Periodicity or periodic may refer to:

Mathematics

*Bott periodicity theorem
In mathematics, the Bott periodicity theorem describes a periodicity in the homotopy groups of classical groups, discovered by , which proved to be of foundational significance for much further research, in particular in K-theory of stable complex ...

, addresses Bott periodicity: a modulo-8 recurrence relation in the homotopy groups of classical groups
* Periodic function
A periodic function is a function that repeats its values at regular intervals, for example, the trigonometric functions
In mathematics
Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number ...

, a function whose output contains values that repeat periodically
* Periodic mapping
Physical sciences

*Periodic table
The periodic table, also known as the periodic table of elements, is a tabular display of the chemical element
Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements
In chemistry ...

of chemical elements
* Periodic trends
Image:Periodic trends.svg, The periodic trends in properties of elements
Periodic trends are specific patterns in the properties of chemical elements that are revealed in the periodic table of elements. Major periodic trends include electronegativ ...

, relative characteristics of chemical elements observed
* Redshift periodicity, astronomical term for redshift quantization
Other uses

* Fokker periodicity blocks, which mathematically relate musical intervals * Periodic acid, a different pronunciation and different meaning of the word ''periodic'' * Principle of periodicity, a concept ingenerally accepted accounting principles
Publicly traded companies typically are subject to the most rigorous standards. Small and midsized businesses often follow more simplified standards, plus any specific disclosures required by their specific lenders and shareholders. Some firms opera ...

* Quasiperiodicity, property of a system that displays irregular periodicity
See also

* Aperiodic (disambiguation) * Cycle (disambiguation) * Frequency (disambiguation) * Period (disambiguation) *Periodical
Periodical literature (also called a periodical publication or simply a periodical) is a category of Serial (publishing), serial published, publications that appear in a new edition on a regular schedule. The most familiar example is the magazine ...

* Seasonality
In time series data, seasonality is the presence of variations that occur at specific regular intervals less than a year, such as weekly, monthly, or quarterly. Seasonality may be caused by various factors, such as weather, vacation, and holidays a ...

, periodic variation, or periodic fluctuations
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