A. Edward Nussbaum of Clayton, a theoretical mathematician and longtime professor at Washington University, died Saturday, Oct. 31 at Barnes-Jewish Hospital from complications from congestive heart failure. He was 84.

Mr. Nussbaum was a Holocaust survivor whose youth was spent in the chaotic years between two world wars and whose adolescence was the stuff of movies.

A serious man who scribbled his mathematical theorems and derivations on napkins and tablecloths and anything else handy, he worked with such giants of 20th-century theoretical physics and mathematics as J. Robert Oppenheimer and John von Neumann. Along the way he also rubbed shoulders with Albert Einstein. He was a devoted husband and family man, whose own parents died at Auschwitz.

Mr. Nussbaum earned both a master’s and Ph.D. at Columbia University in New York, which he entered with almost no formal schooling. Both shy and humble, he eschewed the title of “doctor,” preferring to be addressed simply as “Mr. Nussbaum,” said his wife of 52 years, Anne Nussbaum.

Mr. Nussbaum was born in Rheydt, a small town in northwestern Germany. The youngest of three children, he was essentially orphaned at the age of 14, after the Nazi takeover of Germany.

He and his sister, Lieselotte, survived, but were separated after both were sent on a Kinder Transport to Belgium in 1939. His father, Karl Nussbaum, a wounded veteran of World War I in which he was awarded the Iron Cross, and his mother, Franziska, died in Auschwitz. His brother, Erwin Nussbaum, a Zionist, was also captured and killed.

When Belgium was invaded by Germany, a sponsor from a Jewish women’s organization helped the young Ed Nussbaum escape to southern France, then under the Vichy Regime. There he lived with 100 other children in a castle known as Chateau de la Hille, which at the age of 17, he single-handedly wired for electricity.

It was also here that he started his teaching career. As a teenager and one of the older occupants of the “castle on the hill,” he taught mathematics to the younger children, some who were just three- years-old.

After many harrowing experiences including being twice captured –and once jailed — by the Nazis, he managed to escape on foot, walking through the forest to Switzerland, where he lived with a sponsor and attended a university in Zurich, studying both mathematics and physics. Eventually, when he was in his early 20s, he was able to find sponsorship from relatives who lived in New Jersey.

Shortly thereafter he moved to Manhattan and studied mathematics briefly at Brooklyn College until one day, after seeing a “room for rent,” notice for Washington Heights, he announced he was going to Columbia.

“His friends laughed,” said Anne Nussbaum, smiling. He had no degree, little formal schooling and besides, they said, “Jews can’t get in there.”

Mr. Nussbaum got in. And he received his master of arts degree from Columbia in 1950 and his Ph.D. in 1957.

During the summers while he was writing his thesis for Columbia, Mr. Nussbaum worked at the world-famous Institute for Advanced Study in Princeton with John Von Neumann, the father of the modern computer, among other things. Mr. Nussbaum’s son, Karl Nussbaum, has a picture of his father standing on a ladder and working on the first computer, a monster larger than their living room.

Von Neumann, used a concept called Hilbert Spaces in his development of the mathematical basis of modern computer language. Hilbert Spaces eventually became Mr. Nussbaum’s area of expertise and with von Neumann, he wrote several papers. Also during this period, Mr. Nussbaum sometimes rode to work with Albert Einstein, another of the original group at the Institute for Advanced Study.

“He told us how Einstein would often get into the car with bare feet and Mrs. Einstein would run after him, carrying his shoes,” Anne Nussbaum reported.

Mr. Nussbaum’s thesis was accepted with no revisions and he received his doctorate shortly after his first blind date with his cousin’s sister-in-law, Anne Ebbin, whom he invited to attend the ceremony and who would soon become Mrs. Nussbaum.

In the meantime he had worked at both Rensselaer Polytechnic Institute in Troy, N.Y., and, before that, at the University of Connecticut in Storrs, where he co-authored papers with Allen Devinatz, who would soon move to St. Louis to teach at Washington University.

Mr. Nussbaum proposed to his wife and announced his intention to follow Devinatz practically in the same breath. “I didn’t know exactly where St. Louis was, but I said ‘yes,’ ” Anne Nussbaum said.

That was 1958. Except for their travels and two visiting professorships, the Nussbaums stayed in St. Louis. In 1962, Mr. Nussbaum was a visiting scholar at the Institute for Advanced Studies working with Robert Oppenheimer, father of the atomic bomb; in 1967-68 he was a visiting scholar at Stanford University in Palo Alto, Calif.

In addition to his wife and son, Mr. Nussbaum is survived by a daughter, Franziska Nussbaum, of St. Louis.

A funeral was scheduled for 1 p.m. Wednesday (Nov. 4) at United Hebrew Cemetery, North and South Road at Canton, in University City. After the service, shiva will be held at the Nussbaum home, 8050 Watkins Drive in Clayton. The family sat shiva after the service and Thursday at the Nussbaum home in Clayton.