2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53871In the first part of this lecture I will give an introduction to light-cone field theory, focussing on the ``zero mode problem''. In the second part I discuss $ϕ^4$-theory in 1+1 dimensions. I will show how the dynamics of the zero modes can give rise to spontaneous symmetry breaking in spite of the trivial vacuum structure on the light-cone.17 pages Talk given at Hadron Structure '93, Banska Strianvnica Slovakia, September 5-10, 1993 based on Notes by Oliver Schnetz and Klaus Lucke, Institut für theoretische Physik III, Erlangen of lectures presented to the Graduiertenkoleg Erlangen-Regensburg on May 26, 1993High Energy Physics - Theorytext