A classification of reductive prehomogeneous vector spaces with trivial representation free

Abstract

In this paper, we classify $k$-simple prehomogeneous vector spaces of type $(GL_{1}^{l}\times G_{1}\times \cdots \times G_{k},\rho _{1}^{(1)}\otimes \cdots \otimes \rho _{k}^{(1)}+ \cdots + \rho_{1}^{(l)}\otimes \cdots \otimes \rho _{k}^{(l)})$ where for any $i,j$, each $\rho _{j}^{(i)}$ is a nontrivial irreducible representation of a simple algebraic group $G_{j}$(i.e., $\rho _{j}^{(i)}\neq 1$) with $k\ge 3$ and $l\ge 2$ under full scalar multiplications. We consider everything over the complex number field $\mathbb {C}$.