The absolutely continuous spectrum of discrete canonical systems

Andreas Fischer, Christian Remling
2008 Transactions of the American Mathematical Society  
We prove that if the canonical system J(y n+1 − y n ) = zH n y n has absolutely continuous spectrum of a certain multiplicity, then there is a corresponding number of linearly independent solutions y which are bounded in a weak sense.
doi:10.1090/s0002-9947-08-04711-9 fatcat:qdutnpdxfzb7biubuksxlpgnzu