Brown–Gitler spectrum

In the mathematical discipline of topology, the Brown–Gitler spectrum is a spectrum whose cohomology is a certain cyclic module over the Steenrod algebra.

Brown–Gitler spectra are defined by the isomorphism:

${\displaystyle \Sigma ^{n}A/\{\operatorname {Sq} ^{i}:2i>n\}A\cong G(n).}$