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F-term hybrid inflation with T-model Kähler geometry and beyond

Waqas Ahmed1,*, Constantinos Pallis2,†, and Mansoor Ur Rehman3,‡

  • *Contact author: waqasmit@hbpu.edu.cn
  • †Contact author: kpallis@auth.gr
  • ‡Contact author: m.rehman@iu.edu.sa
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Phys. Rev. D 114, 063516 – Published 8 September, 2026

DOI: https://doi.org/10.1103/qyrv-yn6g

Abstract

We analyze F-term hybrid inflation (FHI) within various grand unified theories in the presence of a Kähler potential for the inflaton field which parametrizes the Kähler manifolds SU(1,1)/U(1) or SU(2)/U(1). We take into account supergravity, radiative, and soft supersymmetry-breaking corrections to the tree-level potential and find that viable FHI can be realized without extrema along the inflationary trajectory for a broad region of the parameter space. For selected superpotential parameters, the models’ predictions are largely influenced by the curvature of the internal space and the magnitude of the tadpole parameter which are constrained so as to achieve compatibility with the current Atacama Cosmology Telescope and the South Pole Telescope data. We also discuss the formation of cosmic strings and their associated gravitational wave signals, potentially detectable by current and upcoming experiments.

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Phys. Rev. D 114, 063516– Published 8 September, 2026
  • Received 13 May 2026
  • Accepted 29 July 2026
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