Sereno M. Role of lambda in the cosmological lens equation.
PHYSICAL REVIEW LETTERS 2009;
102:021301. [PMID:
19257262 DOI:
10.1103/physrevlett.102.021301]
[Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Indexed: 05/27/2023]
Abstract
The cosmological constant Lambda affects cosmological gravitational lensing. Effects due to Lambda can be studied in the framework of the Schwarzschild-de Sitter spacetime. Two novel contributions, which cannot be accounted for by a proper use of angular diameter distances, are derived. First, a term deltaalpha[over ;]_(Lambda)=2mbLambda/3 has to be added to the bending angle, where m is the lens mass and b the impact parameter. Second, Lambda brings about a difference in the redshifts of multiple images. Both effects are quite small for real astrophysical systems, deltaalpha[over ;]_(Lambda) less, similar1muarcsec and Deltaz_(s) less, similar10(-7).
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