  We propose to model the stochastic dynamics of a polymer passing through a
pore (translocation) by means of a fractional Brownian motion, and study its
behavior in presence of an absorbing boundary. Based on scaling arguments and
numerical simulations, we present a conjecture that provides a link between the
persistence exponent $\theta$ and the Hurst exponent $H$ of the process, thus
sheding light on the spatial and temporal features of translocation.
Furthermore, we show that this conjecture applies more generally to a broad
class of self affine processes undergoing anomalous diffusion in bounded
domains, and we discuss some significant examples.
