Static and spherically symmetric wormholes in power-law [formula omitted] gravity model

Abstract

By venturing into gravitational frameworks that extend beyond general relativity (GR), it becomes evident that traversable wormholes (WHs) can conceivably be constructed solely through gravitational means. In GR, the intrinsic degrees of freedom are insufficient for assembling these special kinds of objects without incorporating exotic matter forms. Nevertheless, by stretching gravity into altered frameworks, it becomes possible to satisfy the necessary stability and traversability conditions without relying on such exotic materials. The key concept lies in the view that WH solutions can appear as common features in gravity theories once extra geometrical degrees of freedom are incorporated. Interestingly, we investigate WH solutions in the context of f(R) gravity theory, using a spherically symmetric metric embracing three asymptotically flat regions. More precisely, we are focusing on f(R) gravitational theories formulated in metric formalism, presuming time-independent metric coefficients, and exploiting the well-established Morris–Thorne space–time framework. We thoroughly derived exact solutions for traversable WHs that graciously adhere to energy and pressure constraints, assuming a power-law form for f(R), denoted f(R)=αRn, where α is an arbitrary constant and n is the power-law exponent. Conclusively, our findings open up the possibility of constraining the parameters (α, n, r0) associated with WH solutions. Importantly, we found that the existence of exotic matter was necessary to satisfy the stability and traversability criteria for WHs in all the cases we analyzed.