Galileon models must obey a void-depth limit tied to expansion history to avoid force breakdowns, excluding ~60% of a linear parameterization's space by z less than or equal to 10.
G-inflation: inflation driven by the Galileon field
9 Pith papers cite this work. Polarity classification is still indexing.
abstract
We propose a new class of inflation model, G-inflation, which has a Galileon-like nonlinear derivative interaction of the form $G(\phi, (\nabla\phi)^2)\Box\phi$ in the Lagrangian with the resultant equations of motion being of second order. It is shown that (almost) scale-invariant curvature fluctuations can be generated even in the exactly de Sitter background and that the tensor-to-scalar ratio can take a significantly larger value than in the standard inflation models, violating the standard consistency relation. Furthermore, violation of the null energy condition can occur without any instabilities. As a result, the spectral index of tensor modes can be blue, which makes it easier to observe quantum gravitational waves from inflation by the planned gravitational-wave experiments such as LISA and DECIGO as well as by the upcoming CMB experiments such as Planck and CMBpol.
citation-role summary
citation-polarity summary
roles
background 4polarities
background 4representative citing papers
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.
Derives the elastic two-body unitarity relation for anisotropic scalar fields with different sound speeds, verifies it at one loop in a quartic model, and shows anisotropy modifies the radiatively generated scalon mass while leaving the Gildener-Weinberg flat direction unchanged.
NANOGrav data favors a blue-tilted tensor spectrum with nt ≈ 2.2, radiation-dominated reheating, and alpha-vacuum states over standard Bunch-Davies, with a frequency-dependent alpha suggested to resolve the blue-tilt tension.
Certain inflation models produce right-handed neutrinos via gravitational effects sufficient for leptogenesis to explain the baryon asymmetry, testable by inflationary gravitational waves.
K-inflation with non-canonical kinetic term G(φ) shifts α-attractor T-models and natural inflation into the Planck-ACT-LB-BK18 allowed region while satisfying Swampland conjectures and producing testable GW spectra.
A power-law non-canonical kinetic coupling F(φ)=1+Aφ^n revives the Starobinsky inflation potential's consistency with ACT DR6 CMB data while preserving attractor dynamics and yielding viable reheating.
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.
A review thesis covering Mukhanov parametrization, general scalar-tensor theories, and new slow-roll techniques for canonical and noncanonical inflation observables.
citing papers explorer
-
How deep can a cosmic void be? Voids-informed theoretical bounds in Galileon gravity
Galileon models must obey a void-depth limit tied to expansion history to avoid force breakdowns, excluding ~60% of a linear parameterization's space by z less than or equal to 10.
-
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.
-
Disparity in sound speeds: implications for elastic unitarity and the effective potential in quantum field theory theory
Derives the elastic two-body unitarity relation for anisotropic scalar fields with different sound speeds, verifies it at one loop in a quartic model, and shows anisotropy modifies the radiatively generated scalon mass while leaving the Gildener-Weinberg flat direction unchanged.
-
Constraints on the inflationary vacuum and reheating era from NANOGrav
NANOGrav data favors a blue-tilted tensor spectrum with nt ≈ 2.2, radiation-dominated reheating, and alpha-vacuum states over standard Bunch-Davies, with a frequency-dependent alpha suggested to resolve the blue-tilt tension.
-
Nonthermal leptogenesis via cosmological gravitational particle production is tested by inflationary gravitational waves
Certain inflation models produce right-handed neutrinos via gravitational effects sufficient for leptogenesis to explain the baryon asymmetry, testable by inflationary gravitational waves.
-
Reviving Motivated Inflationary Potentials with $K$-inflation in the light of ACT
K-inflation with non-canonical kinetic term G(φ) shifts α-attractor T-models and natural inflation into the Planck-ACT-LB-BK18 allowed region while satisfying Swampland conjectures and producing testable GW spectra.
-
Starobinsky Inflation in k-Essence Framework: Attractor Dynamics, Reheating, and Consistency with ACT DR6
A power-law non-canonical kinetic coupling F(φ)=1+Aφ^n revives the Starobinsky inflation potential's consistency with ACT DR6 CMB data while preserving attractor dynamics and yielding viable reheating.
-
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.
-
Noncanonical Approaches To Inflation
A review thesis covering Mukhanov parametrization, general scalar-tensor theories, and new slow-roll techniques for canonical and noncanonical inflation observables.