From static to rotating to conformal static solutions: rotating imperfect fluid wormholes with(out) electric or magnetic field

Abstract

We derive a shortcut stationary metric formula for generating imperfect fluid rotating solutions, in BoyerLindquist coordinates, from spherically symmetric static ones. We explore the properties of the curvature scalar and stress-energy tensor for all types of rotating regular solutions we can generate without restricting ourselves to specific examples of regular solutions (regular black holes or wormholes). We show through examples how it is generally possible to generate an imperfect fluid regular rotating solution via radial coordinate transformations. We derive rotating wormholes that are modeled as imperfect fluids and discuss their physical properties. These are independent on the way the stress-energy tensor is interpreted. A solution modeling an imperfect fluid rotating loop black hole is briefly discussed. We then specialize to the recently discussed stable exotic dust Ellis wormhole as emerged in a source-free radial electric or magnetic field, and we generate its, conjecturally stable, rotating counterpart. This turns out to be an exotic imperfect fluid wormhole, and we determine the stress-energy tensor of both the imperfect fluid and the electric or magnetic field.

Shadow and quasinormal modes of a rotating loop quantum black hole

“…Given the above LQG-corrected Schwarzschild metric, we aim to construct its rotating LQBH counterpart by using the Newman-Janis algorithm modified by Azreg-Aïnou's non-complexification procedure [77,78]. The first step of the Newman-Janis algorithm is to transform from the Boyer-Lindqiust coordinates (t, r, θ, φ) to the Eddington-Finkelstein coordinates (u, r, θ, φ).…”

“…This is generally not possible in the usual Newman-Janis algorithm since these functions are fixed once the complexification of r is performed, and there remains no free parameters or functions to achieve the transformation to the Boyer-Lindquist coordinates. Now, if we choose [77,78]…”

“…In this algorithm, one of the critical steps is how to complexify the radial coordinate r. In fact, there does not exist a standard role to follow, and the complexification is rather arbitrary [77]. Recently, one of us has proposed a new procedure [77,78], in which one simply drops the complexification step of the Newman-Janis algorithm. The procedure has been applied to various cases [27,40,[77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96].…”

Rotating normal and phantom Einstein–Maxwell–dilaton black holes: Geodesic analysis

“…The third step of the Newman-Janis algorithm consists in complexifying the radial coordinate r: There are as many ways to complexify r as one wants and this is very ambiguous as shown in Ref [21]. One of us has resorted to a new procedure [21,24] by which one drops the complexification step of the Newman-Janis algorithm. The procedure has known applications in a series of papers [25][26][27][28][29][30][31][32][33][34][35].…”

“…Some authors were fair in citing our original work consisting in dropping the complexification of the radial coordinate r [21,24]. Some other authors have failed to do that [27,34,35]; they have borrowed many steps and equations from our original idea of generating rotating solutions [21,24] without, however, citing the sources. Said otherwise, using different notations they have just repeated "previously obtained results without giving proper references" [40] and with no inferred novelty.…”