Related papers: Boltzmann approach to the large-angle cosmic X-ray…
We construct high-precision models of the Universe that contain radiation, a cosmological constant, and periodically distributed inhomogeneous matter. The density contrasts in these models are allowed to be highly non-linear, and the…
A model of Lorentz invariant random fluctuations in photon polarization is presented. The effects are frequency dependent and affect the polarization of photons as they propagate through space. We test for this effect by confronting the…
We study the surface brightness fluctuations of the cosmic X-ray background (CXB) using Chandra data of XBOOTES. After masking out resolved sources we compute the power spectrum of fluctuations of the unresolved CXB for angular scales from…
We propose a new method to measure the possible large-scale bulk flows in the Universe from the cosmic microwave background (CMB) maps from the upcoming missions, MAP and Planck. This can be done by studying the statistical properties of…
We develop a rigorous theory of hard-sphere dynamics in the kinetic regime, away from thermal equilibrium. In the low density limit, the empirical density obeys a law of large numbers and the dynamics is governed by the Boltzmann equation.…
We present a statistical technique which can be used to detect the presence and properties of moving sources contributing to a diffuse background. The method is a generalization of the 2-point correlation function to include temporal as…
We introduce a simple yet powerful {\it analytic} method which obtains the structure of cosmic microwave background anisotropies to better than 5-10\% in temperature fluctuations on {\it all} scales. It is applicable to {\it any} model in…
In the presence of strong clustering, low-resolution surveys measure the summed contributions of groups of sources within the beam. The counts of bright intensity peaks are therefore shifted to higher flux levels compared to the counts of…
Density inhomogeneities along the line-of-sight distort fluctuations in the cosmic microwave background. Usually, this effect is thought of as a small second-order effect that mildly alters the statistics of the microwave background…
We discuss the constraints on the AGN evolution from the cosmic X-ray background and source counts. A synthesis model to fit the X-ray background is presented. In the model, the spectrum of type 2 AGN has been modeled including Compton…
We study the cosmic X-ray background (CXB) intensity variations on large angular scales using slew data of the RXTE observatory. We detect intensity variations up to ~2% on angular scales of 20--40deg. These variations are partly correlated…
Spatial fluctuations in ultraviolet backgrounds can subtly modulate the distribution of extragalactic sources, a potential signal and systematic for large-scale structure surveys. While this modulation has been shown to be significant for…
The behaviour of the transverse momentum fluctuations with the centrality of the collision shown by the Relativistic Heavy Ion Collider data is naturally explained by the clustering of color sources. In this framework, elementary color…
We propose to use a simple observable, the fractional area of "hot spots" in weak gravitational lensing mass maps which are detected with high significance, to determine background cosmological parameters. Because these high-convergence…
A detailed search has been made for evidence of foreground contributions to the Cosmic Microwave Background (CMB) WMAP, such foregrounds being related to our Galaxy. We find remarkable results. On the largest angular scales we find…
The theory of cosmological perturbations has become a cornerstone of modern quantitative cosmology since it is the framework which provides the link between the models of the very early Universe such as the inflationary Universe scenario…
Relativistically expanding sources of X-rays and gamma-rays cover an enormous range of (central) compactness and Lorentz factor. The underlying physics is discussed, with an emphasis on how the dominant dissipative mode and the emergent…
The fluctuations due to the clustering of color sources can explain the behaviour of the scaled multiplicity variance and transverse momentum fluctuations with centrality. They also predict a nonmonotonic behaviour with centrality for the…
A simple model to explain the phase-dependence of the cyclotron absorption line observed in many X-Ray pulsars is presented. It includes several relativistic effects, namely gravitational redshift, gravitational light deflection, and - most…
This paper presents a completely analytic treatment of cosmological fluctuations whose wavelength is small enough to come within the horizon well before the energy densities of matter and radiation become equal. This analysis yields a…