Simpson, AlexMartín Moruno, María Del PradoVisser, Matt2023-10-182023-10-182019-06-25Simpson, A., Martin-Moruno, P., & Visser, M. (2019). Vaidya spacetimes, black-bounces, and traversable wormholes. Classical and Quantum Gravity, 36(14), 145007.0264-938110.1088/1361-6382/ab28a510.48550/arXiv.1902.04232https://hdl.handle.net/20.500.14352/88335El pdf depositado corresponde a la versión preprintWe consider a non-static evolving version of the regular ‘black-bounce’/ traversable wormhole geometry recently introduced in Simpson and Visser (2019 J. Cosmol. Astropart. Phys. JCAP02(2019)042). We first re-write the static metric using Eddington–Finkelstein coordinates, and then allow the mass parameter m to depend on the null time coordinate (à la Vaidya). The spacetime metric is ds2=−1− 2m(w) √r2+a2 dw2−(±2dwdr)+r2+a2 dθ2+sin2θdφ2 . Here w={u,v} denotes suitably defined {outgoing,ingoing} null time coordinates; representing {retarded,advanced} time, while, (at least for a=0), we allow r∈(−∞,+∞). This spacetime is still simple enough to be tractable, and neatly interpolates between Vaidya spacetime, a blackbounce, and a traversable wormhole. We show how this metric can be used to describe several physical situations of particular interest, including a growing black-bounce, a wormhole to black-bounce transition, and the opposite blackbounce to wormhole transition.engjournal article1361-6382https://iopscience.iop.org/article/10.1088/1361-6382/ab28a5https://doi.org/10.48550/arXiv.1902.04232open access52-33Vaidya spacetime, Regular black hole, Black-bounce, Null-bounce, Traversable wormholeAstrofísica21 Astronomía y Astrofísica