On the Weierstrass Preparation Theorem
Volume 123 / 2019
Abstract
The well-known Weierstrass Preparation Theorem states that if $f( z,w)$ is holomorphic at a point $( z^{0},w^{0})\in \mathbb {C}_{z}^{n}\times {\mathbb {C}}_w$ and $f( z^{0},w^{0} )=0,$ but $f ( z^{0},w ) \not \equiv 0,$ then in some neighborhood $U=V\times W$ of this point $f$ is represented as $$ f ( z,w )= [ {{ ( w-{{w}^{0}} )}^{m}}+{{c}_{m-1}} ( z ){{ ( w-{{w}^{0}} )}^{m-1}}+\dots +{{c}_{0}} ( z ) ]\varphi ( z,w ), $$ where ${c}_{j} ( z ) \in \mathcal {O}(V)$, ${c}_{j} ( z^{0} )=0$ for $j=0,1,\ldots ,m-1$ and $\varphi \in \mathcal {O}(U)$, $\varphi (z,w)\neq 0$.
In this paper, a global multidimensional (in $w$) analogue of this theorem is proved without the condition $f ( {{z}^{0}},w )\not \equiv 0.$