Computational model representing real-world systems are always affected by uncertainties; these are related either to assumptions and simplification in the physical models or to variability in the operating scenarios.  Uncertainty Quantification (UQ) is, therefore, an i

The probability (''persistence'') that a real stochastic variable retains its initial sign up to time $t$ is proven to be represented by the tau-function of a sixth Painlev\'e equation whose monodromy exponents are identical to those of Bonnet surfaces.