Axion-like fields coupled to the Nieh-Yan term generate a chiral GW background during radiation domination, with parameter space explored for detectability in PTA and space-based observatories.
hub Canonical reference
Chern-Simons Modification of General Relativity
Canonical reference. 89% of citing Pith papers cite this work as background.
19
Pith papers citing it
Background
89% of classified citations
abstract
General relativity is extended by promoting the three-dimensional gravitational Chern-Simons term to four dimensions. This entails choosing an embedding coordinate v_\mu -- an external quantity, which we fix to be a non-vanishing constant in its time component. The theory is identical to one in which the embedding coordinate is itself a dynamical variable, rather than a fixed, external quantity. Consequently diffeomorphism symmetry breaking is hidden in the modified theory: the Schwarzschild metric is a solution; gravitational waves possess two polarizations, each traveling at the velocity of light; a conserved energy-momentum (pseudo-) tensor can be constructed. The modification is visible in the intensity of gravitational radiation: the two polarizations of a gravity wave carry intensities that are suppressed/enchanced by the extension.
hub tools
citation-role summary
background 8
method 1
citation-polarity summary
representative citing papers
In Ricci-coupled scalar-Gauss-Bonnet gravity, the change in scalar charge during binary black hole mergers generates a scalar memory contribution that modifies the total memory signal on observable timescales.
A classification of admissible energy density profiles with bounded Kretschmann scalar yields a unified framework for regular static spherically symmetric spacetimes satisfying the weak energy condition, recovering known models and producing new families with hypergeometric and other closed forms.
A reduction scheme transforms arbitrary N-term scalar and matrix recurrence relations from black hole perturbations in modified gravity into three-term relations solvable by continued fractions.
No evidence for cosmological parity violation is found in the first kurto-spectrum analysis of BOSS DR12 and DESI DR1 luminous red galaxies.
New quasi-universal relations connect static tidal deformability Λ⁰ to its dynamical correction Λ² and to Mω* with equation-of-state scatter below 5% and 2.8% respectively across 59 models.
Hierarchical Bayesian inference on 20 high-SNR simulated binary neutron star events shows a linear lnΛ-lnQ relation suffices and constrains dynamical Chern-Simons gravity length scale to ≤10 km.
γ-duality in the EPRL spinfoam model determines the relation between parity-even and parity-odd terms in an effective gravity theory, allowing the Barbero-Immirzi parameter to be measured from inflationary tensor observables.
One-loop integration of a heavy fermion with inflaton-dependent mass in axion inflation generates localized gauge-field production and a detectable chiral gravitational-wave signal in the deci-hertz range.
Model-independent forecasts for the stochastic gravitational-wave background from ultralight dark matter decaying into gravitons and the sensitivity of current and future detectors to this signal.
Neural post-Einsteinian analysis of GWTC-3 finds no GR violation and sets constraints covering both post-Newtonian and beyond-post-Newtonian deviations in a single theory-agnostic setup.
Coupling Chern-Simons gravity to a spectator field in multi-field inflation generates distinctive parity-odd scalar-tensor bispectra with perturbativity bounds on the couplings.
Fuzzy dark matter induces frequency-dependent amplitude birefringence in gravitational waves with periodic time modulation set by the scalar mass, but no velocity birefringence.
A CNN framework using response functions from gravitational wave mismatches classifies signals as GR or beyond-GR with 33 times better sensitivity than raw waveforms and detects massive gravity deviations at graviton masses around 10^{-23} eV/c².
A transient parity-violating phase during inflation generates a robust blue-tilted (n_T ≃ 2) primordial gravitational wave spectrum at small scales with nearly maximal helicity coherence and linear polarization, offering a cosmological template for PTA data distinct from astrophysical sources.
Magnetic fields lower the scalarization threshold for electromagnetic and gravitational Chern-Simons couplings but produce opposite trends on the two Gauss-Bonnet branches, with nonlinear terms converting exponential growth into bounded oscillations.
Unitarity and torsion requirements in (3+1)-dimensional string effective actions introduce only a subleading four-derivative term that leaves the StRVM inflationary dynamics unchanged, confirming the model's phenomenological completeness within string theory.
The paper provides state-of-the-art predictions for the Einstein Telescope's impact on fundamental physics, cosmology, compact-object astrophysics, and multi-messenger astronomy across its proposed configurations.
citing papers explorer
-
Testing General Relativity Through Gravitational Wave Classification: A Convolutional Neural Network Framework
A CNN framework using response functions from gravitational wave mismatches classifies signals as GR or beyond-GR with 33 times better sensitivity than raw waveforms and detects massive gravity deviations at graviton masses around 10^{-23} eV/c².