Light-Front Quantized Fiel Theory: (an Introduction) Spontaneous Symmetry Breaking. Phase Transition in <math>φ4</math> Theory

Nota de FísicaPublicado

Light-Front Quantized Fiel Theory: (an Introduction) Spontaneous Symmetry Breaking. Phase Transition in $<math>\phi^4</math>$ Theory

P. P. Srivastava

1993

Autores: P. P. Srivastava
Tipo: Nota de Física
Estado: Publicado
Fecha de publicación: 1993
Descripción: The field theory quantized on the ''light-front'' is compared with the conventional equal-time quantized theory. The arguments based on the ''microcausality'' principle would imply that the light-front field theory may become nonlocal with respect to the longitudinal coordinate even though the corresponding equal-time formulation is local. This is found to be the case for the scalar theory. The conventional ''instant form'' theory is sometimes required to be constrained by invoking external physical considerations; the analogous conditions seem to be already built in the theory on the light-front. In spite of the different mechanisms of the spontaneous symmetry breaking in the two forms of dynamics they result in the same physical content. The phase transition in <math>(\phi^{4})_2\,\!</math> theory is also discussed. The symmetric vacuum state for vanishingly small coupling is found to turn into an unstable symmetric one when the coupling is increased and may result in a phase transition of the ''second'' order in contrast to the first order transition concluded from the usual variational methods.
Año: 1993
Número: CBPF-NF-075/93
Vínculo con tesis: No
Vínculo con beca: No