critical density

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critical density

See mean density of matter.

critical density

[′krid·ə·kəl ′den·səd·ē]
(astronomy)
The mass density above which, it is believed, the expansion of the universe will slow down and reverse.
(chemistry)
The density of a substance exhibited at its critical temperature and critical pressure.
(civil engineering)
For a highway, the density of traffic when the volume equals the capacity.
(geology)
That degree of density of a saturated, granular material below which, as it is rapidly deformed, it will decrease in strength and above which it will increase in strength.
(thermodynamics)
The density of a substance at the liquid-vapor critical point.

critical density

That unit weight of a saturated granular material above which it will gain strength and below which it will lose strength when subjected to rapid deformation.
References in periodicals archive ?
The general expression of the energy-momentum tensor to the Friedmann equation contains the sum of all contributions [[rho].
the most general Friedmann equation of model universes takes, expressed by dimensionless additives, the form
Here if we consider the case in which the cosmic vacuum dark energy only contains a quintessence field [xi] then with the help of Friedmann equations we have
Solutions to the Friedmann Equations with the Lambda Term for a Dust-Radiation Universe.
The simplest cosmological model that describes the recent acceleration of the universe is governed by the Friedmann equation with a non-zero Einsteinian cosmological constant [1-2, 5].
Exact solutions of the Friedmann equation [25-26] with the cosmological constant were obtained by [27-28].
The objective of this study is to quantitatively study the turning point and expansion characteristics of the recent acceleration universe through analyzing and numerically solving the Friedmann equation with a non-zero cosmological constant.