The general form of the coupled Horndeski Lagrangian that allows cosmological scaling solutions

Abstract

We consider the general scalar field Horndeski Lagrangian coupled to matter. Within this class of models, we present two results that are independent of the particular form of the model. First, we show that in a Friedmann-Robertson-Walker metric the Horndeski Lagrangian coincides with the pressure of the scalar field. Second, we employ the previous result to identify the most general form of the Lagrangian that allows for cosmological scaling solutions, i.e. solutions where the ratio of matter to field density and the equation of state remain constant. Scaling solutions of this kind may help solving the coincidence problem since in this case the presently observed ratio of matter to dark energy does not depend on initial conditions, but rather on the theoretical parameters.

28 pages. arXiv admin note: text overlap with arXiv:1306.3593

References in corpus (7)

• Cosmology and the Fate of Dilatation Symmetry
• Imperfect Dark Energy from Kinetic Gravity Braiding
• Transforming gravity: from derivative couplings to matter to second-order scalar-tensor theories beyond the Horndeski Lagrangian
• Growing Matter
• Challenges for scaling cosmologies
• Towards scaling cosmological solutions with full coupled Horndeski Lagrangian: the KGB model
• How can we tell whether dark energy is composed by multiple fields?

Cited by in corpus (16)

• Dynamical systems applied to cosmology: dark energy and modified gravity
• Coupled quintessence with a $\Lambda$CDM background: removing the ${\sigma }_8$ tension
• Doppelgänger dark energy: modified gravity with non-universal couplings after GW170817
• Kinetically coupled dark energy
• Coupled vector dark energy
• Black branes in asymptotically Lifshitz spacetime and viscosity/entropy ratios in Horndeski gravity
• Rotating black hole with a probe string in Horndeski Gravity
• Most general cubic-order Horndeski Lagrangian allowing for scaling solutions and the application to dark energy
• Noether symmetry in Horndeski Lagrangian
• Dissecting kinetically coupled quintessence: phenomenology and observational tests
• First-order thermodynamics of Horndeski cosmology
• Coupled Quintessence scalar field model in light of observational datasets
• Aller guten Dinge sind drei: Cosmology with three interacting spin-2 fields
• Gödel-type Solutions in Cubic Galileon Gravity
• Cosmological Dynamics and Double Screening of DBI Galileon Gravity
• Modeling dark sector in Horndeski gravity at first-order formalism