# List of mathematical uses of Latin letters

Many letters of the Latin alphabet, both capital and small, are used in mathematics, science, and engineering to denote by convention specific or abstracted constants, variables of a certain type, units, multipliers, or 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.

## Bb

• B represents:
• the digit "11" in hexadecimal and other positional numeral systems with a radix of 12 or greater
• the second point of a triangle
• a ball (also denoted by ℬ (${\mathcal {B}}$ ) or $\mathbb {B}$ )
• a basis of a vector space or of a filter (both also denoted by ℬ (${\mathcal {B}}$ ))
• in econometrics and time-series statistics it is often used for the backshift or lag operator, the formal parameter of the lag polynomial
• the magnetic field, denoted ${\textbf {B}}$ or ${\vec {B}}$ • B with various subscripts represents several variations of Brun's constant and Betti numbers; it can also be used to mean the Bernoulli numbers.
• b represents:

## Cc

• C represents:
• the third point of a triangle
• the digit "12" in hexadecimal and other positional numeral systems with a radix of 13 or greater
• the unit coulomb of electrical charge
• capacitance in electrical theory
• with indices denoting the number of combinations, a binomial coefficient
• together with a degree symbol (°), the Celsius measurement of temperature = °C
• the circumference of a circle or other closed curve
• the complement of a set (lowercase c and the symbol ∁ are also used)
• an arbitrary category
• the number concentration
• $\mathbb {C}$ 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:
• Lowercase Fraktur ${\mathfrak {c}}$ denotes the cardinality of the set of real numbers (the "continuum"), or, equivalently, of the power set of natural numbers.

## Ee

• E represents:
• the digit "14" in hexadecimal and other positional numeral systems with a radix of 15 or greater
• an exponent in decimal numbers. For example, 1.2E3 is 1.2×103 or 1200
• the set of edges in a graph or matroid
• the unit prefix exa (1018)
• energy in physics
• electric field denoted ${\textbf {E}}$ or ${\vec {E}}$ • electromotive force (denoted ${\mathcal {E}}$ and measured in volts), refers to voltage
• an event (as in P(E), which reads "the probability P of event E occurring")
• in statistics, the expected value of a random variable, sometimes as $\mathbb {E}$ • Ek represents kinetic energy
• (Arrhenius) activation energy, denoted Ea or EA
• ionization energy, denoted Ei
• electron affinity, denoted Eea
• dissociation energy, denoted Ed
• e represents:
• Euler's number, 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 in physics
• an electron, usually denoted e to distinguish against a positron e+
• the eccentricity of a conic section
• the identity element in a group

## Jj

• J represents:
• J represents:
• the scheme of a diagram in category theory
• j represents:
• the index to the columns of a matrix, written as the second subscript after the matrix name
• in electrical engineering, the square root of −1, instead of i
• in electrical engineering, the principal cube root of 1: $-{\frac {1}{2}}+{\frac {1}{2}}i{\sqrt {3}}$ ## Oo

• O represents
• the order of asymptotic behavior of a function (upper bound); see Big O notation
• $(0,0,\ldots ,0)$ — the origin of the coordinate system in Cartesian coordinates
• the circumcenter of a triangle or other cyclic polygon, or more generally the center of a circle
• o represents

## Rr

• R represents:
• $\mathbb {R}$ represents the set of real numbers and various algebraic structures built upon the set of real numbers, such as $\mathbb {R} ^{n}$ .
• r represents: