Einstein–Rosen metric
In general relativity, the Einstein–Rosen metric is an exact solution to the Einstein field equations derived in 1937 by Albert Einstein and Nathan Rosen.[1] It is the first exact solution to describe the propagation of a gravitational wave.In 1972 and 1973, J. R. Rao, A. R. Roy, and R. N. Tiwari published a class of exact solutions involving the Einstein-Rosen metric.[2][3][4] In 2021 Robert F. Penna found an algebraic derivation of the Einstein-Rosen metric.[5] In the history of science, one might consider as a footnote to the Einstein-Rosen metric that Einstein, for some time, believed that he had found a non-existence proof for gravitational waves.