Eur. Phys. J. C (2016) 76: 704
https://doi.org/10.1140/epjc/s10052-016-4560-4

Regular Article - Theoretical Physics

Non-minimal coupling of torsion–matter satisfying null energy condition for wormhole solutions

Department of Mathematics, COMSATS Institute of Information Technology, Lahore, 54000, Pakistan

^* e-mail: jawadab181@yahoo.com
^** e-mail: abduljawad@ciitlahore.edu.pk

Received: 1 August 2016
Accepted: 3 December 2016
Published online: 22 December 2016

Abstract

We explore wormhole solutions in a non-minimal torsion–matter coupled gravity by taking an explicit non-minimal coupling between the matter Lagrangian density and an arbitrary function of the torsion scalar. This coupling describes the transfer of energy and momentum between matter and torsion scalar terms. The violation of the null energy condition occurred through an effective energy-momentum tensor incorporating the torsion–matter non-minimal coupling, while normal matter is responsible for supporting the respective wormhole geometries. We consider the energy density in the form of non-monotonically decreasing function along with two types of models. The first model is analogous to the curvature–matter coupling scenario, that is, the torsion scalar with T-matter coupling, while the second one involves a quadratic torsion term. In both cases, we obtain wormhole solutions satisfying the null energy condition. Also, we find that the increasing value of the coupling constant minimizes or vanishes on the violation of the null energy condition through matter.