Two papers from the Soft, Biological and Statistical Physics group appeared in the 22nd April edition of Physical Review Letters.
Both papers relate to nonequilibrium statistical physics, which is a central research theme of the group. In essence, this concerns fundamental theories for forms of condensed matter that exhibit a current or flow of some kind. Although these systems are ubiquitous in nature, theories are still in their infancy. Both papers reveal surprising new information.
In the first - "Diffusion with Stochastic Resetting" by M. R. Evans and S. N. Majumdar, Phys. Rev. Lett. 106 160601 - the fundamental process of diffusion was re-examined when the diffusing particles returned at random times to the initial position. One way to visualise this is to imagine the process of looking for a lost item in a room by taking steps in a random direction, periodically returning to the starting position to begin the search anew. Evans and Majumdar found that this strategy of going back to the beginning can in fact drastically improve the time to locate the object.
The second paper - "Noise-induced dynamical transition in systems with symmetric absorbing states" by D. I. Russell and R. A. Blythe, Phys. Rev. Lett. 106 165702 - shows that the way in which regions of magnetic alignment grow in time depends on the scale of local fluctuations. The model discussed in this paper can also be used to describe the spread of behaviour (like language or fashions) in a human population. In this model, fluctuations increase with the willingness to forget one's existing behaviour, showing that behaviours might spread in a fundamentally different way in populations of culturally forgetful individuals than in those who have a long cultural memory.