Waqas Ahmed, Maria Mehmood, Mansoor Ur Rehman and Umer Zubair
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引用次数: 0
Abstract
We present a realistic supersymmetric μ-hybrid inflation model within the framework of SU(4)C × SU(2)L × U(1)R gauge symmetry, wherein the symmetry breaking SU(4)C × SU(2)L × U(1)R → SU(3)C × SU(2)L × U(1)B-L × U(1)R occurs before observable inflation, effectively eliminating topologically stable primordial monopoles. Subsequent breaking of U(1)B-L × U(1)R → U(1)Y after inflation leads to the formation of superheavy metastable cosmic strings (CSs), capable of producing a stochastic gravitational wave background (SGWB) consistent with the recent PTA data. Moreover, the scalar spectral index ns and the tensor-to-scalar ratio r align with Planck 2018 observations. A consistent scenario for reheating and non-thermal leptogenesis is employed to explain the observed matter content of the universe. Finally, the embedding of G421 into the Pati-Salam gauge symmetry G422 is briefly discussed, predicting potentially observable proton decay rates detectable at facilities such as Hyper Kamiokande and DUNE.
期刊介绍:
Journal of Cosmology and Astroparticle Physics (JCAP) encompasses theoretical, observational and experimental areas as well as computation and simulation. The journal covers the latest developments in the theory of all fundamental interactions and their cosmological implications (e.g. M-theory and cosmology, brane cosmology). JCAP''s coverage also includes topics such as formation, dynamics and clustering of galaxies, pre-galactic star formation, x-ray astronomy, radio astronomy, gravitational lensing, active galactic nuclei, intergalactic and interstellar matter.