A spectrum is a condition or value that is not limited to a specific set of values but can vary infinitely within a continuum. Spectrum may also refer to: Science and technology Physics Continuous spectrum, of any physical quantity that can change smoothly Discrete spectrum Electromagnetic spectrum Visible spectrum or optical spectrum, a subset of the electromagnetic spectrum Emission spectrum, observed in light Absorption spectrum, observed in light Radio spectrum, radio frequency subset of the electromagnetic spectrum Stellar spectrum, the combination of continuum, absorption, and emission lines produced by a star Energy spectrum, of a collection of particles (particle physics) Frequency spectrum, of a signal Power spectrum, of a signal Medicine Spectrum disorder, a group of mental disorders of similar appearance or thought to share an underlying mechanism Autism spectrum, encompassing autism, Asperger's, etc. Antimicrobial spectrum, the range of microorganisms an antibiotic can kill or inhibit Mathematics In mathematics, spectrum frequently denotes a set of numbers associated to an object: Spectrum of a matrix, its set of eigenvalues, in linear algebra Spectrum (functional analysis), a generalization of the concept of matrix eigenvalues to operators Spectrum of a graph, studied in spectral graph theory Pseudospectrum Spectrum of a polygon, the set of numbers of possible equidissections Spectrum of a sentence, in mathematical logic Spectrum of a theory, in mathematical logic There are also several other, unrelated meanings: Spectrum (topology), the fundamental object of study in stable homotopy theory Spectrum of a C*-algebra, a kind of dual object Spectrum of a ring, the set of its prime ideals, in commutative algebra Arts and entertainment Spectrum (brand), a brand name used by Charter Communications for their telecommunication services, including: Spectrum News, a group of six cable news channels Spectrum Sports, a group of nine regional sports networks in the US Spectrum TV Stream, a streaming service Publications IEEE Spectrum, a magazine by the Institute of Electrical and Electronics Engineers Spectrum (magazine), an independent Seventh-day Adventist magazine Spectrum (newspaper), a defunct Toledo, Ohio weekly newspaper Spectrum, a news website published by the Simons Foundation Autism Research Initiative The Spectrum (Utah), also known as The Spectrum & Daily News, a Gannett newspaper in St. George, Utah Spectrum (novel), a 2002 novel by Russian author Sergey Lukyanenko Spectrum, a magazine published with Scotland on Sunday Spectrum, a liftout in The Sydney Morning Herald Student newspapers The Spectrum (USLS), the student newspaper of the University of St.