A method for detecting nonequilibrium dynamics in active matter

Active force generation is an important class of out-of-equilibrium activity in cells. These forces play a crucial role in vital processes such as tissue folding, cell division and intracellular transport. It is important to determine the extent of such nonequilibrium activity during cellular processes to understand cell function. Here we present a framework for measuring nonequilibrium activity in biological active matter using time reversal asymmetry based on the Kullbeck-Leibler Divergence (KLD), also known as relative entropy. We estimate the KLD from a stationary time series using a k-nearest neighbors estimator, comparing the time-forwards process to the time-reversed process Using time series data of probe particles embedded in the actin cortex, we establish a lower bound for the entropy production of cortical activity. Our results demonstrate a reliable way to measure the breaking of detailed balance in mesoscopic systems.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2018

Author dc:creator

• Watson, Garrett (Garrett A.)

Advisor dc:contributor.advisor

• Nikta Fakhri.

• Physics.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/120209

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/120209