James Waddell Aleksander ( born James Waddell Alexander ; September 19, 1888 , Sea Bright, NJ , USA - September 23, 1971 , Princeton , NJ) is an American mathematician .
| James Weddell Alexander | |
|---|---|
| English James Waddell Alexander | |
| Date of Birth | September 19, 1888 |
| Place of Birth | Sea Bright , New Jersey , USA |
| Date of death | September 23, 1971 (83 years old) |
| Place of death | Princeton , New Jersey , USA |
| A country |  USA |
| Scientific field | maths |
| Place of work | Institute for Advanced Study |
| Alma mater | |
| Academic degree | |
| supervisor | Oswald Veblen |
| Known as | one of the founders of knot theory |
| Awards and prizes | Prize named after M. Bocher ( 1928 , 1928 ) |
Member of the US National Academy of Sciences (1930) [1] .
Content
Biography
Since its founding in 1933, he worked at the Institute for Advanced Study at Princeton and was one of its permanent members.
He was also known as a climber (his name is Alexander's Chimney Crater in the Rockies ).
Contribution to Science
The main works lie in the field of algebraic topology . He proved the topological invariance of simplicial homologies by putting the topological works of Henri Poincare on a solid foundation. He investigated the “Alexander duality” - the connection between the homological properties of mutually complementary subsets of a topological space (for polyhedra). Alexander also introduced the concept of cohomology , which acquired great importance in topology and especially in homological algebra (independently, Andrei Kolmogorov and I.I. Gordon (graduate student of Lev Semenovich Pontryagin ) introduced this concept). One of the founders of knot theory , where he introduced the Alexander invariant . In works on general topology, he established a criterion for the compactness of a topological space by the properties of its prebase , known as Alexander’s prebase theorem .
Alexander Horned Orb - Embedding a sphere in bounding region not homeomorphic
His name is
- Horned Orb of Alexander
- Polynom Alexander
- Alexander trick
Policy
Being a left-wing man, he was attacked during Senatorialism by McCarthy , and in 1954 he signed a letter in defense of Robert Oppenheimer .
Notes
Links
- John J. O'Connor and Edmund F. Robertson . Alexander, James (eng.) - biography in the MacTutor archive.
- James, IM Portrait of Alexander (1888-1971) (English) // Bull. Amer. Math. Soc .. - 2001. - Vol. 38, no. 2 . - P. 123-129.
- Cohen, Leon W. James Waddell Alexander (1888-1971) (English) // Bull. Amer. Math. Soc .. - 1973. - Vol. 79, no. 5 . - P. 900–903.