Groupe de Physique Statistique

The motion of a tagged monomer in a long polymer is a remarkable example of sub-diffusion. Although the free motion of this anomalous walker can be studied analytically, its behavior inside an absorbing interval has been approached only numerically. First passage time and absorption problems are important for applications and give a better understanding of the nature of this anomalous diffusion. As a device for capturing part of these effects we replace the finite interval with an harmonic absorption. This problem can be treated analytically. The differences between this model and the diffusion fractional equations will be discussed.