# Reciprocity > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Reciprocity > Markdown URL: https://mediated.wiki/source/Reciprocity.md > Source: https://en.wikipedia.org/wiki/Reciprocity > Source revision: 1270713293 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) **Reciprocity** may refer to: ## Law and trade - [Reciprocity (Canadian politics)](/source/Reciprocity_(Canadian_politics)), free trade with the United States of America - [Reciprocal trade agreement](/source/Reciprocal_trade_agreement), entered into in order to reduce (or eliminate) tariffs, quotas and other trade restrictions on items traded between the signatories - Interstate reciprocity, recognition of sibling federated states' laws: - In the United States specifically: - [Full Faith and Credit Clause](/source/Full_Faith_and_Credit_Clause), which provides for it - [Concealed carry reciprocity](/source/Concealed_carry_in_the_United_States#Reciprocity) - [Occupational licensing](/source/Occupational_licensing), which in some jurisdictions provides for it - [Traffic violations reciprocity](/source/Traffic_violations_reciprocity) where non-resident drivers are treated like residents - [Quid pro quo](/source/Quid_pro_quo#Common_law), a legal concept of the exchange of good or services, each having value ## Social sciences and humanities - [Norm of reciprocity](/source/Norm_of_reciprocity), social norm of in-kind responses to the behavior of others - [Reciprocity (cultural anthropology)](/source/Reciprocity_(cultural_anthropology)), way of defining people's informal exchange of goods and labour - [Reciprocity (evolution)](/source/Reciprocity_(evolution)), mechanisms for the evolution of cooperation - [Reciprocity (international relations)](/source/Reciprocity_(international_relations)), principle that favours, benefits, or penalties that are granted by one state to the citizens or legal entities of another, should be returned in kind - [Reciprocity (social and political philosophy)](/source/Reciprocity_(social_and_political_philosophy)), concept of reciprocity as in-kind positive or negative responses for the actions of others - [Reciprocity (social psychology)](/source/Reciprocity_(social_psychology)), in-kind positively or negatively connoted responses of individuals towards the actions of others - Ethic of reciprocity (the [Golden Rule](/source/Golden_Rule)), that one should treat others as one would like others to treat oneself - [Serial reciprocity](/source/Serial_reciprocity), in which the benefactor of a gift or service will in turn provide benefits to a third party ## Physical sciences and engineering - [Reciprocity (engineering)](/source/Reciprocity_(engineering)), used in the analysis of structures and to resolve complex load conditions - [Reciprocity (electromagnetism)](/source/Reciprocity_(electromagnetism)), theorems relating sources and the resulting fields in classical electromagnetism - [Reciprocity (electrical networks)](/source/Reciprocity_(electrical_networks)), reciprocity theorem as it relates to current and voltage in electrical networks - [Reciprocity (network science)](/source/Reciprocity_(network_science)), measures the tendency of vertex pairs to form mutual connections between each other - [Reciprocity (optoelectronic)](/source/Reciprocity_(optoelectronic)), a diode under illumination to the photon emission of the same diode under applied voltage - [Reciprocity (photography)](/source/Reciprocity_(photography)), the relationship between the intensity of the light and duration of the exposure that result in identical exposure - [Reciprocity of twist and wrench](/source/Screw_theory#Reciprocity_of_twist_and_wrench), in screw theory - [Reciprocity theorem (disambiguation)](/source/Reciprocity_theorem_(disambiguation)), several unrelated results - Reciprocity of [antenna](/source/Antenna_(radio)#Reciprocity) transmitting and receiving characteristics - [Helmholtz reciprocity](/source/Helmholtz_reciprocity), linear propagation. ## Mathematics - [Reciprocity law](/source/Reciprocity_law) (law of reciprocity) in mathematics, including - [Quadratic reciprocity](/source/Quadratic_reciprocity), a fundamental result in number theory - [Cubic reciprocity](/source/Cubic_reciprocity), theorems that state conditions under which the congruence *x*3 ≡ *p* (mod *q*) is solvable - [Quartic reciprocity](/source/Quartic_reciprocity), a collection of theorems in elementary and algebraic number theory that state conditions under which the congruence *x*4 ≡ *p* (mod *q*) is solvable - [Artin reciprocity law](/source/Artin_reciprocity_law), a general theorem in number theory that provided a partial solution to Hilbert's ninth problem - [Reciprocity relation](/source/Reciprocity_relation) or *exact differential*, a mathematical differential of the form *dQ*, for some differentiable function *Q* - [Weil reciprocity law](/source/Weil_reciprocity_law) - [Reciprocal polynomials](/source/Mathematics_of_CRC#Reciprocal_polynomials), the coefficients of the remainder polynomial are the bits of the CRC - [Reciprocal square root](/source/Reciprocal_square_root#Iterative_methods_for_reciprocal_square_roots) - [Reciprocity (projective geometry)](/source/Reciprocity_(projective_geometry)), a collineation from a projective space onto its dual space, taking points to hyperplanes (and vice versa) and preserving incidence - [Frobenius reciprocity](/source/Frobenius_reciprocity), from group representation theory - Reciprocity law for [Dedekind sums](/source/Dedekind_sums) - [Stanley's reciprocity theorem](/source/Stanley's_reciprocity_theorem), states that a certain functional equation is satisfied by the generating function of any rational cone and the generating function of the cone's interior - [Hermite reciprocity](/source/Hermite_reciprocity) for invariants of binary forms. ## Other - [Reciprocity (*Fringe*)](/source/Reciprocity_(Fringe)), a 2011 episode of the television series *Fringe* - [Rural Municipality of Reciprocity No. 32](/source/Rural_Municipality_of_Reciprocity_No._32), Saskatchewan, Canada - "Reciprocity", a song by Loudon Wainwright III from his 1976 album *[T Shirt](/source/T_Shirt_(album))* ## See also - [Reciprocal (disambiguation)](/source/Reciprocal_(disambiguation)) - [Reciprocation (disambiguation)](/source/Reciprocation_(disambiguation)) - [Reciprocity Treaty (disambiguation)](/source/Reciprocity_Treaty_(disambiguation)) - [Reciprocal altruism](/source/Reciprocal_altruism) between individuals of different species - [Meeting of the minds](/source/Meeting_of_the_minds) in contract law, sometimes called reciprocity - [Tit for tat](/source/Tit_for_tat) --- Adapted from the Wikipedia article [Reciprocity](https://en.wikipedia.org/wiki/Reciprocity) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Reciprocity?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.