2013

Asymptotic expansion of beta matrix models in the multi-cut regime

Borot, Gaëtan, Guionnet, Alice

Understand

We establish the asymptotic expansion in $\beta$ matrix models with a confining, off-critical potential, in the regime where the support of the equilibrium measure is a union of segments.

  • We first address the case where the filling fractions of these segments are fixed, and show the existence of a $1/N$ expansion.
  • We then study the asymptotics of the sum over the filling fractions, to obtain the full asymptotic expansion for the initial problem in the multi-cut regime.
  • In particular, we identify the fluctuations of the linear statistics and show that they are approximated in law by the sum of a Gaussian random variable and an independent Gaussian discrete random variable with oscillating center.

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