Starobinsky like inflation and EGB Gravity in the light of ACT

2025/05/08 by Abolhassan Mohammadi, Yogesh, Qiang Wu +4 · 37 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Constraint (computer-aided design) #Cosmology and Gravitation Theories #Coupling (piping) #Curvature #Galaxies: Formation, Evolution, Phenomena #Inflation (cosmology) #Parametric statistics #Quadratic equation #Scalar (mathematics) #Scalar field #Spectral index

paper · pdf · doi:10.48550/arxiv.2505.05363

published in arXiv (Cornell University) (Cornell University)

openalex publication_date 2025/05/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

The ACT data shows an enhancement in the value of the scalar spectral index, as n_s = 0.9743 ± 0.0034, leading to disfavoring many inflationary models, including the Starobinsky model. To satisfy the constraint made by ACT, we will investigate the Starobinsky potential within the Einstein-Gauss-Bonnet(EGB) gravity theory. EGB gravity is motivated by the higher-dimensional theory, which includes quadratic curvature correction terms and a coupling between the scalar field and the GB term that modifies the dynamical equations. The model is considered by using the slow-roll approximation method and the exact numerical approach for two different coupling functions. The results indicate that the model is in good agreement with the data and the results stand in 1σ of the ACT r-n_s plane. Considering the running of the scalar spectral index also implies the consistency of the model with data. In addition, the parametric space of the free parameters of the EGB coupling is explored, where we find the acceptable region of the parameters in which the resulting n_s and r stay in 1σ of the ACT data. Next, the reheating phase is considered. It is determined that the model can simultaneously satisfy the constraint of ACT data and the reheating temperature constraints.

Citations

• 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
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• ACT DR6 Insights on the Inflationary Attractor models and Reheating
• Reheating ACTs on Starobinsky and Higgs inflation
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• 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?
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• Is the CMB revealing signs of pre-inflationary physics?
• Inflation with Gauss-Bonnet correction: beyond slow-roll
• Higgs-Modular Inflation
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• Natural inflation in Palatini F(R,X)
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• The Atacama Cosmology Telescope: DR6 Power Spectra, Likelihoods and ΛCDM Parameters
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• Inflationary Dynamics in Einstein-Gauss-Bonnet Gravity Using New Slow-Roll Approximations considering Generalised Reheating
• Revisiting Einstein-Gauss-Bonnet Theories after GW170817
• F(Q) gravity with Gauss-Bonnet corrections: from early-time inflation to late-time acceleration
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• Unifying inflation with early and late dark energy in Einstein-Gauss-Bonnet gravity
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• The Standard Model Higgs boson as the inflaton
• Reheating and Preheating after Inflation
• Dilatonic Black Holes with Gauss-Bonnet Term
• 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

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• Inflation with Gauss-Bonnet Correction and Higgs Potential
• Curvaton-assisted hilltop inflation
• Single-field D-type inflation in the minimal supergravity in light of Planck-ACT-SPT data
• Domain Wall formation from Z₂ spontaneous symmetry breaking/restoration in Scalar-Einstein-Gauss-Bonnet theory
• Quintessential Inflation in Light of ACT DR6
• Fibre Inflation Meets Quintessence: Implications of Perturbative Stabilisation
• k-inflation: Non-separable case meets ACT measurements
• Symmetry-Protected α-Attractor Hybrid Inflation in Supergravity and Constraints from ACT DR6 and DESI DR2
• The Harrison-Zeldovich attractor: From Planck to ACT
• GUT-Scale Smooth Hybrid Inflation with a Stabilized Modulus in Light of ACT and SPT Data
• The implications of inflation for the last ACT
• Updating GUT-Scale Pole Higgs Inflation After ACT
• Radiative-Corrected Higgs Inflation in Light of the Latest ACT Observations
• Heavy Field Effects on Inflationary Models in Light of ACT Data
• Beyond the Starobinsky model after ACT
• The R²-Higgs inflation: R³ contribution and preheating after ACT and SPT data
• Alleviating the H₀ tension in Rastall gravity
• Deformations of Starobinsky Inflation in No-Scale SU(5) and SO(10) GUTs
• Leptogenesis and neutrino mass with one right-handed neutrino and Higgs inflaton
• Inflationary Models with Gauss-Bonnet Coupling in Light of ACT Observations
• Viability of generalized α-inflation from Planck, ACT, and DESI Data
• Confronting Inflation and Reheating with Observations: Improved Predictions Beyond Slow-Roll
• The Preheating Stage on The Starobinsky Inflation after ACT
• ACT-Inspired Kaehler-Based Inflationary Attractors
• Observational constraints on inflationary models with non-minimally derivative coupling by ACT
• Inflationary attractors and radiative corrections in light of ACT data
• Precision predictions of Starobinsky inflation with self-consistent Weyl-squared corrections
• Primordial Black Holes Save R² Inflation
• Kinetically Modified Palatini Inflation Meets ACT Data
• Minimal Plateau Inflation in light of ACT DR6 Observations
• Inflaton Dynamics in Higher-Derivative Scalar-Tensor Theories of Gravity
• Are single-field models of inflation and PBHs production ruled out by ACT observations?
• Constraining Reheating Temperature, Inflaton-SM Coupling and Dark Matter Mass in Light of ACT DR6 Observations
• Curvature corrections to Starobinsky inflation can explain the ACT results
• Implications of pulsar timing arrays for Gauss-Bonnet Inflation
• Approximate reconstruction of inflationary potential with ACT observations
• Reheating ACTs on Starobinsky and Higgs inflation

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