2026/8/8
Kayoomars Karami

Kayoomars Karami

Academic rank: Professor
ORCID:
Education: PhD.
ResearchGate:
Faculty: Faculty of Science
ScholarId:
E-mail: KKarami [at] uok.ac.ir
ScopusId: Link
Phone:
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Research

Title
Breaking the degeneracy of noncanonical quartic inflation by reheating considerations
Type
JournalPaper
Keywords
Inflation; early universe; gravitational waves; reheating
Year
2026
Journal International Journal of Modern Physics D
DOI
Researchers Iraj Safaei ، Kayoomars Karami

Abstract

Here, the quartic inflationary potential V ðÞ ¼ 4 4 within a noncanonical framework characterized by a power-law Lagrangian is investigated. We demonstrate that the predictions of this model align with the Planck 2018 observational data. We explore how the predictions of the model depend on the noncanonical parameter  and the number of e-folds N. Notably, the sound speed, non-Gaussianity parameter, scalar spectral index and tensor-to-scalar ratio are all affected by variations in . However, the scalar spectral index exhibits a degeneracy with respect to variation in , which can be broken by incorporating reheating consideration. By applying a combination of theoretical and observational constraints on r ns, non-Gaussianity, and reheating parameters, we ¯nd that the duration of inflation is constrained to the range 55  N  55:7 e-folds for 60    130. Finally, we investigate relic gravitational waves and demonstrate that their energy density spectrum falls within the sensitivity range of gravitational waves detectors for this constrained range of e-folds.