Inflationary Models with Gauss-Bonnet Coupling in Light of ACT Observations

2025/08/13 by Zhu, Yigan, Gao, Qing, Gong, Yungui +1 · 9 citations
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc)

paper · doi:10.48550/arxiv.2508.09707

Abstract

Recent analyses combining Atacama Cosmology Telescope (ACT) data with other cosmological datasets report a higher scalar spectral index n_s, creating tension with a wide range of inflationary models. Since a Gauss-Bonnet term with a coupling function ξ(ϕ) = 3λ/[4V(ϕ)] leaves n_s nearly unchanged (up to a field rescaling) while reducing the tensor-to-scalar ratio r by a factor (1-λ), so choosing (1-λ) sufficiently small effectively removes r as a limiting observable, making it easier for inflationary models to satisfy the latest observational constraints and alleviating this tension. Applying this mechanism to chaotic inflation, E-models, T-models, and hilltop inflation, we find that broad regions of parameter space become consistent with the latest ACT-based CMB constraints. These results demonstrate that Gauss-Bonnet couplings can help bring a broad class of inflationary models into agreement with current CMB measurements.

Citations

• Power-law F(R) Gravity as Deformations to Starobinsky Inflation in View of ACT
• String Corrected Scalar Field Inflation Compatible with the ACT Data
• Confronting Inflation and Reheating with Observations: Improved Predictions Beyond Slow-Roll
• Reconciling Fractional Power Potential and EGB Gravity in the light of ACT
• The Preheating Stage on The Starobinsky Inflation after ACT
• Power Law Plateau Inflation and Primary Gravitational Waves in the light of ACT
• Interacting Scalar Fields as Dark Energy and Dark Matter in Einstein scalar Gauss Bonnet Gravity
• Observational constraints on inflationary models with non-minimally derivative coupling by ACT
• Inflationary attractors and radiative corrections in light of ACT data
• GW170817 Viable Einstein-Gauss-Bonnet Inflation Compatible with the Atacama Cosmology Telescope Data
• Perturbative Kähler Moduli Inflation
• Nonminimal infrared gravitational reheating in light of ACT observation
• Kinetically Modified Palatini Inflation Meets ACT Data
• Constraining Reheating Temperature, Inflaton-SM Coupling and Dark Matter Mass in Light of ACT DR6 Observations
• Polynomial Potential Inflation in the ACT Era: From CMB to Primordial Black Holes
• On the present status of inflationary cosmology
• Curvature corrections to Starobinsky inflation can explain the ACT results
• Approximate reconstruction of inflationary potential with ACT observations
• ACT-ing on inflation: Implications of non Bunch-Davies initial condition and reheating on single-field slow roll models
• The curvaton ACTs again
• Starobinsky like inflation and EGB Gravity in the light of ACT
• Improved Predictions on Higgs-Starobinsky Inflation and Reheating with ACT DR6 and Primordial Gravitational Waves
• Keeping the relation between the Starobinsky model and no-scale supergravity ACTive
• Reconciling Higgs Inflation with ACT Observations through Reheating
• ACT DR6 Insights on the Inflationary Attractor models and Reheating
• Reheating ACTs on Starobinsky and Higgs inflation
• Refined Predictions for Starobinsky Inflation and Post-inflationary Constraints in Light of ACT
• Increase of n_s in regularized pole inflation & Einstein-Cartan gravity
• Non-minimal coupling in light of ACT
• Eff-ACT-ive Starobinsky pre-inflation
• Palatini Linear Attractors Are Back in ACTion
• Enhancement of primordial curvature perturbations in R³-corrected Starobinsky-Higgs inflation
• Independent connection in ACTion during inflation
• Has ACT measured radiative corrections to the tree-level Higgs-like inflation?
• Fractional attractors in light of the latest ACT observations
• Is the CMB revealing signs of pre-inflationary physics?
• One-loop correction to primordial tensor modes during radiation era
• The early universe is ACT-ing warm
• Higgs-Modular Inflation
• Einstein-Gauss-Bonnet Cosmology Confronted with Observations
• The Atacama Cosmology Telescope: DR6 Constraints on Extended Cosmological Models
• The Atacama Cosmology Telescope: DR6 Power Spectra, Likelihoods and ΛCDM Parameters
• General Einstein-Cartan quadratic gravity with derivative couplings
• Inflationary Dynamics of Mutated Hilltop Inflation in Einstein-Gauss-Bonnet Gravity Under New Slow-Roll Approximations with Generalised Reheating
• Inflationary Dynamics in Einstein-Gauss-Bonnet Gravity Using New Slow-Roll Approximations considering Generalised Reheating
• Time-convolutionless cosmological master equations: Late-time resummations and decoherence for non-local kernels
• Revisiting Einstein-Gauss-Bonnet Theories after GW170817
• DESI 2024 VI: cosmological constraints from the measurements of baryon acoustic oscillations
• A Case Study of Small Field Inflationary Dynamics in the Einstein-Gauss Bonnet Framework in the Light of GW170817
• Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• GW170817-compatible Constant-roll Einstein-Gauss-Bonnet Inflation and Non-Gaussianities
• Planck2018 results
• Strings in Background Fields
• CMB-S4 Science Book, First Edition
• The Standard Model Higgs boson as the inflaton
• A new inflationary universe scenario: A possible solution of the horizon, flatness, homogeneity, isotropy and primordial monopole problems
• A new type of isotropic cosmological models without singularity

Cited by

• Inflation with Gauss-Bonnet Correction and Higgs Potential
• Quintessential Inflation in Light of ACT DR6
• Fibre Inflation Meets Quintessence: Implications of Perturbative Stabilisation
• k-inflation: Non-separable case meets ACT measurements
• Inflationary models in f(R,T) gravity: Constraints from Planck, BICEP/Keck, and Atacama
• The Harrison-Zeldovich attractor: From Planck to ACT
• The implications of inflation for the last ACT
• ACT Constraints on Marginally Deformed Starobinsky Inflation
• Heavy Field Effects on Inflationary Models in Light of ACT Data

Related

• GW170817 Viable Einstein-Gauss-Bonnet Inflation Compatible with the Atacama Cosmology Telescope Data
• Observational constraints on inflationary models with non-minimally derivative coupling by ACT
• Constraining non-minimally coupled squared-Quartic Hilltop Inflation in light of ACT observations
• Inflation with Gauss-Bonnet Correction and Higgs Potential
• Gauss-Bonnet inflation and swampland