An old quasar in a young dark energy-dominated universe?

Abstract

Dark energy is the invisible fuel that seems to drive the current acceleration of the Universe. Its presence, which is inferred from an impressive convergence of high-quality observational results along with some apparently sucessful theoretical predictions, is also supported by the current estimates of the age of the Universe from dating of local and high-$z$ objects. In this paper we test the viability of several dark energy scenarios in the light of the age estimates of the high redshift ($z=3.91$) quasar APM 08279+5255. Using a chemodinamical model for the evolution of spheroids, we first reevaluate its current estimated age, as given by Hasinger et al. (2002). An age of 2.1 Gyr is set by the condition that Fe/O abundance ratio (normalized to solar values) of the model reaches 3.3, which is the best fit value obtained in the above reference. It is shown that for the currently accepted value of the matter density parameter, most of the existing dark energy scenarios cannot accomodate this old high redshift object unless the Hubble parameter is as low as $H_o = 58$ $\rm{km.s^{-1}.Mpc^{-1}}$, as recently advocated by Sandage and collaborators. Even considering less stringent age limits, only cosmological models that predicts a considerably old Universe at high-$z$ can be compatible with the existence of this object. This is the case of the conventional $\Lambda$CDM scenario and some specific classes of brane world cosmologies.Comment: 7 pages, 3 figures, uses mn.cl

Dark Energy

“…By comparing photometric data acquired from the Beijing-Arizona-TaiwanConnecticut system with up-to-date theoretical synthesis models, Ma et al [467] obtained the ages of 139 globular clusters (GCs) in the M31 galaxy, in which 9 extremely old GCs are older than the present cosmic age predicted by the 7-year WMAP observations [468]. In addition, the existence of high-z quasar APM 08279+5255 at z = 3.91 [469] is also a mystery [470,471,472]. Using the maximum likelihood values of the 7-year WMAP observations Ω m = 0.272 and h = 0.704, the ΛCDM model can only give a cosmic age t = 1.63 Gyr at redshift z = 3.91, while the lower limit of this quasar's age is 1.8 Gyr.…”

Thermodynamical description of the interaction between holographic dark energy and dark matter

“…In Ref. [9] it was investigated whether this model satisfies the current Universe age constraints and allows a considerably older universe at high redshift to be compatible with the existence of some old objects such as the old quasar APM0879+5255 at redshift z = 3.91 [41]. Its age, at that redshift, was estimated as t g = 2.1Gyr.…”

“…The different evolution of the DM due to its interaction with the DE gives rise to a different expansion history of the Universe and a different evolution of the matter density perturbations which alters the standard structure formation scenario as the latter assumes ρ m ∝ a −3 . In [7,9] the matter density perturbations in interacting models were investigated and in [9] the impact of the interaction on the DM perturbations was used to explain why it is possible, as recently observed [41], for the old quasar APM0879+5255 to exist already at the early stages of the Universe (at z = 3.91). As a comparison, in Figs.…”

Metric theory of gravity with torsion in an extra dimension

“…Chen and Jing [23] showed that those equations yield accelerating universe solutions without resorting to dark energy. They show that the model not only fits the supernovae data, but also solves the cosmic age problem of old high redshift objects [24]. Whether the cosmological solutions described in the current work would fit empirical results just as well needs to be investigated.…”