Models of f(Q) gravity with electromagnetic field

TL;DR

This work develops a reconstruction framework for f(Q) gravity in flat FLRW cosmology with an electromagnetic field, deriving modified Friedmann equations and obtaining explicit f(Q) forms that reproduce ΛCDM for multiple fluid contents. It analyzes dust, dark matter, stiff matter, and two-fluid mixtures, producing closed-form or hypergeometric-function–based expressions for f(Q) in each case, and explores ω-based reconstructions (ω = -1, -1/3, 0) to map the corresponding f(Q) structures. The results show that the non-metricity-driven models can yield cosmic acceleration and ΛCDM-like behavior without explicit dark energy, with ω evolving over time and q approaching −1 in several scenarios. The study highlights the potential of f(Q) gravity with electromagnetic fields to describe late-time cosmic acceleration and to offer alternative explanations for cosmological observations at large scales.

Abstract

There are so many ideas that potentially explain the dark energy phenomenon, current research is focusing on a more in-depth analysis of the potential effects of modified gravity on both local and cosmic scales. In this paper we have investigated some cosmic reconstructions in $f (Q)$ cosmology where $Q$ is the non-metricity corresponding to the evolution background in the Friedmann-Lamatre-Robertson-Walker $(FLRW)$ universe. This allows us to determine how any $FLRW$ cosmology can emerge from a particular $f (Q)$ theory. We employ the reconstruction technique to generate explicit formulations of the $f (Q)$ Lagrangian for several types of matter sources like perfect fluid, dust like fluid, stiff fluid and the binary mixture of two fluids. Furthermore, we computed the field equations and equation of state (EoS) parameter $ω$ for two different reconstructed $f(Q)$ models with the variation of the involved constants, which gives the scenario of accelerating universe, quintessence region and cosmological constant. We also observed that the time dependence of $ω$ admits cosmic acceleration. These new $f(Q)$ gravity inspired models may have an impact on gravitational phenomena at other cosmological scales.