Abstract
Consider the test problem about matrix normal mean M with the null hypothesis M = O against the alternative that M is nonnegative definite. In our previous paper (Kuriki (1993, Ann. Statist., 21, 1379–1384)), the null distribution of the likelihood ratio statistic has been given in the form of a finite mixture of χ2 distributions referred to as X2 distribution. In this paper, we investigate differential-geometric structure such as second fundamental form and volume element of the boundary of the cone formed by real nonnegative definite matrices, and give a geometric derivation of this null distribution by virtue of the general theory on the X2 distribution for piecewise smooth convex cone alternatives developed by Takemura and Kuriki (1997, Ann. Statist., 25, 2368–2387).
Similar content being viewed by others
References
Faraut, J. and Korányi, A. (1994). Analysis on Symmetric Cones, Oxford University Press, Oxford.
Kuriki, S. (1993). One-sided test for the equality of two covariance matrices, Ann. Statist., 21, 1379–1384.
Lin, Y. and Lindsay, B. G. (1997). Projections on cones, chi-bar squared distributions, and Weyl's formula, Statist. Probab. Lett., 32, 367–376.
Macdonald, I. G. (1995). Symmetric Functions and Hall Polynomials, 2nd ed., Oxford University Press, Oxford.
Muirhead, R. J. (1982). Aspects of Multivariate Statistical Theory, Wiley, New York.
Ohara, A., Suda, N. and Amari, S. (1996). Dualistic differential geometry of positive definite matrices and its applications to related problems, Linear Algebra Appl., 247, 31–53.
Robertson, T., Wright, F. T. and Dykstra, R. L. (1988). Order Restricted Statistical Inference, Wiley, Chichester.
Sakata, T. (1987). Likelihood ratio test for one-sided hypothesis of covariance matrices of two normal populations, Commun. Statist. Theory Methods, 16, 3157–3168.
Schneider, R. (1993). Convex Bodies: The Brunn-Minkowski Theory, Cambridge University Press, Cambridge.
Shapiro, A. (1988). Towards a unified theory of inequality constrained testing in multivariate analysis, International Statistical Review, 56, 49–62.
Takemura, A. and Kuriki, S. (1997). Weights of \(\bar \chi^2\) 2 distribution for smooth or piecewise smooth cone alternatives, Ann. Statist., 25, 2368–2387.
Uhlig, H. (1994). On singular Wishart and singular multivariate beta distributions, Ann. Statist., 22, 395–405.
Webster, R. (1994). Convexity, Oxford University Press, Oxford.
Weyl, H. (1939). On the volume of tubes, Amer. J. Math., 61, 461–472.
Author information
Authors and Affiliations
About this article
Cite this article
Kuriki, S., Takemura, A. Some Geometry of the Cone of Nonnegative Definite Matrices and Weights of Associated X2 Distribution. Annals of the Institute of Statistical Mathematics 52, 1–14 (2000). https://doi.org/10.1023/A:1004191713375
Issue Date:
DOI: https://doi.org/10.1023/A:1004191713375