Study of Nonlinear Non-Metricity Effects in Early and Late-Time Cosmology

In this article, we investigate cosmological solutions in modified f(Q) gravity using a Friedmann–Robertson–Walker spacetime. We obtain exact solutions to the field equations for several equations of state, including a sub-relativistic fluid, radiation, a fluid with w = 1/2, dust, and stiff matter. We employ a power-law ansatz to examine the cosmic evolution and analyze the associated energy conditions. Moreover, we study two bouncing scenarios: a matter bounce and a generalized exponential bounce related to Type I–IV singularities and Little Rip cosmology. Our findings show that f(Q) gravity is not merely an alternative to ΛCDM, but a robust theoretical framework that may connect early-universe phenomena with present-day cosmological observations.