Shear viscosity in the O(N) model
Feb, 2004Citations per year
Abstract:
We compute the shear viscosity in the O(N) model at first nontrivial order in the large N expansion. The calculation is organized using the 1/N expansion of the 2PI effective action (2PI-1/N expansion) to next-to-leading order, which leads to an integral equation summing ladder and bubble diagrams. We also consider the weakly coupled theory for arbitrary N, using the three-loop expansion of the 2PI effective action. In the limit of weak coupling and vanishing mass, we find an approximate analytical solution of the integral equation. For general coupling and mass, the integral equation is solved numerically using a variational approach. The shear viscosity turns out to be close to the result obtained in the weak-coupling analysis.Note:
- 37 pages, few typos corrected: to appear in JHEP Journal-ref: JHEP 0402 (2004) 061
- field theory: scalar
- symmetry: O(N)
- expansion 1/N
- effective action
- viscosity
- approximation: weak coupling
- mass: gap
- renormalization
- quasiparticle
- vertex function
References(49)
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