2026/02/28 by S. D. Campos
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Pulsars and Gravitational Waves Research #astro-ph.CO #gr-qc
paper · pdf · doi:10.1088/1475-7516/2026/07/097
published as JCAP 07, 097 (2026)
openalex publication_date 2026/07/01 · openalex created_date 2026/07/25 · openalex updated_date 2026/07/26 · arxiv created 2026/07/31 · arxiv updated 2026/08/04
Abstract We investigate an inflationary scenario driven by a complex scalar field nonminimally coupled to gravity and subject to a non-symmetric complex potential. The real part of the potential controls the cosmological background and realizes a plateau-type inflation compatible with α -attractor T-models. In contrast, the imaginary part acts as an effective non-Hermitian deformation encoding dissipative effects. Working in the Jordan frame and imposing ghost-free conditions on the effective Planck mass, we derive the background equations and define a complex equation-of-state parameter whose real part governs the expansion and whose imaginary part quantifies departures from conservative dynamics. Numerical integration shows that the duration of inflation is primarily controlled by the nonminimal coupling ζ . On the other hand, the complex asymmetry parameter Δ ε has a negligible impact on the real background: the real energy density and pressure vary by less than 10 -5 as Δ ε is scanned over its allowed range. Mapping the two-field dynamics to an effective single-field description in the Einstein frame, we obtain a spectral index n s ≃ 0.968–0.971 and a tensor-to-scalar ratio r < 10 -3 , fully consistent with Planck 2018 bounds. We introduce a relevance parameter and show that non-Hermitian effects remain strongly suppressed during slow roll but grow to 𝒪(1) near the end of inflation, triggering an efficient reheating phase without additional fields or ad hoc friction terms. In this sense, the imaginary sector behaves as an effective 𝒫𝒯-symmetric channel for energy transfer, providing a geometrical mechanism for inflation and its exit within a non-Hermitian scalar-tensor framework. We additionally construct a minimal toy model in which the inflaton decays into baryon-number-carrying fermionic degrees of freedom and demonstrate that a complex inflaton sector is capable of generating a baryon asymmetry of the empirically observed order of magnitude for theoretically reasonable reheating temperatures and 𝒞𝒫-violating decay asymmetries.