Gravitational lensing effects on the baryonic acoustic oscillation signature in the redshiftspace correlation function
Abstract
Measurements of the baryonic acoustic oscillation (BAO) peak in the redshiftspace correlation function yield the angular diameter distance D_{A}(z) and the Hubble parameter H(z) as a function of redshift, constraining the properties of dark energy and space curvature. We discuss the perturbations introduced in the galaxy correlation function by gravitational lensing through the effect of magnification bias and its cross correlation with the galaxy density. At the BAO scale, gravitational lensing adds a small and slowly varying component to the galaxy correlation function and does not change its shape significantly, through which the BAO peak is measured. The relative shift in the position of the BAO peak caused by gravitational lensing in the angleaveraged correlation function is 10^{4} at z=1, rising to 10^{3} at z=2.5. Lensing effects are stronger near the line of sight; however, the relative peak shift increases only to 10^{3.3} and 10^{2.4} at z=1 and z=2.5, when the galaxy correlation is averaged within 5 degrees of the line of sight (containing only 0.4% of the galaxy pairs in a survey). Furthermore, the lensing contribution can be measured separately and subtracted from the observed correlation at the BAO scale.
 Publication:

Physical Review D
 Pub Date:
 August 2010
 DOI:
 10.1103/PhysRevD.82.043527
 arXiv:
 arXiv:0901.0708
 Bibcode:
 2010PhRvD..82d3527Y
 Keywords:

 98.80.k;
 98.62.Py;
 98.65.r;
 98.80.Jk;
 Cosmology;
 Distances redshifts radial velocities;
 spatial distribution of galaxies;
 Galaxy groups clusters and superclusters;
 large scale structure of the Universe;
 Mathematical and relativistic aspects of cosmology;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 6 pages, 4 figures, accepted for publication in Physical Review D