Palatini wormholes and energy conditions from the prism of general relativity

Abstract

Wormholes are hypothetical shortcuts in spacetime that in general relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard designer procedure frequently employed in the literature, arise directly from gravitational actions including additional terms resulting from contractions of the Ricci tensor with the metric, and which are formulated assuming independence between metric and connection (Palatini approach). We reinterpret such wormhole solutions under the prism of General Relativity and study the matter sources that thread them. We discuss the size of violation of the energy conditions in different cases and how this is related to the same spacetimes when viewed from the modified gravity side.

Wormholes with nonexotic matter in Born-Infeld gravity

“…The theory is equivalent to Einstein's GR in vacuum but differs from it within matter. Since its introduction, various aspects of EiBI gravity have been studied by many researchers in the recent past, including black holes [47,[51][52][53][54][55][56][57][58][59][60], wormholes [61][62][63][64], compact stars [65][66][67][68][69], cosmological aspects [47,[70][71][72][73][74][75][76][77][78][79][80], astrophysical aspects [81][82][83], gravitational collapse [84,85], gravitational waves [86,87], implications in nongravitational contexts like particle physics [88] etc. See [89] for a recent review on various studies in EiBI gravity.…”

Thin-shell wormholes in $$(2+1)$$-dimensional F(R) theories

“…We also determine the kind of matter (ordinary or exotic) located at the thin-shell by checking the weak energy condition (WEC). 4…”

“…They can represent shortcuts in the same spacetime or connect two different universes. A quite interesting feature is the fact that they are singularityfree gravitational objects; moreover, wormhole throats can replace black hole singularities in solutions within the framework of some modified gravity theories (see [3,4] and references therein).…”

“…For Z = 0 the analytic expressions for the solutions of the cubic equations are cumbersome, hence it is meaningless to show them here 4. In the orthonormal basis, it takes the form σ 0 ≥ 0 and σ 0 + p 0 ≥ 0.…”

Validation of energy conditions in wormhole geometry within viable f(R) gravity

“…Sajadi and Riazi [56] obtained static multi-polytropic wormhole solutions in the framework of general relativity, and they examine gravitational lensing by the wormhole, and calculate the deflection angle for weak and strong field limits as well. Subsequently, various authors have been studied wormholes in different contexts [57][58][59][60][61][62][63][64][65][66][67]. Recently, Barros and Lobo [68] used three form fields and studied static and spherically symmetric wormhole structures.…”