Uploaded February 2026 | Updated September 2026, 2 weeks ago
Speaker: Venus Keus
Title: Radiative Inflation and Dark Energy with a Non-Minimal Coupling to Gravity
Abstract: Following the recent Atacama Cosmology Telescope (ACT) results, we revisit chaotic inflation based on a single complex scalar field with mass term M2|Φ|2, which usually predicts a spectral index ns ≈ 0.96 but a too-large tensor to scalar ratio r ≈ 0.16. With radiative corrections, the potential M2|Φ|2 ln(|Φ|2/Λ2) induces spontaneous symmetry breaking near the scale Λ, yielding a Pseudo Nambu-Goldstone boson which can play the role of a quintessence field, hence radiative inflation and dark energy (RIDE). Including a non-minimal coupling to gravity ξ |Φ|2R2 with ξ ∼ 0.1 reduces the tensor to scalar ratio to r ≲0.03, allowing a good fit of the RIDE model to Planck data. Allowing a small additional quartic coupling correction λ|Φ|4 allows a good fit to ACT data sets for ξ ∼ 1 and λ ∼ 10−5.
Speaker: Venus Keus
Title: Radiative Inflation and Dark Energy with a Non-Minimal Coupling to Gravity
Abstract: Following the recent Atacama Cosmology Telescope (ACT) results, we revisit chaotic inflation based on a single complex scalar field with mass term M2|Φ|2, which usually predicts a spectral index ns ≈ 0.96 but a too-large tensor to scalar ratio r ≈ 0.16. With radiative corrections, the potential M2|Φ|2 ln(|Φ|2/Λ2) induces spontaneous symmetry breaking near the scale Λ, yielding a Pseudo Nambu-Goldstone boson which can play the role of a quintessence field, hence radiative inflation and dark energy (RIDE). Including a non-minimal coupling to gravity ξ |Φ|2R2 with ξ ∼ 0.1 reduces the tensor to scalar ratio to r ≲0.03, allowing a good fit of the RIDE model to Planck data. Allowing a small additional quartic coupling correction λ|Φ|4 allows a good fit to ACT data sets for ξ ∼ 1 and λ ∼ 10−5.
