Pattern of growth in viable f(R) cosmologies
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (Canada)
- Department of Physics, Syracuse University, Syracuse, New York 13244 (United States)
We study the evolution of linear perturbations in metric f(R) models of gravity and identify a potentially observable characteristic scale-dependent pattern in the behavior of cosmological structures. While at the background level viable f(R) models must closely mimic Lambda Cold Dark Matter, the differences in their prediction for the growth of large scale structures can be sufficiently large to be seen with future weak lensing surveys. While working in the Jordan frame, we perform an analytical study of the growth of structures in the Einstein frame, demonstrating the equivalence of the dynamics in the two frames. We also provide a physical interpretation of the results in terms of the dynamics of an effective dark energy fluid with a nonzero shear. We find that the growth of structure in f(R) is enhanced, but that there are no small scale instabilities associated with the additional attractive ''fifth force.'' We then briefly consider some recently proposed observational tests of modified gravity and their utility for detecting the f(R) pattern of structure growth.
- OSTI ID:
- 21035791
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 77, Issue 2; Other Information: DOI: 10.1103/PhysRevD.77.023503; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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