Oral: Microbial run and tumble dynamics modeled with orientational Levy flights

Run and tumble dynamics is a well studied topic. It is usually modeled as straight runs followed by random discrete tumbling events. Gaussian noise is often used to capture stochastic behavior during runs. We reduce this to a single continuous noise model with Levy flights in the orientational dynamics. This method can be used to model the orientation statistics for several microbial species. We find that the orientation statistics, in most cases, can be described by a Voigt profile (the convolution of a Gaussian and Lorentzian distribution). However, the Gaussian component of this distribution is not due to Gaussian noise, but due to the random nature of deterministic behavior across ensembles of non-interacting swimmers (i.e. circular arcs with different radii and helices of different frequencies and sizes). We provide an ensemble theory to capture this behavior. One advantage of this model is that it is analytically solvable in some cases. We also extend this model to study microbes in simple fluid flows.