On the Dependence of Quantum States on the Value of Planck's Constant
  We begin by discussing known theoretical results about the sensitivity of quantum states to changes in the value of Planck's constant h. These questions are related to positivity issues for self-adjoint trace class operators, which are not yet fully understood. We thereafter briefly discuss the implementation of experimental procedures to detect possible fluctuations of h. 
Maurice de Gosson, Makan Mohageg
quant-ph gr-qc math-ph math.MP