Correlation structure of the deltan statistic for chaotic quantum systems.

The existence of a formal analogy between quantum energy spectra and discrete time series has been recently pointed out. When the energy level fluctuations are described by means of the statistic, it is found that chaotic quantum systems are characterized by noise, while regular systems are characterized by . In order to investigate the correlation structure of the statistic, we study the -order height-height correlation function , which measures the momentum of order , i.e., the average power of the signal change after a time delay . It is shown that this function has a logarithmic behavior for the spectra of chaotic quantum systems, modeled by means of random matrix theory. On the other hand, since the power spectrum of chaotic energy spectra considered as time series exhibit noise, we investigate whether the -order height-height correlation function of other time series with noise exhibits the same properties. A time series of this kind can be generated as a linear combination of cosine functions with arbitrary phases. We find that the logarithmic behavior arises with great accuracy for time series generated with random phases.