Abstract
The spectral properties of the off-diagonal infinite-dimensional Hamiltonian operator are studied in this article. Characterizations of the spectrum, the point spectrum and the residual spectrum are given. A spectral inclusion property of numerical range is proved.
Acknowledgements
The authors thank the anonymous referee for his/her helpful suggestions. This work is supported by NNSF of China (grant nos 11101200, 10962004, 11061019), NSF of Inner Mongolia (grant No. 2010MS0108) and SPH-IMU (grant No. Z20090103).