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Perturbative dynamics of fuzzy spheres at large N

Takehiro Azuma·Keiichi Nagao·Jun Nishimura
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Abstract

We clarify some peculiar aspects of the perturbative expansion around a classical fuzzy-sphere solution in matrix models with a cubic term. While the effective action in the large-N limit is saturated at the one-loop level, we find that the ``one-loop dominance'' does not hold for generic observables due to one-particle reducible diagrams. However, we may exploit the one-loop dominance for the effective action and obtain various observables to all orders from one-loop calculation by simply shifting the center of expansion to the ``quantum solution'', which extremizes the effective action. We confirm the validity of this method by comparison with the direct two-loop calculation and with Monte Carlo results in the 3d Yang-Mills-Chern-Simons matrix model. From the all order result we find that the perturbative expansion has a finite radius of convergence.

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Takehiro Azuma, Keiichi Nagao, Jun Nishimura. 2005-06-30. Perturbative dynamics of fuzzy spheres at large N. https://doi.org/10.1088/1126-6708%2F2005%2F06%2F081

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