Stirling's approximation

E300765

Stirling's approximation is a classical formula in mathematics that provides an efficient asymptotic estimate for factorials and the gamma function, especially for large arguments.

All labels observed (2)

Label Occurrences
Stirling's approximation canonical 1
Stirling’s approximation 1

How this entity was disambiguated

Statements (49)

Predicate Object
instanceOf asymptotic formula
mathematical approximation
result in analysis
appliesTo Gamma function
large arguments
n!
approximationType asymptotic equality
logarithmic approximation
describes asymptotic behavior of factorial function
asymptotic behavior of gamma function
field analytic number theory
asymptotic analysis
combinatorics
mathematics
probability theory
statistics
givesApproximation ln Γ(z) ≈ (z − 1/2) ln z − z + (1/2) ln(2π)
ln(n!) ≈ n ln n − n
n! ≈ √(2πn) (n/e)^n
hasErrorTerm relative error tends to 0 as n → ∞
hasExponentialFactor (n/e)^n
hasFormulation logarithmic form
multiplicative form
series expansion form
hasHigherOrderTerm 1/(1260n^5)
1/(12n)
−1/(360n^3)
hasLeadingFactor √(2πn)
hasRefinement Euler–Maclaurin summation formula
surface form: Stirling series
historicalPeriod 18th century
improvesOn earlier approximations of factorials
isAsymptoticExpansionOf ln Γ(z)
namedAfter James Stirling
relatedTo Euler’s reflection formula
surface form: Gamma function reflection formula

Laplace method
surface form: Laplace's method

central limit theorem
entropy of multinomial coefficients
saddle-point method
usedFor approximating binomial coefficients
approximating log-factorials in statistics
asymptotic estimates in combinatorics
complexity estimates in algorithms
deriving normal approximations to distributions
entropy calculations
estimating factorials
usedIn approximation of partition functions in statistical mechanics
derivation of entropy formula in information theory
validFor complex z with |arg z| < π
positive integers n

How these facts were elicited

Referenced by (2)

Full triples — surface form annotated when it differs from this entity's canonical label.

Euler–Maclaurin summation formula relatedTo Stirling's approximation
Riemann–Siegel theta function relatedTo Stirling's approximation
this entity surface form: Stirling’s approximation