TY - JOUR
A1 - Jeon, Jae-Hyung
A1 - Chechkin, Aleksei V.
A1 - Metzler, Ralf
T1 - Scaled Brownian motion: a paradoxical process with a time dependent diffusivity for the description of anomalous diffusion
JF - Physical chemistry, chemical physics : PCCP
N2 - Anomalous diffusion is frequently described by scaled Brownian motion (SBM){,} a Gaussian process with a power-law time dependent diffusion coefficient. Its mean squared displacement is ?x2(t)? [similar{,} equals] 2K(t)t with K(t) [similar{,} equals] t[small alpha]-1 for 0 < [small alpha] < 2. SBM may provide a seemingly adequate description in the case of unbounded diffusion{,} for which its probability density function coincides with that of fractional Brownian motion. Here we show that free SBM is weakly non-ergodic but does not exhibit a significant amplitude scatter of the time averaged mean squared displacement. More severely{,} we demonstrate that under confinement{,} the dynamics encoded by SBM is fundamentally different from both fractional Brownian motion and continuous time random walks. SBM is highly non-stationary and cannot provide a physical description for particles in a thermalised stationary system. Our findings have direct impact on the modelling of single particle tracking experiments{,} in particular{,} under confinement inside cellular compartments or when optical tweezers tracking methods are used.
KW - single-particle tracking
KW - living cells
KW - random-walks
KW - subdiffusion
KW - dynamics
KW - nonergodicity
KW - coefficients
KW - transport
KW - membrane
KW - behavior
Y1 - 2014
U6 - http://dx.doi.org/10.1039/C4CP02019G
VL - 30
IS - 16
SP - 15811
EP - 15817
PB - The Royal Society of Chemistry
CY - Cambridge
ER -
TY - GEN
A1 - Jeon, Jae-Hyung
A1 - Chechkin, Aleksei V.
A1 - Metzler, Ralf
T1 - Scaled Brownian motion: a paradoxical process with a time dependent diffusivity for the description of anomalous diffusion
N2 - Anomalous diffusion is frequently described by scaled Brownian motion (SBM){,} a Gaussian process with a power-law time dependent diffusion coefficient. Its mean squared displacement is ?x2(t)? [similar{,} equals] 2K(t)t with K(t) [similar{,} equals] t[small alpha]-1 for 0 < [small alpha] < 2. SBM may provide a seemingly adequate description in the case of unbounded diffusion{,} for which its probability density function coincides with that of fractional Brownian motion. Here we show that free SBM is weakly non-ergodic but does not exhibit a significant amplitude scatter of the time averaged mean squared displacement. More severely{,} we demonstrate that under confinement{,} the dynamics encoded by SBM is fundamentally different from both fractional Brownian motion and continuous time random walks. SBM is highly non-stationary and cannot provide a physical description for particles in a thermalised stationary system. Our findings have direct impact on the modelling of single particle tracking experiments{,} in particular{,} under confinement inside cellular compartments or when optical tweezers tracking methods are used.
T3 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 180
KW - single-particle tracking
KW - living cells
KW - random-walks
KW - subdiffusion
KW - dynamics
KW - nonergodicity
KW - coefficients
KW - transport
KW - membrane
KW - behavior
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-76302
SP - 15811
EP - 15817
ER -