Affine ANEC obstructs non-static flat and open FRW from being null geodesically complete while ANEC-satisfying, but allows explicit scalar-field realizations for closed FRW with NEC-respecting matter.
Canonical reference
Bouncing Cosmologies: Progress and Problems
Canonical reference. 100% of citing Pith papers cite this work as background.
12
Pith papers citing it
Background
100% of classified citations
abstract
We review the status of bouncing cosmologies as alternatives to cosmological inflation for providing a description of the very early universe, and a source for the cosmological perturbations which are observed today. We focus on the motivation for considering bouncing cosmologies, the origin of fluctuations in these models, and the challenges which various implementations face.
citation-role summary
background 5
citation-polarity summary
roles
background 5polarities
background 5representative citing papers
Proposes phase-resolved invariant path-length criteria and a master formula for lower bound on ε_ek in ekpyrotic cosmologies, using BKL suppression and conversion windows as constraints.
A deformed uncertainty relation for the universe scale factor modifies the Friedmann equation to yield late-universe acceleration or a bounce according to the sign of a single free exponent.
Constructs an explicit closed FRW curvature-supported bounce-inflation model with a canonical scalar field that remains geodesically complete, NEC-compliant, and yields standard slow-roll predictions.
A quantum ghost coupled polynomially to a harmonic oscillator has unitary evolution and a stable vacuum because a conserved quantity possesses a positive discrete spectrum.
Phantom Chaplygin gas forces the Einstein-frame lapse to change sign smoothly while the causal-frame lapse stays positive, yielding a robust non-singular bounce even with extra matter.
Quantum deformation of projective phase-space geometry induces a conformally deformed FLRW metric whose time-dependent corrections modify inflationary background equations, slow-roll parameters, and perturbations in a covariant manner.
A perturbative scalar-tensor construction yields an evolving horizon of size proportional to the perturbation parameter that persists through a radiation-dominated bounce but evolves asymmetrically.
Constrains inflationary tensor parameters to fit the EPTA DR2 signal under CMB, BBN and LVK bounds, favoring radiation-era horizon re-entry but requiring low reheating temperatures.
Refines two-field DHOST bouncing model to match observed f_NL and keep strong-coupling scale above background energy, claiming full viability at linear and non-linear levels.
Bouncing solutions in quadratic curvature gravity with a scalar field satisfy null, weak, and dominant energy conditions but violate the strong one when using the scalar-field energy-momentum tensor, while all four conditions are violated near the bounce in the effective tensor formulation.
Modified gravity theories supply viable mathematical frameworks for inflation, bounces, and dark energy eras that match observational data.
citing papers explorer
-
Affine ANEC selects the closed FRW branch for geodesically complete cosmology
Affine ANEC obstructs non-static flat and open FRW from being null geodesically complete while ANEC-satisfying, but allows explicit scalar-field realizations for closed FRW with NEC-respecting matter.
-
Phase-resolved field-space distance criteria in ekpyrotic, bouncing and cyclic cosmologies
Proposes phase-resolved invariant path-length criteria and a master formula for lower bound on ε_ek in ekpyrotic cosmologies, using BKL suppression and conversion windows as constraints.
-
A Cosmological Uncertainty Relation and Late-Universe Acceleration
A deformed uncertainty relation for the universe scale factor modifies the Friedmann equation to yield late-universe acceleration or a bounce according to the sign of a single free exponent.
-
Geodesically Complete Curvature-Bounce Inflation
Constructs an explicit closed FRW curvature-supported bounce-inflation model with a canonical scalar field that remains geodesically complete, NEC-compliant, and yields standard slow-roll predictions.
-
Unitary Time Evolution and Vacuum for a Quantum Stable Ghost
A quantum ghost coupled polynomially to a harmonic oscillator has unitary evolution and a stable vacuum because a conserved quantity possesses a positive discrete spectrum.
-
Geodesic completion of big bangs from emergent geometry
Phantom Chaplygin gas forces the Einstein-frame lapse to change sign smoothly while the causal-frame lapse stays positive, yielding a robust non-singular bounce even with extra matter.
-
Quantum-Deformed Phase-Space Geometry and Emergent Inflation in Effective Four-Dimensional Spacetime
Quantum deformation of projective phase-space geometry induces a conformally deformed FLRW metric whose time-dependent corrections modify inflationary background equations, slow-roll parameters, and perturbations in a covariant manner.
-
Black Hole Persistence in Scalar Tensor Theories
A perturbative scalar-tensor construction yields an evolving horizon of size proportional to the perturbation parameter that persists through a radiation-dominated bounce but evolves asymmetrically.
-
Inflationary interpretation of the gravitational-wave signal in the European Pulsar Timing Array DR2 with constraints
Constrains inflationary tensor parameters to fit the EPTA DR2 signal under CMB, BBN and LVK bounds, favoring radiation-era horizon re-entry but requiring low reheating temperatures.
-
Non-Gaussianity and Strong-Coupling Problem in a Two-Field DHOST Bouncing Model
Refines two-field DHOST bouncing model to match observed f_NL and keep strong-coupling scale above background energy, claiming full viability at linear and non-linear levels.
-
Energy conditions of bouncing solutions in quadratic curvature gravity coupled with a scalar field
Bouncing solutions in quadratic curvature gravity with a scalar field satisfy null, weak, and dominant energy conditions but violate the strong one when using the scalar-field energy-momentum tensor, while all four conditions are violated near the bounce in the effective tensor formulation.
-
Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution
Modified gravity theories supply viable mathematical frameworks for inflation, bounces, and dark energy eras that match observational data.