No sabía que el tema del "corte" obtiene distintos resultados, según se use una imagen u otra:
Working with a finite cut-off, we have to search for quantities which are not sensitive to the precise mode and value of the cut-off. We then find that the Schrodinger picture is not a suitable one. Solutions of the Schrodinger equation, even the one describing the vacuum state, are very sensitive to the cutoff. But there are some calculations that one can carry out in the Heisenberg picture that lead to results insensitive to the cut-off.
Notablemente, Dirac afirma que por este camino puede obtener el valor del corrimiento Lamb:
One can deduce in this way the Lamb-shift and the anomalous magnetic moment of the electron. The results are the same as those obtained some twenty years ago by the method of working rules with discard of infinities. But now the result can be obtained by a logical process, following standard mathematics in which only small quantities are neglected.
Pero perdemos los avances de la imagen Schrodinger:
As we cannot now use the Schrodinger picture, we cannot use the regular physical interpretation of quantum mechanics involving the square of the modulus of the wave function. We have to feel our way towards a new physical interpretation which can be used with the Heisenberg picture. The situation for quantum electrodynamics is rather like that for elementary quantum mechanics in the early days when we had the equations of motions but no general physical interpretation.
Angel "Java" Lopez