Two phase study for inflation of the universe under constant-roll condition in F(Q) gravity theory

This thesis investigates the high-energy epoch of the universe within the framework of f(Q) gravity. For this purpose, the constant-roll condition is considered in the dynamics of the early universe. Following the unified solution of the field equations of the gravitational theory, the initial phase of the universe is examined through model parameters within the context of a constant-roll inflationary field. Taking into account comparable observational data, it has been identified that the universe may evolve from an initial quasi-de Sitter vacuum state to a quintessence vacuum state. It has been demonstrated that this transition can occur when the constant-roll parameter is constrained to a specific value within the parameter space.