Rho
Rho 


pronunciation  
antique  [ r, rʰ ]  
modern  [ r ]  
Equivalents  
Latin  R.  
Cyrillic  Р  
Hebrew  ר  
Arabic  ر  
Phoenician  ?  
transcription  
From the ancient world  r (rh)  
From the modern  r  

The Rho ( modern Greek neuter Ρω , uppercase Ρ, minuscule ρ or ϱ) is the 17th letter of the Greek alphabet and, according to the Milesian principle, has a numerical value of 100.
At the beginning of an ancient Greek word it is always aspirated / breathed e.g. B. ῥέω (rhéō) I flow .
use
 In physics , that's little Rho
 the symbol for the density , for example the mass density of water (~) 1 kilogram per liter,
 and that for the specific electrical resistance , a temperaturedependent material constant,
 the identifier of a meson ,
 the symbol for the charge density ,
 the density matrix , a representation of the density operator (for systems in quantum mechanically defined states).
 In chemistry , the small rho is a (nonstandard) symbol for the mass concentration .
 In statistics, the small rho is a frequently used symbol for the correlation coefficient.
 In linear algebra and functional analysis , the spectral radius is denoted by a small rho.
 In surveying, the conversion factor between radians and other angular dimensions is denoted with a small rho: ρ = 180 / π for degrees, ρ = 200 / π for gons, ... It is used, for example, in formulas such as α / ρ = b / r, which outside of surveying, the ratio of central angle and arc is usually written as α = b / r.
 In linguistics, the sound change to r is called Rhotazism .
 In queuing theory , it is the degree of utilization .
 In economics , ρ is
 one of the key figures for evaluating an option and
 in growth models usually a parameter that reflects the time preference of household consumption.
Character encoding
Uppercase Ρ  Minuscule ρ  Minuscule ϱ (variant)  

LaTeX code  \Rho 
\rho 
\varrho

Web links
Commons : Rho  collection of images, videos and audio files
Wiktionary: Rho  explanations of meanings, word origins, synonyms, translations