Open AccessNumerical study of the statistical properties of the lensing excursion angles
Author(s) -
Hamana Takashi,
Mellier Yannick
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04685.x
Subject(s) - physics , excursion , spectral density , weak gravitational lensing , cosmic microwave background , gaussian , exponential function , strong gravitational lensing , ray tracing (physics) , astrophysics , statistical physics , optics , computational physics , statistics , mathematical analysis , redshift , galaxy , mathematics , quantum mechanics , anisotropy , political science , law
We present ray tracing simulations combined with sets of large N ‐body simulations. Experiments were performed to explore, for the first time, the statistical properties of fluctuations in angular separation of nearby light‐ray pairs (the so‐called lensing excursion angle) induced by weak lensing by large‐scale structures. We found that the probability distribution function (PDF) of the lensing excursion angles is not simply Gaussian, but has an exponential tail. It is found, however, that the tail, or more generally the non‐Gaussian nature of the PDF has no significant impact on the weak lensing of the cosmic microwave background (CMB). Moreover, we found that the variance in the lensing excursion angles predicted by the power spectrum approach is in good agreement with our numerical results. These results demonstrate the validity of using the power spectrum approach to compute lensing effects on the CMB.