Related papers: The effect of reionization on the COBE normalizati…
We employ a pixel-based likelihood technique to estimate the angular power spectrum of the COBE Differential Microwave Radiometer (DMR) 4-year sky maps. The spectrum is consistent with a scale-invariant power-law form with a normalization,…
Cosmic reionization and dark matter decay can impact observations of the cosmic microwave sky in a similar way. A simultaneous study of both effects is required to constrain unstable dark matter from cosmic microwave background…
New results on the anisotropy of the cosmic microwave background (CMB) and its polarization based on the first 3 years of data from the Wilkinson Microwave Anisotropy Probe (WMAP) have revised the electron scattering optical depth downward…
The cosmic microwave background (CMB) anisotropies have turned out to represent one of the most stringent 'bottle necks' for scenarios of large scale structure formation. As a possibility to relax this constraint, it has been proposed that…
We calculate the secondary anisotropies in the CMB produced by inhomogeneous reionization from simulations in which the effects of radiative and stellar feedback effects on galaxy formation have been included. This allows to…
It was recently shown that applying a Gaussianizing transform, such as a logarithm, to the nonlinear matter density field extends the range of useful applicability of the power spectrum by a factor of a few smaller. Such a transform…
We reanalyse Cosmic Microwave Background data from experiments probing both large and small scales. We assume that measured anisotropies are due not only to primary fluctuations but also, especially at small scales, to secondary effects…
We have studied the effect of gravitational lensing on the Cosmic Microwave Background (CMB) anisotropy in flat and open universes. We develop a formalism to calculate the changes on the radiation power spectrum induced by lensing in the…
The first-year WMAP data release showed that the reionization optical depth to CMB photons is greater than previously thought. This follows from unexpectedly high values of the C^TE_l spectrum, for l up to ~30, presumably allowing a…
The cosmic microwave background (CMB) polarization, whose experimental detection must become the next natural step in the study of the CMB radiation, depends on the dynamics of hydrogen recombination in the Universe, on the relation between…
Details of various unknown physical processes during the cosmic dawn and the epoch of reionization can be extracted from observations of the redshifted 21-cm signal. These observations, however, will be affected by the evolution of the…
When modelling the ionisation of gas in the intergalactic medium after reionisation, it is standard practice to assume a uniform radiation background. This assumption is not always appropriate; models with radiative transfer show that…
We examine the effect of inhomogeneous reionization on the galaxy power spectrum and the consequences for probing dark energy. To model feedback during reionization, we apply an ansatz setting the galaxy overdensity proportional to the…
Many weak lensing calculations make use of the Born approximation where the light ray is approximated by a straight path. We examine the effect of Born-corrections for lensing of the cosmic microwave background in an analytical approach by…
The Cosmic Microwave Background (CMB) anisotropy power on the largest angular scales observed both by WMAP and COBE DMR appears to be lower than the one predicted by the standard model of cosmology with almost scale free primordial…
As the data on CMB anisotropies improve and potential cosmological applications are realized, it will be increasingly important for theoretical calculations to be as accurate as possible. All modern calculations for inflationary-inspired…
This doctorate thesis focuses on the effects of the electromagnetic environment on applied electromagnetic fields in single small junctions as well as arrays. We apply radio-frequency (RF) microwaves in the sub-gigahertz frequency range on…
Recent measurements of the Cosmic Microwave Background Anisotropy have provided evidence for the presence of oscillations in the angular power spectrum. These oscillations are a wonderful confirmation of the standard cosmological scenario…
The COBE satellite has provided the only comprehensive multi-frequency full-sky observations of the microwave sky available today. Assessment of the observations requires a detailed likelihood analysis to extract the maximum amount of…
The ionization history of the universe provides a major source of ambiguity in constraining cosmological models using small angular scale microwave background anisotropies. To clarify these issues, we consider a complete treatment of…