PROPAGATION OF PARTICLES IN SPACETIME FOAM

Scalar particles would be strongly affected if spacetime had a foamlike structure on the scale of the Planck length. They would acquire an effective λφ{symbol}4 interaction with λ ∼ -1 and, possibly, a tachyonic mass of order the Planck value. On the other hand, fermions and vector particles at energies small compared with the Planck mass would be very little affected. There would be, however, small effective interactions which might lead to the gravitational decay of the proton in about 1050 years. © 1979.