Weak gravitational lensing by galaxy clusters on faint higher redshift galaxies has been traditionally used to study the cluster mass distribution and as a tool to identify clusters as peaks in the ...shear maps. However, it becomes soon clear that peak statistics can also be used as a way to constrain the underlying cosmological model due to its dependence on both the cosmic expansion rate and the growth rate of structures. This feature makes peak statistics particularly interesting from the point of view of discriminating between General Relativity and modified gravity. Here we consider a general class of f(R) theories and compute the observable mass function based on the aperture mass statistics. We complement our theoretical analysis with a Fisher matrix forecast of the constraints that an Euclid-like survey can impose on the f(R) model parameters. We show that peak statistics alone can in principle discriminate between General Relativity and f(R) models and strongly constrain the f(R) parameters that are sensitive to the non-linear growth of structure. However, further analysis is needed in order to include possible selection function in the peaks redshift determination.
Modeling Dynamical Dark Energy Mainini, R; Macciò, A. V; Bonometto, S. A ...
The Astrophysical journal,
12/2003, Letnik:
599, Številka:
1
Journal Article
We consider cosmological models with dynamical dark energy (dDE) coupled to cold dark matter (CDM), while simultaneously allowing neutrinos to be massive. Using a MCMC approach, we compare these ...models with a wide range of cosmological data sets. We find a strong correlation between this coupling strength and the neutrino mass. This correlation persists when BAO data are included in the analysis. We add then priors on
ν
mass from particle experiments. The claimed detection of
ν
mass from the Heidelberg–Moscow neutrinoless double-
β
decay experiment would imply a 7–
8
σ
detection of CDM–DE coupling. Similarly, the detection of
ν
mass from coming KATRIN tritium
β
decay experiment will imply a safe detection of a coupling in the dark sector. Previous attempts to accommodate cosmic phenomenology with such possible
ν
mass data made recourse to a
w
<
-
1
eoS. We compare such an option with the coupling option and find that the latter allows a drastic improvement.
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