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We derive the asymptotic mass profile near the collapse center of an initial spherical density perturbation, δ ∝ M, of collision-less particles with non-radial motions. We show that angular momenta introduced at the initial time do not affect the mass profile. Alternatively, we consider a scheme in which a particle moves on a radial orbit until it reaches(More)
An interesting test of Einstein’s equivalence principle (EEP) relies on the observed lag in arrival times of photons emitted from extragalactic transient sources. Attributing the lag between photons of different energies to the gravitational potential of the Milky Way (MW), several authors derive new constraints on deviations from EEP. It is shown here that(More)
Existing models invoking AGN activty to resolve the cooling flow conundrum in galaxy clusters focus exclusively on the role of the central galaxy. Such models require finetuning of highly uncertain microscopic transport properties to distribute the thermal thermal over the entire cluster cooling core. We propose that the ICM is instead heated by multiple,(More)
We present a comparison between the peculiar velocity fields measured from the SFI all-sky Sbc-Sc Tully-Fisher catalog and that derived from the IRAS 1.2 Jy redshift survey galaxy distribution. The analysis is based on the expansion of these data in redshift space using smooth orthonormal functions and is performed using low and high resolution expansions,(More)
We present predictions for the reionization of the intergalactic medium (IGM) by stars in high-redshift galaxies, based on a semi-analytic model of galaxy formation. We calculate ionizing luminosities of galaxies, including the effects of absorption by interstellar gas and dust on the escape fraction fesc, and follow the propagation of the ionization fronts(More)
We present extensive tests of the Fast Action Method (FAM) for recovering the past orbits of mass tracers in an expanding universe from their redshift-space coordinates at the present epoch. The tests focus on the reconstruction of present-day peculiar velocities using mock catalogs extracted from high resolution N -body simulations. The method allows for a(More)
We examine the implications of Modified Newtonian Dynamics (MOND) on the large scale structure in a Friedmann-Robertson-Walker universe. We employ a “Jeans swindle” to write a MOND-type relationship between the fluctuations in the density and the gravitational force, g. In linear Newtonian theory, |g| decreases with time and eventually becomes < g0 , the(More)