Speeding up the Universe using dust with pressure

@article{Luongo2018SpeedingUT,
  title={Speeding up the Universe using dust with pressure},
  author={Orlando Luongo and Marco Muccino},
  journal={Physical Review D},
  year={2018}
}
We revise the cosmological standard model presuming that matter, i.e., baryons and cold dark matter, exhibits a nonvanishing pressure mimicking the cosmological constant effects. In particular, we propose a scalar field Lagrangian ${\mathcal{L}}_{1}$ for matter with the introduction of a Lagrange multiplier as constraint. We also add a symmetry breaking effective potential accounting for the classical cosmological constant problem, by adding a second Lagrangian ${\mathcal{L}}_{2… 

Figures and Tables from this paper

Kinematic and statistical inconsistencies of Ho$\check{\textrm{r}}$ava-Lifshitz cosmology

We investigate the validity of a \emph{minimal} cosmological model derived from the renormalizable Ho$\check{\textrm{r}}$ava action at low redshift scales by using different cosmological and

High-redshift cosmography: auxiliary variables versus Padé polynomials

Cosmography becomes non-predictive when cosmic data span beyond the red shift limit $z\simeq1 $. This leads to a \emph{strong convergence issue} that jeopardizes its viability. In this work, we

A geometric mechanism of vacuum energy cancellation

We explore a mechanism of geometric cancellation of vacuum energy zero-point fluctuations, resolving de facto the cosmological constant problem. To do so, we assume at primordial times that vacuum

Unification of inflation and dark matter in the Higgs–Starobinsky model

In this work, we propose unified picture of inflation and dark matter in the Higgs–Starobinsky (HS) model. As pointed out in the literature, Starobinsky $$R^2$$R2 inflation is induced by quantum

Growth of matter perturbations in nonminimal teleparallel dark energy

We study the growth rate of matter perturbations in the context of teleparallel dark energy in a flat universe. We investigate the dynamics of different theoretical scenarios based on specific forms

Semi-classical gravity in de Sitter spacetime and the cosmological constant

Extended logotropic fluids as unified dark energy models

We study extended classes of logotropic fluids as unified dark energy models. Under the hypothesis of the Anton–Schmidt scenario, we consider a universe obeying a single fluid model with a

Effects of non-vanishing dark matter pressure in the Milky Way Galaxy

We consider the possibility that the Milky Way’s dark matter halo possesses a non-vanishing equation of state. Consequently, we evaluate the contribution due to the speed of sound, assuming that

Kinematic reconstructions of extended theories of gravity at small and intermediate redshifts

In the last few decades, extensions of general relativity have reached always more attention especially in view of possible breakdowns of the standard $$\varLambda $$ΛCDM paradigm at intermediate and

Extensions of modified Chaplygin gas from Geometrothermodynamics

We derive modified classes of Chaplygin gas by using the formalism of Geometrothermodynamics. In particular, our strategy gives us extended versions of Chaplygin gas, providing a novel thermodynamic

References

SHOWING 1-10 OF 52 REFERENCES

Perfect Fluids in General Relativity: Velocity Potentials and a Variational Principle

The equations of hydrodynamics for a perfect fluid in general relativity are cast in Eulerian form, with the four-velocity being expressed in terms of six velocity potentials:

An expanding Universe with constant pressure and no cosmological constant

Thanks to its fitting triumph, the ΛCDM paradigm is assumed to be the most powerful model, for describing the Universe dynamics, over much the myriad of cosmological models. Unfortunately, the quest

Cosmography and constraints on the equation of state of the Universe in various parametrizations

We use cosmography to present constraints on the kinematics of the Universe, without postulating any underlying theoretical model. To this end, we use a Monte Carlo Markov Chain analysis to perform

Dust of dark energy

We introduce a novel class of field theories where energy always flows along timelike geodesics, mimicking in that respect dust, yet which possess non-zero pressure. This theory comprises two scalar

The Cosmon model for an asymptotically vanishing time dependent cosmological 'constant'

We investigate the coupled system of gravity and a scalar with exponential potential. The energy momentum tensor of the scalar field induces a time-dependent cosmological “constant”. This adjusts

Fingerprinting dark energy. II. Weak lensing and galaxy clustering tests

The characterization of dark energy is a central task of cosmology. To go beyond a cosmological constant, we need to introduce at least an equation of state and a sound speed and consider

Non-minimally coupled dark matter: effective pressure and structure formation

We propose a phenomenological model in which a non-minimal coupling between gravity and dark matter is present in order to address some of the apparent small scales issues of ΛCDM model. When

Dynamics of dark energy

We review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating universe. In particular we discuss the arguments for and recent
...