S. Frittelli et al., QUANTIZATION OF THE NULL-SURFACE FORMULATION OF GENERAL-RELATIVITY, Physical review. D. Particles and fields, 56(2), 1997, pp. 889-907
We define and discuss various quantum operators that describe the geom
etry of spacetime in quantum general relativity. These are obtained by
combining the null-surface formulation of general relativity, recentl
y developed, with asymptotic quantization. One of the operators define
d describes a ''fuzzy'' quantum light cone structure. Others, denoted
''spacetime-point operators,'' characterize geometrically defined phys
ical points. We discuss the interpretation of these operators. This se
ems to suggest a picture of quantum spacetime as made of ''fuzzy'' phy
sical points. We derive the commutation algebra of the quantum spaceti
me-point operators in the linearization around flat space.