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Horizon problem in a closed universe dominated by fluid with negative pressure
Author(s) -
Stelmach Jerzy
Publication year - 1999
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/(sici)1521-3889(199912)8:10<837::aid-andp837>3.0.co;2-p
Subject(s) - physics , horizon , cosmic microwave background , cosmological constant , apparent horizon , universe , particle horizon , astrophysics , dark energy , supernova , mathematical physics , metric expansion of space , cosmology , quantum mechanics , event horizon , astronomy , anisotropy
We discuss the horizon problem in a universe dominated by fluid with negative pressure. We show that for generally accepted value of nonrelativistic matter energy density parameter Ω m 0 < 1, the horizon problem can be solved only if the fluid influencing negative pressure (the so‐called “X” component) violates the point‐wise strong energy condition and if its energy density is sufficiently large ( Ω X 0 > 1). The calculated value of the Ω X 0 parameter allowing for the solution of the horizon problem is confronted with some recent observational data. Assuming that p X / ρ X < —0.6 we find that the required amount of the “X” component is not ruled out by the supernova limits. Since the value of energy density parameter Ω v 0 for cosmological constant larger than 1 is excluded by gravitational lensing observations the value of the ratio p X / ρ X should lie between the values —1 and —0.6 if the model has to be free of the horizon problem beeing at the same time consistent with observations. The value of Ω X 0 + Ω m 0 in the model is consistent with the constraints 0.2 < Ω tot < 1.5 following from cosmic microwave background observations provided that Ω m 0 is low (<0.2).