A monoidal representation for linearized gravity
  We propose an alternative representation for linear quantum gravity. It is based on the use of a structure that bears some resemblance to the Abelian loop representation used in electromagnetism but with the difference that space of extended object on which waves functions take values have a structure of commutative monoid instead of Abelian group. The generator of duality of the theory is realized in this representation and a geometrical interpretation is discussed. 
Ernesto Contreras, Cayetano Di Bartolo and Lorenzo Leal
hep-th