MPIDS Colloquium: Quantifying memory effects in random search processes

MPIDS Colloquium

  • Date: Oct 7, 2021
  • Time: 02:15 PM - 03:15 PM (Local Time Germany)
  • Speaker: Prof. Dr. Raphaël Voituriez
  • CNRS / Sorbonne, Paris, France
  • Location: Max-Planck-Institut für Dynamik und Selbstorganisation (MPIDS)
  • Room: Video conference at www.zoom.us Meeting ID: 959 2774 3389 Passcode: 651129
  • Host: MPIDS / LMP
  • Contact: golestanian-office@ds.mpg.de
A general question that arises in random walk theory is the quantification of space exploration by a random walker. A key observable is provided by the first-passage time, which quantifies the kinetics of general target search problems, and as such has a broad range of applications from diffusion limited reactions at the molecular scale, to immune cells patrolling tissues to find antigens, or larger scale organisms looking for resources.

I will present asymptotic results which enable the determination of the first-passage time statistics to a target site for a wide range of random processes, and show how these results generalize to non- Markovian processes, which are needed to model complex searchers with memory skills. I will discuss how these results can be used to assess the optimality of general random search processes. An explicit example of a cellular system where long-range memory effects emerge will be given.
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