TY - JOUR
T1 - Light mass galileons
T2 - Cosmological dynamics, mass screening and observational constraints
AU - Ali, Amna
AU - Gannouji, Radouane
AU - Hossain, Md Wali
AU - Sami, M.
N1 - Funding Information:
The work of RG is supported by the Grant-in-Aid for Scientific Research Fund of the JSPS No. 10329 . MWH acknowledges the funding from CSIR , Govt of India. MWH wants to thank Sumit Kumar for useful discussions on statistical techniques. MS thanks S. Nojiri and K. Bamba for useful discussions. MS is supported by JSPS fellowship and thanks Kobayashi-Maskawa Institute for the Origin of Particles and the Universe for hospitality. MS is also supported by the Department of Science and Technology , India under project No. SR/S2/HEP-002/2008 .
PY - 2012/11/15
Y1 - 2012/11/15
N2 - In this Letter, we examine the cosmological viability of a light mass galileon field consistent with local gravity constraints. The minimal, L 3=□φ(∂ μφ) 2, massless galileon field requires an additional term in order to give rise to a viable ghost free late time acceleration of Universe. The desired cosmological dynamics can either be achieved by incorporating an additional terms in the action such as (L 4, L 5) - the higher order galileon Lagrangians or by considering a light mass field à la galileon field potential. We analyze the second possibility and find that: (1) The model produces a viable cosmology in the regime where the non-linear galileon field is subdominant, (2) the Vainshtein mechanism operates at small scales where the non-linear effects become important and contribution of the field potential ceases to be significant. Also the small mass of the field under consideration is protected against strong quantum corrections thereby providing quantum stability to the system.
AB - In this Letter, we examine the cosmological viability of a light mass galileon field consistent with local gravity constraints. The minimal, L 3=□φ(∂ μφ) 2, massless galileon field requires an additional term in order to give rise to a viable ghost free late time acceleration of Universe. The desired cosmological dynamics can either be achieved by incorporating an additional terms in the action such as (L 4, L 5) - the higher order galileon Lagrangians or by considering a light mass field à la galileon field potential. We analyze the second possibility and find that: (1) The model produces a viable cosmology in the regime where the non-linear galileon field is subdominant, (2) the Vainshtein mechanism operates at small scales where the non-linear effects become important and contribution of the field potential ceases to be significant. Also the small mass of the field under consideration is protected against strong quantum corrections thereby providing quantum stability to the system.
UR - http://www.scopus.com/inward/record.url?scp=84868197199&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2012.10.009
DO - 10.1016/j.physletb.2012.10.009
M3 - Article
AN - SCOPUS:84868197199
SN - 0370-2693
VL - 718
SP - 5
EP - 14
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
ER -