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Blakers–Massey Theorem
In mathematics, the first Blakers–Massey theorem, named after Albert Blakers and William S. Massey, gave vanishing conditions for certain excisive triad, triad homotopy groups of topological space, spaces. Description of the result This connectivity result may be expressed more precisely, as follows. Suppose ''X'' is a topological space which is the Pushout (category theory), pushout of the diagram : A\xleftarrow C \xrightarrow B, where ''f'' is an N-connected space#n-connected map, ''m''-connected map and ''g'' is ''n''-connected. Then the map of pairs : (A,C)\rightarrow (X,B) induces an isomorphism in relative homotopy groups in degrees k\le (m+n-1) and a surjection in the next degree. However the third paper of Blakers and Massey in this area determines the critical, i.e., first non-zero, triad homotopy group as a Tensor product of modules, tensor product, under a number of assumptions, including some simple connectivity. This condition and some dimension conditions were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Blakers
Albert may refer to: Companies * Albert Computers, Inc., a computer manufacturer in the 1980s * Albert Czech Republic, a supermarket chain in the Czech Republic * Albert Heijn, a supermarket chain in the Netherlands * Albert Market, a street market in The Gambia * Albert Music, an Australian music company now known as Alberts ** Albert Productions, a record label * Albert (organisation), an environmental organisation concerning film and television productions Entertainment * Albert (1985 film), ''Albert'' (1985 film), a Czechoslovak film directed by František Vláčil * ''Albert'' (2015 film), a film by Karsten Kiilerich * Albert (2016 film), ''Albert'' (2016 film), an American TV movie * Albert (album), ''Albert'' (album), by Ed Hall, 1988 * Albert (short story), "Albert" (short story), by Leo Tolstoy * Albert (comics), a character in Marvel Comics * Albert (Discworld), Albert (''Discworld''), a character in Terry Pratchett's ''Discworld'' series * Albert, a character in Dario A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |