The Existence of an Old Quasar at $z=3.91$ and its Implications for $\Lambda (t)$ Deflationary Cosmologies

Abstract

We investigate some observational constraints on decaying vacuum cosmologies based on the recently discovered old high redshift quasar APM 08279+5255. This object is located at $z=3.91$ and has an estimated age of 2-3 Gyr. The class of $\Lambda (t)$ cosmologies is characterized by a positive $\beta$ parameter smaller than unity which quantifies the ratio between the vacuum and the total energy density. Assuming the lower limit age (2 Gyr) and that the cold dark matter contributes with ${\Omega }_{\mathrm{M}}=0.2$ we show that $\beta$ is constrained to be $\ge 0.07$ while for an age of 3 Gyr and ${\Omega }_{\mathrm{M}}=0.4$ the $\beta$ parameter must be greater than 0.32. Our analysis includes closed, flat and hyperbolic scenarios, and it strongly suggests that there is no age crisis for this kind of $\Lambda (t)$ cosmologies. Lower limits to the redshift quasar formation are also briefly discussed to the flat case. For ${\Omega }_{\mathrm{M}}=0.4$ we found that the redshift formation is constrained by $z_f\ge 8.0$.

arXiv comment8 pages, 2 figures, submitted to IJMPD

References in corpus (5)

• Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
• Generalized Chaplygin Gas, Accelerated Expansion and Dark Energy-Matter Unification
• Constraining the cosmic equation of state from old galaxies at high redshift
• Cosmological implications of APM 08279+5255, an old quasar at z = 3.91
• Deflationary cosmology: constraints from angular size and ages of globular clusters

Cited by in corpus (37)

• Cosmologies with Energy Exchange
• Kinematic Constraints to the Transition Redshift from SNe Ia Union Data
• Transition Redshift: New Kinematic Constraints from Supernovae
• Interpreting Cosmological Vacuum Decay
• Accelerating Cold Dark Matter Cosmology (${\Omega }_{\Lambda }\equiv 0$)
• Age Problem in the Holographic Dark Energy Model
• The age problem in $\Lambda$CDM model
• An old quasar in a young dark energy-dominated universe?
• Observational constraints on late-time Lambda(t) cosmology
• Supernova constraints on decaying vacuum cosmology
• Alleviation of Cosmic Age Problem In Interacting Dark Energy Model
• New coupled quintessence cosmology
• Chemical Potential and the Nature of the Dark Energy: The case of phantom
• Bianchi Type-I Cosmological Models with Variable G and 4Λ$-Terms in General Relativity
• Cosmic age, Statefinder and $Om$ diagnostics in the decaying vacuum cosmology
• Coupled quintessence and vacuum decay
• Can Old Galaxies at High Redshifts and Baryon Acoustic Oscillations Constrain H_0?
• Clustering, Angular Size and Dark Energy
• Constraining $H_0$ from Sunyaev-Zel'dovich effect, Galaxy Clusters X-ray data, and Baryon Oscillations
• Non-adiabatic perturbations in decaying vacuum cosmology
• RC J0311+0507: A Candidate for Superpowerful Radio Galaxies in the Early Universe at Redshift z=4.514
• On the equivalence of Lambda(t) and gravitationally induced particle production cosmologies
• New Constraints on the Variable Equation of State Parameter from X-Ray Gas Mass Fractions and SNe Ia
• Constraining the dark energy and smoothness-parameter with supernovae
• Black Hole Formation with an Interacting Vacuum Energy Density
• Age Problem in Lemaitre-Tolman-Bondi Void Models
• Test of conformal gravity with astrophysical observations
• Cosmology with an Effective $\Lambda$-Term in Lyra Manifold
• Matter Perturbations in Scaling Cosmology
• Reconciling the cosmic age problem in the R_h=ct Universe
• Variable cosmological term $\Lambda (t)$
• Baryonic matter perturbations in decaying vacuum cosmology
• Constraints from the Old Quasar APM 08279+5255 on Two Classes of $\Lambda ($t$)$-Cosmologies
• Cosmological Models with a Varying $\Lambda$ -Term in Lyra's Geometry
• The torsion cosmology in Kaluza-Klein theory
• Constraining the Nonextensive Mass Function of Halos from BAO, CMB and X-ray data
• Cosmological volume acceleration in dust epoch: using scaling solutions and variable cosmological term $\Lambda (t)$ within an anisotropic cosmological model