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Greek letters used in mathematics, science, and engineering

{{Short description|Symbols for constants, special functions}}

{{Greek Alphabet}}

Greek letters are used in mathematics, science, engineering, and other areas where mathematical notation is used as symbols for constants, special functions, and also conventionally for variables representing certain quantities. In these contexts, the capital letters and the small letters represent distinct and unrelated entities. Those Greek letters which have the same form as Latin letters are rarely used: capital Α, Β, Ε, Ζ, Η, Ι, Κ, Μ, Ν, Ο, Ρ, Τ, Υ, and Χ. Small ι, ο and υ are also rarely used, since they closely resemble the Latin letters i, o and u. Sometimes, font variants of Greek letters are used as distinct symbols in mathematics, in particular for ε/ϵ and π/ϖ. The archaic letter digamma (Ϝ/ϝ/ϛ) is sometimes used.

The Bayer designation naming scheme for stars typically uses the first Greek letter, α, for the brightest star in each constellation, and runs through the alphabet before switching to Latin letters.

In mathematical finance, the Greeks are the variables denoted by Greek letters used to describe the risk of certain investments.

Typography

Some common conventions:

The Greek letter forms used in mathematics are often different from those used in Greek-language text: they are designed to be used in isolation, not connected to other letters, and some use variant forms which are not normally used in current Greek typography.

The OpenType font format has the feature tag "mgrk" ("Mathematical Greek") to identify a glyph as representing a Greek letter to be used in mathematical (as opposed to Greek language) contexts.

The table below shows a comparison of Greek letters rendered in TeX and HTML.

The font used in the TeX rendering is an italic style. This is in line with the convention that variables should be italicized. As Greek letters are more often than not used as variables in mathematical formulas, a Greek letter appearing similar to the TeX rendering is more likely to be encountered in works involving mathematics.

class="wikitable plainrowheaders"

|+ Greek letters in HTML and TeX (α–μ)

scope="col" | Name

! scope="col" | TeX

! scope="col" | HTML

scope="row" | Alpha

| \Alpha \, \alpha || Α α

scope="row" | Beta

| \Beta \, \beta || Β β

scope="row" | Gamma

| \Gamma \, \gamma || Γ γ

scope="row" | Delta

| \Delta \, \delta || Δ δ

scope="row" | Epsilon

| \Epsilon \, \epsilon \, \varepsilon || Ε ϵ ε

scope="row" | Digamma

| \Digamma \, \digamma || Ϝ ϝ

scope="row" | Zeta

| \Zeta \, \zeta || Ζ ζ

scope="row" | Eta

| \Eta \, \eta || Η η

scope="row" | Theta

| \Theta \, \theta \, \vartheta || {{not a typo|Θ θ ϑ}}

scope="row" | Iota

| \Iota \, \iota || Ι ι

scope="row" | Kappa

| \Kappa \, \kappa \, \varkappa || {{not a typo|Κ κ ϰ}}

scope="row" | Lambda

| \Lambda \, \lambda || Λ λ

scope="row" | Mu

| \Mu \, \mu || Μ μ

class="wikitable plainrowheaders"

|+ Greek letters in HTML and TeX (ν–ω)

! scope="col" | Name

! scope="col" | TeX

! scope="col" | HTML

scope="row" | Nu

| \Nu \, \nu || Ν ν

scope="row" | Xi

| \Xi \, \xi || Ξ ξ

scope="row" | Omicron

| \mathrm{\Omicron} \, o || Ο ο

scope="row" | Pi

| \Pi \, \pi \, \varpi || Π π ϖ

scope="row" | Rho

| \Rho \, \rho \, \varrho || Ρ ρ {{not a typo|ϱ}}

scope="row" | Sigma

| \Sigma \, \sigma \, \varsigma || Σ σ ς

scope="row" | Tau

| \Tau \, \tau || Τ τ

scope="row" | Upsilon

| \Upsilon \, \upsilon || Υ υ

scope="row" | Phi

| \Phi \, \phi \, \varphi || {{not a typo|Φ ϕ φ}}

scope="row" | Chi

| \Chi \, \chi || Χ χ

scope="row" | Psi

| \Psi \, \psi || Ψ ψ

scope="row" | Omega

| \Omega \, \omega || Ω ω

class="wikitable plainrowheaders"

|+ Greek letters with typographical variations

scope="col" | Name

! scope="col" | Greek Letter

! scope="col" | Bold

! scope="col" | Italic

! scope="col" | Bold Italic

! scope="col" | Sans-Serif Bold

! scope="col" | Sans-Serif Bold Italic

! scope="col" | APL

! scope="col" | Double struck bold

! scope="col" | Unicode variants or similar

scope="row" | Alpha

| Α α || 𝚨 𝛂 || 𝛢 𝛼 || 𝜜 𝜶 || 𝝖 𝝰 || 𝞐 𝞪 || ⍺ ⍶ ||

|

scope="row" | Beta

| Β β {{not a typo|ϐ ᵝ ᵦ}} || 𝚩 𝛃 || 𝛣 𝛽 || 𝜝 𝜷 || 𝝗 𝝱 || 𝞑 𝞫 || ||

|

scope="row" | Gamma

| {{not a typo|Γ γ ᴦ ᵞ ᵧ}} || 𝚪 𝛄 || 𝛤 𝛾 || 𝜞 𝜸 || 𝝘 𝝲 || 𝞒 𝞬 || || {{not a typo|ℾ ℽ}}

|

scope="row" | Delta

| Δ δ {{not a typo|ᵟ}} || 𝚫 𝛅 || 𝛥 𝛿 || 𝜟 𝜹 || 𝝙 𝝳 || 𝞓 𝞭 || ||

| {{unichar|2206|Increment}}, {{unichar|2207|Nabla}}

scope="row" | Epsilon

| Ε ε ϵ ϶ || 𝚬 𝛆 𝛜 || 𝛦 𝜀 𝜖 || 𝜠 𝜺 𝝐 || 𝝚 𝝴 𝞊 || 𝞔 𝞮 𝟄 || ⍷ ||

| {{unichar|2208|Element Of}}–{{unichar|220D|Small Contains As Member}}

scope="row" | Zeta

| Ζ ζ || 𝚭 𝛇 || 𝛧 𝜁 || 𝜡 𝜻 || 𝝛 𝝵 || 𝞕 𝞯 || ||

|

scope="row" | Eta

| Η η Ͱ ͱ || 𝚮 𝛈 || 𝛨 𝜂 || 𝜢 𝜼 || 𝝜 𝝶 || 𝞖 𝞰 || ||

|

scope="row" | Theta

| {{not a typo|Θ θ ϑ ϴ ᶿ}} || {{not a typo|𝚯 𝛉 𝚹 𝛝}} || {{not a typo|𝛩 𝜃 𝛳 𝜗}} || {{not a typo|𝜣 𝜽 𝜭 𝝑}} || {{not a typo|𝝝 𝝷 𝚹 𝞋}} || {{not a typo|𝞗 𝞱 𝜭 𝟅}} || ||

|

scope="row" | Iota

| {{not a typo|Ι ι ᶥ ℩}} || 𝚰 𝛊 || 𝛪 𝜄 || 𝜤 𝜾 || 𝝞 𝝸 || 𝞘 𝞲 || ⍳ ⍸ ||

|

scope="row" | Kappa

| {{not a typo|Κ κ ϰ}} || {{not a typo|𝚱 𝛋 𝛞}} || {{not a typo|𝛫 𝜅 𝜘}} || {{not a typo|𝜥 𝜿 𝝒}} || {{not a typo|𝝟 𝝹 𝞌}} || {{not a typo|𝞙 𝞳 𝟆}} || ||

|

scope="row" | Lambda

| Λ λ ᴧ || 𝚲 𝛌 || 𝛬 𝜆 || 𝜦 𝝀 || 𝝠 𝝺 || 𝞚 𝞴 || ||

|

scope="row" | Mu

| Μ μ || 𝚳 𝛍 || 𝛭 𝜇 || 𝜧 𝝁 || 𝝡 𝝻 || 𝞛 𝞵 || ||

|

scope="row" | Nu

| Ν ν || 𝚴 𝛎 || 𝛮 𝜈 || 𝜨 𝝂 || 𝝢 𝝼 || 𝞜 𝞶 || ||

|

scope="row" | Xi

| Ξ ξ || 𝚵 𝛏 || 𝛯 𝜉 || 𝜩 𝝃 || 𝝣 𝝽 || 𝞝 𝞷 || ||

|

scope="row" | Omicron

| Ο ο || 𝚶 𝛐 || 𝛰 𝜊 || 𝜪 𝝄 || 𝝤 𝝾 || 𝞞 𝞸 || ||

|

scope="row" | Pi

| Π π ϖ ᴨ || 𝚷 𝛑 𝛡 || 𝛱 𝜋 𝜛 || 𝜫 𝝅 𝝕 || 𝝥 𝝿 𝞏 || 𝞟 𝞹 𝟉 || || {{not a typo|ℿ ℼ}}

| {{unichar|220F|N-Ary Product}}, {{unichar|2210|N-Ary Coproduct}}

scope="row" | Rho

| {{not a typo|Ρ ρ Ῥ ῥ ῤ ϱ ϼ ᴩ ᵨ ☧}} || 𝚸 𝛒 𝛠 || 𝛲 𝜌 𝜚 || 𝜬 𝝆 𝝔 || 𝝦 𝞀 𝞎 || 𝞠 𝞺 𝟈 || ⍴ ||

|

scope="row" | Sigma

| Σ σ ς Ϲ ϲ Ͻ ͻ Ͼ ͼ Ͽ ͽ || 𝚺 𝛔 𝛓 || 𝛴 𝜎 𝜍 || 𝜮 𝝈 𝝇 || 𝝨 𝞂 𝞁 || 𝞢 𝞼 𝞻 || || {{not a typo|⅀}}

| {{unichar|2211|N-Ary Summation}}

scope="row" | Tau

| Τ τ || 𝚻 𝛕 || 𝛵 𝜏 || 𝜯 𝝉 || 𝝩 𝞃 || 𝞣 𝞽 || ||

|

scope="row" | Upsilon

| Υ υ ϒ || 𝚼 𝛖 || 𝛶 𝜐 || 𝜰 𝝊 || 𝝪 𝞄 || 𝞤 𝞾 || ||

|

scope="row" | Phi

| {{not a typo|Φ φ ϕ}} || 𝚽 𝛗 𝛟 || 𝛷 𝜑 𝜙 || 𝜱 𝝋 𝝓 || 𝝫 𝞅 𝞍 || 𝞥 𝞿 𝟇 || ||

|

scope="row" | Chi

| {{not a typo|Χ χᵡᵪ☧}} || 𝚾 𝛘 || 𝛸 𝜒 || 𝜲 𝝌 || 𝝬 𝞆 || 𝞦 𝟀 || ||

|

scope="row" | Psi

| Ψ ψ ᴪ || 𝚿 𝛙 || 𝛹 𝜓 || 𝜳 𝝍 || 𝝭 𝞇 || 𝞧 𝟁 || ||

|

scope="row" | Omega

| Ω ω ꭥ || 𝛀 𝛚 || 𝛺 𝜔 || 𝜴 𝝎 || 𝝮 𝞈 || 𝞨 𝟂 || ⍵ ⍹ ||

| {{unichar|2126|Ohm Sign}}, {{unichar|2127|Inverted Ohm Sign}}

Concepts represented by a Greek letter

= Αα (alpha) =

{{see also|Alpha (disambiguation)}}

  • \alpha represents:
  • the first angle in a triangle, opposite the side a
  • the statistical significance of a result
  • the false positive rate in statistics ("Type I" error){{Cite book |last=Lindenmayer, David. |title=Practical conservation biology |date=2005 |publisher=CSIRO Pub |others=Burgman, Mark A. |isbn=0-643-09310-9 |location=Collingwood, Vic. |pages=404 |oclc=65216357 |quote=These parameters are related by the expression:… where E is effect size, n is sample size, α is the type I error rate and σ is the standard deviation of the variability of the data}}
  • the fine-structure constant in physics{{Cite web |title=fine-structure constant |url=https://physics.nist.gov/cgi-bin/cuu/Value?eqalph%7Csearch_for=fine |access-date=2025-02-10 |website=physics.nist.gov}}{{Cite book |last1=Rabinowitz |first1=Harold |title=The manual of scientific style: a guide for authors, editors, and researchers |last2=Vogel |first2=Suzanne |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |edition=1st |location=Amsterdam Burlington, MA |pages=348}}
  • the angle of attack of an aircraft
  • an alpha particle (He2+)
  • angular acceleration in physics{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=793 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • the linear thermal expansion coefficient
  • the thermal diffusivity{{Cite book |url=https://www.worldcat.org/title/ocm69865403 |title=Significance of tests and properties of concrete and concrete-making materials |date=2006 |publisher=ASTM |isbn=978-0-8031-3367-9 |editor-last=Lamond |editor-first=Joseph F. |edition=Rev. |series=STP |location=Philadelphia, PA |pages=229 |oclc=ocm69865403 |quote=Thermal diffusivity is defined numerically as thermal conductivity divided by the product of specific heat and density, or α= k/ (CxP) |editor-last2=Pielert |editor-first2=J. H.}}
  • In organic chemistry the α-carbon is the backbone carbon next to the carbonyl carbon, most often for amino acids
  • right ascension in astronomy{{Cite book |last=Burns |first=M. Shane |title=A practical guide to observational astronomy |date=2022 |publisher=CRC Press |isbn=978-0-367-76863-8 |edition=First |location=Boca Raton |pages=5 |quote=The two angles that specify the location of a point on the celestial sphere are called the right ascension α and the declination δ}}
  • the brightest star in a constellation{{Cite book |last1=Rabinowitz |first1=Harold |title=The manual of scientific style: a guide for authors, editors, and researchers |last2=Vogel |first2=Suzanne |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |edition=1st |location=Amsterdam Burlington, MA |pages=363 |quote=The primary designation system for bright stars, called Bayer designations… The Greek letters are assigned in order (α,β, γ,δ etc.) according to brightness.}}
  • Iron ferrite and numerous phases within materials science
  • the return in excess of the compensation for the risk borne in investment
  • the α-conversion in lambda calculus
  • the independence number of a graph
  • a placeholder for ordinal numbers in mathematical logic
  •  a type of receptor for the neurotransmitter noradrenaline in neuroscience

= Ββ (beta) =

{{see also|Beta (disambiguation)}}

  • \Beta represents the beta function
  • \beta 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 for predictor or independent variables in linear regression (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){{Cite web |last=Bhandari |first=Pritha |date=2021-01-18 |title=Type I & Type II Errors {{!}} Differences, Examples, Visualizations |url=https://www.scribbr.com/statistics/type-i-and-type-ii-errors/ |access-date=2025-01-22 |website=Scribbr |language=en-US |quote=The probability of making a Type I error is the significance level, or alpha (α), while the probability of making a Type II error is beta (β).}}
  • the beta coefficient, the non-diversifiable risk, of an asset in mathematical finance
  • the sideslip angle of an airplane
  • a beta particle (e− or e+)
  • the beta brain wave in brain or cognitive sciences{{Cite book |last1=Languis |first1=M. L. |title=Cognitive Science (RLE Edu E): Contributions to Educational Practice |last2=Buffer |first2=James J. |last3=Martin |first3=Daniel |last4=Naour |first4=Paul J. |date=2011 |publisher=Taylor and Francis |isbn=978-0-415-68351-7 |series=Routledge Library Editions: Education |location=Hoboken |pages=183 |quote=Vieth (1982) established that cognition could be quantified by summing the value of alpha plus beta brain waves.}}
  • ecliptic latitude in astronomy{{Cite book |title=Hellenistic astronomy: the science in its contexts |date=2020 |publisher=Brill |isbn=978-90-04-24336-1 |editor-last=Bowen |editor-first=Alan C. |series=Brill's companions in classical studies |location=Leiden ; Boston |pages=16–17 |quote=Celestial longitude (λ) is measured eastward from the vernal equinox along the zodiacal circle, and celestial latitude (β) is the angular distance of the arc dropped perpendicularly from the body to the zodiacal circle. |editor-last2=Rochberg |editor-first2=Francesca}}
  • the ratio of plasma pressure to magnetic pressure in plasma physics{{Cite book |last=Freidberg |first=Jeffrey P. |title=Ideal MHD |date=2014 |publisher=Cambridge University Press |isbn=978-1-107-00625-6 |edition=1st |location=West Nyack |pages=68 |quote=The quantity β is a global plasma parameter whose value is critical for a fusion reactor... Qualitatively, β measures the ratio plasma pressure to magnetic pressure:}}
  • β-reduction in lambda calculus
  • the ratio of the velocity of an object to the speed of light as used in the Lorentz factor{{Cite book |last=Volchenkov |first=Dimitri |title=Mathematical Methods in Modern Complexity Science |date=2022 |publisher=Springer International Publishing AG |others=José António Tenreiro Machado |isbn=978-3-030-79411-8 |series=Nonlinear Systems and Complexity Series |location=Cham |pages=36 |quote=We defined β as the ratio v/c, where v the is the modulus of the vector velocity v.}}
  • a type of receptor for the noradrenaline neurotransmitter in neuroscience

= Γγ (gamma) =

{{see also|Gamma (disambiguation)}}

  • \Gamma represents:
  • the circulation in fluid dynamics
  • the reflection coefficient of a transmission or telecommunication line.{{Cite book |title=Electromagnetic Theory for Microwaves and Optoelectronics |date=2008 |publisher=Springer-Verlag Berlin Heidelberg |isbn=978-3-540-74295-1 |editor-last=Zhang |editor-first=Keqian |edition=2nd |series=SpringerLink Bücher |location=Berlin, Heidelberg |pages=82 |quote=The reflection coefficient Γis real when medium 1 and medium 2 are both lossless media,… |editor-last2=Li |editor-first2=Dejie}}
  • the confinement factor of an optical mode in a waveguide
  • the gamma function, a generalization of the factorial{{Cite web |last=Weisstein |first=Eric W. |title=Gamma Function |url=https://mathworld.wolfram.com/GammaFunction.html |access-date=2025-01-22 |website=mathworld.wolfram.com |language=en}}
  • the upper incomplete gamma function
  • the modular group, the group of fractional linear transformations
  • the gamma distribution, a continuous probability distribution defined using the gamma function{{Cite book |last1=Hogg |first1=Robert V. |title=Loss Distributions |last2=Klugman |first2=Stuart A. |date=2009 |publisher=John Wiley & Sons, Inc |isbn=978-0-471-87929-9 |series=Wiley Series in Probability and Statistics |location=Hoboken |pages=225}}
  • second-order sensitivity to price in mathematical finance
  • the Christoffel symbols that describe components of a metric connection{{Cite book |last=Baumann |first=Gerd |title=Mathematica for theoretical physics |date=2005 |publisher=Springer |isbn=978-0-387-01674-0 |edition=2nd |location=New York |pages=731}}
  • the stack alphabet in the formal definition of a pushdown automaton, or the tape-alphabet in the formal definition of a Turing machine
  • the Feferman–Schütte ordinal Γ0{{Cite book |last1=Kahle |first1=Reinhard |title=The legacy of Kurt Schütte |last2=Rathjen |first2=Michael |date=2020 |publisher=Springer |isbn=978-3-030-49423-0 |location=Cham |pages=41 |quote=The Veblen approach was quite sufficient even for the ordinal, now known as the Feferman–Schütte ordinal, Γ{{sub|0}} for predictive analysis}}
  • atmospheric lapse rates in meteorology
  • \gamma represents:
  • the specific weight of substances
  • the lower incomplete gamma function
  • the third angle in a triangle, opposite the side c
  • the Euler–Mascheroni constant in mathematics{{Cite web |title=DLMF: §5.2 Definitions ‣ Properties ‣ Chapter 5 Gamma Function |url=https://dlmf.nist.gov/5.2#E3 |access-date=2025-01-31 |website=dlmf.nist.gov}}
  • gamma rays and the photon
  • the heat capacity ratio in thermodynamics
  • the Lorentz factor in special relativity{{Cite book |last=Fayngold |first=Moses |title=Special relativity and how it works |date=2008 |publisher=Wiley-VCH |isbn=978-3-527-40607-4 |series=Physics textbook |location=Weinheim |pages=32 |quote=Because we will come across this coefficient quite often, we will give it a special name, the Lorentz factor, and stick to our symbol γ(V),...}}
  • the flight path angle of an airplane

= Δδ (delta) =

{{see also|Delta (disambiguation)}}

|first1=Michael H. |last1=Kutner |first2=Christopher J. |last2=Nachtsheim |first3=John |last3=Neter |first4=William |last4=Li |publisher=New York: McGraw-Hill |year=2005 |isbn=0-07-310874-X |pages=xxviii, 1396 }}

= Εε (epsilon) =

{{see also|Epsilon (disambiguation)}}

  • \epsilon represents:
  • a small positive quantity; see limit
  • a random error in regression analysis
  • the absolute value of an error{{cite book|last=Golub|first=Gene|author-link=Gene H. Golub|author2=Charles F. Van Loan|title=Matrix Computations – Third Edition|publisher=The Johns Hopkins University Press|year=1996|location=Baltimore|pages=53|isbn=0-8018-5413-X}}
  • in set theory, the limit ordinal of the sequence \omega,\omega^{\omega},\omega^{\omega^{\omega}},\dots
  • in computer science, the empty string
  • the Levi-Civita symbol
  • in electromagnetics, dielectric permittivity{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=346 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • emissivity
  • strain in continuum mechanics
  • permittivity{{Cite web |title=Vacuum electric permittivity |url=https://physics.nist.gov/cgi-bin/cuu/Value?ep0%7Csearch_for=universal_in! |access-date=2025-02-10 |website=physics.nist.gov}}
  • the Earth's axial tilt in astronomy{{Cite book |title=Cyclostratigraphy and astrochronology |date=2018 |publisher=Academic Press, an imprint of Elsevier |isbn=978-0-12-815098-6 |editor-last=Montenari |editor-first=Michael |edition=1st |series=Stratigraphy and Timescales |location=London San Diego, Calif. Cambridge, Mass. Oxford |pages=84 |quote=The Earth's orbital obliquity or axial tilt (ε) is the angle between the Earth's equatorial plane and its orbital plane,}}
  • elasticity in economics{{Cite book |last=Free |first=Rhona C. |title=21st century economics: a reference handbook |date=2010 |publisher=Sage |isbn=978-1-4129-6142-4 |location=Thousand Oaks (Calif.) |pages=93–94}}
  • electromotive force
  • in chemistry, the molar extinction coefficient of a chromophore
  • in mathematics, a surreal number that is bigger than zero, but smaller than all positive real numbers.
  • set membership symbol ∈ is based on ε

= {{lang|grc|Ϝϝ}} (digamma) =

{{see also|Digamma}}

  • {{lang|grc|Ϝ}} is sometimes used to represent the digamma function, 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, now known to be simply a statistical anomaly

= Ζζ (zeta) =

{{see also|Zeta (disambiguation)}}

  • \zeta represents:
  • the Riemann zeta function and other zeta functions in mathematics
  • the damping ratio{{Cite book |last1=Wilkie |first1=Jacqueline |title=Control engineering: an introductory course |last2=Johnson |first2=Michael |last3=Katebi |first3=Reza |date=2002 |publisher=Palgrave |isbn=978-0-333-77129-7 |location=Basingstoke |pages=179 |quote=We shall refer to ζ as the damping ratio throughout this text.}}
  • the value for the Zeta potential, i.e., the electrical potential at the slipping plane, used often in colloidal chemistry{{Cite book |last=Hunter |first=Robert J. |title=Zeta potential in colloid science: principles and applications |date=1988 |publisher=Academic Press |isbn=978-0-12-361961-7 |edition=New paperback |location=London San Diego |pages=6 |quote=It is also possible to correlate the ζ-potential with the sedimentation behaviour of colloidal systems and with the flotation behaviour of mineral ores.}}

= Ηη (eta) =

{{see also|Eta (disambiguation)}}

  • \Eta represents:
  • the Eta function of Ludwig Boltzmann's H-theorem ("Eta" theorem), in statistical mechanics
  • Information theoretic (Shannon) entropy
  • \eta represents:
  • the intrinsic wave impedance of a medium (e.g. the impedance of free space)
  • the partial regression coefficient in statistics, also interpreted as an effect size measure for analyses of variance
  • the eta meson
  • viscosity{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=346 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • the Dedekind eta function{{Cite book |last=Harada |first=Kōichirō |title="Moonshine" of finite groups |date=2010 |publisher=European Mathematical Society |isbn=978-3-03719-090-6 |series=EMS series of lectures in mathematics |location=Zürich |pages=17}}
  • energy conversion efficiency{{Cite book |last=Struchtrup |first=Henning |title=Thermodynamics and energy conversion |date=2024 |publisher=Springer |isbn=978-3-031-60555-0 |edition=Second |location=Cham |pages=164–165}}
  • efficiency (physics)
  • the Minkowski metric tensor in relativity{{Cite book |last1=Rybicki |first1=George B. |title=Radiative processes in astrophysics |last2=Lightman |first2=Alan P. |date=1979 |publisher=Wiley |isbn=978-0-471-04815-2 |series=A Wiley-Interscience publication |location=New York |pages=123}}
  • η-conversion in lambda calculus{{Cite web |last=Weisstein |first=Eric W. |title=Lambda Calculus |url=https://mathworld.wolfram.com/LambdaCalculus.html |access-date=2025-01-22 |website=mathworld.wolfram.com |language=en}}
  • the learning rate in machine learning and statistics{{Cite book |last=Kubat |first=Miroslav |title=An introduction to machine learning |date=2021 |publisher=Springer Nature |isbn=978-3-030-81934-7 |edition=Third |location=Cham, Switzerland |pages=129 |quote=When describing backpropagation of error, we assumed a constant learning rate, η .}}

= Θθ (theta) =

{{see also|Theta (disambiguation)}}

= Ιι (iota) =

{{see also|Iota (disambiguation)}}

= Κκ (kappa) =

{{see also|Kappa (disambiguation)}}

  • \Kappa represents:
  • the Kappa number, indicating lignin content in pulp
  • \kappa represents:
  • the Von Kármán constant, describing the velocity profile of turbulent flow
  • the kappa curve, a two-dimensional algebraic curve{{Cite web |last=Weisstein |first=Eric W. |title=Kappa Curve |url=https://mathworld.wolfram.com/KappaCurve.html |access-date=2025-02-06 |website=mathworld.wolfram.com |language=en}}
  • the condition number of a matrix in numerical analysis
  • the connectivity of a graph in graph theory{{Cite web |last=Weisstein |first=Eric W. |title=Vertex Connectivity |url=https://mathworld.wolfram.com/VertexConnectivity.html |access-date=2025-02-06 |website=mathworld.wolfram.com |language=en}}
  • curvature{{Cite web |last=Weisstein |first=Eric W. |title=Curvature |url=https://mathworld.wolfram.com/Curvature.html |access-date=2025-02-06 |website=mathworld.wolfram.com |language=en}}
  • dielectric constant (\varepsilon / \varepsilon_0)
  • thermal conductivity (usually a lowercase Latin k){{Cite web |title=Thermal Conductivity - Definition and Detailed Explanation |url=https://byjus.com/chemistry/thermal-conductivity/ |access-date=2025-02-06 |website=BYJUS |language=en |quote=It is generally denoted by the symbol ‘k’ but can also be denoted by ‘λ’ and ‘κ’.}}
  • electrical conductivity of a solution{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=347 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • thermal diffusivity
  • a spring constant (usually a lowercase Latin k)
  • the heat capacity ratio in thermodynamics (usually \gamma)
  • the receptor which dynorphins have the highest affinity for in pharmacology
  • Einstein gravitational constant{{Cite web |title=Einstein gravitational constant |url=https://illuminating.science/historical-constants/einstein-gravitational-constant/ |access-date=2025-02-06 |website=Illuminating Science |language=en-US}}

= Λλ (lambda) =

{{see also|Lambda (disambiguation)}}

= Μμ (mu) =

{{see also|Mu (disambiguation)}}

= Νν (nu) =

{{see also|Nu (disambiguation)}}

  • \nu represents:
  • frequency in physics in hertz (Hz)
  • Poisson's ratio in materials science
  • a neutrino{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=333 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • kinematic viscosity of liquids{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=346 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • stoichiometric coefficient in chemistry
  • true anomaly in celestial mechanics{{Cite book |last=Grossman |first=Nathaniel |title=The Sheer Joy of Celestial Mechanics |date=1996 |publisher=Birkhäuser Boston |isbn=978-0-8176-3832-0 |location=Boston, MA |pages=75 |quote=Introduce variables ζ and η related to the true anomaly f and the eccentric anomaly E by…}}
  • degrees of freedom in statistics
  • the matching number of a graph
  • the p-adic valuation of a number

= Ξξ (xi) =

{{see also|Xi (disambiguation)}}

= Οο (omicron) =

{{see also|Omicron (disambiguation)}}

= Ππ (pi) =

{{see also|Pi (disambiguation)}}

= Ρρ (rho) =

{{see also|Rho (disambiguation)}}

= Σσς (sigma) =

{{see also|Sigma (disambiguation)}}

= Ττ (tau) =

{{see also|Tau (disambiguation)}}

= ϒυ (upsilon) =

{{see also|Upsilon (disambiguation)}}

= Φφ (phi) =

{{see also|Phi (disambiguation)}}

Note: The empty set symbol ∅ looks similar, but is unrelated to the Greek letter.

= Χχ (chi) =

{{see also|Chi (disambiguation)}}

  • \chi represents:
  • the chi distribution in statistics (\chi^2 is the more frequently encountered chi-squared distribution)
  • the chromatic number of a graph in graph theory{{Cite web |last=Weisstein |first=Eric W. |title=Chromatic Number |url=https://mathworld.wolfram.com/ChromaticNumber.html |access-date=2025-02-09 |website=mathworld.wolfram.com |language=en |quote=The chromatic number of a graph G is most commonly denoted χ (G) (e.g., Skiena 1990, West 2000, Godsil and Royle 2001, Pemmaraju and Skiena 2003),...}}
  • the Euler characteristic in algebraic topology{{Cite web |last=Weisstein |first=Eric W. |title=Euler Characteristic |url=https://mathworld.wolfram.com/EulerCharacteristic.html |access-date=2025-02-09 |website=mathworld.wolfram.com |language=en}}
  • electronegativity in the periodic table
  • the Fourier transform of a linear response function
  • a character in mathematics; especially a Dirichlet character in number theory
  • sometimes the mole fraction
  • a characteristic or indicator function in mathematics
  • the magnetic susceptibility of a material in physics{{Cite journal |last1=Mugiraneza |first1=Sam |last2=Hallas |first2=Alannah M. |date=2022-04-19 |title=Tutorial: a beginner's guide to interpreting magnetic susceptibility data with the Curie-Weiss law |url=https://www.nature.com/articles/s42005-022-00853-y |journal=Communications Physics |language=en |volume=5 |issue=1 |page=95 |doi=10.1038/s42005-022-00853-y |issn=2399-3650 |quote=However, for newly synthesized materials, there is one indispensable characterization technique that is as old as the field of magnetism itself: magnetic susceptibility, χ,...|arxiv=2205.07107 |bibcode=2022CmPhy...5...95M }}
  • the fission neutron energy spectrum in neutron transport

= Ψψ (psi) =

{{see also|Psi (disambiguation)}}

  • \Psi represents:
  • a quaternary combinator in combinatory logic
  • a symbol for psychology
  • the wave function in the Schrödinger equation of quantum mechanics{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=347 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • \psi represents:
  • the J/psi mesons in particle physics
  • the stream function in fluid dynamics
  • the reciprocal Fibonacci constant{{Cite web |last=Weisstein |first=Eric W. |title=Reciprocal Fibonacci Constant |url=https://mathworld.wolfram.com/ReciprocalFibonacciConstant.html |access-date=2025-02-08 |website=mathworld.wolfram.com |language=en}}
  • the second Chebyshev function in number theory{{Cite web |last=Weisstein |first=Eric W. |title=Chebyshev Functions |url=https://mathworld.wolfram.com/ChebyshevFunctions.html |access-date=2025-02-08 |website=mathworld.wolfram.com |language=en}}
  • the polygamma function in mathematics{{Cite web |last=Weisstein |first=Eric W. |title=Polygamma Function |url=https://mathworld.wolfram.com/PolygammaFunction.html |access-date=2025-02-08 |website=mathworld.wolfram.com |language=en |quote=A special function mostly commonly denoted ψ_n(z), ψ^((n))(z), or F_n(z-1)...}}
  • the supergolden ratio{{cite journal | url=https://www.jstor.org/stable/3620208 | jstor=3620208 | title=A Supergolden Rectangle | last1=Crilly | first1=Tony | journal=The Mathematical Gazette | date=1994 | volume=78 | issue=483 | pages=320–325 | doi=10.2307/3620208 | url-access=subscription }}
  • In circadian physiology, ψ represents the phase relationship between a zeitgeber and a biological rhythm.{{Cite journal |last1=Srivastava |first1=Manishi |last2=Varma |first2=Vishwanath |last3=Abhilash |first3=Lakshman |last4=Sharma |first4=Vijay Kumar |last5=Sheeba |first5=Vasu |date=June 2019 |title=Circadian Clock Properties and Their Relationships as a Function of Free-Running Period in Drosophila melanogaster |url=https://pubmed.ncbi.nlm.nih.gov/30939971/ |journal=Journal of Biological Rhythms |volume=34 |issue=3 |pages=231–248 |doi=10.1177/0748730419837767 |issn=1552-4531 |pmid=30939971 |quote=... 2) accuracy (i.e., day-to-day stability of the phase relationship (ψ), where ψ is the duration between a phase of the rhythm and a phase of the external cycle) is greater for clocks with τ close to 24 h; ...}}
  • In virology the ψ site is a viral packaging signal.{{Cite journal |last=Rein |first=Alan |date=2020-07-28 |title=The heart of the HIV RNA packaging signal? |journal=Proceedings of the National Academy of Sciences of the United States of America |language=en |volume=117 |issue=33 |pages=19621–19623 |doi=10.1073/pnas.2013378117 |doi-access=free |pmid=32723818 |pmc=7443930 |bibcode=2020PNAS..11719621R |quote=vRNA is selectively packaged because it contains a “packaging signal” or “ψ” [also designated the “core encapsidation signal” (2)].}}
  • Water potential in movement of water between plant cells.{{Cite journal |last1=WELBAUM |first1=GREGORY E. |last2=BRADFORD |first2=KENT J. |date=1991-03-01 |title=Water Relations of Seed Development and Germination in Muskmelon (Cucumis melo L.): VI. INFLUENCE OF PRIMING ON GERMINATION RESPONSES TO TEMPERATURE AND WATER POTENTIAL DURING SEED DEVELOPMENT |url=https://academic.oup.com/jxb/article-abstract/42/3/393/495356?redirectedFrom=fulltext |journal=Journal of Experimental Botany |volume=42 |issue=3 |pages=393–399 |doi=10.1093/jxb/42.3.393 |issn=0022-0957 |quote=Germination sensitivities to temperature and water potential (ψ) were quantified as indicators of the influence of seed maturity and priming on seed vigour.|url-access=subscription }}

= Ωω (omega) =

{{see also|Omega (disambiguation)}}

  • \Omega represents:
  • Absolute infinite
  • the SI unit measure of electrical resistance, the ohm{{Cite web |date=2025-01-03 |title=Ohm {{!}} Electricity, Resistance & Voltage {{!}} Britannica |url=https://www.britannica.com/science/ohm |access-date=2025-02-08 |website=www.britannica.com |language=en |quote=ohm, abbreviation Ω, unit of electrical resistance in the metre-kilogram-second system,}}{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=347 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • the right ascension of the ascending node (RAAN) or Longitude of the ascending node in astronomy and orbital mechanics
  • the omega constant 0.5671432904097838729999686622...{{Cite web |last=Weisstein |first=Eric W. |title=Omega Constant |url=https://mathworld.wolfram.com/OmegaConstant.html |access-date=2025-02-06 |website=mathworld.wolfram.com |language=en}}
  • an asymptotic lower bound notation related to big O notation
  • in probability theory and statistical mechanics, the support
  • a solid angle{{Cite web |last=Weisstein |first=Eric W. |title=Solid Angle |url=https://mathworld.wolfram.com/SolidAngle.html |access-date=2025-02-07 |website=mathworld.wolfram.com |language=en |quote=The solid angle Ω subtended by a surface S is defined as the surface area Ω of a unit sphere covered by the surface's projection onto the sphere.}}{{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=346 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • the omega baryon
  • the arithmetic function counting a number's prime factors counted with multiplicity
  • the density parameter in cosmology{{Cite web |title=Density Parameter {{!}} COSMOS |url=https://astronomy.swin.edu.au/cosmos/D/Density+Parameter |access-date=2025-02-07 |website=astronomy.swin.edu.au}}
  • the first uncountable ordinal (also written as ω1){{Cite web |last=Weisstein |first=Eric W. |title=Ordinal Number |url=https://mathworld.wolfram.com/OrdinalNumber.html |access-date=2025-02-06 |website=mathworld.wolfram.com |language=en |quote=The first transfinite ordinal, denoted ω ...}}
  • Chaitin's constant for a given computer program
  • the vacuum state in quantum field theory
  • \omega represents:
  • angular velocity / radian frequency (rad/sec){{Cite book |url=https://www.worldcat.org/title/156811865 |title=The manual of scientific style: a guide for authors, editors, and researchers |date=2009 |publisher=Elsevier/Academic Press |isbn=978-0-12-373980-3 |editor-last=Rabinowitz |editor-first=Harold |edition=1st |location=Amsterdam ; Burlington, MA |pages=346 |oclc=156811865 |editor-last2=Vogel |editor-first2=Suzanne}}
  • the argument of periapsis in astronomy and orbital mechanics
  • a complex cube root of unity — the other is \omega^2 — (used to describe various ways of calculating the discrete Fourier transform)
  • the differentiability class (i.e. C^\omega) 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 (although \mathbb{N} or N is more common in other areas of mathematics)
  • an asymptotic dominant notation related to big O notation
  • in probability theory, a possible outcome of an experiment
  • the arithmetic function counting a number's distinct prime factors{{Cite web |last=Weisstein |first=Eric W. |title=Distinct Prime Factors |url=https://mathworld.wolfram.com/DistinctPrimeFactors.html |access-date=2025-02-06 |website=mathworld.wolfram.com |language=en}}
  • 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)
  • the first uncountable ordinal \omega_1 (also written as Ω)
  • the clique number (number of vertices in a maximum clique) of a graph in graph theory{{Cite web |last=Weisstein |first=Eric W. |title=Clique |url=https://mathworld.wolfram.com/Clique.html |access-date=2025-02-07 |website=mathworld.wolfram.com |language=en |quote=A clique of a graph G is a complete subgraph of G, and the clique of largest possible size is referred to as a maximum clique (which has size known as the (upper) clique number ω(G)).}}

See also

References

{{reflist}}

External links

  • [http://www.skyandtelescope.com/astronomy-resources/the-greek-alphabet/ A pronunciation guide with audio]
  • [https://www.greekalphabetletters.com/ Greek alphabet letters onclick copy paste ]

{{Mathematical symbols notation language}}

{{DEFAULTSORT:Greek Letters Used In Mathematics, Science, And Engineering}}

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