nLab spectrum - disambiguation

There are several different (sometimes related) mathematical objects called ‘’spectrum’‘ or whose name has ‘’spectral’‘ as prefix:

• spectrum in stable homotopy theory.

• spectrum (geometry) in geometry, Cole's theory of spectrum

• including spectral theory such spectrum of an operator, spectra of families, of a Banach algebra, Gelfand spectrum, spectrum of a commutative ring, prime spectrum of a ring (not necessarily commutative), analytic spectrum, Cole's theory of spectrum, spectrum of an abelian category, Orlov spectrum, spectrum of a triangulated category, prime spectrum of a symmetric monoidal stable (∞,1)-category, etc.

There is also a notion of

• spectral sequence

which has no particular relation to other notions of spectrum, except that filtered spectra give rise to spectral sequences of filtered spectra.

In physics:

• atomic spectrum