Stability of cosmological solutions in extended quasidilaton massive gravity

Abstract

We consider the stability of self-accelerating solutions to extended quasidilaton massive gravity in the presence of matter. By making a second or extended fiducial metric dynamical in this model, matter can cause it to evolve from a Lorentzian to Euclidean signature, triggering a ghost instability. We study this possibility with scalar field matter as it can model a wide range of cosmological expansion histories. For the $\Lambda$CDM expansion history, stability considerations substantially limit the available parameter space while for a kinetic energy dominated expansion, no choice of quasidilaton parameters is stable. More generally these results show that there is no mechanism intrinsic to the theory to forbid such pathologies from developing from stable initial conditions and that stability can only be guaranteed for particular choices for the matter configuration.

11 pages; minor changes matching published version

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Cited by in corpus (9)

• A new quasidilaton theory of massive gravity
• Cosmological perturbations in Gauss-Bonnet quasi-dilaton massive gravity
• Revisiting perturbations in extended quasidilaton massive gravity
• Role of matter in extended quasidilaton massive gravity
• Cosmology of Dirac-Born-Infeld dRGT massive gravity
• Cosmology of Massive Gravity and its Extensions
• The Trans-Planckian Censorship Conjecture in different frameworks of viable inflation
• Linear growth of structure in massive gravity
• Cosmology of Quasi-Dilaton Massive Gravity with Non-minimal Kinetic Coupling