Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometrical constraints on the tangling of bacterial flagellar filaments   Many species of bacteria swim through viscous environments by rotating
multiple helical flagella. The filaments gather behind the cell body and form a
close helical bundle, which propels the cell forward during a "run". The
filaments inside the bundle cannot be continuously actuated, nor can they
easily unbundle, if they are tangled around one another. The fact that bacteria
can passively form coherent bundles, i.e. bundles which do not contain tangled
pairs of filaments, may appear surprising given that flagella are actuated by
uncoordinated motors. In this article, we establish the theoretical conditions
under which a pair of rigid helical filaments can form a tangled bundle, and we
compare these constraints with experimental data collected from the literature.
Our results suggest that bacterial flagella are too straight and too far apart
to form tangled bundles based on their intrinsic, undeformed geometry alone.
This makes the formation of coherent bundles more robust against the passive
nature of the bundling process, where the position of individual filaments
cannot be controlled.

33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci