TY  - JOUR
A1  - Schulz, Johannes H. P.
A1  - Barkai, Eli
A1  - Metzler, Ralf
T1  - Aging effects and population splitting in single-particle trajectoryaverages
JF  - Physical review letters
N2  - We study time averages of single particle trajectories in scale-free anomalous diffusion processes, in which the measurement starts at some time t(a) > 0 after initiation of the process at t = 0. Using aging renewal theory, we show that for such nonstationary processes a large class of observables are affected by a unique aging function, which is independent of boundary conditions or the external forces. Moreover, we discuss the implications of aging induced population splitting: with growing age ta of the process, an increasing fraction of particles remains motionless in a measurement of fixed duration. Consequences for single biomolecule tracking in live cells are discussed.
Y1  - 2013
U6  - https://doi.org/10.1103/PhysRevLett.110.020602
SN  - 0031-9007
SN  - 1079-7114
VL  - 110
IS  - 2
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Jeon, Jae-Hyung
A1  - Barkai, Eli
A1  - Metzler, Ralf
T1  - Noisy continuous time random walks
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2  - Experimental studies of the diffusion of biomolecules within biological cells are routinely confronted with multiple sources of stochasticity, whose identification renders the detailed data analysis of single molecule trajectories quite intricate. Here, we consider subdiffusive continuous time random walks that represent a seminal model for the anomalous diffusion of tracer particles in complex environments. This motion is characterized by multiple trapping events with infinite mean sojourn time. In real physical situations, however, instead of the full immobilization predicted by the continuous time random walk model, the motion of the tracer particle shows additional jiggling, for instance, due to thermal agitation of the environment. We here present and analyze in detail an extension of the continuous time random walk model. Superimposing the multiple trapping behavior with additive Gaussian noise of variable strength, we demonstrate that the resulting process exhibits a rich variety of apparent dynamic regimes. In particular, such noisy continuous time random walks may appear ergodic, while the bare continuous time random walk exhibits weak ergodicity breaking. Detailed knowledge of this behavior will be useful for the truthful physical analysis of experimentally observed subdiffusion.
Y1  - 2013
U6  - https://doi.org/10.1063/1.4816635
SN  - 0021-9606
SN  - 1089-7690
VL  - 139
IS  - 12
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - GEN
A1  - Barkai, Eli
A1  - Garini, Yuval
A1  - Metzler, Ralf
T1  - Electrostatic effects in living cells Reply
T2  - PHYSICS TODAY
Y1  - 2013
SN  - 0031-9228
SN  - 1945-0699
VL  - 66
IS  - 7
SP  - 11
EP  - 11
PB  - AMER INST PHYSICS
CY  - MELVILLE
ER  -