English
Related papers

Related papers: The variance-gamma ratio distribution

200 papers

Let $X$ and $Y$ be independent variance-gamma random variables with zero location parameter; then the exact probability density function of the product $XY$ is derived. Some basic distributional properties are also derived, including…

Probability · Mathematics 2024-05-14 Robert E. Gaunt , Siqi Li

Let $X_1,\ldots,X_M$ and $Y_1,\ldots,Y_N$ be independent zero mean normal random variables with variances $\sigma_{X_i}^2$, $i=1,\ldots,M$, and $\sigma_{Y_j}^2$, $j=1,\ldots,N$, respectively, and let $X=X_1\cdots X_M$ and $Y=Y_1\cdots Y_N$.…

Probability · Mathematics 2026-01-21 Robert E. Gaunt , Heather L. Sutcliffe

We derive the exact probability density function of the product of $N$ independent variance-gamma random variables with zero location parameter. We then apply this formula to derive formulas for the cumulative distribution function and…

Probability · Mathematics 2025-08-05 Robert E. Gaunt , Siqi Li , Heather Sutcliffe

In this investigation, the distribution of the ratio of two independently distributed xgamma (Sen et al. 2016) random variables X and Y , with different parameters, is proposed and studied. The related distributional properties such as,…

Methodology · Statistics 2024-02-23 Subhradev Sen , Suman K. Ghosh , Hazem Al-Mofleh

Exact formulas are derived for the probability density functions of the sum and difference of two independent non-central gamma distributed random variables, with both series and integral representations of the density presented. These…

Probability · Mathematics 2026-05-18 Robert E. Gaunt , Heather L. Sutcliffe

For a sample of absolutely bounded i.i.d. random variables with a continuous density the cumulative distribution function of the sample variance is represented by a univariate integral over a Fourier series. If the density is a polynomial…

Statistics Theory · Mathematics 2008-10-10 T. Royen

The statistical distribution of the ratio of two normal random variables is characterized by its heavy-tailed nature and absence of finite moments. The shape of its density function is highly variable, capable of exhibiting unimodal or…

Probability · Mathematics 2023-11-07 Sheng Yang , Zhengtao Gui

We obtain exact formulas for the cumulative distribution function of the variance-gamma distribution, as infinite series involving the modified Bessel function of the second kind and the modified Lommel function of the first kind. From…

Probability · Mathematics 2024-11-20 Robert E. Gaunt

In this paper, using inverse integral transforms, we derive the exact distribution of the random variable $X$ that is involved in the ratio $Z \stackrel{d}{=} X/(X+Y)$ where $X$ and $Y$ are independent random variables having the same…

Probability · Mathematics 2023-07-14 Roberto Vila , Narayanaswamy Balakrishnan , Marcelo Bourguignon

The XGamma distribution is a generated distribution from a mixture of Exponential and Gamma distributions. It is found that in many cases the XGamma has more flexibility than the Exponential distribution. In this paper we consider the sum…

Statistics Theory · Mathematics 2025-04-22 Therrar Kadri , Rahil Omairi , Khaled Smaili , Seifedine Kadry

Several numerical evaluations of the density and distribution of convolution of independent gamma variables are compared in their accuracy and speed. In application to renewal processes, an efficient formula is derived for the probability…

Computation · Statistics 2022-12-15 Chaoran Hu , Vladimir Pozdnyakov , Jun Yan

The gamma difference distribution is defined as the difference of two gamma distributions, with in general different shape and rate parameters. Starting with knowledge of the corresponding characteristic function, a second order linear…

Statistics Theory · Mathematics 2023-09-26 Peter J. Forrester

The variance-gamma (VG) distributions form a four-parameter family which includes as special and limiting cases the normal, gamma and Laplace distributions. Some of the numerous applications include financial modelling and distributional…

Statistics Theory · Mathematics 2023-03-13 Adrian Fischer , Robert E. Gaunt , Andrey Sarantsev

We consider two random variables $X$ and $Y$ following correlated Gamma distributions, characterized by identical scale and shape parameters and a linear correlation coefficient $\rho$. Our focus is on the parameter: \[ D(X,Y) = \frac{|X -…

Statistics Theory · Mathematics 2025-03-13 Elise Colin , Razvigor Ossikovski

We obtain exact formulas for the absolute raw and central moments of the variance-gamma distribution, as infinite series involving the modified Bessel function of the second kind and the modified Lommel function of the first kind. When the…

Probability · Mathematics 2024-09-10 Robert E. Gaunt

We obtain new closed-form formulas for the moments and absolute moments of the variance-gamma distribution. We thus deduce new formulas for the moments and absolute moments of the product of two correlated zero mean normal random variables.

Probability · Mathematics 2023-06-06 Robert E. Gaunt

Many existing approaches for estimating parameters in settings with distributional shifts operate under an invariance assumption. For example, under covariate shift, it is assumed that $p(y|x)$ remains invariant. We refer to such…

Methodology · Statistics 2025-02-07 Yujin Jeong , Dominik Rothenhäusler

Measurements of a weighted energy density average taken in the vacuum state of a conformal field theory in $1+1$ dimensions are randomly distributed with vanishing expectation value. The probability distribution is computed in closed form…

High Energy Physics - Theory · Physics 2020-01-29 Matthew C. Anthony , Christopher J. Fewster

The empirical probability density function for the conditional distribution of the true value of Poisson distribution parameter on one measurement is constructed by computer experiment. The analysis of the obtained distributions confirms…

Data Analysis, Statistics and Probability · Physics 2009-11-10 S. I. Bityukov , V. A. Medvedev , V. V. Smirnova , Yu. V. Zernii

This note contains sufficient conditions for the probability density function of an arbitrary continuous univariate distribution, supported on $(0,\infty),$ such that the corresponding Mills ratio to be reciprocally convex (concave). To…

Classical Analysis and ODEs · Mathematics 2013-05-06 Árpád Baricz
‹ Prev 1 2 3 10 Next ›