In this paper we address the solution of linear systems of equations with multiple right-hand sides given at once. When the dimension of the problem is known to be large, preconditioned block Krylov subspace methods are usually considered as the method of choice. Nevertheless to be effective in terms of computational operations it is known that these methods must incorporate a strategy for dete...

T he notion that information has physical, and in particular, thermodynamic, content can be traced to the paradox of Maxwell’s demon, a sly creature who observes the microscopic motions of gas particles on both sides of a partition (1). By controlling a trap door the demon segregates fast particles from slow ones to create a temperature difference across the partition, seemingly without expendi...

In a recent Letter in Nature, Gaspard et al. 1] claimed to present empirical evidence for microscopic chaos on a molecular scale from an ingenious experiment using a time series of the positions of a Brownian particle in a liquid. The Letter was preceded by a lead article 2] emphasising the fundamental nature of the experiment. In this note we demonstrate that virtually identical results can be...