Zobrazeno 1 - 10
of 134
pro vyhledávání: '"RUBANO, CLAUDIO"'
Publikováno v:
Monthly Notices of the Royal Astronomical Society, 426, pp. 1396-1415 (2012)
The explanation of the accelerated expansion of the Universe poses one of the most fundamental questions in physics and cosmology today. If the acceleration is driven by some form of dark energy, one can try to constrain the parameters using a cosmog
Externí odkaz:
http://arxiv.org/abs/1206.7046
On exact solutions for quintessential (inflationary) cosmological models with exponential potentials
We first study dark energy models with a minimally-coupled scalar field and exponential potentials, admitting exact solutions for the cosmological equations: actually, it turns out that for this class of potentials the Einstein field equations exhibi
Externí odkaz:
http://arxiv.org/abs/1112.0502
Noether symmetry for Gauss-Bonnet-Dilatonic interaction exists for a constant dilatonic scalar potential and a linear functional dependence of the coupling parameter on the scalar field. The symmetry with the same form of the potential and coupling p
Externí odkaz:
http://arxiv.org/abs/1107.0560
In the framework of renormalization-group improved cosmologies, we analyze both theoretically and observationally the exact and general solution of the matter-dominated cosmological equations, using the expression of \Lambda = \Lambda(G) already dete
Externí odkaz:
http://arxiv.org/abs/1104.3029
It has been recently empirically established that some of the directly observed pa- rameters of GRBs are correlated with their important intrinsic parameters, like the luminosity or the total radiated energy. These correlations were derived, tested a
Externí odkaz:
http://arxiv.org/abs/1010.0855
We study some problems arising from the introduction of a complex scalar field in cosmology, modelling its possible behaviors in both the inflationary and dark energy stages of the universe. Such examples contribute to show that, while the complex na
Externí odkaz:
http://arxiv.org/abs/1009.2887
Publikováno v:
Class.Quant.Grav.24:6255-6266,2007
This paper investigates the Arnowitt--Deser--Misner (hereafter ADM) form of spherically symmetric gravity with variable Newton parameter G and cosmological term Lambda(c). The Newton parameter is here treated as a dynamical variable, rather than bein
Externí odkaz:
http://arxiv.org/abs/0709.1403
Noether symmetry approach to scalar-field-dominated cosmology with dynamically evolving G and Lambda
Publikováno v:
Int.J.Geom.Meth.Mod.Phys.5:329-337,2008
This paper studies the cosmological equations for a scalar field Phi in the framework of a quantum gravity modified Einstein--Hilbert Lagrangian where G and Lambda are dynamical variables. It is possible to show that there exists a Noether symmetry f
Externí odkaz:
http://arxiv.org/abs/0708.0525
Publikováno v:
Gen.Rel.Grav.39:189-209,2007
In the framework of renormalization-group improved cosmologies, we use the Noether symmetry approach to get exact and general integration of the matter-dominated cosmological equations. This is performed by using an expression of Lambda=Lambda(G) det
Externí odkaz:
http://arxiv.org/abs/astro-ph/0612091
Publikováno v:
Phys.Rev.D74:123513,2006
The covariant gauge invariant perturbation theory of scalar cosmological perturbations is developed for a general Scalar-Tensor Friedmann-Lemaitre-Robertson-Walker cosmology in a vacuum. The perturbation equations are then solved exactly in the long
Externí odkaz:
http://arxiv.org/abs/gr-qc/0611113