TY - JOUR
T1 - The universe is accelerating. Do we need a new mass scale?
AU - Nesseris, Savvas
AU - Piazza, Federico
AU - Tsujikawa, Shinji
N1 - Funding Information:
F.P. is indebted to Bruce A. Bassett for many valuable conversations during his visit at Perimeter Institute. We thank Justin Khoury for his suggestions on the manuscript. S.N. acknowledges support from the Niels Bohr International Academy , the EU FP6 Marie Curie Research & Training Network “UniverseNet” under Contract No. MRTN-CT-2006-035863 and the Danish Research Council under FNU Grant No. 272-08-0285 . The research of F.P. at Perimeter Institute is supported in part by the Government of Canada through NSERC and by the Province of Ontario through the Ministry of Research & Innovation . S.T. thanks financial support for JSPS (Grant No. 30318802 ).
PY - 2010/5/31
Y1 - 2010/5/31
N2 - We try to address quantitatively the question whether a new mass is needed to fit current supernovae data. For this purpose, we consider an infra-red modification of gravity that does not contain any new mass scale but systematic subleading corrections proportional to the curvature. The modifications are of the same type as the one recently derived by enforcing the "Ultra Strong Equivalence Principle" (USEP) upon a Friedmann-Lemaître-Robertson-Walker universe in the presence of a scalar field. The distance between two comoving observers is altered by these corrections and the observations at high redshift are affected at any time during the cosmic evolution. While the specific values of the parameters predicted by USEP are ruled out, there are regions of parameter space that fit SnIa data very well. This allows an interesting possibility to explain the apparent cosmic acceleration today without introducing either a dark energy component or a new mass scale.
AB - We try to address quantitatively the question whether a new mass is needed to fit current supernovae data. For this purpose, we consider an infra-red modification of gravity that does not contain any new mass scale but systematic subleading corrections proportional to the curvature. The modifications are of the same type as the one recently derived by enforcing the "Ultra Strong Equivalence Principle" (USEP) upon a Friedmann-Lemaître-Robertson-Walker universe in the presence of a scalar field. The distance between two comoving observers is altered by these corrections and the observations at high redshift are affected at any time during the cosmic evolution. While the specific values of the parameters predicted by USEP are ruled out, there are regions of parameter space that fit SnIa data very well. This allows an interesting possibility to explain the apparent cosmic acceleration today without introducing either a dark energy component or a new mass scale.
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U2 - 10.1016/j.physletb.2010.04.061
DO - 10.1016/j.physletb.2010.04.061
M3 - Article
AN - SCOPUS:77953289562
SN - 0370-2693
VL - 689
SP - 122
EP - 128
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 - 4-5
ER -