Related papers: Delayed Recombination
In this letter, we propose a model of inflationary cosmology with a bounce preceded and study its primordial curvature perturbations. Our model gives rise to a primordial power spectrum with a feature of oscillation on large scales compared…
We study the formation of first molecules, negative Hydrogen ions and molecular ions in model of the Universe with cosmological constant and cold dark matter. The cosmological recombination is described in the framework of modified model of…
We expose the scenarios of primordial baryon-photon plasma evolution within the framework of the Milne-like universe models. Recently, such models find a second wind and promise an inflation-free solution of a lot of cosmological puzzles…
Measurements of the cosmic microwave background (CMB) radiation provide a unique opportunity for a direct study of the primordial cosmic plasma at redshift z ~1000. The angular power spectra of temperature and polarisation fluctuations are…
Measurements of the Hubble parameter from the distance ladder are in tension with indirect measurements based on the cosmic microwave background (CMB) data and the inverse distance ladder measurements at 3-4 $\sigma$ level. We consider…
The Hubble tension, reflecting a persistent discrepancy between early- and late-time determinations of the Hubble constant, continues to motivate extensions of the standard cosmological model The Hubble tension motivates extensions of the…
Understanding the origin of strong galactic outflows and the suppression of star formation in dwarf galaxies is a key problem in galaxy formation. Using a set of radiation-hydrodynamic simulations of an isolated dwarf galaxy embedded in a…
Spectral features in the CMB energy spectrum contain a wealth of information about the physical processes in the early Universe, z < 2 x 10^6. The CMB spectral distortions are complementary to all other probes of cosmology. In fact, most of…
We combine complementary datasets to constrain dark energy. Using standard Big Bang Nucleosynthesis and the observed abundances of primordial nuclides to put constraints on $\Omega_Q$ at temperatures near $T \sim 1MeV$, we find the strong…
Dark matter in spiral galaxies like the Milky Way may take the form of a dark plasma. Hidden sector dark matter charged under an unbroken $U(1)'$ gauge interaction provides a simple and well defined particle physics model realising this…
We derive the full set of second-order equations governing the evolution of cosmological perturbations, including the effects of the first-order electron number density perturbations, \delta_e. We provide a detailed analysis of the…
We compute the spectral distortions of the Cosmic Microwave Background (CMB) arising during the epoch of cosmological hydrogen recombination within the standard cosmological (concordance) model for frequencies in the range 1 GHz-3500 GHz.…
Recent cosmological observations, such as the measurement of the primordial 4He abundance, CMB, and large scale structure, give preference to the existence of extra radiation component, Delta N_nu > 0. The extra radiation may be accounted…
We investigate observational constraints on the curvature of the universe not restricting ourselves to a cosmological constant as dark energy, in particular allowing a dark energy equation of state to evolve with time in several ways. We…
The cosmic microwave background (CMB) fluctuations effectively measure the basic properties of the universe during the recombination epoch. CMB measurements fix the distance to the surface of last scatter, the sound horizon of the…
Imagine a scenario in which the dark energy forms via the condensation of dark matter at some low redshift. The Compton wavelength therefore changes from small to very large at the transition, unlike quintessence or metamorphosis. We study…
We study some cosmological constraints on the two phenomenological models of oscillating dark energy. In these scenarios, the equation of state of dark energy varies periodically and may provide a way to unify the early acceleration…
Following the pioneering observations with COBE in the early 1990s, studies of the cosmic microwave background (CMB) have focused on temperature and polarization anisotropies. CMB spectral distortions - tiny departures of the CMB energy…
The high ionization level and universal metallicity (1% solar) of the intergalactic gas at redshifts z<5 implies that nonlinear structure had started to form in the universe at earlier times than we currently probe. In Cold Dark Matter…
Precision measurement of the cosmological recombination spectrum can provide an entire new window to look at the early universe. We aim to quantify the information hidden in the cosmological recombination spectrum and for this purpose we…