Home / All Definitions / Numbers & Symbols / Xi (Ξ, ξ) Definition

Xi (Ξ, ξ) Definition

Xi (Ξ, ξ) is the 14th letter of the Greek Alphabet. In the system of Greek Numerals, it has a value of 60. Xi was derived from the Phoenician letter samekh. Xi is distinct from the letter chi, which gave its form to the Latin letter X.

Usage in Mathematics & Science

The uppercase Xi (Ξ) is used for:

  • The cascade particles in particle physics

  • Indicating no change of state in Z notation

  • The partition function under the grand canonical ensemble in statistical mechanics

  • Harish-Chandra's Ξ function

  • The Riemann Xi function

  • Monetary units of the cryptocurrency Ether, equal to 1018 Wei

The lowercase Xi (ξ) is used for:

  • Random variables

  • Propositional variables in some philosophical works, first found in Wittgenstein's Tractatus

  • Dimensionless distance variable used in the Lane–Emden equation

  • Extent of reaction, a concept in physical chemistry used often in chemical engineering kinetics and thermochemistry

  • Unknown stereochemistry or stereocentre configuration in a planar ring system in organic chemistry, as well as uppercase Xi for unknown R/S/E/Z configuration in general

  • Eigenvectors

  • Damping Ratio C/Ccr(vibrational analysis)

  • A parameter in a generalized Pareto distribution

  • The symmetric function equation of the Riemann zeta function in mathematics, also known as the Riemann Xi function

  • A universal set in set theory

  • A number used in the remainder term of Taylor's theorem that falls between the limits a and b

  • A number used in error approximations for formulas that are applications of Taylor's theorem, such as Newton–Cotes formulas

  • One of the two different polypeptide chains of the human embryonic hemoglobin types Hb-Portland (ξ2γ2) and Hb-Gower I (ξ2ε2)

  • The initial mass function in astronomy.

  • The correlation function in astronomy.

  • Spatial frequency, also sometimes temporal frequency.

  • A small displacement in MHD plasma stability theory

  • A parameter denoted as warped time used to derive the equations for homogeneous azeotropic distillation

  • The x-coordinate of computational space as used in computational fluid dynamics

  • Potential difference in physics (in volts)

  • The radial integral in the spin-orbit matrix operator in atomic physics.

  • The Killing vector in general relativity.

  • Average logarithmic energy decrement per collision (neutron calculations in nuclear physics)

  • Pippard's cohesion length in superconductors

  • State Price Density in mathematical finance

  • The diameter of a crystal nucleus in nucleation theory

  • Microturbulence velocity in a stellar atmosphere

  • The information vector in the Information Filter, GraphSLAM, and a number of other algorithms used for robot localization and robotic mapping.

  • The dimensionless longitudinal momentum loss of a beam particle after a two-body interaction in accelerator physics.

Greek Alphabet

The letters of the Ancient Greek Alphabet, which are frequently utilized in math and science:

Greek Alphabet

Symbol

Letter

Symbol

Letter

Uppercase

Lowercase

Uppercase

Lowercase

Α

α

Alpha

Ν

ν

Nu

Β

β

Beta

Ξ

ξ

Xi

Γ

γ

Gamma

Ο

ο

Omicron

Δ

δ

Delta

Π

π

Pi

Ε

ε

Epsilon

Ρ

ρ

Rho

Ζ

ζ

Zeta

Σ

σ

Sigma

Η

η

Eta

Τ

τ

Tau

Θ

θ

Theta

Υ

υ

Upsilon

Ι

ι

Iota

Φ

φ

Phi

Κ

κ

Kappa

Χ

χ

Chi

Λ

λ

Lambda

Ψ

ψ

Psi

Μ

μ

Mu

Ω

ω

Omega

Sources

“Xi (Letter).” Wikipedia, Wikimedia Foundation, 6 Apr. 2020, en.wikipedia.org/wiki/Xi_(letter).

×

Welcome to Math Converse

Maintenance Icon

Our site is presently undergoing maintenance in order to upgrade the site.

Please be patient and understand that it will take some time to complete this work and random things may not work as intended.

App

App Icon

Check out our free app for iOS & Android.

For more information about our app visit here!

Browser Extension

Browser Extension Icon

Check out our free browser extension for Chrome, Firefox, Edge, Safari, & Opera.

For more information about our browser extension visit here!

Add to Home Screen

Add to Home Screen Icon

Add Math Converse as app to your home screen.

QR Code

Take a photo of the qr code to share this page or to open it quickly on your phone:

Cite This Page

Popular

Data Storage Showcase
Acceleration Showcase
Angle Showcase

Share

Print
Copy Link
Cite Page
Email
Facebook
Twitter
WhatsApp
Reddit
SMS
Skype
Line
Google Classroom
Google Bookmarks
Facebook Messenger
Evernote
Telegram
Linkedin
Pocket
Douban
WeChat
MySpace
Trello
QR Code