Possible wormholes in generalized geometry-matter coupling gravity induced by the Dekel-Zhao dark matter profile

TL;DR

This paper explores the possibility of traversable wormholes within an extended gravity framework that incorporates matter coupling, demonstrating that such wormholes can be sustained by both exotic and ordinary matter, with potential observable effects like gravitational lensing.

Contribution

It introduces a first-order approximation of wormhole solutions in an $f(R, L_m, T)$ gravity model using the Dekel-Zhao dark matter profile, highlighting the coexistence of exotic and ordinary matter.

Findings

Wormhole solutions satisfy traversability conditions.

Wormholes can be supported by both exotic and ordinary matter.

Gravitational lensing shows a repulsive effect in extended gravity.

Abstract

In the late 1980s, Morris and Thorne led in theoretical physics by creating solutions to wormholes and formulating the crucial requirements for safe traversability of wormholes. They found that exotic matter must meet the requirement $P_r + \rho < 0$, where $P_r$ is radial pressure and $\rho$ is energy density. This is a rudimentary grasp of our understanding of general relativity. In this paper, we continue their excellent work by looking at how to build traversable wormhole solutions in an extended theory of gravity. We adopt a process of linearly modifying the matter Lagrangian and the energy-momentum tensor with some coupling strengths $\lambda$ and $\chi$. This may be considered as a special case of linear $f(R, T)$ gravity with matter coupling variability or as an additively separable simple $f(R, L_m, T)$ model. We undertake a detailed analysis of static wormhole solutions with a constant redshift function. This allows us to present our results as a first-order approximation in the $f(R, L_m, T)$ scenario. We derive the wormhole shape function from the Dekel-Zhao dark matter distribution in such a way that our solutions satisfy the needed conditions for traversability as well as the requirement of exotic matter. This is particularly exciting as it shows that wormholes in $f(R, L_m, T)$ gravity can sustain both exotic as well as ordinary matter. To ensure that the shape function meets the requirement of flaring-out and is asymptotically flat, we place some constraints on the couplings. We also examine the gravitational lensing effects, which exhibit a repulsive gravitational force that appears in our extended gravity for positive couplings.