Spectrum (homotopy Theory)
In algebraic topology, a branch of mathematics, a spectrum is an object representing a generalized cohomology theory. There are several different constructions of categories of spectra, any of which gives a context for the same stable homotopy theory.
Read more about Spectrum (homotopy Theory): The Definition of A Spectrum, Functions, Maps, and Homotopies of Spectra, The Triangulated Homotopy Category of Spectra, Smash Products of Spectra, Generalized Homology and Cohomology of Spectra, Examples, History