Exact Distribution of the Noncentral Complex Roy's Largest Root Statistic via Pieri's Formula

In this study, we derive the exact distribution and moment of the noncentral complex Roy’s largest root statistic, expressed as a product of complex zonal polynomials. We show that the linearization coefficients arising from the product of complex zonal polynomials in the distribution of Roy’s test under a specific alternative hypothesis can be explicitly computed using Pieri’s formula, a well-known result in combinatorics. These results were then applied to compute the power of tests in the complex multivariate analysis of variance (MANOVA).