On the generalized wormhole in the Eddington-inspired Born–Infeld gravity

Abstract

In this paper, we wish to investigate certain observable effects in the recently obtained wormhole solution of the Eddington-inspired Born–Infeld (EiBI) theory, which generalizes the zero-mass Ellis–Bronnikov wormhole of general relativity. The solutions of EiBI theory contain an extra parameter κ having the inverse dimension of the cosmological constant Λ, and which is expected to modify various general relativistic observables such as the masses of wormhole mouths, tidal forces and light deflection. A remarkable result is that a non-zero κ could prevent the tidal forces in the geodesic orthonormal frame from becoming arbitrarily large near a small throat radius () contrary to what happens near a small Schwarzschild horizon radius (). The role of κ in the flare-out and energy conditions is also analyzed, which reveals that the energy conditions are violated. We show that the exotic matter in the EiBI wormhole cannot be interpreted as a phantom () or ghost field ϕ of general relativity due to the fact that both ρ and pr are negative for all κ.