Thomas GUERIN

Research interests

My current research activity aims to characterize theoretically the stochastic dynamics  of complex objects (polymers, interfaces, assemblies of molecular motors or active particles, ….) or simple objects moving in a complex environement (such as a tracer in a heterogeneous medium or viscoelastic fluid). The general context is to understand out-of-equilibrium properties of such complex motion, such as calculating effective diffusivities (thus characterizing how fast a cloud of initially close particles will spread) or first passage times to a target (in which case absorbing conditions impose non-equilibrium steady states). My approach is based on analytical calculations, completed by numerical simulations. I also develop certain theoretical approaches to better understand some experiments developed in the LOMA. More specifically, up to now, I have worked on

– the dispersion in heterogeneous media, notably in presence of obstacles, potentially sticky,

– the theory of first passage times for non-Markovian random walks with memory,

– the effect of boundaries on the collective dynamics of self-propelled robots,

– the formation of conical interfaces between two non-miscible fluids under the action of  a laser,

– the collective dynamics of molecular motors, which can display oscillations or bidirectional motion,

– the theory of conformational transitions in viral capsids.

First passage problem: what is the statistics of the duration of trajectories starting from a source point (green star) and finding a target (red sphere) for the first time ?

Collaborations

David Dean (LOMA)

Olivier Bénichou, Raphaël Voituriez, Maxim Dolgushev (Laboratoire de Physique Théorique de la Matière Condensée, Paris)

Hamid Kellay, Jean-François Boudet (LOMA)

Yann Louyer, Yacine Amarouchène (LOMA)

Ulysse Delabre, Jean-Pierre Delville (LOMA)

Main publications

List of my publications on Hal Archive

[31] N Levernier, M Dolgushev, O Benichou, R Voituriez, T Guérin, Survival probability of stochastic processes beyond persistence exponents, Nature communications 10 (1), 2990 (2019)
[30] A Girot, J Petit, R Saiseau, T Guérin, H Chraibi, U Delabre, JP Delville, Conical Interfaces between Two Immiscible Fluids Induced by an Optical Laser Beam, Phys. Rev. Lett., 122 (17), 174501 (2019)
[29] Y Amarouchene, M Mangeat, BV Montes, L Ondic, T Guérin, DS Dean, Y Louyer, Nonequilibrium dynamics induced by scattering forces for optically trapped nanoparticles in strongly inertial regimes, Phys. Rev. Lett. 122 (18), 183901 (2019)
[25] A. Deblais, T. Barois, T. Guerin, P-H. Delville, R. Vaudaine, J. S. Lintuvuori, J. F. Boudet, J. C Baret, H. Kellay, Boundaries Control Collective Dynamics of Inertial Self-Propelled Robots. Phys. Rev. Lett., 120, 188002 (2018).
[19] T. Guérin, N. Levernier, O. Bénichou, R. Voituriez, Mean first-passage times of non-Markovian random walkers in confinement, Nature, 534, 356-359 (2016)
[16] M. Dolgushev, T. Guérin, A. Blumen, O. Bénichou, R. Voituriez, Contact kinetics in fractal macromolecules, Phys. Rev. Lett., 115, 208301 (2015)
[15] T. Guérin, D.S. Dean, Force-Induced Dispersion in Heterogeneous Media, Phys. Rev. Lett., 115, 020601 (2015)
[8] T. Guérin, O. Bénichou, and R. Voituriez, Non Markovian polymer reaction kinetics, Nature Chemistry, 4, 568-573 (2012)
[5] T. Guérin, J. Prost, and J.-F. Joanny, Motion Reversal of Molecular Motor Assemblies due to Weak Noise, Phys. Rev. Lett., 106, 068101 (2011)
[4] T. Guérin, J. Prost, and J.-F. Joanny, Dynamic Instabilities in Assemblies of Molecular Motors with Finite Stiffness, Phys. Rev. Lett., 104, 248102 (2010)
[2] P.-Y. Plaçais, M. Balland, T. Guérin, J.-F. Joanny, and P. Martin, Spontaneous Oscillations of a Minimal Actomyosin System under Elastic Loading, Phys. Rev. Lett., 103, 158102 (2009)

Curriculum vitae

Informations à venir…