Related papers: Global textures and the Doppler peaks
The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations…
Baryon-density perturbations of large amplitude may exist if they are compensated by dark-matter perturbations so that the total density remains unchanged. Big-bang nucleosynthesis and galaxy clusters allow the amplitudes of these…
Observations indicate that large-scale anomalies exist in the fluctuations of the cosmic microwave background. In these anomalies, the hemispherical power amplitude asymmetry has a correlation length comparable to that of the observable…
Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…
In a universe reionized in patches, the Doppler effect from Thomson scattering off free electrons generates secondary cosmic microwave background (CMB) anisotropies. For a simple model with small patches and late reionization, we…
In this work it is shown for some spatially homogeneous but anisotropic models how the inhomogeneities in the distribution of matter on the surface of the last scattering produce anisotropies in large angular scales (larger than $\vartheta…
Global, symmetry-breaking phase transitions in the early universe can generate scaling seed networks which lead to metric perturbations. The acoustic waves in the photon-baryon plasma sourced by these metric perturbations, when Silk damped,…
The current suite of results from Cosmic Microwave Background anisotropy experiments is fulfilling the promise of providing extraordinary levels of discrimination between cosmological models. We calculate a binned anisotropy power spectrum,…
Pursuing the original idea proposed in our previous paper (Paper I), we improve the method to determine the shape of the initial curvature perturbation spectrum $P(k)$ from the CMB data. The thickness of the last scattering surface (LSS)…
We carry out the determination of the amplitude of relic gravitational waves power spectrum. Indirect best-fit technique was applied to compare observational data and theory predictions. As observations we have used data on large-scale…
The perturbations in the electron number density during recombination contributes to the Cosmic Microwave Background bispectrum through second order terms. Perturbations in the electron density can be a factor of ~5 larger than the baryon…
We show that there are inflationary models for which perturbations in the energy momentum tensor, which are of second order in the scalar field, cannot be neglected. We first specify the conditions under which the usual first order…
Under the standard model for recombination of the primeval plasma, and the cold dark matter model for structure formation, recent measurements of the first peak in the angular power spectrum of the cosmic microwave background temperature…
If one is willing to give up the cherished hypothesis of spatial isotropy, many interesting cosmological models can be developed beyond the simple anisotropically expanding scenarios. One interesting possibility is presented by shear-free…
Probing primordial curvature perturbations on small scales, beyond those accessible using cosmic microwave background (CMB) primary anisotropies and Lyman-$\alpha$ forest data, remains a major open challenge. Current constraints on the…
Scalar fields in the minimal supersymmetric standard model may have large field values during inflation. Because of approximate global symmetry, it is plausible that the phase directions of them are nearly massless during inflation and…
Although the cosmic microwave background (CMB) is largely understood to be homogeneous and isotropic, the CMB angular power spectra present anomalies that seem to break down parity symmetry at large angular scales. We argue that the…
We present a new method for time-efficient and accurate extraction of the power spectrum from future cosmic microwave background (CMB) maps based on properties of peaks and troughs of the Gaussian CMB sky. We construct a statistic…
Recently, we have shown that scalar spectra with lower power on large scales and certain other features naturally occur in {\it punctuated inflation}, i.e. the scenario wherein a brief period of rapid roll is sandwiched between two stages…
Scaling properties of the cosmic microwave background (CMB) radiation are studied using satellite (COBE-DMR maps), balloon-borne and ground-based (combined QMASK map) data. Quantitative consistency is found between the multiscaling…