TY - JOUR

T1 - Block Toeplitz operators with frequency-modulated semi-almost periodic symbols

AU - Böttcher, A.

AU - Grudsky, S.

AU - Spitkovsky, I.

PY - 2003

Y1 - 2003

N2 - This paper is concerned with the influence of frequency modulation on the semi-Fredholm properties of Toeplitz operators with oscillating matrix symbols. The main results give conditions on an orientation-preserving homeomorphism a of the real line that ensure the following: if b belongs to a certain class of oscillating matrix functions (periodic, almost periodic, or semi-almost periodic matrix functions) and the Toeplitz operator generated by the matrix function b (x) is semi-Fredholm, then the Toeplitz operator with the matrix symbol b (a (x)) is also semi-Fredholm.

AB - This paper is concerned with the influence of frequency modulation on the semi-Fredholm properties of Toeplitz operators with oscillating matrix symbols. The main results give conditions on an orientation-preserving homeomorphism a of the real line that ensure the following: if b belongs to a certain class of oscillating matrix functions (periodic, almost periodic, or semi-almost periodic matrix functions) and the Toeplitz operator generated by the matrix function b (x) is semi-Fredholm, then the Toeplitz operator with the matrix symbol b (a (x)) is also semi-Fredholm.

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U2 - 10.1155/S0161171203107107

DO - 10.1155/S0161171203107107

M3 - Article

AN - SCOPUS:11044238264

VL - 2003

SP - 2157

EP - 2176

JO - International Journal of Mathematics and Mathematical Sciences

JF - International Journal of Mathematics and Mathematical Sciences

SN - 0161-1712

IS - 34

ER -