Dirac delta function
E199880
The Dirac delta function is a mathematical construct used in physics and engineering to model an idealized point mass or point charge, being zero everywhere except at a single point where it is infinitely large yet integrates to one.
All labels observed (6)
| Label | Occurrences |
|---|---|
| Dirac delta function canonical | 4 |
| Dirac delta distribution | 2 |
| Dirac comb | 1 |
| Dirac delta | 1 |
| Dirac measure | 1 |
| delta function | 1 |
Statements (60)
| Predicate | Object |
|---|---|
| instanceOf |
distribution
ⓘ
generalized function ⓘ idealized function ⓘ mathematical concept ⓘ tempered distribution ⓘ |
| actsOn | test functions ⓘ |
| alsoKnownAs |
Dirac delta function
ⓘ
surface form:
Dirac delta
Dirac delta function ⓘ
surface form:
delta function
impulse function ⓘ |
| appearsIn |
Green's function methods
ⓘ
Maxwell's equations with point charges ⓘ Poisson equation ⓘ
surface form:
Poisson's equation
Schrödinger equation with point interactions ⓘ |
| approximationSequence |
narrow Gaussian functions with unit area
ⓘ
rectangular pulses with shrinking width and fixed area ⓘ sinc-based kernels in limit ⓘ |
| characterizedBy |
defined as a linear functional on test functions
ⓘ
integral over entire real line equals one ⓘ not a function in the classical sense ⓘ zero everywhere except at a single point ⓘ |
| codomain | space of distributions ⓘ |
| convolutionIdentity | f * δ = f for suitable functions f ⓘ |
| definingProperty |
∫_{-∞}^{∞} δ(x) φ(x) dx = φ(0) for test functions φ
ⓘ
∫_{-∞}^{∞} δ(x-a) φ(x) dx = φ(a) ⓘ |
| derivative | distribution δ′ (delta prime) ⓘ |
| distributionOrder | 0 ⓘ |
| domain |
distribution theory
ⓘ
functional analysis ⓘ real analysis ⓘ |
| evenFunction | true ⓘ |
| FourierTransform | constant function 1 (in suitable normalization) ⓘ |
| generalizationOf |
Kronecker delta
ⓘ
surface form:
Kronecker delta (discrete case)
|
| introducedInContext | quantum mechanics ⓘ |
| inverseFourierTransform | constant function 1 (in suitable normalization) ⓘ |
| LaplaceTransform | 1 ⓘ |
| linearity | linear functional ⓘ |
| mathematicalFramework | theory of distributions by Laurent Schwartz ⓘ |
| models |
idealized point charge
ⓘ
idealized point mass ⓘ instantaneous impulse ⓘ |
| namedAfter | Paul Dirac ⓘ |
| relatedConcept |
Heaviside step function
ⓘ
unit impulse in discrete time ⓘ |
| scalingProperty | δ(ax) = δ(x)/|a| for nonzero a ⓘ |
| support |
single point
ⓘ
{0} ⓘ |
| supportType | compact support ⓘ |
| symbol | δ ⓘ |
| testFunctionSpace | space of smooth functions with compact support ⓘ |
| translationProperty | δ(x-a) is delta centered at a ⓘ |
| usedIn |
classical mechanics
ⓘ
control theory ⓘ electrical engineering ⓘ physics ⓘ probability theory ⓘ quantum mechanics ⓘ signal processing ⓘ systems theory ⓘ |
| usedToDefine |
Green's functions as responses to point sources
ⓘ
impulse response of linear time-invariant systems ⓘ |
Referenced by (10)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Dirac delta distribution
this entity surface form:
delta function
this entity surface form:
Dirac delta
subject surface form:
Gelfand triple
this entity surface form:
Dirac delta distribution
this entity surface form:
Dirac comb
this entity surface form:
Dirac measure