6.728 Applied Quantum and Statistical Physics, Fall 2002

Krishna Rajagopal

Iain W. Stewart

Jordyn Roach

45 pages. A thesis presented to the Department of Applied Physics, Cinema Studies, and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Fall 2016.

Krishna Rajagopal

Aephraim M. Steinberg

It is a commonplace to claim that quantum mechanics supports the old idea that a tree falling in a forest makes no sound unless there is a listener present. In fact, this conclusion is far from obvious. Furthermore, if a tunnelling particle is observed in the barrier region, it collapses to a state in which it is no longer tunnelling. Does this imply that while tunnelling, the particle can not have any physical effects? I argue that this is not the case, and moreover, speculate that it may be possible for a particle to have effects on two spacelike separate apparatuses simultaneously. I discuss the measurable consequences of such a feat, and speculate about possible statistical tests which could distinguish this view of quantum mechanics from a ``corpuscular'' one. Brief remarks are made about an experiment underway at Toronto to investigate these issues.

Giuseppe Mussardo

Abstract The integrable quantum field theories analyzed in the previous chapters provide the exact solution of many statistical models away from the critical point. Despite the elegance and the undeniable success of these methods, the generic situation that occurs in statistical physics is that of non-integrable dynamics: many interesting statistical models fall within this class and therefore it would be highly desirable to develop an appropriate formalism to deal with the lack of integrability. This task is notoriously difficult for the rich phenomenology that arises when the dynamics are not integrable: there are decays and production scattering processes, confinement phenomena and nucleation of false vacua, resonance peaks in the cross-sections, etc.