inhomogeneous spacetime, designed to exactly reproduce a LambdaCDM expansion history along the past light cone, is shown to exceed the upper bound…

The 21 cm intensity mapping provides a promising probe of the large-scale structure. Astrophysical foregrounds, as the main source of contamination to the cosmological 21 cm signal, persist in a wedge-like region of Fourier space due to the…

Measurements of cosmic microwave background spectral distortions have profound implications for our understanding of physical processes taking place over a vast window in cosmological history. Foreground contamination is unavoidable in such…

One of the main challenges facing upcoming CMB experiments will be to distinguish the cosmological signal from foreground contamination. We present a comprehensive treatment of this problem and study how foregrounds degrade the accuracy…

The redshifted 21 cm line of cosmic atomic hydrogen is one of the most auspicious tools in deciphering the early Universe. Recovering this signal remains an ongoing problem for cosmologists in the field, with the signal being hidden behind…

Embedded defects are predicted in a host of particle physics theories, in particular in the standard electroweak theory. They can be stabilized by interactions with the cosmological plasma, but will decay once the plasma falls out of…

The redshifted 21~cm signal from neutral hydrogen (HI) is potentially a very powerful probe for cosmology, but a difficulty in its observation is that it is much weaker than foreground radiation from the Milky Way as well as extragalactic…

The presence of an extra radio background besides the cosmic microwave background has important implications for the observation of the 21-cm signal during the cosmic Dark Ages, Cosmic Dawn, and epoch of Reionization. The strong absorption…