Related papers: Delayed Recombination
With the recent measurement of full sky cosmic microwave background polarization from WMAP, key cosmological degeneracies have been broken, allowing tighter constraints to be placed on cosmological parameters inferred assuming a standard…
One way of recovering information about the initial conditions of the Universe is by measuring features of the cosmological density field which are preserved during gravitational evolution and galaxy formation. In this paper we study the…
In this paper we specifically studied one aspect of foreground primordial matter density perturbations: the relative gravitational time delay between a pair of light paths converging towards an observer and originating from two points on…
The thermal and expansion history of the Universe before big bang nucleosynthesis is unknown. We investigate the evolution of cosmological perturbations through the transition from an early matter era to radiation domination. We treat…
Spectral distortions of the CMB have recently experienced an increased interest. One of the inevitable distortion signals of our cosmological concordance model is created by the cosmological recombination process, just a little before…
We place new constraints on sources of ionizing and resonance radiation at the epoch of the recombination process using the recent CMB temperature and polarization spectra coming from WMAP. We find that non-standard recombination scenarios…
A simple speed-up cosmology model is proposed to account for the dark energy puzzle. We condense contributions from dark energy and curvature term into one effective parameter in order to reduce parameter degeneracies and to find any…
The small-scale structure problems of the universe can be solved by self-interacting dark matter that becomes strongly interacting at low energies. A particularly predictive model is resonant short-range self-interactions, with a…
The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73K Cosmic Microwave Background. Tiny inhomogeneities in the early Universe left their imprint on the…
Supernova evidence for a negative-pressure dark energy (e.g., cosmological constant or quintessence) that contributes a fraction $\Omega_\Lambda\simeq0.7$ of closure density has been bolstered by the discrepancy between the total density,…
The recombination history of the Universe depends exponentially on the temperature, T_0, of the cosmic microwave background. Therefore tiny changes of T_0 are expected to lead to significant changes in the free electron fraction. Here we…
In the late Universe, and on cosmological scales, dark matter is conventionally assumed to be collisionless, as a consequence of the strong existing bounds on dark matter interactions at the Cosmic Microwave Background last-scattering…
This work is a supplement on the previous research about primordial electromagnetic fields. In this work, three important problems are discussed: the evolution of primordial electric fields, the electric and particle densities' solitons in…
Anisotropies of the cosmic microwave background are thought to be due to perturbations of the primordial medium, which, post recombination, lead to the formation of galaxy clusters and galaxies. Aims: We analyse the perturbation wave modes…
The cold dark matter may be in a meta-stable state and decays to other particles with a very long lifetime. If the decaying products of the dark matter are weakly interacting, e.g. neutrinos, then it would have little impact on…
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…
Precision measurements of the cosmic microwave background temperature anisotropy on scales $\ell > 500$ will be available in the near future. Successful interpretation of these data is dependent on a detailed understanding of the damping…
The coupling of photons and baryons by Thomson scattering in the early universe imprints features in both the Cosmic Microwave Background (CMB) and matter power spectra. The former have been used to constrain a host of cosmological…
We solve the recombination equation by taking into account the induced recombinations and a physical cut off in the hydrogen spectrum. The effective recombination coefficient is parametrized as a function of temperature and free electron…
Details of how the primordial plasma recombined and how the universe later reionized are currently somewhat uncertain. This uncertainty can restrict the accuracy of cosmological parameter measurements from the Cosmic Microwave Background…