Henry Helson

Henry Berge Helson (June 2, 1927 – January 10, 2010) was an American mathematician at the University of California at Berkeley who worked on analysis.

With the support of a Harvard travelling fellowship, he spent the academic year 1947–1948 in Europe; he visited London, Paris, Prague, and Vienna, but spent most of his time in Warsaw and then from spring 1948 in Wroclaw, where he worked with Marczewski.

Helson received his Ph.D. in 1950 from Harvard with supervisor Lynn Loomis[1] and then spent the academic year 1950–1951 primarily in Uppsala working with Beurling but with frequent trips elsewhere in Europe.

[2] If G is an infinite, nondiscrete, locally compact group, then a Helson set is defined to be a compact set P in G such that every continuous function on P can be extended to a function in the Fourier algebra A(G) in the group G.[3] Helson was the first to prove that there exist perfect Helson sets for the case of the group consisting of the real line.

Upon his death he was survived by his wife Ravenna Helson, a renowned personality psychologist, their daughter, two sons, and three grandchildren.