Running Spectral Index from Inflation with Modulations
read the original abstract
We argue that a large negative running spectral index, if confirmed, might suggest that there are abundant structures in the inflaton potential, which result in a fairly large (both positive and negative) running of the spectral index at all scales. It is shown that the center value of the running spectral index suggested by the recent CMB data can be easily explained by an inflaton potential with superimposed periodic oscillations. In contrast to cases with constant running, the perturbation spectrum is enhanced at small scales, due to the repeated modulations. We mention that such features at small scales may be seen by 21 cm observations in the future.
This paper has not been read by Pith yet.
Forward citations
Cited by 5 Pith papers
-
One Feature, Three Clocks: Phase-Locked Gravitational Waves, Primordial Black Holes, and Non-Gaussianity from Periodic Warm Inflation
Periodic warm inflation imprints one log-periodic feature on the curvature spectrum that saturates asteroid-mass PBHs, generates dual-band GW backgrounds, and offsets the bispectrum phase by a quarter cycle fixed by s...
-
A Designer's Guide to Lunar Far-Side Interferometer Array: Power Spectrum Measurement and Cosmological Constraints from the Dark Ages
A lunar array needs at least ~30,000 Fourier modes and distributed stations to reach σ(α_s)=0.034 on inflation, competitive with Planck, though thermal noise limits high-redshift small-scale access.
-
The End of the First Act: Spectral Running, Interacting Dark Radiation, and the Hubble Tension in Light of ACT DR6 Data
Including spectral running α_s, β_s and self-interacting dark radiation relaxes the ACT DR6 bound on ΔN_eff to <0.58 and lowers the Hubble tension to 2.2σ with three extra parameters.
-
Blue-tilted Runnings and the JWST Early Galaxy Tension
A blue-tilted spectrum with running parameters α_s ≈ 0.2 and β_s ≈ 0.2 resolves the JWST early-galaxy abundance tension at 1σ in a joint CMB analysis.
-
Blue-tilted Runnings and the JWST Early Galaxy Tension
Blue-tilted running spectrum with α_s ≈ 0.02 and β_s ≈ 0.02 resolves JWST early galaxy tension at 1σ in joint CMB analysis.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.