Kaniadakis Erlang distribution

{{Notability|date=February 2023}}{{one source|date=August 2022}}

{{Short description|Continuous probability distribution}}

{{Infobox probability distribution|name=κ-Erlang distribution|type=density|parameters= 0 \leq \kappa < 1
n = \textrm{positive} \,\,\textrm{integer} |support=x \in [0, +\infty)|pdf= \prod_{m = 0}^n \left[ 1 + (2m -n)\kappa \right] \frac{ x^{n - 1} }{ (n - 1)! } \exp_\kappa(-x) |cdf= \frac{1}{ (n - 1)! } \prod_{m = 0}^n \left[ 1 + (2m -n)\kappa \right] \int_0^x z^{n - 1} \exp_\kappa(-z) dz |pdf_image=FILE:Kaniadakis Erlang Distribution pdf.png|pdf_caption=Plot of the κ-Erlang distribution for typical κ-values and n=1, 2,3. The case κ=0 corresponds to the ordinary Erlang distribution.}}

The Kaniadakis Erlang distribution (or κ-Erlang Gamma distribution) is a family of continuous statistical distributions, which is a particular case of the κ-Gamma distribution, when \alpha = 1 and \nu = n = positive integer. The first member of this family is the κ-exponential distribution of Type I. The κ-Erlang is a κ-deformed version of the Erlang distribution. It is one example of a Kaniadakis distribution.

Characterization

= Probability density function =

The Kaniadakis κ-Erlang distribution has the following probability density function:{{Cite journal |last=Kaniadakis |first=G. |date=2021-01-01 |title=New power-law tailed distributions emerging in κ-statistics (a) |url=https://iopscience.iop.org/article/10.1209/0295-5075/133/10002 |journal=Europhysics Letters |volume=133 |issue=1 |pages=10002 |doi=10.1209/0295-5075/133/10002 |issn=0295-5075|arxiv=2203.01743 |bibcode=2021EL....13310002K |s2cid=234144356 }}

:

f_{_{\kappa}}(x) = \frac{1}{ (n - 1)! } \prod_{m = 0}^n \left[ 1 + (2m -n)\kappa \right] x^{n - 1} \exp_\kappa(-x)

valid for x \geq 0 and n = \textrm{positive} \,\,\textrm{integer} , where 0 \leq |\kappa| < 1 is the entropic index associated with the Kaniadakis entropy.

The ordinary Erlang Distribution is recovered as \kappa \rightarrow 0.

= Cumulative distribution function =

The cumulative distribution function of κ-Erlang distribution assumes the form:

: F_\kappa(x) = \frac{1}{ (n - 1)! } \prod_{m = 0}^n \left[ 1 + (2m -n)\kappa \right] \int_0^x z^{n - 1} \exp_\kappa(-z) dz

valid for x \geq 0, where 0 \leq |\kappa| < 1. The cumulative Erlang distribution is recovered in the classical limit \kappa \rightarrow 0.

= Survival distribution and hazard functions =

The survival function of the κ-Erlang distribution is given by:

S_\kappa(x) = 1 - \frac{1}{ (n - 1)! } \prod_{m = 0}^n \left[ 1 + (2m -n)\kappa \right] \int_0^x z^{n - 1} \exp_\kappa(-z) dz
The survival function of the κ-Erlang distribution enables the determination of hazard functions in closed form through the solution of the κ-rate equation:
\frac{ S_\kappa(x) }{ dx } = -h_\kappa S_\kappa(x)
where h_\kappa is the hazard function.

Family distribution

A family of κ-distributions arises from the κ-Erlang distribution, each associated with a specific value of n, valid for x \ge 0 and 0 \leq |\kappa| < 1. Such members are determined from the κ-Erlang cumulative distribution, which can be rewritten as:

: F_\kappa(x) = 1 - \left[ R_\kappa(x) + Q_\kappa(x) \sqrt{1 + \kappa^2 x^2} \right] \exp_\kappa(-x)

where

: Q_\kappa(x) = N_\kappa \sum_{m=0}^{n-3} \left( m + 1 \right) c_{m+1} x^m + \frac{N_\kappa}{1-n^2\kappa^2} x^{n-1}

: R_\kappa(x) = N_\kappa \sum_{m=0}^{n} c_{m} x^m

with

: N_\kappa = \frac{1}{ (n - 1)! } \prod_{m = 0}^n \left[ 1 + (2m -n)\kappa \right]

: c_n = \frac{ n\kappa^2 }{ 1 - n^2 \kappa^2}

: c_{n - 1} =0

: c_{n - 2} = \frac{ n - 1 }{ (1 - n^2 \kappa^2) [1 - (n-2)^2\kappa^2]}

: c_m = \frac{ (m + 1)(m+2) }{ 1 - m^2 \kappa^2} c_{m+2} \quad \textrm{for} \quad 0 \leq m \leq n-3

= First member =

The first member (n = 1) of the κ-Erlang family is the κ-Exponential distribution of type I, in which the probability density function and the cumulative distribution function are defined as:

:

f_{_{\kappa}}(x) = (1 - \kappa^2) \exp_\kappa(-x)

: F_\kappa(x) = 1-\Big(\sqrt{1+\kappa^2 x^2} + \kappa^2 x \Big)\exp_k({-x)}

= Second member =

The second member (n = 2) of the κ-Erlang family has the probability density function and the cumulative distribution function defined as:

:

f_{_{\kappa}}(x) = (1 - 4\kappa^2)\,x \,\exp_\kappa(-x)

: F_\kappa(x) = 1-\left(2\kappa^2 x^2 + 1 + x\sqrt{1+\kappa^2 x^2} \right) \exp_k({-x)}

= Third member =

The second member (n = 3) has the probability density function and the cumulative distribution function defined as:

:

f_{_{\kappa}}(x) = \frac{1}{2} (1 - \kappa^2) (1 - 9\kappa^2)\,x^2 \,\exp_\kappa(-x)

: F_\kappa(x) = 1-\left\{ \frac{3}{2} \kappa^2(1 - \kappa^2)x^3 + x + \left[ 1 + \frac{1}{2}(1-\kappa^2)x^2 \right] \sqrt{1+\kappa^2 x^2}\right\} \exp_\kappa(-x)

Related distributions

  • The κ-Exponential distribution of type I is a particular case of the κ-Erlang distribution when n = 1;
  • A κ-Erlang distribution corresponds to am ordinary exponential distribution when \kappa = 0 and n = 1;

See also

References

{{Reflist}}