THE TACHYON FIELD BELOW THE MASS BARRIER

We consider & tachyon field whose Fourier components correspond to spa tial momenta with modulus smaller than the mass parameter. The plane w ave solutions have then a time evolution which is a real exponential. The field is quantized and the solution of the eigenvalue problem for the Hamiltonian leads to the evaluation of the vacuum expectation valu e of products of field operators. The propagator turns out to be half- advanced and half-retarded. This completes the proof4 that the total p ropagator is the Wheeler Green function.4,7