# On the Decomposition of Unitary Operators into a Product of Finitely Many Positive Operators

### G. Peltri

Universität Leipzig, Germany

## Abstract

We will show that in an infinite-dimensional separable Hilbert space $H$, there exist constants $N∈N$ and $c,d∈R$ such that every unitary operator can be written as the product of at most $N$ positive invertible operators ${a_{k}}⊆B(H)$ with $∥a_{k}∥≤c$ and $∥a_{k}∥≤d$ for all $k$. Some consequences of this result in the context of von Neumann algebras are discussed.

## Cite this article

G. Peltri, On the Decomposition of Unitary Operators into a Product of Finitely Many Positive Operators. Z. Anal. Anwend. 14 (1995), no. 2, pp. 235–248

DOI 10.4171/ZAA/673