Complex commonly refers to: *

Complexity Complexity characterises the behaviour of a system or model whose components interaction, interact in multiple ways and follow local rules, leading to nonlinearity, randomness, collective dynamics, hierarchy, and emergence. The term is generall ...

, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe ** Complex system, a system composed of many components which may interact with each other *

Complex (psychology) A complex is a structure in the unconscious that is objectified as an underlying theme—like a power or a status—by grouping clusters of emotions, memories, perceptions and wishes in response to a threat to the stability of the self. In p ...

, a core pattern of emotions etc. in the personal unconscious organized around a common theme such as power or status Complex may also refer to:

Arts, entertainment and media

Complex (English band) Complex were an English band formed in 1968 consisting of lead guitarist Brian Lee, lead vocalist and drummer Tony Shakespeare, bass guitarist Lance Fogg and rhythm guitarist Tony Fisher. After some initial personnel changes, in early 1970 the l ...

, formed in 1968, and their 1971 album ''Complex'' *

Complex (band) Complex was a Japanese rock duo composed of guitarist Tomoyasu Hotei and singer Koji Kikkawa. They released their self-titled debut in 1989, along with their first single and video, "Be My Baby". After a tour to promote the album, they released i ...

, a Japanese rock band * ''Complex'' (album), by Montaigne, 2019, and its title track * ''Complex'' (EP), by Rifle Sport, 1985 * "Complex" (song), by Gary Numan, 1979 * Complex Networks, publisher of magazine ''Complex'', now online

Biology

Protein–ligand complex A protein–ligand complex is a complex of a protein bound with a ligand that is formed following molecular recognition between proteins that interact with each other or with various other molecules. Formation of a protein-ligand complex is based ...

, a complex of a protein bound with a ligand *

Exosome complex The exosome complex (or PM/Scl complex, often just called the exosome) is a multi-protein intracellular Protein complex, complex capable of degrading various types of RNA (ribonucleic acid) molecules. Exosome complexes are found in both eukaryo ...

, a multi-protein intracellular complex *

Protein complex A protein complex or multiprotein complex is a group of two or more associated polypeptide chains. Protein complexes are distinct from multienzyme complexes, in which multiple catalytic domains are found in a single polypeptide chain. Protein c ...

, a group of two or more associated polypeptide chains *

Species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, a cluster of very similar species difficult to delimit *

Pre-Bötzinger complex The preBötzinger complex, sometimes written pre-Bötzinger complex (preBötC), is a functionally and anatomically specialized site in the ventral-lateral region of the lower medulla oblongata (i.e., lower brainstem). The preBötC is part of the v ...

, a cluster of interneurons in the ventral respiratory group of the medulla of the brainstem

Chemistry

Coordination complex A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as '' ligands'' or complexing agents. ...

, a central atom or ion and a surrounding array of bound molecules or ions *

Chelate complex Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are ...

, a coordination complex with more than one bond

Mathematics

Complex number In mathematics, a complex number is an element of a number system that extends the real numbers with a specific element denoted , called the imaginary unit and satisfying the equation i^= -1; every complex number can be expressed in the form ...

, an extension of real numbers obtained by adjoining imaginary numbers *

Complex polytope In geometry, a complex polytope is a generalization of a polytope in real space to an analogous structure in a complex Hilbert space, where each real dimension is accompanied by an imaginary one. A complex polytope may be understood as a collect ...

, a generalization of a polytope in a complex Hilbert space *

Complex analysis Complex analysis, traditionally known as the theory of functions of a complex variable, is the branch of mathematical analysis that investigates Function (mathematics), functions of complex numbers. It is helpful in many branches of mathemati ...

, the study of functions of complex numbers * Complex, an element of a

field of sets In mathematics, a field of sets is a mathematical structure consisting of a pair ( X, \mathcal ) consisting of a set X and a family \mathcal of subsets of X called an algebra over X that contains the empty set as an element, and is closed un ...

Chain complex In mathematics, a chain complex is an algebraic structure that consists of a sequence of abelian groups (or modules) and a sequence of homomorphisms between consecutive groups such that the image of each homomorphism is included in the kernel of t ...

, an algebraic structure * Simplicial complex, a kind of topological space **

CW complex A CW complex (also called cellular complex or cell complex) is a kind of a topological space that is particularly important in algebraic topology. It was introduced by J. H. C. Whitehead (open access) to meet the needs of homotopy theory. This cl ...

, a kind of topological space *

Line complex In algebraic geometry, a line complex is a 3-fold given by the intersection of the Grassmannian ''G''(2, 4) (embedded in projective space ''P''5 by Plücker coordinates In geometry, Plücker coordinates, introduced by Julius Plücker in t ...

, a 3-dimensional family of lines in space

Geology

Complex (geology) In geology, a complex is a lithodemic unit consisting of two or more lithodemes of more than one genetic class (metamorphic, igneous or sedimentary). The law of superposition The law of superposition is an axiom that forms one of the bases ...

, a unit of rocks composed of rocks of two or three types *

Complex crater Complex craters are a type of large impact crater morphology. Above a certain threshold size, which varies with planetary gravity, the collapse and modification of the transient cavity is much more extensive, and the resulting structure is cal ...

, a type of large impact crater morphology *

Volcanic complex A complex volcano, also called a compound volcano or a volcanic complex, is a mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock. They may form due to changes in eruptive habit or in ...

, a group of volcanoes *

Complex volcano A complex volcano, also called a compound volcano or a volcanic complex, is a mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock. They may form due to changes in eruptive habit or in t ...

, a volcano of mixed form *

Accretionary complex An accretionary wedge or accretionary prism forms from sediments accreted onto the non-subducting tectonic plate at a convergent plate boundary. Most of the material in the accretionary wedge consists of marine sediments scraped off from the d ...

, a fossil accretionary wedge

Other uses

* Building complex, a group of inter-related buildings **

Housing complex A housing estate (or sometimes housing complex or housing development) is a group of homes and other buildings built together as a single development. The exact form may vary from country to country. Popular throughout the United States ...

, specifically residential * UCL Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), part of

UCL Faculty of Mathematical and Physical Sciences The UCL Faculty of Mathematical and Physical Sciences is one of the 11 constituent faculties of University College London (UCL). The Faculty, the UCL Faculty of Engineering Sciences and the UCL Faculty of the Built Envirornment (The Bartlett) t ...