Luca's Notes

Greek Character

15 min read

Αα (alpha)

Ββ (beta)

  • Β represents the beta function

  • β represents:

    • the thermodynamic beta, equal

      to (kBT)−1, where kB is

      the Boltzmann constant and T is the absolute temperature.

    • the second angle in a triangle, opposite

      the side b

    • the [standardized regression

      coefficient](standardized_coefficient “wikilink”) for predictor

      or independent variables in [linear

      regression](linear_regression “wikilink”) (unstandardized

      regression coefficients are represented with the lower-case

      Latin b, but are often called “betas” as well)

    • the ratio of collector current to base current in a bipolar

      junction transistor (BJT) in

      electronics (current gain)

    • the false negative rate

      in statistics (“Type II” error)

    • the beta coefficient, the

      non-diversifiable risk, of an asset in [mathematical

      finance](mathematical_finance “wikilink”)

    • the sideslip angle of an airplane

    • a beta particle (e− or

      e+)

    • the beta brain wave in brain or [cognitive

      sciences](cognitive_sciences “wikilink”)

    • ecliptic latitude in

      astronomy

    • the ratio of [plasma pressure to magnetic

      pressure](Beta_(plasma_physics) “wikilink”) in [plasma

      physics](plasma_physics “wikilink”)

    • β-reduction in [lambda

      calculus](lambda_calculus “wikilink”)

    • the ratio of the velocity of an object to the [speed of

      light](speed_of_light “wikilink”) as used in the [Lorentz

      factor](Lorentz_factor “wikilink”)

    • a type of receptor for the

      noradrenaline neurotransmitter in

      neuroscience

Γγ (gamma)

  • Γ represents:

    • the circulation in

      fluid dynamics

    • the reflection coefficient

      of a transmission or telecommunication line.

    • the confinement factor of an optical mode in a

      waveguide

    • the gamma function, a

      generalization of the factorial

    • the [upper incomplete gamma

      function](incomplete_gamma_function “wikilink”)

    • the modular group, the group of

      fractional linear transformations

    • the gamma distribution, a

      continuous probability distribution defined using the [gamma

      function](gamma_function “wikilink”)

    • [second-order sensitivity to

      price](Greeks_(finance)#Gamma “wikilink”) in [mathematical

      finance](mathematical_finance “wikilink”)

    • the Christoffel symbols that

      describe components of a metric connection

    • the stack alphabet in the formal definition of a [pushdown

      automaton](pushdown_automaton “wikilink”), or the tape-alphabet

      in the formal definition of a [Turing

      machine](Turing_machine “wikilink”)

    • the [Feferman–Schütte

      ordinal](Feferman–Schütte_ordinal “wikilink”) Γ0

  • γ represents:

Δδ (delta)

Εε (epsilon)

(digamma)

  • is sometimes used to represent the [digamma

    function](digamma_function “wikilink”), though the Latin letter F

    (which is nearly identical) is usually substituted.

  • A hypothetical particle Ϝ speculated to be implicated in the

    [750 GeV diphoton

    excess](750 GeV_diphoton_excess “wikilink”), now known to be

    simply a statistical anomaly

Ζζ (zeta)

Ηη (eta)

Θθ (theta)

  • Θ (uppercase) represents:

    • an asymptotically tight bound related to [big O

      notation](big_O_notation “wikilink”).

    • [sensitivity to the passage of

      time](Greeks_(finance)#Theta “wikilink”) in [mathematical

      finance](mathematical_finance “wikilink”)

    • in set theory, a certain [ordinal

      number](ordinal_number “wikilink”)

    • Heaviside step function

  • θ (lowercase) represents:

  • (“script theta”), the cursive form of theta, often used in

    handwriting, represents

Ιι (iota)

Κκ (kappa)

Λλ (lambda)

Μμ (mu)

Νν (nu)

Ξξ (xi)

  • Ξ represents:

    • the original [Riemann Xi

      function](Riemann_Xi_function “wikilink”), i.e. Riemann’s lower

      case ξ, as denoted by Edmund Landau

      and currently

    • the xi baryon

  • ξ represents:

    • the original [Riemann Xi

      function](Riemann_Xi_function “wikilink”)

    • the modified definition of Riemann xi function, as denoted by

      Edmund Landau

    • the extent of reaction

Οο (omicron)

Ππ (pi)

  • Π represents:

    • the product

      operator in mathematics

    • a plane

    • the unary projection operation in [relational

      algebra](relational_algebra “wikilink”)

    • the Pi function, i.e. the [Gamma

      function](Gamma_function “wikilink”) when offset to coincide

      with the factorial

    • the [complete elliptic integral of the third

      kind](Elliptic_integral#Complete_elliptic_integral_of_the_third_kind “wikilink”)

    • the fundamental groupoid

    • osmotic pressure

  • π represents:

  • ϖ (a graphic variant, see pomega) represents:

Ρρ (rho)

Σσς (sigma)

Ττ (tau)

ϒυ (upsilon)

Φφ (phi)

  • Φ represents:

    • the work function in physics; the

      energy required by a photon to remove an electron from the

      surface of a metal

    • magnetic flux or [electric

      flux](electric_flux “wikilink”)

    • the [cumulative distribution

      function](cumulative_distribution_function “wikilink”) of the

      normal distribution in

      statistics

    • phenyl functional group in organic

      chemistry ([pseudoelement

      symbol](pseudoelement_symbol “wikilink”))

    • the reciprocal of the

      golden ratio (represented by ϕ,

      below), also represented as 1/ϕ

    • the value of the integration of information in a system (based

      on [integrated information

      theory](integrated_information_theory “wikilink”))

    • Geopotential

    • Alternative symbol for a [wave

      function](wave_function “wikilink”) in [quantum

      mechanics](quantum_mechanics “wikilink”)

Note: The empty set symbol ∅ looks similar, but

is unrelated to the Greek letter.

Χχ (chi)

  • χ represents:

    • the chi distribution in

      statistics (χ2 is the more

      frequently encountered [chi-squared

      distribution](chi-squared_distribution “wikilink”))

    • the chromatic number of a graph

      in graph theory

    • the Euler characteristic in

      algebraic topology

    • electronegativity in the

      periodic table

    • the Fourier transform of a [linear response

      function](linear_response_function “wikilink”)

    • a character in

      mathematics; especially a [Dirichlet

      character](Dirichlet_character “wikilink”) in [number

      theory](number_theory “wikilink”)

    • sometimes the mole fraction

    • a characteristic or [indicator

      function](indicator_function “wikilink”) in mathematics

    • the [magnetic

      susceptibility](magnetic_susceptibility “wikilink”) of a

      material in physics

    • the fission neutron energy spectrum in [neutron

      transport](neutron_transport “wikilink”)

Ψψ (psi)

Ωω (omega)

  • Ω represents:

    • Absolute infinite

    • the SI unit measure of [electrical

      resistance](electrical_resistance “wikilink”), the

      ohm

    • the [right ascension of the ascending

      node](right_ascension_of_the_ascending_node “wikilink”) (RAAN)

      or [Longitude of the ascending

      node](Longitude_of_the_ascending_node “wikilink”) in

      astronomy and [orbital

      mechanics](orbital_mechanics “wikilink”)

    • the omega constant

      0.5671432904097838729999686622…

    • an asymptotic lower bound notation related to [big O

      notation](big_O_notation “wikilink”)

    • in probability theory and

      statistical mechanics, the

      support

    • a solid angle

    • the omega baryon

    • the [arithmetic

      function](arithmetic_function#Ω(n),_ω(n),νp(n)–_prime_power_decomposition “wikilink”)

      counting a number’s prime factors counted with multiplicity

    • the density parameter in

      cosmology

    • the [first uncountable

      ordinal](first_uncountable_ordinal “wikilink”) (also written as

      ω1)

    • Chaitin’s constant for a given

      computer program

    • the vacuum state in [quantum

      field theory](quantum_field_theory “wikilink”)

  • ω represents:

    • angular velocity / [radian

      frequency](angular_velocity “wikilink”) (rad/sec)

    • the argument of periapsis in

      astronomy and [orbital

      mechanics](orbital_mechanics “wikilink”)

    • a complex

      cube [root of

      unity](root_of_unity “wikilink”) — the other is ω2

      — (used to describe various ways of calculating the [discrete

      Fourier transform](discrete_Fourier_transform “wikilink”))

    • the differentiability class (i.e. Cω) for

      functions that are infinitely differentiable because they are

      complex analytic

    • the first infinite

      ordinal

    • the omega meson

    • the set of natural numbers in [set

      theory](set_theory “wikilink”) (although ℕ or N is more

      common in other areas of mathematics)

    • an asymptotic dominant notation related to [big O

      notation](big_O_notation “wikilink”)

    • in probability theory, a

      possible outcome of an experiment

    • the [arithmetic

      function](arithmetic_function#Ω(n),_ω(n),νp(n)–_prime_power_decomposition “wikilink”)

      counting a number’s distinct prime factors

    • the symbol ϖ, a graphic variant of π, is sometimes construed as

      omega with a bar over it; see π

    • the unsaturated fats nomenclature

      in biochemistry (e.g. [ω−3 fatty

      acids](Omega-3_fatty_acid “wikilink”))

    • the first uncountable ordinal ω1 (also written as

      Ω)

    • the clique number (number of

      vertices in a maximum clique) of a graph in [graph

      theory](graph_theory “wikilink”)

Graph View