TY - UNPB

T1 - Active fractal networks with stochastic force monopoles and force dipoles unravel subdiffusion of chromosomal loci

AU - Singh, Sadhana

AU - Granek, Rony

N1 - 18 pages: 6 pages - main text, and 12 pages - Supplemental. 12 figues: 4 figures - main text, and 8 figures -s Supplemental

PY - 2023/7/23

Y1 - 2023/7/23

N2 - We study the Rouse-type dynamics of elastic fractal networks with embedded, stochastically driven, active force monopoles and dipoles, that are temporally correlated. We compute, analytically -- using a general theoretical framework -- and via Langevin dynamics simulations, the mean square displacement of a network bead. Following a short-time super-diffusive behavior, force monopoles yield anomalous subdiffusion with an exponent identical to that of the thermal system. Force dipoles do not induce subdiffusion, and result in rotational motion of the whole network -- as found for micro-swimmers -- and network collapses beyond a critical force amplitude. The collapse persists with increasing system size, signifying a true first-order dynamical phase transition. We conclude that the observed identical subdiffusion exponents of chromosomal loci in normal and ATP-depleted cells are attributed to active force monopoles rather than force dipoles.

AB - We study the Rouse-type dynamics of elastic fractal networks with embedded, stochastically driven, active force monopoles and dipoles, that are temporally correlated. We compute, analytically -- using a general theoretical framework -- and via Langevin dynamics simulations, the mean square displacement of a network bead. Following a short-time super-diffusive behavior, force monopoles yield anomalous subdiffusion with an exponent identical to that of the thermal system. Force dipoles do not induce subdiffusion, and result in rotational motion of the whole network -- as found for micro-swimmers -- and network collapses beyond a critical force amplitude. The collapse persists with increasing system size, signifying a true first-order dynamical phase transition. We conclude that the observed identical subdiffusion exponents of chromosomal loci in normal and ATP-depleted cells are attributed to active force monopoles rather than force dipoles.

KW - cond-mat.soft

KW - cond-mat.stat-mech

M3 - Preprint

BT - Active fractal networks with stochastic force monopoles and force dipoles unravel subdiffusion of chromosomal loci

ER -