Sandra Chapman Department of Physics, University of Warwick Universal fluctuations- extremal statistics in turbulence, models for critical phenomena, and football scores Thursday 3rd August 15-16pm, Carslaw Building Room 373. This talk is part of the ARC Complex Open Systems Research Network Distinguished Visitor Program. COSNet is funding this event. Scaling is an important feature of natural phenomena, arising in many degree of freedom systems that are highly correlated. These systems include a disparate range of phenomena and somewhat surprisingly they show a common signature in the statistics of fluctuations in a global measure of activity. This probability distribution function (PDF) has been compared numerically for a range of models including for out of equilibrium critical phenomena, notably a sandpile, a forest fire model, a depinning model and a stacking model for granular media. After normalization to the first two moments these PDF were found to collapse onto that in models for equilibrium critical phenomena. Curve collapse has also been demonstrated between the latter and a global measure of power dissipated in a closed turbulence experiment. We derive the functional form of this PDF explicitly from the assumption of scaling in a generic finite sized system. A single parameter that depends upon the details of the system specifies this curve. This may offer a direct insight into the origin of characteristic features of sandpiles and other complex systems, and offer a first step in generalizing the central limit theorem for correlated systems. This also opens up the possibility of using extremal statisitics to probe natural systems where a global observable is available, and we consider two examples, the highly intermittent X- ray flux from accretion disks, and the final scores from league football games.