アーベル群
In mathematics, specifically algebraic topology, there is a distinguished class of spectra called Eilenberg–Maclane spectra formula_1 for any Abelian group formula_2pg 134. Note, this construction can be generalized to commutative rings formula_3 as well from its underlying Abelian group. These are an important class of spectra because they model ordinary integral cohomology and cohomology with coefficients in an abelian group. In addition, they are a lift of the homological structure in the derived category formula_4 of abelian groups in the homotopy category of spectra. In addition, these spectra can be used to construct resolutions of spectra, called Adams resolutions, which are used in the construction of the Adams spectral sequence.