Zobrazeno 1 - 10
of 362
pro vyhledávání: '"Zimdahl, W."'
Publikováno v:
Eur. Phys. J. C 80, 1110 (2020)
Models with non-gravitational interactions between the dark matter and dark energy components are an alternative to the standard cosmological scenario. These models are characterized by an interaction term, and a frequently used parameterization is $
Externí odkaz:
http://arxiv.org/abs/1909.10336
Publikováno v:
Physics of the Dark Universe, Volume 23, 2019, 100248
We reconsider the dynamics of the Universe in the presence of interactions in the cosmological dark sector. A class of interacting models is introduced via a real function $f\left(r\right)$ of the ratio $r$ between the energy densities of the (pressu
Externí odkaz:
http://arxiv.org/abs/1807.11380
Publikováno v:
IJMPD Vol. 28, No. 06, 1950086 (2019)
On the basis of a previously established scalar-tensor extension of the $\Lambda$CDM model we develop an effective fluid approach for the matter growth function. This extended $\Lambda$CDM (henceforth $e_{\Phi}\Lambda$CDM) cosmology takes into accoun
Externí odkaz:
http://arxiv.org/abs/1706.06143
Both scalar fields and (generalized) Chaplygin gases have been widely used separately to characterize the dark sector of the Universe. Here we investigate the cosmological background dynamics for a mixture of both these components and quantify the fr
Externí odkaz:
http://arxiv.org/abs/1703.04149
Yes, but only for a parameter value that makes it almost coincide with the standard model. We reconsider the cosmological dynamics of a generalized Chaplygin gas (gCg) which is split into a cold dark matter (CDM) part and a dark energy (DE) component
Externí odkaz:
http://arxiv.org/abs/1702.00651
An interaction between dark matter and dark energy, proportional to the product of their energy densities, results in a scaling behavior of the ratio of these densities with respect to the scale factor of the Robertson-Walker metric. This gives rise
Externí odkaz:
http://arxiv.org/abs/1610.01665
We construct a cosmological scalar-tensor-theory model in which the Brans-Dicke type scalar $\Phi$ enters the effective (Jordan-frame) Hubble rate as a simple modification of the Hubble rate of the $\Lambda$CDM model. This allows us to quantify diffe
Externí odkaz:
http://arxiv.org/abs/1607.03952
We discuss the possibility to implement a viscous cosmological model, attributing to the dark matter component a behaviour described by bulk viscosity. Since bulk viscosity implies negative pressure, this rises the possibility to unify the dark secto
Externí odkaz:
http://arxiv.org/abs/1512.00921
Publikováno v:
Eur.Phys.J. C74 (2014) 11, 3160
The observational fact that the present values of the densities of dark energy and dark matter are of the same order of magnitude, $\rho_{de0}/\rho_{dm0} \sim \mathcal{O}(1)$, seems to indicate that we are currently living in a very special period of
Externí odkaz:
http://arxiv.org/abs/1410.2509
Publikováno v:
MNRAS 457 (2016) n.3, 2958-2967
A suitable nonlinear interaction between dark matter with an energy density $\rho_{M}$ and dark energy with an energy density $\rho_{X}$ is known to give rise to a non-canonical scaling $\rho_{M} \propto \rho_{X}a^{-\xi}$ where $\xi$ is a parameter w
Externí odkaz:
http://arxiv.org/abs/1409.7706