Subluminal Galilean Genesis

Abstract

We put forward an improved version of the Galilean Genesis model that addresses the problem of superluminality. We demote the full conformal group to Poincare symmetry plus dilations, supplemented with approximate galilean shift invariance in the UV and at small field values. In this way fluctuations around the NEC-violating cosmological background are made substantially subluminal, and superluminality cannot be reached by any small change of the solution, in contrast with the original model. Dilation invariance still protects the scale-invariance of correlation functions of a massless test scalar - which is the source of the observed cosmological fluctuations - but the explicit breaking of the conformal group can be potentially observed in higher-order correlators. We also highlight a subtlety in matching the NEC-violating phase with the standard cosmological evolution, and discuss the possible couplings of the Galileon to gravity.

18 pages, 1 figure

References in corpus (22)

• Perturbations in k-inflation
• Causality, Analyticity and an IR Obstruction to UV Completion
• Ghost Condensation and a Consistent Infrared Modification of Gravity
• Strong Interactions and Stability in the DGP Model
• Starting the Universe: Stable Violation of the Null Energy Condition and Non-standard Cosmologies
• Classical and Quantum Consistency of the DGP Model
• Null energy condition and superluminal propagation
• Galilean Genesis: an alternative to inflation
• Galileon inflation
• Energy's and amplitudes' positivity
• Conformal consistency relations for single-field inflation
• Conformal Symmetries of Adiabatic Modes in Cosmology
• Symmetries for Galileons and DBI scalars on curved space
• Galilean symmetry in the effective theory of inflation: new shapes of non-Gaussianity
• The quantum mechanics of perfect fluids
• General Embedded Brane Effective Field Theories
• Harrison--Zeldovich spectrum from conformal invariance
• Superluminal censorship
• The Pseudo-Conformal Universe: Scale Invariance from Spontaneous Breaking of Conformal Symmetry
• Non-linear Realizations of Conformal Symmetry and Effective Field Theory for the Pseudo-Conformal Universe
• Scale-Invariant Fluctuations from Galilean Genesis
• Boundary Terms and Junction Conditions for the DGP Pi-Lagrangian and Galileon

Cited by in corpus (82)

• Beyond the Cosmological Standard Model
• Massive Gravity
• Horndeski theory and beyond: a review
• Bouncing Cosmologies: Progress and Problems
• A Critical Review of Classical Bouncing Cosmologies
• Solid Inflation
• The Null Energy Condition and its violation
• A formal introduction to Horndeski and Galileon theories and their generalizations
• Generic instabilities of non-singular cosmologies in Horndeski theory: a no-go theorem
• An Infinite Set of Ward Identities for Adiabatic Modes in Cosmology
• Generalized Galileons: instabilities of bouncing and Genesis cosmologies and modified Genesis
• Dynamical analysis of generalized Galileon cosmology
• DBI Genesis: An Improved Violation of the Null Energy Condition
• Slavnov-Taylor Identities for Primordial Perturbations
• When Matter Matters
• Unbraiding the Bounce: Superluminality around the Corner
• Screening the fifth force in the Horndeski's most general scalar-tensor theories
• Matter bispectrum in cubic Galileon cosmologies
• Cuscuton Bounce
• Galilean Creation of the Inflationary Universe
• Inflation from Minkowski Space
• From Satisfying to Violating the Null Energy Condition
• Scalar and Tensor Perturbations in DHOST Bounce Cosmology
• On Cosmological Perturbations of Quasidilaton
• Intermittent null energy condition violations during inflation and primordial gravitational waves
• On the Potential for General Relativity and its Geometry
• Galileon bounce after ekpyrotic contraction
• Generalized Galilean Genesis
• Consistency Relations for the Conformal Mechanism
• Emergent Universe and Genesis from the DHOST Cosmology
• Cosmological perturbations and stability of nonsingular cosmologies with limiting curvature
• Nonsingular cosmological models with strong gravity in the past
• Consistent NEC-violation: towards creating a universe in the laboratory
• Curvaton with nonminimal derivative coupling to gravity
• Non-linear Representations of the Conformal Group and Mapping of Galileons
• Pulsar timing array observations as possible hints for nonsingular cosmology
• Genesis with general relativity asymptotics in beyond Horndeski theory
• More about wormholes in generalized Galileon theories
• The anamorphic universe
• Multiple Soft Limits of Cosmological Correlation Functions
• Cosmology of the Spinor Emergent Universe and Scale-invariant Perturbations
• Cosmological consequences of a principle of finite amplitudes
• Proof of the most general multiple-scalar field theory in Minkowski space-time free of Ostrogradski Ghost
• Cosmological Perturbations Across an S-brane
• Toward evading the strong coupling problem in Horndeski genesis
• On the Initial State and Consistency Relations
• Nanohertz gravitational waves from NEC violation in the early universe
• Generating enhanced primordial GWs during inflation with intermittent violation of NEC and diminishment of GW propagating speed
• Improved DHOST Genesis
• Horndeski genesis: consistency of classical theory
• Cosmological matching conditions and galilean genesis in Horndeski's theory
• Scale-invariant perturbations from NEC violation: A new variant of Galilean Genesis
• Probing the primordial universe with gravitational waves detectors
• Subluminal cosmological bounce beyond Horndeski
• Generating cosmological perturbations in non-singular Horndeski cosmologies
• Can Galileons support Lorentzian wormholes?
• Perturbative unitarity and NEC violation in genesis cosmology
• Quantum Stability of Generalized Proca Theories
• Behavior of perturbations on spherically symmetric backgrounds in multi-Galileon theory
• Singularities in Spherically Symmetric Solutions with Limited Curvature Invariants
• Superluminality in DHOST theory with extra scalar
• Gauge-ready formulation of cosmological perturbations in scalar-vector-tensor theories
• A Positive Energy Theorem for P(X,phi) Theories
• Superluminality in beyond Horndeski theory with extra scalar field
• Primordial non-Gaussianity from Galilean Genesis without strong coupling problem
• Primordial flat frame -- a new view on inflation
• The great emptiness at the beginning of the Universe
• Double screening
• Conformal Universe as false vacuum decay
• Towards conformal cosmology
• Multi-field Cuscuton Cosmology
• Null energy condition violation and beyond Horndeski physics in light of DESI DR2 data
• Conformal/Poincaré Coset, Cosmology, and Descendants of Lovelock Terms
• Superluminality in dilatationally invariant generalized Galileon theories
• Can Horndeski Genesis be Nonpathological?
• Recent Developments in Degenerate Higher Order Scalar Tensor Theories
• Geodesic completeness, cosmological bounces and inflation
• The primordial non-Gaussianities for non-singular Horndeski cosmologies
• Strong coupling and instabilities in singularity-free inflation from an infinite sum of curvature corrections
• Apparent $w<-1$ and a Lower $S_8$ from Dark Axion and Dark Baryons Interactions
• Non-minimal Effective Scalar-Tensor Gravity in the Early Universe
• No-Go theorem in the cubic subclass of Horndeski theory for spherically symmetric dynamical background