# 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} }

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…

## 7 Citations

### Running vacuum cosmological models: linear scalar perturbations

- Physics
- 2017

In cosmology, phenomenologically motivated expressions for running vacuum are commonly parameterized as linear functions typically denoted by Λ(H2) or Λ(R). Such models assume an equation of state…

### Possible signals of vacuum dynamics in the Universe

- Physics
- 2018

We study a generic class of time-evolving vacuum models which can provide a better phenomenological account of the overall cosmological observations as compared to the $\Lambda$CDM. Among these…

### Cosmic Acceleration from Varying Masses in Five Dimensions

- Physics
- 2015

Much effort has been made in trying to solve or at least evade the inconsistencies that emerge from general relativity as the framework for a cosmological model. The extradimensional models rise as…

### Growth index of matter perturbations in running vacuum models

- Materials Science, Mathematics
- 2015

We derive for the first time the growth index of matter perturbations of the Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) flat cosmological models in which the vacuum energy depends on redshift. A…

### The $R_{\mathrm{h}}=ct$ universe and quintessence

- Physics
- 2016

Over the last few years the $R_{\mathrm{h}}=ct$ universe has received a lot of attention, particularly when observational evidence seems to favor this over the standard $\Lambda$ cold dark matter…

### Fundamental Constants in Physics and Their Time Variation

- Physics, Education
- 2015

There is no doubt that the field of Fundamental Constants in Physics and Their Time Variation is one of the hottest subjects in modern theoretical and experimental physics, with potential…

### Fundamental constants and cosmic vacuum: the micro and macro connection

- Physics
- 2015

The idea that the vacuum energy density $\rho_{\Lambda}$ could be time dependent is a most reasonable one in the expanding Universe; in fact, much more reasonable than just a rigid cosmological…

## References

SHOWING 1-10 OF 37 REFERENCES

### Cosmic structure and dark energy

- Physics
- 2003

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

- Physics
- 2004

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

- Physics
- 2008

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

- Physics
- 2015

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

- Physics
- 2003

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

- Physics
- 2010

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

- Physics
- 2005

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

- Physics
- 2010

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

- Physics
- 1998

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

- Physics, Economics
- 2014

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…