TY - JOUR

T1 - Palatini formulation of modified gravity with ln R terms

AU - Meng, Xin He

AU - Wang, Peng

N1 - Funding Information:
We would especially like to thank Sergei Odintsov for stimulating this work and many helpful suggestions. We would also like to thank Éanna Flanagan, Nadeem Haque, Shin'ichi Nojiri for helpful discussions. This work is partly supported by China NSF, Doctoral Foundation of National Education Ministry and ICSC-World Lab. scholarship.

PY - 2004/3/25

Y1 - 2004/3/25

N2 - Recently, corrections to the standard Einstein-Hilbert action are proposed to explain the current cosmic acceleration instead of introducing dark energy. We discuss the Palatini formulation of the modified gravity with a lnR term suggested by Nojiri and Odintsov. We show that in the Palatini formulation, the lnR gravity can drive a current exponential accelerated expansion and it reduces to the standard Friedmann evolution for high redshift region. We also discuss the equivalent scalar-tensor formulation of the theory. We indicate that the lnR gravity may still have a conflict with electron-electron scattering experiment which stimulates us to pursue a more fundamental theory which can give the lnR gravity as an effective theory. Finally, we discuss a problem faced with the extension of the lnR gravity by adding Rm terms.

AB - Recently, corrections to the standard Einstein-Hilbert action are proposed to explain the current cosmic acceleration instead of introducing dark energy. We discuss the Palatini formulation of the modified gravity with a lnR term suggested by Nojiri and Odintsov. We show that in the Palatini formulation, the lnR gravity can drive a current exponential accelerated expansion and it reduces to the standard Friedmann evolution for high redshift region. We also discuss the equivalent scalar-tensor formulation of the theory. We indicate that the lnR gravity may still have a conflict with electron-electron scattering experiment which stimulates us to pursue a more fundamental theory which can give the lnR gravity as an effective theory. Finally, we discuss a problem faced with the extension of the lnR gravity by adding Rm terms.

UR - http://www.scopus.com/inward/record.url?scp=1542411346&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2004.01.052

DO - 10.1016/j.physletb.2004.01.052

M3 - Article

AN - SCOPUS:1542411346

SN - 0370-2693

VL - 584

SP - 1

EP - 7

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

IS - 1-2

ER -