Noun
English Wikipedia has an article on:Dirac deltaWikipedia
Dirac delta (plural Dirac deltas)
(mathematics) A function-like symbol denoted as δ, with the property
∫
f
(
t
)
δ
(
x
−
t
)
d
t
=
f
(
x
)
{\displaystyle \int f(t)\delta (x-t)\mathrm {d} t=f(x)}
, informally understood as a function with an infinite value at 0 and zero elsewhere, and formally as a distribution or a measure.