Obstructions for Compactness of Hankel Operators: Compactness Multipliers

We establish a connection between compactness of Hankel operators and geometry of the underlying domain through compactness multipliers for the $\bar{\mathrm{\partial }}$-Neumann operator. In particular, we prove that any compactness multiplier induces a compact Hankel operator. We also generalize the notion of compactness multipliers to vector fields and matrices and then we use this generalization to generate compact Hankel operators.