# Cosmology with a Master Coupling in Flipped SU(5) $\times$ U(1): The $\lambda_6$ Universe

## TL;DR

This paper presents a comprehensive cosmological model based on flipped SU(5)×U(1) GUT, where a single coupling governs inflation, dark matter, neutrino masses, and baryogenesis, integrating these phenomena into a unified framework.

## Contribution

It introduces a novel flipped SU(5)×U(1) GUT model with a master coupling that links multiple cosmological processes, providing a unified approach to early universe phenomena.

## Key findings

- Successful integration of Starobinsky-like inflation with GUT physics.
- The master coupling $$ controls reheating, dark matter, neutrino masses, and baryon asymmetry.
- Consistent cosmological evolution within the proposed GUT framework.

## Abstract

We propose a complete cosmological scenario based on a flipped SU(5) $\times$ U(1) GUT model that incorporates Starobinsky-like inflation, taking the subsequent cosmological evolution carefully into account. A single master coupling, $\lambda_6$, connects the singlet, GUT Higgs and matter fields, controlling 1) inflaton decays and reheating, 2) the gravitino production rate and therefore the non-thermal abundance of the supersymmetric cold dark matter particle, 3) neutrino masses and 4) the baryon asymmetry of the Universe.