Consistent modified gravity: dark energy, acceleration and the absence of cosmic doomsday

By M. Abdalla, Shin'ichi Nojiri, Sergei D.Odintsov. 2004

195 citations recorded by the source corpus.

We discuss modified gravity which includes negative and positive powers of curvature and provides gravitational dark energy. It is shown that in GR plus a term containing a negative power of curvature, cosmic speed-up may be achieved while the effective phantom phase (with w less than −1) follows when such a term contains a fractional positive power of curvature. Minimal coupling with matter makes the situation more interesting: even 1/R theory coupled with the usual ideal fluid may describe the (effective phantom) dark energy. The account of the R2 term (consistent modified gravity) may help to escape cosmic doomsday.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/0f3c4d444785ef14c20c47438996a48bba50db37

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Citations in the corpus

Cosmological constraints on f(R) gravity theories within the Palatini approach (2005, unknown): “…2001) or dark energy (Dvali et al. 2000; Deffayet 2001; Dvali & Turner 2003; Arkani-Hamed et al. 2002; Nojiri & Odintsov 2003, 2004a,b, 2005; Abdalla et al. 2005; Freese & Lewis 2002; Meng & Wang 2003; Dolgov & Kawasaki 2003; Shao et al. 2005; Gong et al. 2004; Lima 2004; Ahmed et al. 2004;…”
A Bird's Eye View of f (R)-Gravity (2009, background): “Various authors have contended that this problem can be cured by adding, for example, a quadratic term 2 R ! to the action as first [88, 90].”
Modified Gravity and Cosmology (2011, background): “This instability is caused by the fact that for the scalar degree of freedom in f(R) theories curvature singularities can occur at finite field value and energy level, a phenomenon previously investigated in [4, 203].”