Traversable wormholes and energy conditions in Lovelock-Brans-Dicke gravity

Abstract

Following the recent theory of Lovelock-Brans-Dicke gravity, we continue to investigate the conditions to support traversable wormholes by the gravitational effects of spacetime parity and topology, which arise from the nonminimal couplings of a background scalar field to the Chern-Pontryagin density and the Gauss-Bonnet invariant. The flaring-out condition indicates that a Morris-Thorne-type wormhole can be maintained by violating the generalized null energy condition, and thus also breaking down the generalized weak, strong, and dominant energy conditions; meanwhile, analyses of the zero-tidal-force solution show that the standard null energy condition in general relativity can still be respected by the physical matter threading the wormhole. This way, the two topological effects have to dominate over the ordinary-matter source of gravity, and the scalar field is preferred to be noncanonical. By treating Brans-Dicke gravity as a reduced situation of Lovelock-Brans-Dicke gravity, we also examine the Brans-Dicke wormholes and energy conditions.

10 informative figures, 14 subfigures, 21 pages

References in corpus (16)

• Dark energy in modified Gauss-Bonnet gravity: late-time acceleration and the hierarchy problem
• Traversable wormholes: Some simple examples
• Wormhole geometries in f(R) modified theories of gravity
• Wormholes supported by hybrid metric-Palatini gravity
• Einstein-Gauss-Bonnet traversable wormholes satisfying the weak energy condition
• Wormhole geometries supported by a nonminimal curvature-matter coupling
• Nonminimal curvature-matter coupled wormholes with matter satisfying the null energy condition
• Wormholes in viable $f(R)$ modified theories of gravity and Weak Energy Condition
• General class of wormhole geometries in conformal Weyl gravity
• New asymptotically flat phantom wormhole solutions
• Wormholes minimally violating the null energy condition
• Derivation of the Null Energy Condition
• Modified Chaplygin Traversable Wormholes
• Friedmann equations from nonequilibrium thermodynamics of the Universe: A unified formulation for modified gravity
• Wormholes admitting conformal Killing vectors and supported by generalized Chaplygin gas
• Lessons from $f(R,R_c^2,R_m^2,L_m)$ gravity: Smooth Gauss-Bonnet limit, energy-momentum conservation and nonminimal coupling

Cited by in corpus (1)

• Static spherically symmetric wormholes in generalized $f(R,\varphi )$ gravity