A remark on the discrete spectrum of non-self-adjoint Jacobi operators

We study the trace class perturbations of the whole-line, discrete Laplacian and obtain a new bound for the perturbation determinant of the corresponding non-self-adjoint Jacobi operator. Based on this bound, we refine the Lieb–Thirring inequality due to Hansmann–Katriel. The spectral enclosure for such operators is also discussed.