Figure 4

Model’s discriminative power. Panel (a) behavior of the logarithm of the normalized DW-NMR signal divided by \(g^2\) as a function of \(\Delta\), obtained from synthetic NMR signals of BM and SS model at two different g. We used a Gamma distribution as P(D) with \(\theta =2\times 10^{-9}\; {\text {m}}^2~{\text {s}}^{-1}\) and \(k=0.5\). The other parameters are: \(D=2\times 10^{-9} \; {\text {m}}^2~{\text {s}}^{-1}\) and \(\delta =0.01\) s. Panel (b) behavior of the same quantity as in panel (a), obtained from synthetic NMR signals of FBM and CTRW with \(\alpha =0.5\), \(D_{\alpha }=2\times 10^{-9}\; {\text {m}}^2~{\text {s}}^{-\alpha }\) and \(\delta =0.01\) s. The different gradient rescaling of the curves is apparent and it is due to the fact that BM and FBM are based on Gaussian processes satisfying (6) and (7), while SS and CTRW are not.