We study the concentration parameters, their mass dependence and redshift evolution, of dark-matter halos in different dark-energy cosmologies with constant and time-variable equation of state, and compare them with "standard" ΛCDM and OCDM models. The dependence of averaged halo concentrations on mass and redshift permits a simple fit of the form (1+z)c=c0(M/M0)α, with α≈-0.1 throughout. We find that the cluster concentration depends on the dark energy equation of state at the cluster formation redshift zcoll through the linear growth factor D+(zcoll). As a simple correction accounting for dark-energy cosmologies, we propose scaling c0 from ΛCDM with the ratio of linear growth factors, c0→c0D+(zcoll)/D+,ΛCDM(zcoll).
Properties of Galaxy Clusters in Cosmologies with Dark Energy / Dolag, K.; Bartelmann, M.; Moscardini, L.; Perrotta, F.; Baccigalupi, C.; Meneghetti, M.; Tormen, G.. - In: MODERN PHYSICS LETTERS A. - ISSN 0217-7323. - 19:13-16(2004), pp. 1079-1082. [10.1142/S0217732304014392]
Properties of Galaxy Clusters in Cosmologies with Dark Energy
Perrotta, F.;Baccigalupi, C.;
2004-01-01
Abstract
We study the concentration parameters, their mass dependence and redshift evolution, of dark-matter halos in different dark-energy cosmologies with constant and time-variable equation of state, and compare them with "standard" ΛCDM and OCDM models. The dependence of averaged halo concentrations on mass and redshift permits a simple fit of the form (1+z)c=c0(M/M0)α, with α≈-0.1 throughout. We find that the cluster concentration depends on the dark energy equation of state at the cluster formation redshift zcoll through the linear growth factor D+(zcoll). As a simple correction accounting for dark-energy cosmologies, we propose scaling c0 from ΛCDM with the ratio of linear growth factors, c0→c0D+(zcoll)/D+,ΛCDM(zcoll).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
