1k citations · 2.5k across the 22 of their papers we have counts for
22 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…
Adaptive non-intrusive reconstruction of solutions to high-dimensional parametric PDEs
Martin Eigel, Nando Farchmin, Sebastian Heidenreich +1
Numerical methods for random parametric PDEs can greatly benefit from adaptive refinement schemes, in particular when functional approximations are computed as in stochastic Galerk…
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…
Efficient approximation of high-dimensional exponentials by tensornetworks
Martin Eigel, Nando Farchmin, Sebastian Heidenreich +1
In this work a general approach to compute a compressed representation of the exponential of a high-dimensional function is presented. Such exponential functions play…
Invertible Neural Networks versus MCMC for Posterior Reconstruction in Grazing Incidence X-Ray Fluorescence
Anna Andrle, Nando Farchmin, Paul Hagemann +3
Grazing incidence X-ray fluorescence is a non-destructive technique for analyzing the geometry and compositional parameters of nanostructures appearing e.g. in computer chips. In t…
Motility-Induced Clustering and Meso-Scale Turbulence in Active Polar Fluids
Vasco M. Worlitzer, Gil Ariel, Avraham Be'er +3
Meso-scale turbulence was originally observed experimentally in various suspensions of swimming bacteria, as well as in the collective motion of active colloids. The corresponding…
Heterogeneous bacterial swarms with mixed lengths
Shlomit Peled, Shawn D. Ryan, Sebastian Heidenreich +3
Heterogeneous systems of active matter exhibit a range of complex emergent dynamical patterns. In particular, it is difficult to predict the properties of the mixed system based on…
The anisotropy in the optical constants of quartz crystals for soft X-rays
A. Andrle, P. Hönicke, J. Vinson +5
The refractive index of a y-cut SiO crystal surface is reconstructed from polarization dependent soft X-ray reflectometry measurements in the energy range from 45 eV to 620 eV.…
Efficient Bayesian inversion for shape reconstruction of lithography masks
Nando Farchmin, Martin Hammerschmidt, Philipp-Immanuel Schneider +4
Background: Scatterometry is a fast, indirect and non-destructive optical method for quality control in the production of lithography masks. To solve the inverse problem in complia…
A phase diagram for bacterial swarming
Avraham Be`er, Bella Ilkanaiv, Renan Gross +4
Bacterial swarming is a rapid mass-migration, in which thousands of cells spread collectively to colonize a surface. Physically, swarming is a natural example of active particles t…
An efficient approach to global sensitivity analysis and parameter estimation for line gratings
Nando Farchmin, Martin Hammerschmidt, Philipp-Immanuel Schneider +4
Scatterometry is a fast, indirect and nondestructive optical method for the quality control in the production of lithography masks. Geometry parameters of line gratings are obtaine…
Self-Propelled Rods: Insights and Perspectives for Active Matter
Markus Bär, Robert Großmann, Sebastian Heidenreich +1
A wide range of experimental systems including gliding, swarming and swimming bacteria, in-vitro motility assays as well as shaken granular media are commonly described as self-pro…
Asymmetric pattern formation in microswimmer suspensions induced by orienting fields
Henning Reinken, Sebastian Heidenreich, Markus Bär +1
This paper studies the influence of orienting external fields on pattern formation, particularly mesoscale turbulence, in microswimmer suspensions. To this end, we apply a hydrodyn…
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…
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…
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…
M87 at metre wavelengths: the LOFAR picture
F. de Gasperin, E. Orru', M. Murgia +92
M87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4x10^9 M_sun, whose activity is responsible for the…
Meso-scale turbulence in living fluids
Henricus H. Wensink, Jörn Dunkel, Sebastian Heidenreich +4
Turbulence is ubiquitous, from oceanic currents to small-scale biological and quantum systems. Self-sustained turbulent motion in microbial suspensions presents an intriguing examp…
Minimal continuum theories of structure formation in dense active fluids
Jörn Dunkel, Sebastian Heidenreich, Markus Bär +1
Self-sustained dynamical phases of living matter can exhibit remarkable similarities over a wide range of scales, from mesoscopic vortex structures in microbial suspensions and mot…
Non-linear rheology of active particle suspensions: Insights from an analytical approach
Sebastian Heidenreich, Siegfried Hess, Sabine H. L. Klapp
We consider active suspensions in the isotropic phase subjected to a shear flow. Using a set of extended hydrodynamic equations we derive a variety of {\em analytical} expressions…