Related papers: Reionization and Cosmic Microwave Anisotropies
Injection of high energy electromagnetic particles around the recombination epoch can modify the standard recombination history and therefore the CMB anisotropy power spectrum. Previous studies have put strong constraints on the amount of…
We study the effect of a prolonged epoch of reionization on the angular power spectrum of the Cosmic Microwave Background. Typically reionization studies assume a sudden phase transition, with the intergalactic gas moving from a fully…
We explore the phenomenology of having a second epoch of dark matter annihilation into dark radiation long after the standard thermal freeze-out. Such a hidden reannihilation process could affect visible sectors only gravitationally. As a…
In the inhomogeneous Universe, the cosmological conversion of dark photons into ordinary photons (and vice versa) may happen at a great number of resonance redshifts. This alters the CMB observed energy spectrum and degree of small-scale…
We discuss the contribution of gravitational wave to the cosmic microwave background radiation (CMBR) anisotropy and polarization. It is found that the large-scale polarization of CMBR is less than 1\% for a standard recombination universe.…
We develop a linear perturbation theory for the spectral $y$-distortions of the cosmic microwave background (CMB). The $y$-distortions generated during the recombination epoch are usually negligible because the energy transfer due to the…
We present constraints on the reionization optical depth, $\tau$, obtained using several independent methods. First, we perform a non-parametric reconstruction of the reionization history, using Lyman-$\alpha$ constraints on the evolution…
The intergalactic helium became fully ionized by the end of cosmic noon ($z\sim2$). Similarly to the reionization of hydrogen, helium reionization is expected to be patchy, driven by luminous quasars that ionize the intergalactic gas in…
Possible signatures of primordial magnetic fields on the Cosmic Microwave Background (CMB) temperature and polarization anisotropies are reviewed. The signals that could be searched for include excess temperature anisotropies particularly…
The dominant linear contribution to cosmic microwave background (CMB) fluctuations at small angular scales (less than one arcsec) is a second-order contribution known as the Vishniac or Ostriker-Vishniac effect. This effect is caused by the…
We study the E and B mode polarisation of the cosmic microwave background (CMB) originating from the transverse peculiar velocity of free electrons, at second order in perturbation theory, during the reionisation and post-reionisation eras.…
We study the effects of dark matter annihilation during and after the cosmic recombination epoch on the cosmic microwave background anisotropy, taking into account the detailed energy deposition of the annihilation products. It is found…
Forthcoming CMB experiments will allow us to accurately investigate the power spectrum at very small scales ($\ell > 1000$). We predict the level of the primary anisotropies, given the actual CMB measurements. The secondary anisotropies…
The nature of dark matter is increasingly constrained by cosmological data. In this paper, we examine the implications of the Cosmic Microwave Background anisotropy limits on the density of cold dark matter under different theoretical…
The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological…
The Thomson optical depth from reionization is a limiting factor in measuring the amplitude of primordial fluctuations, and hence in measuring physics that affects the low-redshift amplitude, such as the neutrino masses. Current constraints…
We present a model independent and non-parametric reconstruction with a Machine Learning algorithm of the redshift evolution of the Cosmic Microwave Background (CMB) temperature from a wide redshift range $z\in \left[0,3\right]$ without…
The DASI discovery of CMB polarization, confirmed by WMAP, has opened a new chapter in cosmology. Most of the useful information about inflationary gravitational waves and reionization is on large angular scales where Galactic foreground…
We study the cosmic microwave background (CMB) anisotropy in the scenario with late-decaying scalar condensations which arise in many class of cosmological scenarios based on supersymmetric models. With such a scalar condensation \phi, the…
It has been several years since the first detection of Gunn-Peterson troughs in the z > 6 Ly-alpha forest and since the first measurement of the Thomson scattering optical depth through reionization from the cosmic microwave background…