2005/11/30 by Pengjie Zhang · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1103/physrevd.73.123504
published as Phys.Rev.D73:123504,2006 · 5 pages, 2 figures. Accepted to PRD. v2: Revised to address to more general audience. v3: added discussions
arxiv created 2006/05/12 · openalex publication_date 2006/06/02 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
A generic prediction of general relativity is that the cosmological linear density growth factor D is scale independent. But in general, modified gravities do not preserve this signature. A scale dependent D can cause time variation in gravitational potential at high redshifts and provides a new cosmological test of gravity, through early time integrated Sachs-Wolfe (ISW) effect-large scale structure (LSS) cross correlation. We demonstrate the power of this test for a class of f(R) gravity, with the form f(R)=\ensuremath-\ensuremathλ1H02exp(\ensuremath-R/\ensuremathλ2H02). Such f(R) gravity, even with degenerate expansion history to \ensuremathΛCDM, can produce detectable ISW effect at z\ensuremath\gtrsim3 and l\ensuremath\gtrsim20. Null-detection of such effect would constrain \ensuremathλ2 to be \ensuremathλ2>1000 at >95% confidence level. On the other hand, robust detection of ISW-LSS cross correlation at high z will severely challenge general relativity.