Roman Werpachowski On the approximation of real powers of sparse, infinite, bounded and Hermitian matrices (218K, PDF) ABSTRACT. We describe a method to approximate the matrix elements of a real power $\alpha$ of a positive (for $\alpha \in \mathbb{R}$) or non-negative (for $\alpha \ge 0$), infinite, bounded, sparse and Hermitian matrix $W$. The approximation uses only a finite part of the matrix $W$.