HOME

TheInfoList



OR:

{{Unreferenced, date=September 2022 This is a list of various types of equilibrium, the condition of a
system A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and express ...
in which all competing influences are balanced.


Biology

*
Equilibrioception The sense of balance or equilibrioception is the perception of balance and spatial orientation. It helps prevent humans and nonhuman animals from falling over when standing or moving. Equilibrioception is the result of a number of sensory syste ...
, the sense of a balance present in human beings and animals *
Equilibrium unfolding In biochemistry, equilibrium unfolding is the process of unfolding a protein or RNA molecule by gradually changing its environment, such as by changing the temperature or pressure, pH, adding chemical denaturants, or applying force as with an ...
, the process of unfolding a protein or RNA molecule by gradually changing its environment *
Genetic equilibrium Genetic equilibrium is the condition of an allele or genotype in a gene pool (such as a population) where the frequency does not change from generation to generation. Genetic equilibrium describes a theoretical state that is the basis for determini ...
, theoretical state in which a population is not evolving *
Homeostasis In biology, homeostasis ( British also homoeostasis) (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and ...
, the ability of an open system, especially living organisms, to regulate its internal environment *
Punctuated equilibrium In evolutionary biology, punctuated equilibrium (also called punctuated equilibria) is a theory that proposes that once a species appears in the fossil record, the population will become stable, showing little evolutionary change for most of ...
, theory in evolutionary biology *
Sedimentation equilibrium Sedimentation equilibrium in a suspension of different particles, such as molecules, exists when the rate of transport of each material in any one direction due to sedimentation equals the rate of transport in the opposite direction due to diffusi ...
, analytical ultracentrifugation method for measuring protein molecular masses in solution * Equilibrium Theory (
Island biogeography Insular biogeography or island biogeography is a field within biogeography that examines the factors that affect the species richness and diversification of isolated natural communities. The theory was originally developed to explain the pattern of ...
), MacArthur-Wilson theory explaining biodiversity character of ecological islands *
Osmotic equilibrium Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane. It is also defined as the measure of the tendency of a solution to take in a pure s ...
, balance between solvent flow and pressure across a membrane


Physics

* Equilibrant force, which keeps any object motionless and acts on virtually every object in the world that is not moving * Equilibrium figures of Earth and planets (physical geodesy) *
Equilibrium mode distribution The equilibrium mode owerdistribution of light travelling in an optical waveguide or fiber, is the distribution of light that is no longer changing with fibre length or with input modal excitation. This phenomenon requires both mode filtering and ...
, the state of fiber optic or waveguide transmission in which the propagation mode does not vary with distance along the fiber or changes in the launch mode *
Hydrostatic equilibrium In fluid mechanics, hydrostatic equilibrium (hydrostatic balance, hydrostasy) is the condition of a fluid or plastic solid at rest, which occurs when external forces, such as gravity, are balanced by a pressure-gradient force. In the planeta ...
, the state of a system in which compression due to gravity is balanced by a pressure gradient force * Hyperbolic equilibrium point, a mathematical concept in physics *
Mechanical equilibrium In classical mechanics, a particle is in mechanical equilibrium if the net force on that particle is zero. By extension, a physical system made up of many parts is in mechanical equilibrium if the net force on each of its individual parts is zero ...
, the state in which the sum of the forces, and torque, on each particle of the system is zero *
Radiative equilibrium Radiative equilibrium is the condition where the total thermal radiation leaving an object is equal to the total thermal radiation entering it. It is one of the several requirements for thermodynamic equilibrium, but it can occur in the absence of ...
, the state where the energy radiated is balanced by the energy absorbed * Secular equilibrium, a state of radioactive elements in which the production rate of a daughter nucleus is balanced by its own decay rate *
Thermodynamic equilibrium Thermodynamic equilibrium is an axiomatic concept of thermodynamics. It is an internal state of a single thermodynamic system, or a relation between several thermodynamic systems connected by more or less permeable or impermeable walls. In the ...
, the state of a thermodynamic system in which there are no net flows of matter or energy *
Isostatic equilibrium Isostasy (Greek ''ísos'' "equal", ''stásis'' "standstill") or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its ...
, in geology, the balance between gravitation and buoyancy of the earth's crust in the mantle


Chemistry

*
Chemical equilibrium In a chemical reaction, chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the ...
, the state in which the concentrations of the reactants and products have stopped changing in time * Diffusive equilibrium, when the concentrations of each type of particle have stopped changing *
Thermal equilibrium Two physical systems are in thermal equilibrium if there is no net flow of thermal energy between them when they are connected by a path permeable to heat. Thermal equilibrium obeys the zeroth law of thermodynamics. A system is said to be in ...
, a state where an object and its surroundings cease to exchange energy in the form of heat, i.e. they are at the same temperature *
Donnan equilibrium Donnan can refer to: * Donnan (surname) * Donnan, Iowa, a community in the United States * Donnán of Eigg, Gaelic priest of the 7th century * Donnan equilibrium ** Donnan potential {{disambig ...
, the distribution of ion species between two ionic solutions separated by a semipermeable membrane or boundary *
Dynamic equilibrium In chemistry, a dynamic equilibrium exists once a reversible reaction occurs. Substances transition between the reactants and products at equal rates, meaning there is no net change. Reactants and products are formed at such a rate that the co ...
, the state in which two reversible processes occur at the same rate *
Equilibrium constant The equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium, a state approached by a dynamic chemical system after sufficient time has elapsed at which its composition has no measurable tendency ...
, a quantity characterizing a chemical equilibrium in a chemical reaction * Partition equilibrium, a type of chromatography that is typically used in GC * Quasistatic equilibrium, the quasi-balanced state of a thermodynamic system near to equilibrium in some sense or degree *
Schlenk equilibrium Schlenk can refer to: People * Wilhelm Schlenk (1879-1943), German chemist In chemistry * Schlenk flask * Schlenk line The Schlenk line (also vacuum gas manifold) is a commonly used chemistry apparatus developed by Wilhelm Schlenk. It consists ...
, a chemical equilibrium named after its discoverer Wilhelm Schlenk taking place in solutions of Grignard reagents *
Solubility equilibrium Solubility equilibrium is a type of dynamic equilibrium that exists when a chemical compound in the solid state is in chemical equilibrium with a solution of that compound. The solid may dissolve unchanged, with dissociation, or with chemical reac ...
, any chemical equilibrium between solid and dissolved states of a compound at saturation *
Vapor–liquid equilibrium In thermodynamics and chemical engineering, the vapor–liquid equilibrium (VLE) describes the distribution of a chemical species between the vapor phase and a liquid phase. The concentration of a vapor in contact with its liquid, especially a ...
, where the rates of condensation and vapourization of a material are equal


Economics

*
Competitive equilibrium Competitive equilibrium (also called: Walrasian equilibrium) is a concept of economic equilibrium introduced by Kenneth Arrow and Gérard Debreu in 1951 appropriate for the analysis of commodity markets with flexible prices and many traders, and se ...
, economic equilibrium when all buyers and sellers are small relative to the market *
Economic equilibrium In economics, economic equilibrium is a situation in which economic forces such as supply and demand are balanced and in the absence of external influences the ( equilibrium) values of economic variables will not change. For example, in the st ...
, a condition in economics * Equilibrium price, the price at which quantity supplied equals quantity demanded *
General equilibrium theory In economics, general equilibrium theory attempts to explain the behavior of supply, demand, and prices in a whole economy with several or many interacting markets, by seeking to prove that the interaction of demand and supply will result in an ov ...
, a branch of theoretical microeconomics that studies multiple individual markets *
Intertemporal equilibrium Intertemporal equilibrium is a notion of economic equilibrium conceived over many periods of time. In modern economic theory, most models explicitly take into account the fact that the economy evolves over time, and that its equilibrium cannot be ...
, an equilibrium concept over time *
Lindahl equilibrium A Lindahl tax is a form of taxation conceived by Erik Lindahl in which individuals pay for public goods according to their marginal benefits. In other words, they pay according to the amount of satisfaction or utility they derive from the consumpt ...
, a method proposed by Erik Lindahl for financing public goods *
Partial equilibrium In economics, partial equilibrium is a condition of economic equilibrium which analyzes only a single market, ''ceteris paribus'' (everything else remaining constant) except for the one change at a time being analyzed. In general equilibrium ana ...
, the equilibrium price and quantity which come from the cross of supply and demand in a competitive market * Radner equilibrium, an economic concept defined by economist Roy Radner in the context of general equilibrium * Recursive competitive equilibrium, an economic equilibrium concept associated with a dynamic program *
Static equilibrium (economics) In economics, economic equilibrium is a situation in which economic forces such as supply and demand are balanced and in the absence of external influences the ( equilibrium) values of economic variables will not change. For example, in the s ...
, the intersection of supply and demand in any market * Sunspot equilibrium, an economic equilibrium in which non-fundamental factors affect prices or quantities *
Underemployment equilibrium In Keynesian economics, underemployment equilibrium is a situation with a persistent shortfall relative to full employment and potential output so that unemployment is higher than at the NAIRU or the "natural" rate of unemployment. Theoretical f ...
, a situation in Keynesian economics with a persistent shortfall relative to full employment and potential output *
Dynamic stochastic general equilibrium Dynamic stochastic general equilibrium modeling (abbreviated as DSGE, or DGE, or sometimes SDGE) is a macroeconomic method which is often employed by monetary and fiscal authorities for policy analysis, explaining historical time-series data, as w ...
, an econometric method that applies
general equilibrium theory In economics, general equilibrium theory attempts to explain the behavior of supply, demand, and prices in a whole economy with several or many interacting markets, by seeking to prove that the interaction of demand and supply will result in an ov ...
and microeconomic principles.


Game theory

*
Correlated equilibrium In game theory, a correlated equilibrium is a solution concept that is more general than the well known Nash equilibrium. It was first discussed by mathematician Robert Aumann in 1974. The idea is that each player chooses their action according ...
, a solution concept in game theory that is more general than Nash equilibrium *
Nash equilibrium In game theory, the Nash equilibrium, named after the mathematician John Nash, is the most common way to define the solution of a non-cooperative game involving two or more players. In a Nash equilibrium, each player is assumed to know the equili ...
, the basic solution concept in game theory **
Quasi-perfect equilibrium Quasi-perfect equilibrium is a refinement of Nash Equilibrium for extensive form games due to Eric van Damme. Informally, a player playing by a strategy from a quasi-perfect equilibrium takes observed as well as potential future mistakes of hi ...
, a refinement of Nash Equilibrium for extensive form games due to Eric van Damme ** Sequential equilibrium, a refinement of Nash Equilibrium for games of incomplete information due to David M. Kreps and Robert Wilson **
Perfect Bayesian equilibrium In game theory, a Perfect Bayesian Equilibrium (PBE) is an equilibrium concept relevant for dynamic games with incomplete information (sequential Bayesian games). It is a refinement of Bayesian Nash equilibrium (BNE). A perfect Bayesian equilibriu ...
, a refinement of Nash equilibrium for games of incomplete information that is simpler to use than sequential equilibrium *
Symmetric equilibrium In game theory, a symmetric equilibrium is an equilibrium where all players use the same strategy (possibly mixed) in the equilibrium. In the Prisoner's Dilemma game pictured to the right, the only Nash equilibrium is (''D'', ''D''). Since bot ...
, an equilibrium where all players use the same strategy * Trembling hand perfect equilibrium assumes that the players, through a "slip of the hand" or tremble, may choose unintended strategies **
Proper equilibrium Proper equilibrium is a refinement of Nash Equilibrium due to Roger B. Myerson. Proper equilibrium further refines Reinhard Selten's notion of a trembling hand perfect equilibrium by assuming that more costly trembles are made with significant ...
due to Roger B. Myerson, where costly trembles are made with smaller probabilities


Other

*
Social equilibrium In sociology, a system is said to be in social equilibrium when there is a dynamic working balance among its interdependent parts. Each subsystem will adjust to any change in the other subsystems and will continue to do so until an equilibrium is ...
, a system in which there is a dynamic working balance among its interdependent parts * Equilibrium moisture content, the moisture content at which the wood is neither gaining nor losing moisture *
Equilibrium point In mathematics, specifically in differential equations, an equilibrium point is a constant solution to a differential equation. Formal definition The point \tilde\in \mathbb^n is an equilibrium point for the differential equation :\frac = \ ...
, in mathematics, a constant solution to a differential equation *
Reflective equilibrium Reflective equilibrium is a state of balance or coherence among a set of beliefs arrived at by a process of deliberative mutual adjustment among general principles and particular judgements. Although he did not use the term, philosopher Nelson G ...
, the state of balance or coherence among a set of beliefs arrived at by a process of deliberative mutual adjustment


External links


Equilibrium
article in
Scholarpedia ''Scholarpedia'' is an English-language wiki-based online encyclopedia with features commonly associated with open-access online academic journals, which aims to have quality content in science and medicine. ''Scholarpedia'' articles are writ ...
by Eugene Izhikevich Equilibrium