Can f(R) modified gravity theories mimic a {lambda}CDM cosmology?
- School of Mathematical Sciences, Queen Mary, University of London (United Kingdom)
- Department of Physics, University of Ioannina (Greece)
We consider f(R) modified gravity theories in the metric variation formalism and attempt to reconstruct the function f(R) by demanding a background {lambda}CDM cosmology. In particular we impose the following requirements: (a) A background cosmic history H(z) provided by the usual flat {lambda}CDM parametrization though the radiation (w{sub eff}=1/3), matter (w{sub eff}=0), and de Sitter (w{sub eff}=-1) eras. (b) Matter and radiation dominate during the ''matter'' and ''radiation'' eras, respectively, i.e. {omega}{sub m}=1 when w{sub eff}=0 and {omega}{sub r}=1 when w{sub eff}=1/3. We have found that the cosmological dynamical system constrained to obey the {lambda}CDM cosmic history has four critical points in each era which correspondingly lead to four forms of f(R). One of them is the usual general relativistic form f(R)=R-2{lambda}. The other three forms in each era, reproduce the {lambda}CDM cosmic history but they do not satisfy requirement (b) stated above.
- OSTI ID:
- 21027754
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 76, Issue 6; Other Information: DOI: 10.1103/PhysRevD.76.063504; (c) 2007 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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