Viable cosmic bounce with viscous effects in f(Q,Lm): Novel cosmic insights beyond the singularity

This study investigates the impact of bulk viscosity on the viability of cosmic bounce solutions in the framework of [Formula: see text] gravity, where non-metricity is defined by Q and matter-Lagrangian density is represented by [Formula: see text]. For this purpose, we study the behavior of a flat Friedmann–Robertson–Walker universe model with isotropic matter configuration and new formulation of the bulk viscosity coefficient as [Formula: see text]. Here, [Formula: see text] and n are positive constants and [Formula: see text] represents the bounce epoch. We analyze the influence of this modified framework on the evolution of the universe by considering a specific functional form of this modified theory. We examine several cosmological parameters to analyze the evolution of the universe. Our outcomes indicate that the pressure is negative, energy density is positive and the presence of a singularity-free bounce in this gravitational model is ensured by the violation of null energy condition. The state parameter suggests behavior consistent with a quintessence regime or a phantom era. We conclude that it provides effective substitutes for the standard paradigms of cosmology, hence this yields important perspectives into the early universe and the nature of force of gravitation.