Extended cuscuton as dark energy
Aya Iyonaga, Kazufumi Takahashi, Tsutomu Kobayashi
Abstract
Late-time cosmology in the extended cuscuton theory is studied, in which gravity is modified while one still has no extra dynamical degrees of freedom other than two tensor modes. We present a simple example admitting analytic solutions for the cosmological background evolution that mimics CDM cosmology. We argue that the extended cuscuton as dark energy can be constrained, like usual scalar-tensor theories, by the growth history of matter density perturbations and the time variation of Newton's constant.
Topics & Concepts
PhysicsCosmologyDark energyCosmological perturbation theoryDark matterTensor (intrinsic definition)Cosmological modelTheoretical physicsSimple (philosophy)Lambda-CDM modelClassical mechanicsDegrees of freedom (physics and chemistry)Inflation (cosmology)GravitationEnergy densityObservational cosmologyDark fluidPerturbation theory (quantum mechanics)Cosmological constantQuantum electrodynamicsBaryon acoustic oscillationsMetric expansion of spaceNon-standard cosmologyUniverseAstrophysicsPhysical cosmologyEnergy (signal processing)Formalism (music)Einstein field equationsCold dark matterScalar field dark matterCosmology and Gravitation TheoriesBlack Holes and Theoretical PhysicsNoncommutative and Quantum Gravity Theories