Combinatorial Approach to Boson Anti-Normal Ordering Problem
We address a systematic combinatorial approach to the anti-normal ordering problem. In this way, we use the Stirling numbers and their generating function, the so-called Bell polynomials, together with the operational methods to anti-normal the operator ${e^{λ{a^†}a}}$. In fact, we exploit the new theorem given by Shähandeh et al. in a special case of anti-normal ordering.
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