Hillel Furstenberg

Hillel Furstenberg (born September 29, 1935) is an Israeli-American mathematician renowned for his pioneering work in ergodic theory and its applications to probability, group theory, number theory, and combinatorics. His innovative approaches, including the introduction of probabilistic methods to dynamical systems and the development of concepts like "disjointness" in ergodic actions, have profoundly influenced modern mathematics.

Born in Berlin to a Jewish family, Furstenberg fled Nazi Germany with his mother and sister in 1939, settling in New York City after his father died during the journey. He earned a B.A. and M.S. from Yeshiva University in 1955, during which he published early papers, including one on the infinitude of primes, and completed his Ph.D. at Princeton University in 1958 under Salomon Bochner, with a thesis on Prediction Theory. Furstenberg held positions at Princeton and MIT as an instructor, became an assistant professor at the University of Minnesota in 1961, and advanced to full professor there before joining the Hebrew University of Jerusalem's Einstein Institute of Mathematics in 1965, where he spent the majority of his career and became professor emeritus in 2003.

Hillel Furstenberg was born on September 29, 1935, in Berlin, Germany, to Solly Furstenberg, a self-taught advocate's assistant who later managed a furniture store, and Berta Gryzb, a homemaker; both parents were German-born Jews whose own parents had emigrated from Poland and Russia. He had an older sister, Ruth Charlotte, born in 1932, and the family belonged to a religious, middle-class Jewish household in a city increasingly gripped by Nazi antisemitism following the regime's rise to power in 1933.

In November 1938, shortly after Kristallnacht, the family was ordered to leave Germany under escalating anti-Jewish laws that targeted their lack of deep national ties and Jewish heritage. They fled first to England with assistance from relatives, including an aunt in Palestine, but tragedy struck when Furstenberg's father died in London in 1940 from complications following surgery for a chronic ailment. That same year, on October 18, Furstenberg, his mother, and sister sailed from Glasgow, arriving in New York on October 28 amid the ongoing persecution that had already claimed many Jewish lives and driven thousands into exile.

Upon arrival, the family initially stayed on their uncle Morris Giles's poultry farm in East Brunswick, New Jersey, supported by relatives who had established themselves in America, before relocating to Washington Heights in New York City, a neighborhood that had become a haven for German Jewish refugees escaping the Holocaust. This immigrant enclave provided a supportive community where Yiddish and German were commonly spoken, helping the family rebuild amid the cultural and economic challenges of wartime displacement.