We show that the spectra of Wishart matrices built from magnetization time
series can describe the phase transitions and the critical phenomena of the
Potts model with a different number of states. We can statistically determine
the transition points, independent of their order, by studying the density of
the eigenvalues and corresponding fluctuations. In some way, we establish a
relationship between the actual thermodynamics with the spectral thermodynamics
described by the eigenvalues. The histogram of correlations between time series
interestingly supports our results. In addition, we present an analogy to the
study of the spectral properties of the Potts model, considering matrices
correlated artificially. For such matrices, the eigenvalues are distributed in
two groups that present a gap depending on such correlation.Comment: 10 pages, 11 figure