Narrow escape problem (nonfiction)

The soldier in this picture represents a Brownian particle seeking a narrow escape through a window.

The narrow escape problem is a ubiquitous problem in biology, biophysics and cellular biology.

The formulation is the following: a Brownian particle (ion, molecule, or protein) is confined to a bounded domain (a compartment or a cell) by a reflecting boundary, except for a small window through which it can escape.

The narrow escape problem is that of calculating the mean escape time.

This time diverges as the window shrinks, thus rendering the calculation a singular perturbation problem.

Fiction cross-reference

• Brownian racket

Nonfiction cross-reference

• Brownian motion (nonfiction)

External links:

• Narrow escape problem @ Wikipedia