1.1k citations · 3.2k across the 28 of their papers we have counts for
28 papers
Pattern selection and the route to turbulence in incompressible polar active fluids
Henning Reinken, Sebastian Heidenreich, Markus Bär +1
Active fluids, such as suspensions of microswimmers, are known to self-organize into complex spatio-temporal flow patterns. An intriguing example is mesoscale turbulence, a state o…
MedalCare-XL: 16,900 healthy and pathological 12 lead ECGs obtained through electrophysiological simulations
Karli Gillette, Matthias A. F. Gsell, Claudia Nagel +8
Mechanistic cardiac electrophysiology models allow for personalized simulations of the electrical activity in the heart and the ensuing electrocardiogram (ECG) on the body surface.…
Biophysics underlying the swarm to biofilm transition
Vasco M. Worlitzer, Ajesh Jose, Ilana Grinberg +5
Bacteria organize in a variety of collective states, from swarming, which has been attributed to rapid surface exploration, to biofilms, which are highly dense immobile communities…
Turbulence-induced clustering in compressible active fluids
Vasco M. Worlitzer, Gil Ariel, Avraham Be'er +3
We study a novel phase of active polar fluids, which is characterized by the continuous creation and destruction of dense clusters due to self-sustained turbulence. This state aris…
Ising-like critical behavior of vortex lattices in an active fluid
Henning Reinken, Sebastian Heidenreich, Markus Bär +1
Turbulent vortex structures emerging in bacterial active fluids can be organized into regular vortex lattices by weak geometrical constraints such as obstacles. Here we show, using…
Derivation of a hydrodynamic theory for mesoscale dynamics in microswimmer suspensions
Henning Reinken, Sabine H. L. Klapp, Markus Bär +1
In this paper we systematically derive a fourth-order continuum theory capable of reproducing mesoscale turbulence in a three-dimensional suspension of microswimmers. We start from…
Extinction spectra of suspensions of microspheres: Determination of spectral refractive index and particle size distribution with nanometer accuracy
Jonas Gienger, Markus Bär, Jörg Neukammer
A method is presented to infer simultaneously the wavelength-dependent real refractive index (RI) of the material of microspheres and their size distribution from extinction measur…
Mesoscale pattern formation of self-propelled rods with velocity reversal
Robert Großmann, Fernando Peruani, Markus Bär
We study self-propelled particles with velocity reversal interacting by uniaxial (nematic) alignment within a coarse-grained hydrodynamic theory. Combining analytical and numerical…
Diffusion properties of active particles with directional reversal
Robert Großmann, Fernando Peruani, Markus Bär
The diffusion properties of self-propelled particles which move at constant speed and, in addition, reverse their direction of motion repeatedly are investigated. The internal dyna…
Hydrodynamic length-scale selection and effective viscosity in microswimmer suspensions
Sebastian Heidenreich, Jörn Dunkel, Sabine H. L. Klapp +1
A universal characteristic of mesoscale turbulence in active suspensions is the emergence of a typical vortex length scale, distinctly different from the scale-invariance of turbul…
Superdiffusion, large-scale synchronization and topological defects
Robert Großmann, Fernando Peruani, Markus Bär
We study an ensemble of random walkers carrying internal noisy phase oscillators which are synchronized among the walkers by local interactions. Due to individual mobility, the int…
Pattern formation in active particle systems due to competing alignment interactions
Robert Großmann, Pawel Romanczuk, Markus Bär +1
Recently, we proposed a self-propelled particle model with competing alignment interactions: nearby particles tend to align their velocities whereas they anti-align their direction…
A geometric approach to self-propelled motion in isotropic and anisotropic environments
Robert Großmann, Fernando Peruani, Markus Bär
We propose a geometric perspective to describe the motion of self-propelled particles moving at constant speed in d dimensions. We exploit the fact that the vector that conveys the…
Spatio-temporal dynamics induced by competing instabilities in two asymmetrically coupled nonlinear evolution equations
David Schueler, Sergio Alonso, Alessandro Torcini +1
Pattern formation often occurs in spatially extended physical, biological and chemical systems due to an instability of the homogeneous steady state. The type of the instability us…
Vortex arrays and meso-scale turbulence of self-propelled particles
Robert Grossmann, Pawel Romanczuk, Markus Bär +1
Inspired by the Turing mechanism for pattern formation, we propose a simple self-propelled particle model with short-ranged alignment and anti-alignment at larger distances. It is…
Cluster dynamics and cluster size distributions in systems of self-propelled particles
Fernando Peruani, Lutz Schimansky-Geier, Markus Baer
Systems of self-propelled particles (SPP) interacting by a velocity alignment mechanism in the presence of noise exhibit a rich clustering dynamics. It can be argued that clusters…
Dynamics of reaction-diffusion patterns controlled by asymmetric nonlocal coupling as limiting case of differential advection
Julien Siebert, Sergio Alonso, Markus Bär +1
A one-component bistable reaction-diffusion system with asymmetric nonlocal coup ling is derived as limiting case of a two-component activator-inhibitor reaction -diffusion model w…
An active poroelastic model for mechanochemical patterns in protoplasmic droplets of Physarum polycephalum
Markus Radszuweit, Harald Engel, Markus Bär
Motivated by recent experimental studies, we derive and analyze a twodimensional model for the contraction patterns observed in protoplasmic droplets of Physarum polycephalum. The…
A kinetic model and scaling properties for non-equilibrium clustering of self-propelled particles
Fernando Peruani, Markus Baer
We demonstrate that the clustering statistics and the corresponding phase transition to non-equilibrium clustering found in many experiments and simulation studies with self-propel…
Fluid dynamics of bacterial turbulence
Jörn Dunkel, Sebastian Heidenreich, Knut Drescher +3
Self-sustained turbulent structures have been observed in a wide range of living fluids, yet no quantitative theory exists to explain their properties. We report experiments on act…
Polar vs. apolar alignment in systems of polar self-propelled particles
Fernando Peruani, Francesco Ginelli, Markus Bar +1
The symmetry of the alignment mechanism in systems of polar self-propelled particles determines the possible macroscopic large-scale patterns that can emerge. Here we compare polar…
Propagation Of Waves In Periodic-Heterogeneous Bistable Systems
Jakob Löber, Markus Bär, Harald Engel
Wave propagation in one-dimensional heterogeneous bistable media is studied using the Schlögl model as a representative example. Starting from the analytically known traveling wave…
Active Brownian Particles. From Individual to Collective Stochastic Dynamics
Pawel Romanczuk, Markus Bär, Werner Ebeling +2
We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a pa…
Large-scale collective properties of self-propelled rods
F. Ginelli, F. Peruani, M. Baer +1
We study, in two space dimensions, the large-scale properties of collections of constant-speed polar point particles interacting locally by nematic alignment in the presence of noi…