2010/08/31 by Antonio Padilla, Paul M. Saffin, Shuang-Yong Zhou · 73 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Galilean #Galilean invariance #Invariant (physics) #Phenomenology (philosophy) #Quantum and Classical Electrodynamics #Scalar (mathematics) #Solar and Space Plasma Dynamics #Tachyon #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1007/jhep01(2011)099
published in Journal of High Energy Physics 2011(1) (Springer Nature) · Erratum added presenting arguments similar in spirit to those presented in 1303.0274, and alluding to the inevitability of superluminality in the absence of strong coupling . We emphasize, however, that the generic formalism developed here, and extensively used in 1303.0274, is correct
openalex publication_date 2011/01/01 · arxiv created 2013/03/05 · arxiv updated 2013/03/06 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We continue to introduce bi-galileon theory, the generalisation of the single galileon model introduced by Nicolis et al. The theory contains two coupled scalar fields and is described by a Lagrangian that is invariant under Galilean shifts in those fields. This paper is the second of two, and focuses on the phenomenology of the theory. We are particularly interesting in models that admit solutions that are asymptotically self accelerating or asymptotically self tuning. In contrast to the single galileon theories, we find examples of self accelerating models that are simultaneously free from ghosts, tachyons and tadpoles, able to pass solar system constraints through Vainshtein screening, and do not suffer from problems with superluminality, Cerenkov emission or strong coupling. We also find self tuning models and discuss how Weinberg's no go theorem is evaded by breaking Poincaré invariance in the scalar sector. Whereas the galileon description is valid all the way down to solar system scales for the self-accelerating models, unfortunately the same cannot be said for self tuning models owing to the scalars backreacting strongly on to the geometry.