Physics – High Energy Physics – High Energy Physics - Theory
Scientific paper
2010-09-14
Nucl.Phys.B844:243-265,2011
Physics
High Energy Physics
High Energy Physics - Theory
v2: 25 pages, 4 eps figures, introduction expanded, matches published version
Scientific paper
10.1016/j.nuclphysb.2010.11.004
The theta dependence of the vacuum energy density in CP^{N-1} models is re-analysed in the semiclassical approach, the 1/N expansion and arguments based on the nodal structure of vacuum wavefunctionals. The 1/N expansion is shown not to be in contradiction with instanton physics at finite (spacetime) volume V. The interplay of large volume V and large N parameter gives rise to two regimes with different theta dependence, one behaving as a dilute instanton gas and the other dominated by the traditional large N picture, where instantons reappear as resonances of the one-loop effective action, even in the absence of regular instantonic solutions. The realms of the two regimes are given in terms of the mass gap m by m^2 V << N and m^2 V >> N, respectively. The small volume regime m^2 V << N is relevant for physical effects associated to the physics of the boundary, like the leading role of edge states in the quantum Hall effect, which, however, do not play any role in the thermodynamic limit at large N. Depending on the order in which the limits N -> \infty and V -> \infty are taken, two different theories are obtained; this is the hallmark of a phase transition at 1/N = 0.
Aguado Miguel
Asorey Manuel
No associations
LandOfFree
Theta-vacuum and large N limit in CP^{N-1} sigma models does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Theta-vacuum and large N limit in CP^{N-1} sigma models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Theta-vacuum and large N limit in CP^{N-1} sigma models will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-395860