delta
delta 


pronunciation  
antique  [ d ]  
modern  [ ð ]  
Equivalents  
Latin  D.  
Cyrillic  Д  
Hebrew  ד  
Arabic  د  
Phoenician  ?  
transcription  
From the ancient world  d  
From the modern  d  

The delta ( Greek Δέλτα , capital letter : Δ, lower case letter : δ) is the fourth letter in the Greek alphabet and has the numerical value 4 according to the Milesian system .
origin
The sign comes from the Phoenician letter Daleth .
example
 Diogenes ( Διογένης )
use
In Greek
In the Greek number font lowercase letter represents δ the number 4 and together with subscript number sign as ͵δ the number 4000. Because of the shape of the capital letter Δ is (since Herodotus histories 2.13 and more often) the lying between the Nilarmen part Lower Egypt as Delta designated , as in the German river delta in general. In addition, the comedy writer Aristophanes uses Delta in Lysistrata verse 151 to denote female shame .
The Greek letter delta as such  and derived as a symbol for calculation quantities, parameters and the like  is also used in many different contexts and areas of knowledge .
mathematics
 The large delta (Δ) serves as the difference sign for
 the difference, see subtraction
 the difference operator  further parameters are derived from this
 the symmetrical difference of set theory
 the Laplace operator (the sum of the second partial derivatives in each spatial direction)
 The small delta (δ) denotes
 the derivative of variation or virtual displacement
 Dirac's δ 'function', see delta distribution
 the Kronecker Delta
 an infinitesimal (hence a small delta), pathdependent change (not a complete differential) of process variables that only occur when the state changes.
An inverted large delta ∇ is called a nabla . The symbol ( TeX ) that denotes a triangle is not a delta .
triangle
Science and Technology
 The large delta (Δ) is used
 in physics as an identifier for four baryons (Δ ^{++} , Δ ^{+} , Δ ^{0} and Δ ^{} ).
 in molecular biology as a marking of deletions .
 as a term symbol for the characterization of energy states, for example in the singlet oxygen ^{1} Δ _{g}
 The small delta (δ) denotes
 generally a small difference in arithmetic or measured variables , e.g. B. of times (mostly δt ) or distances ( δs ), in geodesy of small angle and vector differences , or in geometry and adjustment calculations of coordinate allowances (e.g. δx , δy )
 in NMR spectroscopy the chemical shift
 in electrical engineering the socalled loss angle , as well as the equivalent thickness of the conductive layer in the skin effect
 in chassis or vehicle technology, etc. a. the steering angle
 in anatomy, in Aδ fiber , a nerve fiber
 in electroplating the layer thickness
 a clast type in structural geology (see delta clast )
chemistry
 A large delta (Δ) indicates
 on a reaction arrow the supply of heat
 with one or more subsequent superscript locants the position of double bonds in
 partly hydrogenated cyclic compounds (e.g., Δ ^{3} carene , Δ ^{9} tetrahydrocannabinol , often in the literature for steroids and Indigo used derivatives)
 unsaturated fatty acids (such as Δ ^{9,12,15} octadecatrienoic acid )
 A small delta (δ) denotes
 an atomic or molecular partial charge
 the δ bond , a metaltometal quadruple bond that occurs when two parallel d orbitals of two metals overlap
 as locant the distance of an atom from a reference atom or a linkage point ( e.g. δvalerolactone )
 with a preceding locant and the following superscript number the position and number of cumulative double bonds based on an atom, see δconvention
astronomy
 The small delta (δ) denotes the declination (astronomy) , one of the two equatorial coordinates of stars,
 as well as the third to fifth brightest star of each of the 88 constellations ,
 and the more detailed designation of some meteor streams in order to describe the position of the radiant more precisely in large constellations.
Named sizes and procedures
 Data processing:
 Delta coding , differential storage, a possibility of data compression
 Economics:
 in option theory, the first partial derivation of the option price model based on the price of the underlying asset or underlying.
 an indicator from the valuation of options; see option (economy) #Delta
 as a small delta (δ) the depreciation rate of a capital stock (compare Solow model ).
Others
In the Canadian syllabary there is one letter that looks like the great delta.