The concept of a cospectrum is the formal dual to the concept of a (sequential) spectrum object. Where a sequential spectrum is a sequence of objects (X n)(X_n) equipped with a sequence of morphisms of the form ΣX nX n+1\Sigma X_n \to X_{n+1} (for Σ\Sigma a reduced suspension operation), a cospectrum is such a sequence of objects, but with the direction of the structure maps reversed: X n+1ΣX nX_{n+1} \to \Sigma X_{n}.


  • Elon L. Lima, The Spanier-Whitehead duality in new homotopy categories, Summa Brasil. Math. 4 (1959) 91–148 (1959) MR0116332

  • A. Jankowski, Remarks on generalized homology theories, Comment. Math. Prace Mat. 15 (1971) 185–199 MR405404

  • Mizuho Hikida, On CW cospectra, Hiroshima Math. J. Volume 11, Number 2 (1981), 347-368 (Euclid)

Last revised on September 4, 2017 at 19:02:36. See the history of this page for a list of all contributions to it.