The exact distribution of indefinite quadratic forms in noncentral normal vectors

1996 ◽  
Vol 48 (2) ◽  
pp. 381-394 ◽  
Author(s):  
Serge B. Provost ◽  
Edmund M. Rudiuk

Author(s):  
Akbar Mohsenipour ◽  
Serge B. Provost

General representations of quadratic forms and quadratic expressions in singular normal vectors are given in terms of the difference of two positive definite quadratic forms and an independentlydistributed linear combination of normal random variables. Up to now, only special cases have been treated in the statistical literature. The densities of the quadratic forms are then approximated with gamma and generalized gamma density functions. A moment-based technique whereby the initial approximations are adjusted by means of polynomials is presented. Closed form and integral formulae are provided for the approximate density functions of the quadratic forms and quadratic expressions. A detailed step-by-step algorithm for implementing the proposed density approximation technique is also provided. Two numerical examples illustrate the methodology.



1957 ◽  
Vol 9 ◽  
pp. 526-548 ◽  
Author(s):  
G. L. Watson

The main object of this paper is to find the number of classes in a genus of indefinite quadratic forms, with integral coefficients, in k ≥ 4 variables, distinguishing for even k two cases, according as improper equivalence is or is not admitted.



1991 ◽  
Vol 37 (3) ◽  
pp. 260-278 ◽  
Author(s):  
Satish K. Aggarwal ◽  
D.P. Gupta




1990 ◽  
Vol 26 (1) ◽  
pp. 341-351
Author(s):  
Nikolaos Marmaridis




2018 ◽  
Vol 36 (3) ◽  
pp. 173-192
Author(s):  
Ahmet Tekcan ◽  
Seyma Kutlu

Let $k\geq 1$ be an integer and let $P=k+2,Q=k$ and $D=k^{2}+4$. In this paper, we derived some algebraic properties of quadratic ideals $I_{\gamma}$ and indefinite quadratic forms $F_{\gamma }$ for quadratic irrationals $\gamma$, and then we determine the set of all integer solutions of the Diophantine equation $F_{\gamma }^{\pm k}(x,y)=\pm Q$.



1977 ◽  
Vol 29 (2) ◽  
pp. 355-361 ◽  
Author(s):  
Tsuneo TAMAGAWA


Sign in / Sign up

Export Citation Format

Share Document