Unfolding of the Spectrum for Chaotic and Mixed Systems

Understand

Random Matrix Theory (RMT) is capable of making predictions for the spectral fluctuations of a physical system only after removing the influence of the level density by unfolding the spectra.

• When the level density is known, unfolding is done by using the integrated level density to transform the eigenvalues into dimensionless variables with unit mean spacing.
• When it is not known, as in most practical cases, one usually approximates the level staircase function by a polynomial.
• We here study the effect of unfolding procedure on the spectral fluctuation of two systems for which the level density is known asymptotically.