相关论文: Pre-recombinational energy release and narrow feat…
It is generally assumed that for energy injection before recombination, all of the injected energy is dissipated as heat in the baryon-photon plasma, giving rise to the $y$-type, $i$-type, and $\mu$-type distortions in the CMB spectrum. We…
The redshifted 21-cm emission by neutral hydrogen offers a unique tool for mapping structure formation in the early universe in three dimensions. Here we provide the first detailed calculation of the 21-cm emission signal during and after…
Current constraints on energy injection in the form of energetic particles before the epoch of recombination using CMB spectral distortions assume that all energy goes into $y$ and $\mu$-type distortions. We revisit these constraints with…
We consider the pumping of the $63.2 \mu$m fine structure line of neutral OI in the high--redshift intergalactic medium (IGM), in analogy with the Wouthuysen--Field effect for the 21cm line of cosmic HI. We show that the soft UV background…
The feasibility of making highly redshifted HI 21-cm (rest frame) measurements from an early epoch of the Universe between the Dark Ages and Reionization (i.e., z>6 and nu<200 MHz) to probe the effects of feedback from the first stars and…
Extra radiation injection after neutrino decoupling in the early Universe contributes to the effective number of neutrino species that can be constrained by the cosmic microwave background (CMB). However, any effective neutrino number…
Energy release in the early Universe leads to spectral distortions of the cosmic microwave background (CMB) which in the future might allow probing different physical processes in the pre-recombination (z>~10^3) epoch. Depending on the…
We calculate the post-recombination contribution to the Cosmic Microwave Background (CMB) spectral distortion due to general exotic energy injections, including dark matter (DM) decaying or annihilating to Standard Model particles. Upon…
In this paper we explore the potential effects of DM annihilations on the cosmological recombination spectrum. With this example we want to demonstrate that the cosmological recombination spectrum in principle is sensitive to details…
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…
The blackbody spectrum of CMB was created in the blackbody photosphere at redshifts z>2x10^6. At these early times, the Universe was dense and hot enough that complete thermal equilibrium between baryonic matter (electrons and ions) and…
The products of primordial nucleosynthesis and the cosmic microwave background (CMB) photons are relics from the early evolution of the Universe whose observations probe the standard model of cosmology and provide windows on new physics…
We compute the spectral distortions of the Cosmic Microwave Background (CMB) created by an exotic process that extracts or injects photons of a particular frequency into the CMB. Such signatures are a natural prediction of a class of…
A key assumption of the standard cosmological model is that the temperature of the cosmic microwave background (CMB) radiation scales with cosmological redshift $z$ as $T_{\rm CMB}(z) \propto (1+z)$ at all times after recombination at…
As atoms formed for the first time during primordial recombination, they emitted bound-bound and free-bound radiation leading to spectral distortions to the cosmic microwave background. These distortions might become observable in the…
The formation of first stars and galaxies at the Cosmic Dawn had been preceded by the chain of primordial chemistry reactions during Dark Ages which generated first molecules, mostly H$_2$, HD, and HeH$^+$, so crucial for first stars to…
Current observational data favor cosmological models which differ from the standard model due to the presence of some form of dark energy and, perhaps, by additional contributions to the more familiar dark matter. Primordial nucleosynthesis…
We present the first fast and detailed computation of the cosmological recombination radiation released during the hydrogen (redshift z ~ 1300) and helium (z ~ 2500 and z ~ 6000) recombination epochs, introducing the code CosmoSpec. Our…
We explore the imprint of the cosmological hydrogen recombination lines on the power spectrum of the cosmic microwave background (CMB). In particular, we focus our analysis in the three strongest lines for the Balmer, Paschen and Brackett…
In this paper, we provide the first computations for the distortion transfer functions of the cosmic microwave background (CMB) in the perturbed Universe, following up on paper I and II in this series. We illustrate the physical effects…