I. Ayuso, F. S. N. Lobo, J. P. Mimoso
Abstract
In this work, we explore wormhole geometries in a recently proposed modified gravity theory arising from a non-conservative gravitational theory, tentatively denoted action-dependent Lagrangian theories. The generalized gravitational field equation essentially depends on a background four-vector λμ, that plays the role of a coupling parameter associated with the dependence of the gravitational Lagrangian upon the action, and may generically depend on the spacetime coordinates. Considering wormhole configurations, by using "Buchdahl coordinates", we find that the four-vector is given by λμ = (0, 0, λθ, 0), and that the spacetime geometry is severely restricted by the condition gttguu = −1, where u is the radial coordinate. We find a plethora of specific asymptotically flat, symmetric and asymmetric, solutions with power law choices for the function λ, by generalizing the Ellis-Bronnikov solutions and the recently proposed black bounce geometries, amongst others. We show that these compact objects possess a far richer geometrical structure than their general relativistic counterparts.
Keywords
General relativity; alternative theories of gravity; wormhole; action-dependent Lagrangian theories; energy conditions
Proceedings of the MG16 Meeting on General Relativity
Remo Ruffini, Gregory Vereshchagin
World Scientific Publishing Co. Pte. Ltd., Page 756
2023 March
