Work

Supersymmetric cubic Galileons have ghosts

Year: 2013

Type: article

Abstract: Galileons are higher-derivative theories of a real scalar which nevertheless admit second-order equations of motion. They have interesting applications as dark energy models and in early universe cosmology, and have been conjectured to arise as descriptions of brane dynamics in string theory. In the present paper, we study the bosonic sector of globally $N=1$ supersymmetric extensions of the cubic Galileon Lagrangian in detail. Supersymmetry requires that the Galileon scalar now becomes paired with a second real scalar field. We prove that the presence of this second scalar causes the equations of motion to become higher than second order, thus leading to the appearance of ghosts. We also analyze the energy scales up to which, in an effective field theory description, the ghosts can be tamed.

Source: Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields

DOI: 10.1103/physrevd.88.023528

Authors: Michael Koehn, Jean-Luc Lehners, Burt A. Ovrut

Institutions: Max Planck Society, Max Planck Institute for Gravitational Physics, University of Pennsylvania

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, U.S. Department of Energy, FP7 Ideas: European Research Council

Award: String Cosmology and Observational Signatures