What nationality was the man who derived the Einstein–Rosen metric with Albert Einstein?
Einstein–Rosen metric: The Einstein–Rosen metric is an exact solution of Einstein's field equation. Einstein–Rosen metric:  It was derived by Albert Einstein and Nathan Rosen in 1937. Nathan Rosen: Nathan Rosen (Hebrew: נתן רוזן; March 22, 1909 – December 18, 1995) was an American-Israeli physicist noted for his study on the structure of the hydrogen atom and his work with Albert Einstein and Boris Podolsky on entangled wave functions and the EPR paradox.
American-Israeli