In pure axion inflation, detectable gravitational wave signals arise only in parameter regions with strong backreaction that violate the upper bound on ΔN_eff.
Canonical reference
Probing the early universe with inflationary gravitational waves
Canonical reference. 80% of citing Pith papers cite this work as background.
10
Pith papers citing it
Background
80% of classified citations
abstract
Near comoving wavenumber k, the gravitational-wave background (GWB) from inflation carries information about the physical conditions near two moments in cosmic history: the moment when k ``left the horizon'' during inflation, and the moment when it ``re-entered the horizon'' after inflation. We investigate the extent to which this information can be extracted if the GWB is measured by a combination of cosmic-microwave-background (CMB) polarization experiments on large scales and space-based laser-interferometer experiments on small scales. To disentangle this information, we derive a new gravitational-wave transfer function that incorporates a number of physical effects that were treated less accurately, less generally, or were missing altogether in previous treatments. In particular, it incorporates: (i) dark energy with time-varying equation-of-state w(z); (ii) tensor anisotropic stress due to free-streaming relativistic particles in the early universe; and (iii) a variety of physical effects that cause deviations from the standard equation-of-state w=1/3 during the radiation era. Based on this transfer function, we consider the degree to which the GWB can be used to test inflation and to probe the ``primordial dark age'' between the end of inflation and the electroweak phase transition.
citation-role summary
background 4
baseline 1
citation-polarity summary
representative citing papers
Spectral features of primordial gravitational-wave backgrounds can directly reconstruct the mass and decay rate of long-lived BSM particles via the frequencies imprinted by an early matter-dominated epoch.
Gravitino masses in the 100 TeV to 10^10 TeV range can be inferred from two frequency features in the stochastic gravitational wave spectrum produced by an early matter-dominated phase.
High-frequency primordial gravitational waves extend to higher frequencies due to post-inflation inflaton dynamics, and their detailed spectrum shape can distinguish inflation models.
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.
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.
Collider experiments can strongly constrain p-wave-suppressed derivative operators and thereby limit reheating temperature, DM mass, and interaction scale needed to match observed DM abundance during reheating.
citing papers explorer
-
Gravitational waves from axion inflation in the gradient expansion formalism. Part I. Pure axion inflation
In pure axion inflation, detectable gravitational wave signals arise only in parameter regions with strong backreaction that violate the upper bound on ΔN_eff.
-
Irreducible Gravitational Wave Background as a Particle Detector
Spectral features of primordial gravitational-wave backgrounds can directly reconstruct the mass and decay rate of long-lived BSM particles via the frequencies imprinted by an early matter-dominated epoch.
-
Whispers of Supergravity in Gravitational Wave Backgrounds: Determining the Gravitino Mass from Cosmic Thermal History
Gravitino masses in the 100 TeV to 10^10 TeV range can be inferred from two frequency features in the stochastic gravitational wave spectrum produced by an early matter-dominated phase.
-
High Frequency Spectrum of Primordial Gravitational Waves
High-frequency primordial gravitational waves extend to higher frequencies due to post-inflation inflaton dynamics, and their detailed spectrum shape can distinguish inflation models.
-
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.
-
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.
-
From WIMP to FIMP during reheating: collider vs non-collider probes for p-wave annihilation
Collider experiments can strongly constrain p-wave-suppressed derivative operators and thereby limit reheating temperature, DM mass, and interaction scale needed to match observed DM abundance during reheating.
- Gravitational Waves from Post-Inflationary Magnetism: Direct and Scalar-Induced Contributions
- A Unified Bogoliubov Approach to Primordial Gravitational Waves: From Inflation to Reheating