Crossing the phantom divide: theoretical implications and observational status
Φόρτωση...
Ημερομηνία
Συγγραφείς
Nesseris, S.
Perivolaropoulos, L.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Journal of Cosmology and Astroparticle Physics
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Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
If the dark energy equation of state parameter w( z) crosses the phantom divide line w = - 1 ( or equivalently if the expression d(H(2)(z))/dz-3 Omega(0m)H(0)(2) ( 1 + z)(2) changes sign) at recent redshifts, then there are two possible cosmological implications. Either the dark energy consists of multiple components with at least one non-canonical phantom component or general relativity needs to be extended to a more general theory on cosmological scales. The former possibility requires the existence of a phantom component which has been shown to suffer from serious theoretical problems and instabilities. Therefore, the latter possibility is the simplest realistic theoretical framework in which such a crossing can be realized. After providing a pedagogical description of various dark energy observational probes, we use a set of such probes ( including the Gold SnIa ( supernovae type Ia) sample, the first-year SNLS ( Supernova Legacy Survey) data-set, the three-year WMAP CMB ( Wilkinson Microwave Anisotropy Probe cosmic microwave background) shift parameter, the SDSS (Sloan Digital Sky Survey) baryon acoustic oscillations peak (BAO), the x-ray gas mass fraction in clusters and the linear growth rate of perturbations at z = 0.15 as obtained from the 2dF (Two-Degree Field) Galaxy Redshift Survey) to investigate the priors required for cosmological observations to favour crossing of the phantom divide. We find that a low Omega(0m) prior ( 0.2 < Omega(0m) < 0.25) leads, for most observational probes ( except of the SNLS data), to an increased probability ( mild trend) for phantom divide crossing. An interesting degeneracy of the integrated Sachs-Wolfe effect in the CMB perturbation spectrum is also pointed out.
Περιγραφή
Λέξεις-κλειδιά
cmbr theory, dark energy theory, cosmology of theories beyond the sm, high-redshift supernovae, equation-of-state, microwave background anisotropies, hubble-space-telescope, digital sky survey, dark energy, cosmological constant, accelerating universe, extra dimensions, power spectrum
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000244080700018
http://iopscience.iop.org/1475-7516/2007/01/018/pdf/1475-7516_2007_01_018.pdf
http://iopscience.iop.org/1475-7516/2007/01/018/pdf/1475-7516_2007_01_018.pdf
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών