Abstract
Lorentz-invariant massive gravity is usually associated with a strong coupling scale $\Lambda_3$. By including non-trivial effects from the Stueckelberg modes, we show that about these vacua, one can push the strong coupling scale to higher values and evade the linear vDVZ-discontinuity. For generic parameters of the theory and generic vacua for the Stueckelberg fields, the $\Lambda_2$-decoupling limit of the theory is well-behaved and free of any ghost or gradient-like instabilities. We also discuss the implications for nonlinear sigma models with Lorentzian target spaces.
Highlights
(BD) ghost [2,3,4]
Lorentz-invariant massive gravity is usually associated with a strong coupling scale Λ3
By including non-trivial effects from the Stuckelberg modes, we show that about these vacua, one can push the strong coupling scale to higher values and evade the linear vDVZ-discontinuity
Summary
We start by considering a theory of N scalar fields φA living on a D-dimensional flat spacetime metric ημν. These N scalar fields may be thought as coordinates of a non-trivial target (field space, or internal) manifold specified by the metric fAB(φ) This corresponds to a nonlinear sigma model whose action can typically be written as LΣ. One possible way out is to ensure that the mode associated with the negative direction is not dynamical or a gauge mode This is the resolution for the Polyakov action for a p-brane 3 where the spacetime metric ημν is promoted to an auxiliary field gμν(x) and diffeomorphism invariance ensures that the would-be ghost DoF associated with the negative direction of the internal space is a gauge mode:. Signaling that not all of the N scalar fields φA are dynamical
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
