Fluctuation may refer to:
Physics and mathematics
*
Statistical fluctuations
Statistical fluctuations are fluctuations in quantities derived from many identical random processes. They are fundamental and unavoidable. It can be proved that the relative fluctuations reduce as the square root of the number of identical proces ...
, in statistics, statistical mechanics, and thermodynamics
**
Thermal fluctuations
In statistical mechanics, thermal fluctuations are random deviations of a system from its average state, that occur in a system at equilibrium.In statistical mechanics they are often simply referred to as fluctuations. All thermal fluctuations b ...
, statistical fluctuations in a thermodynamic variable
*
Quantum fluctuation
In quantum physics, a quantum fluctuation (also known as a vacuum state fluctuation or vacuum fluctuation) is the temporary random change in the amount of energy in a point in space, as prescribed by Werner Heisenberg's uncertainty principle. ...
, arising from the uncertainty principle
**
Primordial fluctuations
Primordial fluctuations are density variations in the early universe which are considered the seeds of all structure in the universe. Currently, the most widely accepted explanation for their origin is in the context of cosmic inflation. According ...
, density variations in the early universe
**
Universal conductance fluctuations, a quantum physics phenomenon encountered in electrical transport experiments in mesoscopic species
Finance and economics
*
Economic conjuncture, a critical combination of events in economics
*
Volatility (finance)
In finance, volatility (usually denoted by ''σ'') is the degree of variation of a trading price series over time, usually measured by the standard deviation of logarithmic returns.
Historic volatility measures a time series of past market price ...
, price fluctuation
{{disambiguation