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Large-scale structure effects on the gravitational lens image positions and time delayWe compute the fluctuations in gravitational lens image positions and time delay caused by large-scale structure correlations. We show that these fluctuations can be expressed as a simple integral over the density power spectrum. Using the Cosmic Background Explorer (COBE) normalization we find that positions of objects at cosmological distances are expected to deviate from their true positions by few arcminutes. These deflections are not directly observable. The positions of the images relative to one another fluctuate by a few percent of the relative separation, implying that one does not expect multiple images to be produced by large-scale structure. Nevertheless, the fluctuations are larger than the observational errors on the positions and affect reconstructions of the lens potential. The time delay fluctuations have a geometrical and a gravitational contribution. Both are much larger than the expected time delay from the primary lens, but partially cancel each other. We find that large-scale structure weakly affects the time delay and time delay measurements can be used as a probe of the distance scale in the universe.
Document ID
19950037384
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Seljak, Uros
(MIT, Cambridge, MA United States)
Date Acquired
August 16, 2013
Publication Date
December 1, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 436
Issue: 2
ISSN: 0004-637X
Subject Category
Astronomy
Accession Number
95A68983
Funding Number(s)
CONTRACT_GRANT: NAGW-2807
CONTRACT_GRANT: NSF AST-90-01762
Distribution Limits
Public
Copyright
Other

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