Cosmic expansion and structure formation in running vacuum cosmologies

@article{Basilakos2015CosmicEA,
  title={Cosmic expansion and structure formation in running vacuum cosmologies},
  author={Spyros Basilakos},
  journal={arXiv: Cosmology and Nongalactic Astrophysics},
  year={2015}
}
  • S. Basilakos
  • Published 15 January 2015
  • Physics
  • arXiv: Cosmology and Nongalactic Astrophysics
We investigate the dynamics of the FLRW flat cosmological models in which the vacuum energy varies with redshift. A particularly well motivated model of this type is the so-called quantum field vacuum, in which both kind of terms $H^{2}$ and constant appear in the effective dark energy density affecting the evolution of the main cosmological functions at the background and perturbation levels. Specifically, it turns out that the functional form of the quantum vacuum endows the vacuum energy of… 

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References

SHOWING 1-10 OF 37 REFERENCES

Cosmic structure and dark energy

Dark energy has a dramatic effect on the dynamics of the Universe, causing the recently discovered acceleration of the expansion. The dynamics are also central to the behaviour of the growth of

Dark energy and the evolution of spherical overdensities

We use the non-linear spherical model in cold dark matter (CDM) cosmologies with dark energy to investigate the effects of dark energy on the growth of structure and the formation of virialized

Probing dark energy at galactic and cluster scales

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

Number counts and dynamical vacuum cosmologies

We study non-linear structure formation in an interacting model of the dark sector of the Universe in which the dark energy density decays linearly with the Hubble parameter, $\rho_{\Lambda} \propto

Cluster Formation Rate in Models with Dark Energy

Based on flat Friedmann-Robertson-Walker cold dark matter (CDM) models driven by nonrelativistic matter and an exotic fluid (quintessence) with an equation of state pQ = wρQ (-1 ≤ w < 0), we

Spherical collapse model in dark‐energy cosmologies

We study the spherical collapse model for several dark-energy scenarios using the fully non-linear differential equation for the evolution of the density contrast within homogeneous spherical

On virialization with dark energy

We review the inclusion of dark energy in the formalism of spherical collapse, and the virialization of a two-component system, made of matter and dark energy. We compare two approaches in previous

Spherical collapse model in time varying vacuum cosmologies

We investigate the virialization of cosmic structures in the framework of flat Friedmann-Lemaitre-Robertson-Walker cosmological models, in which the vacuum energy density evolves with time. In

Cluster Abundance Constraints for Cosmological Models with a Time-varying, Spatially Inhomogeneous Energy Component with Negative Pressure

The abundance of rich clusters is a strong constraint on the mass power spectrum. The current constraint can be expressed in the form σ8 Ω=0.5±0.1, where σ8 is the rms mass fluctuation on 8 h-1 Mpc

Constraining the dark energy perturbations using growth index analysis

We derive a new formulation of the growth index of matter fluctuations in the regime where the dark energy is allowed to have clustering. In particular, we find that the growth index is not only