Reciprocity may refer to:

Law and trade

Reciprocity (Canadian politics) Reciprocity, in 19th- and early 20th-century Canadian politics, meant free trade, the removal of protective tariffs on all natural resources between Canada and the United States. Reciprocity and free trade have been emotional issues in Canadian ...

, free trade with the United States of America **

Reciprocal trade agreement A trade agreement (also known as trade pact) is a wide-ranging taxes, tariff and trade treaty that often includes investment guarantees. It exists when two or more countries agree on terms that help them trade with each other. The most common t ...

, 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 Article IV, Section 1 of the United States Constitution, the Full Faith and Credit Clause, addresses the duty that states within the United States have to respect the "public acts, records, and judicial proceedings of every other state." Acc ...

, which provides for it **

Occupational licensing Occupational licensing, also called occupational licensure, is a form of regulation, government regulation requiring a license to pursue a particular profession or vocation for compensation. It is related to occupational closure. Professions tha ...

, which in some jurisdictions provides for it * Traffic violations reciprocity where non-resident drivers are treated like residents *

Quid pro quo Quid pro quo ('what for what' in Latin) is a Latin phrase used in English to mean an exchange of goods or services, in which one transfer is contingent upon the other; "a favor for a favor". Phrases with similar meanings include: "give and take ...

, a legal concept of the exchange of good or services, each having value

Social sciences and humanities

Norm of reciprocity The norm of reciprocity requires that we repay in kind what another has done for us.Whatley, M, A., Rhodes, A., Smith, R. H., Webster, J. M. (1999) ''The Effect of a Favor on Public and Private Compliance: How Internalized is the Norm of Reciprocit ...

, social norm of in-kind responses to the behavior of others *

Reciprocity (cultural anthropology) In cultural anthropology, reciprocity refers to the non-market exchange of goods or labour ranging from direct barter (immediate exchange) to forms of gift exchange where a return is eventually expected (delayed exchange) as in the exchange of bi ...

, way of defining people's informal exchange of goods and labour *

Reciprocity (evolution) Reciprocity in evolutionary biology refers to mechanisms whereby the evolution of cooperative or altruistic behaviour may be favoured by the probability of future mutual interactions. A corollary is how a desire for revenge can harm the collective ...

, mechanisms for the evolution of cooperation *

Reciprocity (international relations) In international relations and treaties, the principle of reciprocity states that favors, benefits, or penalties that are granted by one state to the citizens or legal entities of another, should be returned in kind. For example, reciprocity has ...

, 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) The social norm of reciprocity is the expectation that people will respond to each other in similar ways—responding to gifts and kindnesses from others with similar benevolence of their own, and responding to harmful, hurtful acts from others wi ...

, concept of reciprocity as in-kind positive or negative responses for the actions of others *

Reciprocity (social psychology) In social psychology, reciprocity is a social norm of responding to a positive action with another positive action, rewarding kind actions. As a social construct, reciprocity means that in response to friendly actions, people are frequently much n ...

, in-kind positively or negatively connoted responses of individuals towards the actions of others * Ethic of reciprocity (the Golden Rule), that one should treat others as one would like others to treat oneself * 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), used in the analysis of structures and to resolve complex load conditions *

Reciprocity (electromagnetism) In classical electromagnetism, reciprocity refers to a variety of related theorems involving the interchange of time-harmonic electric current densities (sources) and the resulting electromagnetic fields in Maxwell's equations for time-invarian ...

, theorems relating sources and the resulting fields in classical electromagnetism *

Reciprocity (electrical networks) Reciprocity in electrical networks is a property of a circuit that relates voltages and currents at two points. The reciprocity theorem states that the current at one point in a circuit due to a voltage at a second point is the same as the current ...

, reciprocity theorem as it relates to current and voltage in electrical networks *

Reciprocity (network science) In network science, reciprocity is a measure of the likelihood of vertices in a directed network to be mutually linked. Like the clustering coefficient, scale-free degree distribution, or community structure, reciprocity is a quantitative mea ...

, measures the tendency of vertex pairs to form mutual connections between each other * Reciprocity (optoelectronic), a diode under illumination to the photon emission of the same diode under applied voltage *

Reciprocity (photography) In photography, reciprocity is the inverse relationship between the intensity and duration of light that determines the reaction of light-sensitive material. Within a normal exposure range for film stock, for example, the reciprocity law states th ...

, the relationship between the intensity of the light and duration of the exposure that result in identical exposure * Reciprocity of twist and wrench, in screw theory *

Reciprocity theorem (disambiguation) Reciprocity theorem may refer to: *Quadratic reciprocity, a theorem about modular arithmetic **Cubic reciprocity **Quartic reciprocity **Artin reciprocity ** Weil reciprocity for algebraic curves * Frobenius reciprocity theorem for group representat ...

, several unrelated results * Reciprocity of

antenna Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two collid ...

transmitting and receiving characteristics *

Helmholtz reciprocity The Helmholtz reciprocity principle describes how a ray of light and its reverse ray encounter matched optical adventures, such as reflections, refractions, and absorptions in a passive medium, or at an interface. It does not apply to moving, non ...

, linear propagation.

Mathematics

Reciprocity law In mathematics, a reciprocity law is a generalization of the law of quadratic reciprocity to arbitrary monic irreducible polynomials f(x) with integer coefficients. Recall that first reciprocity law, quadratic reciprocity, determines when an ir ...

(law of reciprocity) in mathematics, including **

Quadratic reciprocity In number theory, the law of quadratic reciprocity is a theorem about modular arithmetic that gives conditions for the solvability of quadratic equations modulo prime numbers. Due to its subtlety, it has many formulations, but the most standard s ...

, a fundamental result in number theory **

Cubic reciprocity Cubic reciprocity is a collection of theorems in elementary and algebraic number theory that state conditions under which the congruence ''x''3 ≡ ''p'' (mod ''q'') is solvable; the word "reciprocity" comes from the form of ...

, theorems that state conditions under which the congruence is solvable **

Quartic reciprocity Quartic or biquadratic reciprocity is a collection of theorems in elementary and algebraic number theory that state conditions under which the congruence ''x''4 ≡ ''p'' (mod ''q'') is solvable; the word "reciprocity" comes from the form ...

, a collection of theorems in elementary and algebraic number theory that state conditions under which the congruence is solvable **

Artin reciprocity law The Artin reciprocity law, which was established by Emil Artin in a series of papers (1924; 1927; 1930), is a general theorem in number theory that forms a central part of global class field theory. The term "reciprocity law" refers to a long line ...

, a general theorem in number theory that provided a partial solution to Hilbert's ninth problem **

Reciprocity relation In multivariate calculus, a differential or differential form is said to be exact or perfect (''exact differential''), as contrasted with an inexact differential, if it is equal to the general differential dQ for some differentiable function ...

or ''exact differential'', a mathematical differential of the form ''dQ'', for some differentiable function ''Q'' *

Weil reciprocity law In mathematics, the Weil reciprocity law is a result of André Weil holding in the function field ''K''(''C'') of an algebraic curve ''C'' over an algebraically closed field ''K''. Given functions ''f'' and ''g'' in ''K''(''C''), i.e. rational fun ...

* Reciprocal polynomials, the coefficients of the remainder polynomial are the bits of the CRC *

Reciprocal square root Methods of computing square roots are numerical analysis algorithms for approximating the principal, or non-negative, square root (usually denoted \sqrt, \sqrt /math>, or S^) of a real number. Arithmetically, it means given S, a procedure for fin ...

* 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 In mathematics, and in particular representation theory, Frobenius reciprocity is a theorem expressing a duality between the process of restricting and inducting. It can be used to leverage knowledge about representations of a subgroup to find a ...

, from group representation theory * Reciprocity law for Dedekind sums *

Stanley's reciprocity theorem In combinatorial mathematics, Stanley's reciprocity theorem, named after MIT mathematician Richard P. Stanley, states that a certain functional equation is satisfied by the generating function of any rational cone (defined below) and the generati ...

, 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 for invariants of binary forms.

Other

* Reciprocity (''Fringe''), a 2011 episode of the television series ''Fringe'' *

Rural Municipality of Reciprocity No. 32 The Rural Municipality of Reciprocity No. 32 (Canada 2016 Census, 2016 population: ) is a List of rural municipalities in Saskatchewan, rural municipality (RM) in the Provinces and territories of Canada, Canadian province of Saskatchewan within ...

, Saskatchewan, Canada

Law and trade

Social sciences and humanities

Physical sciences and engineering

Mathematics

Other

See also