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Light propagation and the distance-redshift relation in a realistic inhomogeneous universeThe propagation of light rays in a clumpy universe constructed by cosmological version of the post-Newtonian approximation was investigated. It is shown that linear approximation to the propagation equations is valid in the region where zeta is approximately less than 1 even if the density contrast is much larger than unity. Based on a gerneral order-of-magnitude statistical consideration, it is argued that the linear approximation is still valid where zeta is approximately greater than 1. A general formula for the distance-redshift relation in a clumpy universe is given. An explicit expression is derived for a simplified situation in which the effect of the gravitational potential of inhomogeneities dominates. In the light of the derived relation, the validity of the Dyer-Roeder distance is discussed. Also, statistical properties of light rays are investigated for a simple model of an inhomogeneous universe. The result of this example supports the validity of the linear approximation.
Document ID
19890017420
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Futamase, Toshifumi (Hirosaki Univ. Batavia, IL, United States)
Sasaki, Misao (Fermi National Accelerator Lab.)
Date Acquired
September 6, 2013
Publication Date
April 1, 1989
Subject Category
Astrophysics
Report/Patent Number
NASA-CR-185041
NAS 1.26:185041
FERMILAB-PUB-89/111-A
Accession Number
89N26791
Funding Number(s)
CONTRACT_GRANT: NAGW-1340
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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