Physical properties of some McVittie metrics

Journal Article · Tue Jul 01 04:00:00 EDT 1986 · Int. J. Theor. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00668720· OSTI ID:7168823

Knutsen, H

A class of McVittie's new nonquadratic solutions is investigated in some detail with regard to its physical properties. It is found that decreasing pressure and density are not compatible with center regularity for these perfect fluid spheres. It is further seen that for ''gaseous'' spheres (i.e., the density /rho/ drops to zero at the outer boundary of the sphere together with the pressure /rho/) oscillatory motions are not possible. For these ''gaseous'' models the pressure and the density are both positive inside the outer surface, and their respective gradients are negative. For the outer ''gaseous'' shells models are constructed where for a certain time interval the pressure is increasing for contracting models. Without any restriction with respect to time, for these shell models it found that the density is increasing for contracting models, and the adiabatic speed of sound is less than the speed of light. It is also found that the trace of the energy-momentum tensor is positive, the total mass is negative, and for collapsing shells the rate of change of circumference as measured by an observer riding on the shell is an increasing function of time. However, all these models have the strange geometric feature that the ''physical radius'' is a decreasing function of comoving radial coordinate.

• Research Organization: Stavanger College of Engineering, Stavanger
• OSTI ID: 7168823
• Journal Information: Int. J. Theor. Phys.; (United States), Journal Name: Int. J. Theor. Phys.; (United States) Vol. 25:7; ISSN IJTPB
• Country of Publication: United States
• Language: English

Related Subjects

640106* -- Astrophysics & Cosmology-- Cosmology
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMOLOGICAL MODELS
EINSTEIN FIELD EQUATIONS
ENERGY-MOMENTUM TENSOR
EQUATIONS
EXPANSION
FIELD EQUATIONS
FIELD THEORIES
FLUIDS
GENERAL RELATIVITY THEORY
GRAVITATIONAL COLLAPSE
GRAVITATIONAL FIELDS
MATHEMATICAL MODELS
METRICS
PRESSURE DEPENDENCE
PRESSURE GRADIENTS
QUANTUM FIELD THEORY
QUANTUM FLUIDS
QUANTUM GRAVITY
SPHERES
STAR MODELS
TENSORS