Study of exponential wormhole metric in f(R) gravity

Abstract

In this work, we have studied ‘the exponential form’ of space-time metric in some of the viable f(R) gravity models, viz. exponential gravity model, Starobinsky gravity model, Tsujikawa model, and Gogoi-Goswami f(R) gravity model. Here, we have calculated the parameters including energy density, tangential pressure, and radial pressure for these corresponding models of f(R) gravity. Subsequently, we have investigated the energy conditions, viz. null energy condition (NEC), weak energy condition (WEC), strong energy condition (SEC), and dominant energy condition (DEC) for the considered models. We have also explained the suitable stability conditions for these models through related plots. We observed that the exponential wormhole metric obeys all the necessary energy conditions in f(R) gravity without violating any flare-out or stability conditions. Out of four considered viable f(R) gravity models, the exponential, the Tsujikawa, and the Gogoi-Goswami f(R) gravity models are found to be more suitable for the exponential wormhole to exist, although all these models have some constraints on the ranges of the parameters used.