Duality may refer to:

Mathematics

* Duality (mathematics), a mathematical concept ** Dual (category theory), a formalization of mathematical duality ** Duality (optimization) ** Duality (order theory), a concept regarding binary relations ** Duality (projective geometry), general principle of projective geometry ** Duality principle (Boolean algebra), the extension of order-theoretic duality to Boolean algebras ** S-duality (homotopy theory) *

Philosophy, logic, and psychology

* Dualistic cosmology, a twofold division in several spiritual and religious worldviews * Dualism (philosophy of mind), where the body and mind are considered to be irreducibly distinct * De Morgan's laws, specifically the ability to generate the dual of any logical expression * Complementary duality of Carl Jung's functions and types in Socionics * Duality (CoPs), refers to the notion of a duality in a Community of Practice

Science

Electrical and mechanical

* Duality (electrical circuits), regarding isomorphism of electrical circuits * Duality (mechanical engineering), regarding isomorphism of some mechanical laws

Physics

* AdS/CFT correspondence (anti de Sitter/conformal field theory correspondence), sometimes called the Maldacena duality * Dual resonance model * Duality (electricity and magnetism) * Englert–Greenberger duality relation * Holographic duality * Kramers–Wannier duality * *

Mirror symmetry (string theory) In algebraic geometry and theoretical physics, mirror symmetry is a relationship between geometry, geometric objects called Calabi–Yau manifolds. The term refers to a situation where two Calabi–Yau manifolds look very different geometrically ...

* Montonen–Olive duality * Mysterious duality * String duality, a class of symmetries ** S-duality ** T-duality ** U-duality * Wave–particle duality

Music

Albums

* ''Duality'' (Peter Leitch and John Hicks album), 1994 * ''Duality'' (Lisa Gerrard and Pieter Bourke album), 1998 * ''Duality'' (Set It Off album), 2014 * ''Duality'' (Ra album), 2005 * ''Duality'' (mixtape), 2012 * ''Duality'' (Luna Li album), 2022 * ''Duality'' (Lindsey Stirling album), 2024 * ''Duality'', a 2009 album by Darker Half * ''Duality'', a 2020 album by Duke Dumont * ''Duality'', a 2018 album by Big Scoob

Songs

* "Duality", a 2014 single from pop rock/punk rock band Set It Off * "Duality" (song), a 2004 single by metal band Slipknot * "Duality", a 2007 single from alternative rock/punk band Bayside

Other

* ''Duality'' (film), a 2001 Star Wars fan film by Dave Macomber and Mark Thomas * Duality, a large format audio mixing console by Solid State Logic * Dual (grammatical number), grammatical number that some languages use in addition to singular and plural