Hubble and Planck scale limits on the determination of orbital angular   momentum states of light
  We review Heisenberg's uncertainty principle for the orbital angular momentum (OAM) of light. By taking into account the largest and smallest scales present in nature, such as the the Hubble radius and the Planck length, we have found that there exist upper and lower physical limits to the determination of the OAM of a photon. 
F. Tamburini, B. Thid\'e and A. Sponselli
physics.optics gr-qc quant-ph