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, statistical fluctuations in a thermodynamic variable * Quantum fluctuation, 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 Universal conductance fluctuations (UCF) in mesoscopic physics is a phenomenon encountered in electrical transport experiments in mesoscopic species. The measured electrical conductance will vary from sample to sample, mainly due to inhomogeneous s ...

, a quantum physics phenomenon encountered in electrical transport experiments in mesoscopic species

Finance and economics

Economic conjuncture Business cycles are intervals of expansion followed by recession in economic activity. These changes have implications for the welfare of the broad population as well as for private institutions. Typically business cycles are measured by examini ...

, a critical combination of events in economics * Volatility (finance), price fluctuation {{disambiguation