# A DOUBLY COMMUTING PAIR OF HYPONORMAL OPERATORS

• Kim, Yong-Tae (Department of mathematics, Sungkyunkwan University)
• Published : 1999.05.01

#### Abstract

If ($H_1$, $H_2$) is a doubly commuting pair of hyponormal operators on a Hilbert spaces H, then there exists a commuting pair ($T_1$,$T_1$) of contractions on H such that $H_i$=$H_i^*$$T_i$ for each i=1,2.

#### References

1. Subnormal Operators J.B. Conway
2. Proc. Amer. Math. Soc. v.17 On majorization, factorization and range inclusion of operators on Hilbert space R. G. Douglas
3. A Hilbert Space Problem Book P. R. Halmos
4. Harmonic analysis of operators on Hilbert spaces B. Sz-Nagy;C. Foias