Pontryagin kohomologi operation - Pontryagin cohomology operation
I matematik er en Pontryagin cohomology operation en cohomology operation, der tager cohomology klasser i H 2 n ( X , Z / p r Z ) til H 2 pn ( X , Z / p r +1 Z ) for et primtal p . Da p = 2 blev disse operationer introduceret af Pontryagin ( 1942 ) og blev navngivet Pontrjagin -firkanter af Whitehead (1949) (med udtrykket " Pontryagin square " også brugt). De blev generaliseret til vilkårlige primtal af Thomas (1956) .
Se også
Referencer
- Browder, William; Thomas, E. (1962), "Axioms for the generalized Pontryagin cohomology operations", The Quarterly Journal of Mathematics , Second Series, 13 (1): 55–60, doi : 10.1093/qmath/13.1.55 , ISSN 0033-5606 , MR 0140103
- Malygin, SN; Postnikov, MM (2001) [1994], "Pontryagin square" , Encyclopedia of Mathematics , EMS Press
- Pontryagin, L. (1942), "Mappings of the tredimensionale sfære til et n -dimensionelt kompleks", CR (Doklady) Acad. Sci. URSS , New Series, 34 : 35–37, MR 0008135
- Thomas, Emery (1956), "A generalization of the Pontrjagin square cohomology operation", Proceedings of the National Academy of Sciences of the United States of America , 42 (5): 266–269, Bibcode : 1956PNAS ... 42 .. 266T , doi : 10.1073/pnas.42.5.266 , ISSN 0027-8424 , JSTOR 89856 , MR 0079254 , PMC 528270 , PMID 16589865
- Whitehead, JHC (1949), "On simple connected, 4-dimensional polyhedra", Commentarii Mathematici Helvetici , 22 : 48–92, doi : 10.1007/bf02568048 , ISSN 0010-2571 , MR 0029171 , S2CID 121723000