Roman letters used in mathematics - AbsoluteAstronomy.com

Many letters of the Latin alphabet

Latin alphabet

The Latin alphabet, also called the Roman alphabet, is the most recognized alphabet used in the world today. It evolved from a western variety of the Greek alphabet called the Cumaean alphabet, which was adopted and modified by the Etruscans who ruled early Rome...

, both capital and small, are used in mathematics

Mathematics

Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

, science

Science

Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...

and engineering

Engineering

Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

to denote by convention specific or abstracted constants, variables of a certain type, units, multipliers, physical entities. Certain letters, when combined with special formatting, take on special meaning.

Below is an alphabetical list of the letters of the alphabet with some of their uses. The field in which the convention applies is mathematics unless otherwise noted.

Aa

A represents:
- the first corner of a triangle
  Triangle
  A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted ....
- the digit "10" in hexadecimal
  Hexadecimal
  In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
  
  and other positional numeral systems with a radix of 11 or greater
- the unit ampere
  Ampere
  The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...
  
  for electrical current
- the Area
  Area
  Area is a quantity that expresses the extent of a two-dimensional surface or shape in the plane. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat...
- the Mass number
  Mass number
  The mass number , also called atomic mass number or nucleon number, is the total number of protons and neutrons in an atomic nucleus. Because protons and neutrons both are baryons, the mass number A is identical with the baryon number B as of the nucleus as of the whole atom or ion...
  
  of an element
- The Helmholtz free energy
  Helmholtz free energy
  In thermodynamics, the Helmholtz free energy is a thermodynamic potential that measures the “useful” work obtainable from a closed thermodynamic system at a constant temperature and volume...
  
  of a closed thermodynamic system of constant Pressure & Temperature
- A Vector potential
  Vector potential
  In vector calculus, a vector potential is a vector field whose curl is a given vector field. This is analogous to a scalar potential, which is a scalar field whose negative gradient is a given vector field....
  
  , in Electromagnetics it can refer to the magnetic vector potential
represents the algebraic numbers or affine space in Algebraic Geometry
Algebraic geometry
Algebraic geometry is a branch of mathematics which combines techniques of abstract algebra, especially commutative algebra, with the language and the problems of geometry. It occupies a central place in modern mathematics and has multiple conceptual connections with such diverse fields as complex...
a represents:
- the first side of a triangle (opposite corner A)
- the scale factor
  Scale factor (Universe)
  The scale factor or cosmic scale factor parameter of the Friedmann equations is a function of time which represents the relative expansion of the universe. It is sometimes called the Robertson-Walker scale factor...
  
  of the expanding universe in cosmology
  Cosmology
  Cosmology is the discipline that deals with the nature of the Universe as a whole. Cosmologists seek to understand the origin, evolution, structure, and ultimate fate of the Universe at large, as well as the natural laws that keep it in order...
- the acceleration
  Acceleration
  In physics, acceleration is the rate of change of velocity with time. In one dimension, acceleration is the rate at which something speeds up or slows down. However, since velocity is a vector, acceleration describes the rate of change of both the magnitude and the direction of velocity. ...
  
  in mechanics equations
- the x-intercept of a line using the line equation
  Linear equation
  A linear equation is an algebraic equation in which each term is either a constant or the product of a constant and a single variable....
- the unit are
  ARE
  Are, ARE or Åre may refer to: United Arab Emirates using ISO 3166-1 alpha-3 country code*The second-person singular and plural forms of the verb "to be", copula of the English language...
  
  for area (100 m²)
- the unit prefix atto (10⁻¹⁸)
- the first term in a sequence or series (e.g. S_n = n(a+l)/2)

Bb

B represents:
- the digit "11" in hexadecimal
  Hexadecimal
  In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
  
  and other positional numeral systems with a radix of 12 or greater
- the second corner of a triangle
- a ball
  Ball (mathematics)
  In mathematics, a ball is the space inside a sphere. It may be a closed ball or an open ball ....
  
  (also denoted by or )
- a basis
  Basis (linear algebra)
  In linear algebra, a basis is a set of linearly independent vectors that, in a linear combination, can represent every vector in a given vector space or free module, or, more simply put, which define a "coordinate system"...
  
  of a vector space or of a filter
  Filter (mathematics)
  In mathematics, a filter is a special subset of a partially ordered set. A frequently used special case is the situation that the ordered set under consideration is just the power set of some set, ordered by set inclusion. Filters appear in order and lattice theory, but can also be found in...
  
  (both also denoted by )
- in econometrics and time-series statistics it is often used for the (back)lag operator, the formal parameter of the lag polynomial
B with various subscripts represents several variations of Brun's constant and Betti number
Betti number
In algebraic topology, a mathematical discipline, the Betti numbers can be used to distinguish topological spaces. Intuitively, the first Betti number of a space counts the maximum number of cuts that can be made without dividing the space into two pieces....

s
b represents:
- the second side of a triangle (opposite corner B)
- The Impact parameter
  Impact parameter
  The impact parameter b is defined as the perpendicular distance between the path of a projectile and the center of the field U created by an object that the projectile is approaching...
  
  in Nuclear scattering
  Scattering
  Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of...
- the y-intercept of a line using the line equation
  Linear equation
  A linear equation is an algebraic equation in which each term is either a constant or the product of a constant and a single variable....
- (usually with an index, sometimes with an arrow over it) a basis vector

Cc

C represents:
- the third corner of a triangle
- the digit "12" in hexadecimal
  Hexadecimal
  In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
  
  and other positional numeral systems with a radix of 13 or greater
- the unit coulomb of electrical charge
- capacitance
  Capacitance
  In electromagnetism and electronics, capacitance is the ability of a capacitor to store energy in an electric field. Capacitance is also a measure of the amount of electric potential energy stored for a given electric potential. A common form of energy storage device is a parallel-plate capacitor...
  
  in electrical theory
- with indices denotes the number of combinations, a binomial coefficient
- together with a degree symbol (°) represents the Celsius
  Celsius
  Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...
  
  measurement of temperature = °C
represents the set of complex numbers
A vertically elongated C with an integer subscript n sometimes denotes the n-th coefficient of a formal power series.
c represents:
- the unit prefix centi (10⁻²)
- the Molar concentration in Chemes
c represents:
- the speed of light
  Speed of light
  The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
  
  in vacuum
- the third side of a triangle (opposite corner C)
Small bold C denotes the cardinality of the set of real numbers (the "continuum"), or, equivalently, of the power set of natural numbers

Dd

D represents the digit "13" in hexadecimal
Hexadecimal
In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...

and other positional numeral systems with a radix of 14 or greater
d represents
- the differential operator
  Differential operator
  In mathematics, a differential operator is an operator defined as a function of the differentiation operator. It is helpful, as a matter of notation first, to consider differentiation as an abstract operation, accepting a function and returning another .This article considers only linear operators,...
- the unit day of time (86,400 s)
- the difference in an arithmetic sequence (e.g. S_n = n(2a+(n-1)d)/2)
- a metric operator/function

Ee

E represents:
- the digit "14" in hexadecimal
  Hexadecimal
  In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
  
  and other positional numeral systems with a radix of 15 or greater
- an exponent in decimal numbers 1.2E3 is 1.2×10³ or 1200
- the set of edges in a graph
  Graph (mathematics)
  In mathematics, a graph is an abstract representation of a set of objects where some pairs of the objects are connected by links. The interconnected objects are represented by mathematical abstractions called vertices, and the links that connect some pairs of vertices are called edges...
  
  or matroid
  Matroid
  In combinatorics, a branch of mathematics, a matroid or independence structure is a structure that captures the essence of a notion of "independence" that generalizes linear independence in vector spaces....
- the unit prefix exa
  Exa
  Exa- is a prefix in the metric system denoting 1018 or .Adopted in 1975, it comes from the Greek ἕξ, used as a prefix ἑξά-, meaning six , because it is equal to 10006.Examples:* 1 EeV = 1018 electronvolts = 0.1602 joule...
  
  (10¹⁸)
- Energy
  Energy
  In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
  
  in physics
- an event
  Event (probability theory)
  In probability theory, an event is a set of outcomes to which a probability is assigned. Typically, when the sample space is finite, any subset of the sample space is an event...
  
  (as in P(E), which reads "the probability P of event E happening")
e represents:
- Euler's number
  E (mathematical constant)
  The mathematical constant ' is the unique real number such that the value of the derivative of the function at the point is equal to 1. The function so defined is called the exponential function, and its inverse is the natural logarithm, or logarithm to base...
  
  , a transcendental number equal to 2.71828182845... which is used as the base for natural logarithms
- a vector of unit length, especially in the direction of one of the coordinates axes
- the elementary charge
  Elementary charge
  The elementary charge, usually denoted as e, is the electric charge carried by a single proton, or equivalently, the absolute value of the electric charge carried by a single electron. This elementary charge is a fundamental physical constant. To avoid confusion over its sign, e is sometimes called...
  
  in physics
  Physics
  Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
- an electron
  Electron
  The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
  
  , usually donated e^- to distinguish against a positron
  Positron
  The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
  
  e⁺
- the eccentricity of an ellipse

Ff

F represents
- the digit "15" in hexadecimal
  Hexadecimal
  In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
  
  and other positional numeral systems with a radix of 16 or greater
- the unit farad
  Farad
  The farad is the SI unit of capacitance. The unit is named after the English physicist Michael Faraday.- Definition :A farad is the charge in coulombs which a capacitor will accept for the potential across it to change 1 volt. A coulomb is 1 ampere second...
  
  of electrical capacity
- The Helmholtz free energy
  Helmholtz free energy
  In thermodynamics, the Helmholtz free energy is a thermodynamic potential that measures the “useful” work obtainable from a closed thermodynamic system at a constant temperature and volume...
  
  of a closed thermodynamic system of constant pressure & temperature
- together with a degree symbol (°) represents the Fahrenheit
  Fahrenheit
  Fahrenheit is the temperature scale proposed in 1724 by, and named after, the German physicist Daniel Gabriel Fahrenheit . Within this scale, the freezing of water into ice is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees...
  
  measurement of temperature = °F
F represents
- force in mechanics equations
- _pF_q is a hypergeometric series
  Hypergeometric series
  In mathematics, a generalized hypergeometric series is a series in which the ratio of successive coefficients indexed by n is a rational function of n. The series, if convergent, defines a generalized hypergeometric function, which may then be defined over a wider domain of the argument by...
- the probability distribution
  Probability distribution
  In probability theory, a probability mass, probability density, or probability distribution is a function that describes the probability of a random variable taking certain values....
  
  function
  Function (mathematics)
  In mathematics, a function associates one quantity, the argument of the function, also known as the input, with another quantity, the value of the function, also known as the output. A function assigns exactly one output to each input. The argument and the value may be real numbers, but they can...
  
  in statistics
  Statistics
  Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
f represents:
- the unit prefix femto (10⁻¹⁵)
f represents:
- the generic designation of a function
  Function (mathematics)
  In mathematics, a function associates one quantity, the argument of the function, also known as the input, with another quantity, the value of the function, also known as the output. A function assigns exactly one output to each input. The argument and the value may be real numbers, but they can...

Gg

G represents
- an arbitrary graph
  Graph (mathematics)
  In mathematics, a graph is an abstract representation of a set of objects where some pairs of the objects are connected by links. The interconnected objects are represented by mathematical abstractions called vertices, and the links that connect some pairs of vertices are called edges...
  
  , as in: G(V,E)
- an arbitrary group
  Group (mathematics)
  In mathematics, a group is an algebraic structure consisting of a set together with an operation that combines any two of its elements to form a third element. To qualify as a group, the set and the operation must satisfy a few conditions called group axioms, namely closure, associativity, identity...
- the unit prefix giga
  Giga
  Giga is a unit prefix in the metric system denoting a factor of billion . It has the symbol G.Giga is derived from the Greek γίγας, meaning 'giant'...
  
  (10⁹)
- Newton's gravitational constant
  Gravitational constant
  The gravitational constant, denoted G, is an empirical physical constant involved in the calculation of the gravitational attraction between objects with mass. It appears in Newton's law of universal gravitation and in Einstein's theory of general relativity. It is also known as the universal...
- the Einstein tensor
  Einstein tensor
  In differential geometry, the Einstein tensor , named after Albert Einstein, is used to express the curvature of a Riemannian manifold...
- the Gibbs free energy
  Gibbs free energy
  In thermodynamics, the Gibbs free energy is a thermodynamic potential that measures the "useful" or process-initiating work obtainable from a thermodynamic system at a constant temperature and pressure...
g represents:
- the generic designation of a second function
- the acceleration due to gravity on Earth
  Free fall
  Free fall is any motion of a body where gravity is the only force acting upon it, at least initially. These conditions produce an inertial trajectory so long as gravity remains the only force. Since this definition does not specify velocity, it also applies to objects initially moving upward...

Hh

H represents:
- a Hilbert space
  Hilbert space
  The mathematical concept of a Hilbert space, named after David Hilbert, generalizes the notion of Euclidean space. It extends the methods of vector algebra and calculus from the two-dimensional Euclidean plane and three-dimensional space to spaces with any finite or infinite number of dimensions...
- the unit henry of magnetic inductance
- the homology
  Homology (mathematics)
  In mathematics , homology is a certain general procedure to associate a sequence of abelian groups or modules with a given mathematical object such as a topological space or a group...
  
  and cohomology
  Cohomology
  In mathematics, specifically in algebraic topology, cohomology is a general term for a sequence of abelian groups defined from a co-chain complex. That is, cohomology is defined as the abstract study of cochains, cocycles, and coboundaries...
  
  functor
  Functor
  In category theory, a branch of mathematics, a functor is a special type of mapping between categories. Functors can be thought of as homomorphisms between categories, or morphisms when in the category of small categories....
  
  s
- the (Shannon) entropy of information
H₀ represents Hubble's parameter
Dimensionless Hubble parameter
Instead of working with the Hubble parameter, a common practice is to introduce the dimensionless Hubble parameter, usually noted h, and to write the Hubble's parameter H0 as being...

as measures today (100 h km·s
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....

⁻¹·Mpc⁻¹ with h being the associated error)

represents the quaternion
Quaternion
In mathematics, the quaternions are a number system that extends the complex numbers. They were first described by Irish mathematician Sir William Rowan Hamilton in 1843 and applied to mechanics in three-dimensional space...

s (after William Rowan Hamilton
William Rowan Hamilton
Sir William Rowan Hamilton was an Irish physicist, astronomer, and mathematician, who made important contributions to classical mechanics, optics, and algebra. His studies of mechanical and optical systems led him to discover new mathematical concepts and techniques...

)
represents the Hamiltonian in Hamiltonian mechanics
Hamiltonian mechanics
Hamiltonian mechanics is a reformulation of classical mechanics that was introduced in 1833 by Irish mathematician William Rowan Hamilton.It arose from Lagrangian mechanics, a previous reformulation of classical mechanics introduced by Joseph Louis Lagrange in 1788, but can be formulated without...
h represents:
- the class number in algebraic number theory
  Algebraic number theory
  Algebraic number theory is a major branch of number theory which studies algebraic structures related to algebraic integers. This is generally accomplished by considering a ring of algebraic integers O in an algebraic number field K/Q, and studying their algebraic properties such as factorization,...
- a small increment in the argument of a function
- the unit hour
  Hour
  The hour is a unit of measurement of time. In modern usage, an hour comprises 60 minutes, or 3,600 seconds...
  
  for time
  Time
  Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
  
  (3600 s)
- the Planck constant
  Planck constant
  The Planck constant , also called Planck's constant, is a physical constant reflecting the sizes of energy quanta in quantum mechanics. It is named after Max Planck, one of the founders of quantum theory, who discovered it in 1899...
  
  (6.624 608 96(33) × 10⁻³⁴ J·s)
- the unit prefix hecto
  Hecto
  Hecto or hecta is a prefix in the metric system denoting a factor of one hundred. Adopted in 1795, it comes from the Greek hekaton, meaning hundred.It is rarely used, except for certain specific applications:...
  
  (10²)

Ii

I represents:
- the closed unit interval, which contains all real numbers from 0 to 1, inclusive
- the identity matrix
  Identity matrix
  In linear algebra, the identity matrix or unit matrix of size n is the n×n square matrix with ones on the main diagonal and zeros elsewhere. It is denoted by In, or simply by I if the size is immaterial or can be trivially determined by the context...
- the Irradiance
  Irradiance
  Irradiance is the power of electromagnetic radiation per unit area incident on a surface. Radiant emittance or radiant exitance is the power per unit area radiated by a surface. The SI units for all of these quantities are watts per square meter , while the cgs units are ergs per square centimeter...
- Moment of inertia
  Moment of inertia
  In classical mechanics, moment of inertia, also called mass moment of inertia, rotational inertia, polar moment of inertia of mass, or the angular mass, is a measure of an object's resistance to changes to its rotation. It is the inertia of a rotating body with respect to its rotation...
- Intensity
i represents:
- the imaginary unit
  Imaginary number
  An imaginary number is any number whose square is a real number less than zero. When any real number is squared, the result is never negative, but the square of an imaginary number is always negative...
  
  , a complex number that is the square root of −1
- a subscript to denote the ith term (that is, a general term or index) in a sequence or list
- the index to the elements of a vector, written as a subscript after the vector name
- the index to the rows of a matrix, written as the first subscript after the matrix name
- an index of summation using the sigma notation
- the unit vector in Cartesian coordinates going in the X-direction, usual bold i

Jj

J represents:
- the unit joule
  Joule
  The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
  
  of energy
- the current density
  Current density
  Current density is a measure of the density of flow of a conserved charge. Usually the charge is the electric charge, in which case the associated current density is the electric current per unit area of cross section, but the term current density can also be applied to other conserved...
  
  in electromagnetism
  Electromagnetism
  Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...
- the Radiosity
  Radiosity
  Radiosity is a global illumination algorithm used in 3D computer graphics rendering. Radiosity is an application of the finite element method to solving the rendering equation for scenes with purely diffuse surfaces...
  
  in thermal mechanics
j represents:
- the index to the columns of a matrix, written as the second subscript after the matrix name
- in electrical engineering
  Electrical engineering
  Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
  
  , the square root of −1, instead of i
- in electrical engineering
  Electrical engineering
  Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
  
  , the principal cube root of 1:

Kk

K represents:
- the unit kelvin
  Kelvin
  The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
  
  of temperature
- the functor
  Functor
  In category theory, a branch of mathematics, a functor is a special type of mapping between categories. Functors can be thought of as homomorphisms between categories, or morphisms when in the category of small categories....
  
  s of K-theory
- an unspecified (real) constant
- a field
  Field (mathematics)
  In abstract algebra, a field is a commutative ring whose nonzero elements form a group under multiplication. As such it is an algebraic structure with notions of addition, subtraction, multiplication, and division, satisfying certain axioms...
  
  in algebra
k represents
- the unit prefix kilo- (10³)
- the Boltzmann constant, this is often represented as k_B to avoid confusion with
- the Wavenumber
  Wavenumber
  In the physical sciences, the wavenumber is a property of a wave, its spatial frequency, that is proportional to the reciprocal of the wavelength. It is also the magnitude of the wave vector...
  
  of the wave equation
  Wave equation
  The wave equation is an important second-order linear partial differential equation for the description of waves – as they occur in physics – such as sound waves, light waves and water waves. It arises in fields like acoustics, electromagnetics, and fluid dynamics...
- an integer
  Integer
  The integers are formed by the natural numbers together with the negatives of the non-zero natural numbers .They are known as Positive and Negative Integers respectively...
  
  , e.g. a dummy variable in summation
  Summation
  Summation is the operation of adding a sequence of numbers; the result is their sum or total. If numbers are added sequentially from left to right, any intermediate result is a partial sum, prefix sum, or running total of the summation. The numbers to be summed may be integers, rational numbers,...
  
  s, or an index of a matrix
  Matrix (mathematics)
  In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...
  
  .
- an unspecified (real) constant
- the spring constant of Hooke's law
  Hooke's law
  In mechanics, and physics, Hooke's law of elasticity is an approximation that states that the extension of a spring is in direct proportion with the load applied to it. Many materials obey this law as long as the load does not exceed the material's elastic limit. Materials for which Hooke's law...
- the spacetime Curvature
  Curvature
  In mathematics, curvature refers to any of a number of loosely related concepts in different areas of geometry. Intuitively, curvature is the amount by which a geometric object deviates from being flat, or straight in the case of a line, but this is defined in different ways depending on the context...
  
  from the Friedmann equations
  Friedmann equations
  The Friedmann equations are a set of equations in physical cosmology that govern the expansion of space in homogeneous and isotropic models of the universe within the context of general relativity...
  
  in cosmology

Ll

L represents:
- Length
  Length
  In geometric measurements, length most commonly refers to the longest dimension of an object.In certain contexts, the term "length" is reserved for a certain dimension of an object along which the length is measured. For example it is possible to cut a length of a wire which is shorter than wire...
  
  , used often in quantum mechanics as the size of an infinite square well
- Angular momentum
  Angular momentum
  In physics, angular momentum, moment of momentum, or rotational momentum is a conserved vector quantity that can be used to describe the overall state of a physical system...
- the unit of volume the litre
  Litre
  pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
- the radiance
  Radiance
  Radiance and spectral radiance are radiometric measures that describe the amount of radiation such as light or radiant heat that passes through or is emitted from a particular area, and falls within a given solid angle in a specified direction. They are used to characterize both emission from...
- the space of all integrable real (or complex) functions
- the space of linear maps, as in L(E,F) or L(E) = End
  Endomorphism
  In mathematics, an endomorphism is a morphism from a mathematical object to itself. For example, an endomorphism of a vector space V is a linear map ƒ: V → V, and an endomorphism of a group G is a group homomorphism ƒ: G → G. In general, we can talk about...
  
  (E)
- the Likelihood function
  Likelihood function
  In statistics, a likelihood function is a function of the parameters of a statistical model, defined as follows: the likelihood of a set of parameter values given some observed outcomes is equal to the probability of those observed outcomes given those parameter values...
- a formal language
  Formal language
  A formal language is a set of words—that is, finite strings of letters, symbols, or tokens that are defined in the language. The set from which these letters are taken is the alphabet over which the language is defined. A formal language is often defined by means of a formal grammar...
l represents:
- the length of a side of a rectangle or a rectangular prism (e.g. V = lwh; A = lw)
- the last term of a sequence or series (e.g. S_n = n(a+l)/2)
represents:
- the Lagrangian
  Lagrangian
  The Lagrangian, L, of a dynamical system is a function that summarizes the dynamics of the system. It is named after Joseph Louis Lagrange. The concept of a Lagrangian was originally introduced in a reformulation of classical mechanics by Irish mathematician William Rowan Hamilton known as...
  
  (sometimes just L)
- Exposure
  Exposure
  -Entertainment:* Exposure , the practice of revealing the secrets of magic to non-magicians* Exposure , a short film anthology series on Sci-Fi Channel from 2000–2002* Exposure , a current affairs strand on ITV in 2011...
  
  (in particle physics)

Mm

M represents:
- a manifold
  Manifold
  In mathematics , a manifold is a topological space that on a small enough scale resembles the Euclidean space of a specific dimension, called the dimension of the manifold....
- a metric space
  Metric space
  In mathematics, a metric space is a set where a notion of distance between elements of the set is defined.The metric space which most closely corresponds to our intuitive understanding of space is the 3-dimensional Euclidean space...
- a matroid
  Matroid
  In combinatorics, a branch of mathematics, a matroid or independence structure is a structure that captures the essence of a notion of "independence" that generalizes linear independence in vector spaces....
- the unit prefix mega- (10⁶)
- the Madelung constant
  Madelung constant
  The Madelung constant is used in determining the electrostatic potential of a single ion in a crystal by approximating the ions by point charges. It is named after Erwin Madelung, a German physicist....
  
  for crystal structures held by ionic bonding
m represents:
- the number of rows in a matrix
  Matrix (mathematics)
  In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...
- the slope
  Gradient
  In vector calculus, the gradient of a scalar field is a vector field that points in the direction of the greatest rate of increase of the scalar field, and whose magnitude is the greatest rate of change....
  
  in a linear regression or in any line
  Linear equation
  A linear equation is an algebraic equation in which each term is either a constant or the product of a constant and a single variable....
- the mass
  Mass
  Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
  
  in mechanics equations
- the unit metre
  Metre
  The metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology...
  
  of length
- the unit prefix milli
  Milli
  Milli is a prefix in the metric system denoting a factor of one thousandth . Adopted in 1795, the prefix comes from the Latin mille, meaning one thousand ....
  
  (10⁻³)

Nn

N represents
- the unit newton of force
- the Neutron number
  Neutron number
  The neutron number, symbol N, is the number of neutrons in a nuclide.Atomic number plus neutron number equals mass number: Z+N=A....
- the Particle number
  Particle number
  The particle number of a thermodynamic system, conventionally indicated with the letter N, is the number of constituent particles in that system. The particle number is a fundamental parameter in thermodynamics which is conjugate to the chemical potential. Unlike most physical quantities, particle...
  
  in thermodynamics
- The number of particles
  Particle number
  The particle number of a thermodynamic system, conventionally indicated with the letter N, is the number of constituent particles in that system. The particle number is a fundamental parameter in thermodynamics which is conjugate to the chemical potential. Unlike most physical quantities, particle...
  
  of a thermodynamical system
N_A represents the Avogadro constant which is the number of entities in one mole (used mainly in the counting of molecules and atoms) and is 6.022 141 79(30) × 10,²³ mol ⁻¹
represents the natural number
Natural number
In mathematics, the natural numbers are the ordinary whole numbers used for counting and ordering . These purposes are related to the linguistic notions of cardinal and ordinal numbers, respectively...

s
n represents
- the number of columns in a matrix
  Matrix (mathematics)
  In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...
- the "number of" in algebra
  Algebra
  Algebra is the branch of mathematics concerning the study of the rules of operations and relations, and the constructions and concepts arising from them, including terms, polynomials, equations and algebraic structures...
  
  ic equations.
- A neutron
  Neutron
  The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
  
  , often shown as ¹₀n
- the Number density
  Number density
  In physics, astronomy, and chemistry, number density is an intensive quantity used to describe the degree of concentration of countable objects in the three-dimensional physical space...
  
  of particles in a Volume
- the unit prefix nano
  Nano
  Nano- is a prefix meaning a billionth. Used primarily in the metric system, this prefix denotes a factor of 10−9 or . It is frequently encountered in science and electronics for prefixing units of time and length, such as 30 nanoseconds , 100 nanometres or in the case of electrical capacitance,...
  
  (10⁻⁹)
- the nth term of a sequence or series (e.g. t_n = a+(n-1)d)

Oo

O represents
- the order of asymptotic behavior of a function (upper bound); see Big O notation
  Big O notation
  In mathematics, big O notation is used to describe the limiting behavior of a function when the argument tends towards a particular value or infinity, usually in terms of simpler functions. It is a member of a larger family of notations that is called Landau notation, Bachmann-Landau notation, or...
- — the origin of the coordinate system in Cartesian coordinates
o represents
- the order of asymptotic behavior of a function (strict upper bound); see Big O notation
  Big O notation
  In mathematics, big O notation is used to describe the limiting behavior of a function when the argument tends towards a particular value or infinity, usually in terms of simpler functions. It is a member of a larger family of notations that is called Landau notation, Bachmann-Landau notation, or...
- the order of an element in a group
  Group (mathematics)
  In mathematics, a group is an algebraic structure consisting of a set together with an operation that combines any two of its elements to form a third element. To qualify as a group, the set and the operation must satisfy a few conditions called group axioms, namely closure, associativity, identity...

Pp

P represents:
- the pressure
  Pressure
  Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
  
  in physics equations
- the unit prefix peta
  Peta (prefix)
  Peta- is a prefix in the metric system denoting 1015 or . For example:1 petametre = 1015 metres1 petasecond = 1015 seconds...
  
  (10¹⁵)
- Probability
  Probability
  Probability is ordinarily used to describe an attitude of mind towards some proposition of whose truth we arenot certain. The proposition of interest is usually of the form "Will a specific event occur?" The attitude of mind is of the form "How certain are we that the event will occur?" The...
  
  in Statistics and Statistical Mechanics
represents
- the prime number
  Prime number
  A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example 5 is prime, as only 1 and 5 divide it, whereas 6 is composite, since it has the divisors 2...
  
  s
- projective space
  Projective space
  In mathematics a projective space is a set of elements similar to the set P of lines through the origin of a vector space V. The cases when V=R2 or V=R3 are the projective line and the projective plane, respectively....
- a probability
  Probability
  Probability is ordinarily used to describe an attitude of mind towards some proposition of whose truth we arenot certain. The proposition of interest is usually of the form "Will a specific event occur?" The attitude of mind is of the form "How certain are we that the event will occur?" The...
  
  (as in P(E), which reads "the probability P of event E happening")
p represents
- the unit prefix pico
  Pico
  Pico- is a prefix in the metric system denoting a factor of 10−12 or .Derived from the Italian piccolo, meaning small, this was one of the original 12 prefixes defined in 1960 when the International System of Units was established....
  
  (10⁻¹²)
- a proton
  Proton
  The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number....
  
  , often p⁺ or ¹₁p
- the linear momentum
  Momentum
  In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object...
  
  in physics equations

Qq

Q represents:
- Heat
  Heat
  In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
  
  energy
represents the rational number
Rational number
In mathematics, a rational number is any number that can be expressed as the quotient or fraction a/b of two integers, with the denominator b not equal to zero. Since b may be equal to 1, every integer is a rational number...

s
q represents:
- the Deceleration parameter in Cosmology

Rr

R represents:
- the Ricci tensor
represents the set of real numbers and various algebraic structure
Algebraic structure
In abstract algebra, an algebraic structure consists of one or more sets, called underlying sets or carriers or sorts, closed under one or more operations, satisfying some axioms. Abstract algebra is primarily the study of algebraic structures and their properties...

s built upon the set of real numbers, such as
r represents:
- the radius
  Radius
  In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter. If the object does not have an obvious center, the term may refer to its...
  
  of a circle or sphere
- the ratio of a geometric series (e.g. ar^n-1)
- the separation of two objects, for example in Coulomb's law
  Coulomb's law
  Coulomb's law or Coulomb's inverse-square law, is a law of physics describing the electrostatic interaction between electrically charged particles. It was first published in 1785 by French physicist Charles Augustin de Coulomb and was essential to the development of the theory of electromagnetism...

Ss

S represents
- a sum
  SUM
  SUM can refer to:* The State University of Management* Soccer United Marketing* Society for the Establishment of Useful Manufactures* StartUp-Manager* Software User’s Manual,as from DOD-STD-2 167A, and MIL-STD-498...
- the unit siemens
  Siemens (unit)
  The siemens is the SI derived unit of electric conductance and electric admittance. Conductance and admittance are the reciprocals of resistance and impedance respectively, hence one siemens is equal to the reciprocal of one ohm, and is sometimes referred to as the mho. In English, the term...
  
  of electric conductance
- the unit sphere
  Sphere
  A sphere is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle in two dimensions, a perfect sphere is completely symmetrical around its center, with all points on the surface lying the same distance r from the center point...
  
  (with superscript denoting dimension)
- the scattering matrix
- entropy
  Entropy
  Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...
s represents:
- an arclength
- the displacement
  Displacement (vector)
  A displacement is the shortest distance from the initial to the final position of a point P. Thus, it is the length of an imaginary straight path, typically distinct from the path actually travelled by P...
  
  in mechanics equations
- the unit second
  Second
  The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
  
  of time
- a complex
  Complex number
  A complex number is a number consisting of a real part and an imaginary part. Complex numbers extend the idea of the one-dimensional number line to the two-dimensional complex plane by using the number line for the real part and adding a vertical axis to plot the imaginary part...
  
  variable s = σ + i t in analytic number theory
  Analytic number theory
  In mathematics, analytic number theory is a branch of number theory that uses methods from mathematical analysis to solve problems about the integers. It is often said to have begun with Dirichlet's introduction of Dirichlet L-functions to give the first proof of Dirichlet's theorem on arithmetic...
represents a system's action
Action (physics)
In physics, action is an attribute of the dynamics of a physical system. It is a mathematical functional which takes the trajectory, also called path or history, of the system as its argument and has a real number as its result. Action has the dimension of energy × time, and its unit is...

in physics

Tt

T represents:
- the top element
  Greatest element
  In mathematics, especially in order theory, the greatest element of a subset S of a partially ordered set is an element of S which is greater than or equal to any other element of S. The term least element is defined dually...
  
  of a lattice
  Lattice (order)
  In mathematics, a lattice is a partially ordered set in which any two elements have a unique supremum and an infimum . Lattices can also be characterized as algebraic structures satisfying certain axiomatic identities...
- a tree
  Tree (graph theory)
  In mathematics, more specifically graph theory, a tree is an undirected graph in which any two vertices are connected by exactly one simple path. In other words, any connected graph without cycles is a tree...
  
  (a special kind of graph)
- temperature
  Temperature
  Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
  
  in physics equations
- the unit tesla
  Tesla (unit)
  The tesla is the SI derived unit of magnetic field B . One tesla is equal to one weber per square meter, and it was defined in 1960 in honour of the inventor, physicist, and electrical engineer Nikola Tesla...
  
  of magnetic flux density
- the unit prefix tera (10¹²)
- the stress-energy tensor
  Stress-energy tensor
  The stress–energy tensor is a tensor quantity in physics that describes the density and flux of energy and momentum in spacetime, generalizing the stress tensor of Newtonian physics. It is an attribute of matter, radiation, and non-gravitational force fields...
t represents:
- time
  Time
  Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
  
  in graphs, functions or equations
- a term in a sequence or series (e.g. t_n = t_n-1+5)
- the imaginary part of the complex
  Complex number
  A complex number is a number consisting of a real part and an imaginary part. Complex numbers extend the idea of the one-dimensional number line to the two-dimensional complex plane by using the number line for the real part and adding a vertical axis to plot the imaginary part...
  
  variable s = σ + i t in analytic number theory
  Analytic number theory
  In mathematics, analytic number theory is a branch of number theory that uses methods from mathematical analysis to solve problems about the integers. It is often said to have begun with Dirichlet's introduction of Dirichlet L-functions to give the first proof of Dirichlet's theorem on arithmetic...
- the sample statistic resulting from a Student's t-test

Uu

U represents:
- a U-set which is a set of uniqueness
  Set of uniqueness
  In mathematics, a set of uniqueness is a concept relevant to trigonometric expansions which are not necessarily Fourier series. Their study is a relatively pure branch of harmonic analysis.- Definition :...
- a unitary operator
  Unitary operator
  In functional analysis, a branch of mathematics, a unitary operator is a bounded linear operator U : H → H on a Hilbert space H satisfyingU^*U=UU^*=I...
- In thermodynamics, the internal energy
  Internal energy
  In thermodynamics, the internal energy is the total energy contained by a thermodynamic system. It is the energy needed to create the system, but excludes the energy to displace the system's surroundings, any energy associated with a move as a whole, or due to external force fields. Internal...
  
  of a system
U(n) represents the unitary group
Unitary group
In mathematics, the unitary group of degree n, denoted U, is the group of n×n unitary matrices, with the group operation that of matrix multiplication. The unitary group is a subgroup of the general linear group GL...

of degree n represents the union
Union (set theory)
In set theory, the union of a collection of sets is the set of all distinct elements in the collection. The union of a collection of sets S_1, S_2, S_3, \dots , S_n\,\! gives a set S_1 \cup S_2 \cup S_3 \cup \dots \cup S_n.- Definition :...

operator

Vv

V represents:
- volume
  Volume
  Volume is the quantity of three-dimensional space enclosed by some closed boundary, for example, the space that a substance or shape occupies or contains....
- the unit volt
  Volt
  The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
  
  of voltage
  Voltage
  Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
- the set of vertices in a graph
v represents the velocity
Velocity
In physics, velocity is speed in a given direction. Speed describes only how fast an object is moving, whereas velocity gives both the speed and direction of the object's motion. To have a constant velocity, an object must have a constant speed and motion in a constant direction. Constant ...

in mechanics equations

Ww

- W represents the unit watt
  Watt
  The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
  
  of power
- In physics is also represents the work, both the mechanical & thermodynamical
  Work (thermodynamics)
  In thermodynamics, work performed by a system is the energy transferred to another system that is measured by the external generalized mechanical constraints on the system. As such, thermodynamic work is a generalization of the concept of mechanical work in mechanics. Thermodynamic work encompasses...
- Also in thermodynamics, it can represent the number of possible quantum states in Boltzmann's entropy formula
  Boltzmann's entropy formula
  In statistical thermodynamics, Boltzmann's equation is a probability equation relating the entropy S of an ideal gas to the quantity W, which is the number of microstates corresponding to a given macrostate:...

Xx

x represents
- an unknown variable
  Variable (mathematics)
  In mathematics, a variable is a value that may change within the scope of a given problem or set of operations. In contrast, a constant is a value that remains unchanged, though often unknown or undetermined. The concepts of constants and variables are fundamental to many areas of mathematics and...
  
  , most often (but not always) from the set of real number
  Real number
  In mathematics, a real number is a value that represents a quantity along a continuum, such as -5 , 4/3 , 8.6 , √2 and π...
  
  s, while a complex
  Complex number
  A complex number is a number consisting of a real part and an imaginary part. Complex numbers extend the idea of the one-dimensional number line to the two-dimensional complex plane by using the number line for the real part and adding a vertical axis to plot the imaginary part...
  
  unknown would rather be called z, and an integer
  Integer
  The integers are formed by the natural numbers together with the negatives of the non-zero natural numbers .They are known as Positive and Negative Integers respectively...
  
  by a letter like m from the middle of the alphabet.
- the coordinate on the first or horizontal axis in a cartesian coordinate system
  Cartesian coordinate system
  A Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length...
  
  , the viewport
  Viewport
  A viewport is a rectangular viewing region in computer graphics, or a term used for optical components. It has several definitions in different contexts:- Computing :...
  
  in a graph
  Computer graphics
  Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....
  
  or window in computer graphics

Yy

Y represents:
- the unit prefix yotta
  Yotta
  Yotta is the largest unit prefix in the International System of Units denoting a factor of 1024 or . It has the unit symbol Y.The prefix name is derived from the Greek , meaning eight, because it is equal to 10008...
  
  (10²⁴)
y represents:
- the unit prefix yocto
  Yocto
  Yocto- is a prefix in the metric system denoting a factor of 10−24 or .Adopted in 1991 by the General Conference on Weights and Measures, it comes from the Greek οκτώ, meaning "eight", because it is equal to 1000−8. , yocto is the smallest confirmed SI prefix.It can be used to state a subatomic...
  
  (10⁻²⁴)
y represents:
- a second unknown variable
  Variable (mathematics)
  In mathematics, a variable is a value that may change within the scope of a given problem or set of operations. In contrast, a constant is a value that remains unchanged, though often unknown or undetermined. The concepts of constants and variables are fundamental to many areas of mathematics and...
- the coordinate on the second or vertical axis (backward axis
  Cartesian coordinate system
  A Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length...
  
  in three dimensions) in a linear coordinate system, or in the viewport
  Viewport
  A viewport is a rectangular viewing region in computer graphics, or a term used for optical components. It has several definitions in different contexts:- Computing :...
  
  of a graph
  Computer graphics
  Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....
  
  or window
  Window (computing)
  In computing, a window is a visual area containing some kind of user interface. It usually has a rectangular shape that can overlap with the area of other windows...
  
  in computer graphics

Zz

Z represents:
- the unit prefix zetta
  Zetta
  Zetta- is a prefix in the metric system denoting a factor of 1021 or .Added to the SI in 1991, it is evocative of the French numeral sept, meaning seven, because it is equal to 10007....
  
  (10²¹)
- the atomic number
  Atomic number
  In chemistry and physics, the atomic number is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z. The atomic number uniquely identifies a chemical element...
  
  in Chemistry and Physics
- a standarized normal random variable
  Random variable
  In probability and statistics, a random variable or stochastic variable is, roughly speaking, a variable whose value results from a measurement on some type of random process. Formally, it is a function from a probability space, typically to the real numbers, which is measurable functionmeasurable...
  
  in Probability Theory
  Probability theory
  Probability theory is the branch of mathematics concerned with analysis of random phenomena. The central objects of probability theory are random variables, stochastic processes, and events: mathematical abstractions of non-deterministic events or measured quantities that may either be single...
  
  and Statistics
  Statistics
  Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
- The Partition function
  Partition function (statistical mechanics)
  Partition functions describe the statistical properties of a system in thermodynamic equilibrium. It is a function of temperature and other parameters, such as the volume enclosing a gas...
  
  in statistical mechanics
represents the integer
Integer
The integers are formed by the natural numbers together with the negatives of the non-zero natural numbers .They are known as Positive and Negative Integers respectively...

s
z represents:
- the unit prefix zepto
  Zepto
  Zepto- is a prefix in the metric system denoting a factor of 10−21 or .Adopted in 1991, it comes from the French sept or Latin septem, meaning "seven", since it is equal to 1000−7.Examples of its use:...
  
  (10⁻²¹)
- the coordinate on the third or vertical axis in three dimension
  Dimension
  In physics and mathematics, the dimension of a space or object is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one because only one coordinate is needed to specify a point on it...
  
  al space
- the view depth in computer graphics
  Computer graphics
  Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....
  
  , see also "z-buffering
  Z-buffering
  In computer graphics, z-buffering is the management of image depth coordinates in three-dimensional graphics, usually done in hardware, sometimes in software. It is one solution to the visibility problem, which is the problem of deciding which elements of a rendered scene are visible, and which...
  
  "
- the argument of a complex function
  Complex analysis
  Complex analysis, traditionally known as the theory of functions of a complex variable, is the branch of mathematical analysis that investigates functions of complex numbers. It is useful in many branches of mathematics, including number theory and applied mathematics; as well as in physics,...
  
  , or any other variable used to represent a complex value
- in astronomy, it can donate wavelength redshift
  Redshift
  In physics , redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum...

Aa

Bb

Cc

Dd

Ee

Ff

Gg

Hh

Ii

Jj

Kk

Ll

Mm

Nn

Oo

Pp

Qq

Rr

Ss

Tt

Uu

Vv

Ww

Xx

Yy

Zz

See also