WORMHOLE ORIGINS. “This idea of an existing connection in spacetime was taken further by Einstein himself in 1935, together with the Israeli-American physicist Nathan Rosen, and their work has led to a solution known as the Einstein–Rosen bridge, also known as a wormhole connecting a BH and a WH.” (BH = black hole; WH = white hole).
https://link.springer.com/chapter/10.1007/978-3-030-51081-7_62