Zeno dynamics and constraints

P Facchi, G Marmo, S Pascazio, A Scardicchio, E C G Sudarshan
2004 Journal of Optics B-Quantum and Semiclassical Optics  
We investigate some examples of quantum Zeno dynamics, when a system undergoes very frequent (projective) measurements that ascertain whether it is within a given spatial region. In agreement with previously obtained results, the evolution is found to be unitary and the generator of the Zeno dynamics is the Hamiltonian with hard-wall (Dirichlet) boundary conditions. By using a new approach to this problem, this result is found to be valid in an arbitrary N-dimensional compact domain. We then
more » ... pose some preliminary ideas concerning the algebra of observables in the projected region and finally look at the case of a projection onto a lower dimensional space: in such a situation the Zeno ansatz turns out to be a procedure to impose constraints.
doi:10.1088/1464-4266/6/6/006 fatcat:b4esxdcszvf7jkq5tyknj4seyu