Work

Harrison-Zeldovich attractor: From Planck to ACT results

Year: 2026

Type: article

Abstract: In the era of Planck cosmology, the inflationary paradigm is best fitted toward the cosmological attractor scenarios, including the induced inflation, universal attractors, conformal attractors, and special attractors that are cataloged as $ξ$-models and $α$-models. The recent hint from the ACT results pushes the scalar spectral index closer to the scale-invariant Harrison-Zeldovich spectrum, calling for a theoretical paradigm shift toward a Harrison-Zeldovich attractor, which is difficult to realize in the standard single-field slow-roll inflationary scenario. In this work, we achieve the Harrison-Zeldovich attractor scenario via nonminimal derivative coupling, attracting the monomial inflation, hilltop inflation, and $α$-attractor E-model toward the Harrison-Zeldovich spectrum.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/cm1c-kfpn

Authors: Chengjie Fu, Di Lu, Shao-Jiang Wang

Institutions: Anhui Normal University, Asia Pacific Center for Theoretical Physics

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Natural Science Foundation of China, National Key Research and Development Program of China