Universality in the random-matrix theory of quantum transport.
A random-matrix formula is derived for the variance of an arbitrary linear statistic on the transmission eigenvalues. The variance is independent of the eigenvalue density and has a universal dependence on the symmetry of the matrix ensemble. The formula generalises the Dyson-Mehta theorem in the statistical theory of energy levels. It demonstrates that the universality of the conductance fluctuations is generic for a whole class of transport properties in mesoscopic systems