A fast route to modified gravitational growth
Ημερομηνία
2014ISSN
1550-7998Source
Physical Review D - Particles, Fields, Gravitation and CosmologyVolume
89Issue
2Google Scholar check
Metadata
Εμφάνιση πλήρους εγγραφήςΕπιτομή
The growth rate of the large-scale structure of the Universe has been advocated as the observable par excellence for testing gravity on cosmological scales. By considering linear-order deviations from general relativity, we show that corrections to the growth rate, f, can be expressed as an integral over a "source" term, weighted by a theory-independent "response kernel." This leads to an efficient and accurate "plug-and-play" expression for generating growth rates in alternative gravity theories, bypassing lengthy theory-specific computations. We use this approach to explicitly show that f is sensitive to a degenerate combination of modified expansion and modified clustering effects. Hence the growth rate, when used in isolation, is not a straightforward diagnostic of modified gravity. © 2014 American Physical Society.