Imperfect fluid description of modified gravities

Abstract

The Brans-Dicke-like field of scalar-tensor gravity can be described as an imperfect fluid in an approach in which the field equations are regarded as effective Einstein equations. After completing this approach we recover, as a special case, the known effective fluid for a scalar coupled nonminimally to the Ricci curvature and we describe the imperfect fluid equivalent of f(R) gravity. A symmetry of electrovacuum Brans-Dicke gravity is translated into a symmetry of the corresponding effective fluid. The discussion is valid for any spacetime geometry.

arXiv commentAdded some explanation in the text, typographical errors corrected. Matches version to appear in Phys. Rev. D

References in corpus (67)

• f(R) Theories Of Gravity
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Modified Gravity and Cosmology
• f(R) theories
• Introduction to Modified Gravity and Gravitational Alternative for Dark Energy
• Is Cosmic Speed-Up Due to New Gravitational Physics?
• Testing General Relativity with Present and Future Astrophysical Observations
• Can modified gravity explain accelerated cosmic expansion?
• Cosmological viability of f(R)-gravity as an ideal fluid and its compatibility with a matter dominated phase
• Cosmological perturbations
• Action functionals for relativistic perfect fluids
• The importance of the bulk viscosity of QCD in ultrarelativistic heavy-ion collisions
• Quintessence without scalar fields
• Relativistic Fluid Dynamics: Physics for Many Different Scales
• Dark Energy: the equation of state description versus scalar-tensor or modified gravity
• Gravitational waves from instabilities in relativistic stars
• Matter instability in modified gravity
• Dust of Dark Energy
• The Lagrangian description of perfect fluids and modified gravity with an extra force
• Complete constraints on a nonminimally coupled chaotic inflationary scenario from the cosmic microwave background
• The Imperfect Fluid behind Kinetic Gravity Braiding
• Non-minimal coupling of the scalar field and inflation
• Contact Hamiltonian Mechanics
• Linking Tests of Gravity On All Scales: from the Strong-Field Regime to Cosmology
• Superconformal Symmetry, Supergravity and Cosmology
• String Theory and Quantum Chromodynamics
• Illusions of general relativity in Brans-Dicke gravity
• The non-adiabatic pressure in general scalar field systems
• Geometric Reheating after Inflation
• Evolution of Structures in Generalized Gravity Theories
• Unified Analysis of Cosmological Perturbations in Generalized Gravity
• Superinflation, quintessence, and nonsingular cosmologies
• Imperfect Dark Matter
• Covariantizing the interaction between dark energy and dark matter
• The omega-tends-to-infinity limit of Brans-Dicke theory
• A note on the equivalence of a barotropic perfect fluid with a K-essence scalar field
• Constraints on the chaotic inflationary scenario with a nonminimally coupled "inflaton" field from the cosmic microwave background radiation anisotropy
• Phase space geometry in scalar-tensor cosmology
• The correspondence between a scalar field and an effective perfect fluid
• A crucial ingredient of inflation
• STATIONARY SOLUTIONS IN BRANS-DICKE STOCHASTIC INFLATIONARY COSMOLOGY
• Quantum fluctuations of Cosmological Perturbations in Generalized Gravity
• Gravitational Wave Spectrums from Pole-like Inflations based on Generalized Gravity Theories
• Perfect fluid Lagrangian and its cosmological implications in theories of gravity with nonminimally coupled matter fields
• The Fluid/Gravity Correspondence: a new perspective on the Membrane Paradigm
• Extended Inflation with a Curvature-Coupled Inflaton
• The Energy-Momentum Tensor for a Dissipative Fluid in General Relativity
• Renormalization-Group Improved Effective Potential for Finite Grand Unified Theories in Curved Spacetime
• Stationary Configurations Imply Shift Symmetry: No Bondi Accretion for Quintessence / k-Essence
• A note on perfect scalar fields
• From an Action Principle for Action-dependent Lagrangians toward non-conservative Gravity: accelerating Universe without dark energy
• Cosmic relic abundance and f(R) gravity
• Matter Lagrangian of particles and fluids
• Note on the thermodynamics and the speed of sound of a scalar field
• Thermodynamics of perfect fluids from scalar field theory
• A Singularity-Free Cosmological Model with a Conformally Coupled Scalar Field
• Non-adiabatic Chaplygin gas
• Coarse-Graining and Renormalization Group in the Einstein Universe
• Chaotic inflation with running nonminimal coupling
• Non-perturbative renormalization group approach for a scalar theory in higher-derivative gravity
• Oscillating Inflation with a non-minimally coupled scalar field
• Symmetry of Brans-Dicke gravity as a novel solution-generating technique
• A new solution for inflation
• Note on scalars, perfect fluids, constrained field theories, and all that
• Revealing the non-adiabatic nature of dark energy perturbations from galaxy clustering data
• Degeneracy between nonadiabatic dark energy models and $\Lambda$CDM: ISW effect and the cross correlation of CMB with galaxy clustering data
• Scalar-tensor extension of the $\Lambda$CDM model

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• Constraints on a Bianchi type I spacetime extension of the standard $\Lambda$CDM model
• Testing spatial curvature and anisotropic expansion on top of the $\Lambda$CDM model
• First-order thermodynamics of Horndeski gravity
• Thermodynamics of scalar-tensor gravity
• Screening anisotropy via energy-momentum squared gravity: $\Lambda$CDM model with hidden anisotropy
• First-order thermodynamics of scalar-tensor cosmology
• Scalar field as a perfect fluid: thermodynamics of minimally coupled scalars and Einstein frame scalar-tensor gravity
• Anisotropic massive Brans-Dicke gravity extension of the standard $\Lambda$CDM model
• Equivalence between Horndeski and beyond Horndeski theories and imperfect fluids
• Fluid nature constrains Horndeski gravity
• More on the first-order thermodynamics of scalar-tensor and Horndeski gravity
• Peculiar thermal states in the first-order thermodynamics of gravity
• Thermal stability of stealth and de Sitter spacetimes in scalar-tensor gravity
• Past-directed scalar field gradients and scalar-tensor thermodynamics
• Do Solar System experiments constrain scalar-tensor gravity?
• Multi-fluid cosmology in Einstein gravity: analytical solutions
• Two new approaches to the anomalous limit of Brans-Dicke to Einstein gravity
• Thermal origin of the attractor-to-general-relativity in scalar-tensor gravity
• f(R) Gravity in an Ellipsoidal Universe
• Generalized nonconservative gravitational field equations from Herglotz action principle
• First-order thermodynamics of Horndeski cosmology
• First-order thermodynamics of scalar-tensor gravity
• Generalized McVittie geometry in Horndeski gravity with matter
• Alternative formulations of the thermodynamics of scalar-tensor theories
• A new symmetry of the spatially flat Einstein-Friedmann equations
• Scalar field as a null dust
• General analysis of Noether symmetries in Horndeski gravity
• Matter Growth in Imperfect Fluid Cosmology
• Comoving curvature perturbation in Jordan and Einstein frames
• Minimally coupled scalar fields as imperfect fluids
• Role of internal space correlations in the dynamics of a higher-dimensional Bianchi type-I universe: shear scalar and Hubble parameter perspectives
• Stochastic dark matter: Covariant Brownian motion from Planckian discreteness
• Scalar fluid in scalar-tensor gravity from an equivalent picture of thermodynamic and fluid descriptions of gravitational dynamics
• Eckart heat-flux applicability in $F(\Phi ,X)R$ theories and the existence of temperature gradients
• Cosmological analogies for geophysical flows, Lagrangians, and new analogue gravity systems
• Thermal description of braneworld effective theories
• Covariant single-field formulation of effective cosmological bounces
• A new approach to the thermodynamics of scalar-tensor gravity
• Stealth metastable state of scalar-tensor thermodynamics
• Accelerating imperfect fluid
• Matter growth in extended $\Lambda$CDM cosmology