bounded variation and absolutely continuous spectrum of Jacobi matrices
arXiv:1702.05245 · doi:10.1007/s00220-017-3015-6
Abstract
We disprove a conjecture of Breuer-Last-Simon concerning the absolutely continuous spectrum of Jacobi matrices with coefficients that obey an bounded variation condition with step . We prove existence of a.c. spectrum on a smaller set than that specified by the conjecture and prove that our result is optimal.
21 pages