Recovery of fluctuation spectrum evolution from tomographic shear spectra

Forthcoming large angle surveys are planned to obtain high precision tomographic shear data. In principle, they will allow us to recover the spectra of matter density fluctuation, at various redshift, through the inversion of the expressions yielding shear from fluctuation spectra. This was discussed in previous work, where SVD techniques for matrix inversion were also shown to be the optimal tool to this aim. Here we show the significant improvements obtainable by using a 7 bin tomography, as allowed by future Euclid data, as well as the question of error propagation from shear to fluctuation spectra. We find that the technique is a promising tool, namely for the analysis of baryon physics throug high-l shear spectra and to test the consistency between expansion rate and fluctuation growth.Comment: 22 pages, 10 figure

Coupled DM heating in SCDEW cosmologies

Strongly Coupled Dark Energy plus Warm dark matter (SCDEW) cosmologies admit the stationary presence of $\sim 1\, \%$ of coupled-DM and DE, since inflationary reheating. Coupled-DM fluctuations therefore grow up to non-linearity even in the early radiative expansion. Such early non-linear stages are modelized here through the evolution of a top-hat density enhancement, reaching an early virial balance when the coupled-DM density contrast is just 25-26 and DM density enhancement is $\sim 10\, \%$ of total density. During the time needed to settle in virial equilibium, the virial balance conditions however continue to modify, so that "virialized" lumps undergo a complete evaporation. Here we outline that DM particles processed by overdentities preserve a fraction of their virial momentum. Although fully non-relativistic, the resulting velocities (moderately) affect the fluctuation dynamics over greater scales, entering the horizon later on.Comment: 20 pages, 7 figures; updated to match the published versio

Scaling Laws and Luminosity Segregation

We debate how the scaling properties of the angular correlation function w(θ) depend on luminosity segregation. Under the approximation that there is no deviation from Euclidean geometry and no evolution, we find that the scaling with catalog depth (D*) is the same both for a luminosity (L) independent clustering length (r0) and for a generic dependence of r0 on L. Recent angular data, however, extend to depths where the above approximation is unsuitable and the simple scaling w ∝ D should be modified. We find that such modifications depend on the shape of the L-dependence of r0 and are indeed different depending on whether luminosity segregation is or is not considered. In particular, we find that a luminosity segregation as observed at z = 0 causes effects of the same order as varying the rate of clustering evolution. For the sake of example, we apply our expressions to available angular galaxy data in the B- and R-bands and show that significant constraints on the evolution of clustering can already be found with public data