Probing Dark Energy at Galactic and Cluster Scales

Understand

We investigate dark matter halo properties as a function of a time--varying dark energy equation of state.

• The dynamics of the collapse of the halo is governed by the form of the quintessence potential, the time evolution of its equation of state, the initial conditions of the field and its homogeneity nature in the highly non--linear regime.
• These have a direct impact on the turnaround, virialisation and collapse times, altering in consequence the non--linear density contrast and virial radius.
• We compute halo concentrations using the Eke, Navarro & Steinmetz algorithm, examining two extreme scenarios: first, we assume that the quintessence field does not exhibit fluctuations on cluster scales and below - homogeneous fluid; second, we assume that the field inside the overdensity collapses along with the dark matter - inhomogeneous fluid.