Speaker
Description
We study the relic abundance of the lightest neutralino in Finite Unified Theory FUTB, a fully finite N=1 supersymmetric SU(5) model whose all-orders vanishing beta functions uniquely fix the soft SUSY-breaking spectrum in terms of a single gaugino mass parameter M. We couple this theory to Starobinsky R²-inflationary cosmology and systematically examine whether the observed dark matter abundance Ωh² ≈ 0.12 can be reproduced within this minimal framework.
Three post-inflationary production mechanisms are analyzed: non-thermal gravitational production via scalaron oscillations (Arbuzova, Dolgov & Singh 2021), standard freeze-out during reheating, and early freeze-out in the pre-reheating epoch. In all cases, the model fails to reproduce the observed relic density. The two compounding sources of failure are identified: the bino-dominated nature of the FUTB LSP, which suppresses the annihilation cross section by ~10² relative to a wino or higgsino of equal mass, and the rigidity of the Starobinsky reheating parameters fixed by CMB normalization (m_φ ~ 3×10¹³ GeV), which sets a dilution hierarchy insufficient to compensate the bino overabundance.
We conclude that the minimal FUTB + Starobinsky framework cannot account for the observed dark matter abundance across the full parameter space. Embedding FUTB into N=1 supergravity is identified as a promising direction to open new viable scenarios, and is discussed as the natural next step of this program.