2026/4/22
Kayoomars Karami

Kayoomars Karami

Academic rank: Professor
ORCID:
Education: PhD.
H-Index:
Faculty: Faculty of Science
ScholarId:
E-mail: KKarami [at] uok.ac.ir
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Research

Title
Reheating and relic gravitational waves as remedies for degeneracies of non-canonical natural inflation
Type
JournalPaper
Keywords
inflation, early universe, gravitational waves, reheating
Year
2026
Journal Physica Scripta
DOI
Researchers Karam Bahadori ، Soma Heydari ، Kayoomars Karami

Abstract

Here, a natural non-canonical inflationary model based on a power-law Lagrangian is investigated. We analyze the scalar spectral index ns and the tensor-to-scalar ratio r of the model and identify their degeneracies with respect to the free parameters. Notably, ns and r show effective independence from the model parameters due to degeneracies in the slow-roll parameters that leads to unresolved parameter degeneracies. Employing the constraints on reheating parameters such as the reheating duration Nreh, the reheating temperature Treh, and the equation of state parameterωreh, is found to be insufficient to fully break these degeneracies. However, the relic gravitational wave spectrum provides a way to break degeneracy with respect to the non-canonical parameterα, degeneracy with respect to the potential parameter f persist. Finally, we specify the allowed ranges for the inflationary duration N and the parameterα, in light of the latest observational data. These results highlight the role of relic gravitational waves in refining inflationary models and illustrate the challenges in fully resolving parameter degeneracies.