Mean values of the principal components of A₂₃, defined in Eq. (26), as a function of density, n, in the simulations introduced in Soler et al. (2013). The component associated with the most negative eigenvalue of the symmetric part of the strain tensor, which corresponds to the dominant compressive mode, is represented by the diamonds. These values are outside of the range in the case of the β₀ = 100 simulation, thus they are presented separately in the lower panel. The intermediate and maximum eigenvalues are represented by circles and squares, respectively.