We show that in the point process limit of the bulk eigenvalues of β-ensembles of random matrices, the probability of having no eigenvalue in a fixed interval of size λ is given by
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(κβ+o(1))λγβ exp((−β/64)λ2+(β/8−1/4)λ)
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as λ→∞, where
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γβ=1/4(β/2+2/β−3)
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and κβ is an undetermined positive constant. This is a slightly corrected version of a prediction by Dyson [J. Math. Phys. 3 (1962) 157–165]. Our proof uses the new Brownian carousel representation of the limit process, as well as the Cameron–Martin–Girsanov transformation in stochastic calculus.