Equivalence of the Fermat potential and the lensing potential approaches to computing the integrated Sachs-Wolfe effect
Cosmology and Nongalactic Astrophysics
2020-01-07 v1
Abstract
We show in detail that the recently derived expression for evaluating the integrated Sachs-Wolfe (ISW) temperature shift in the cosmic microwave background (CMB) caused by individual embedded (compensated) lenses is equivalent to the conventional approach for flat background cosmologies. The conventional approach requires evaluating an integral of the time derivative of the lensing potential, whereas the new Fermat potential approach is simpler and only requires taking a derivative of the potential part of the time delay.
Keywords
Cite
@article{arxiv.2001.00945,
title = {Equivalence of the Fermat potential and the lensing potential approaches to computing the integrated Sachs-Wolfe effect},
author = {R. Kantowski and B. Chen and X. Dai},
journal= {arXiv preprint arXiv:2001.00945},
year = {2020}
}
Comments
14 pages. arXiv admin note: text overlap with arXiv:1410.4608