Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: outer factorization

Sortuj według:

Ogranicz wyniki do:

Outer factorization of operator valued weight functions on the torus

100%

Cheng R.

Studia Mathematica

1994

tom 110

nr 1

19-34

An exact criterion is derived for an operator valued weight function $W(e^{is},e^{it})$ on the torus to have a factorization $W(e^{is},e^{it}) = Φ(e^{is},e^{it})*Φ(e^{is},e^{it})$, where the operator valued Fourier coefficients of Φ vanish outside of the Helson-Lowdenslager halfplane $Λ = {(m,n) ∈ ℤ^2: m ≥ 1} ∪ {(0,n): n ≥ 0}$, and Φ is "outer" in a related sense. The criterion is expressed in terms of a regularity condition on the weighted space $L^2(W)$ of vector valued functions on the torus. A logarithmic integrability test is also provided. The factor Φ is explicitly constructed in terms of Toeplitz operators and other structures associated with W. The corresponding version of Szegö's infimum is given.

Ograniczanie wyników

1 Studia Mathematica

1 Cheng R.

1 1994

Wyniki wyszukiwania

Outer factorization of operator valued weight functions on the torus