Séminaire du LPTMS: Lev Truskinovsky

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20/03/2018    
11:00 - 12:00

LPTMS, salle 201, 2ème étage, Bât 100, Campus d'Orsay
15 Rue Georges Clemenceau, Orsay, 91405
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Rigidity generation by nonthermal fluctuations and muscle contraction

Lev Truskinovsky (ESPCI, Paris)

Active stabilization in systems with zero or negative  stiffness is an essential element of a wide variety of technological processes. We discuss a prototypical example of this  phenomenon in a  biological setting and show how active rigidity, interpreted as a formation of a pseudo-well in the effective energy  landscape, can be generated in an over-damped stochastic system. We link the transition from negative to positive  rigidity with time correlations in the additive noise, and  show that subtle differences in the out-of-equilibrium  driving may compromise the emergence of a pseudo-well. We apply our results to the description of  the power  stroke machinery in skeletal muscles  which is behind their  remarkable  ability to take up an applied slack in a ms time  scale. Along the way we draw some interesting parallels between muscle  physiology and the theory of spin glasses.

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