Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surfing and crawling macroscopic active particles under strong
  confinement -- inertial dynamics   We study two types of active (self-propelled) macroscopic particles under
confinement: camphor surfers and hexbug crawlers, using a combined
experimental, theoretical, and numerical approach. Unlike widely studied
microscopic active particles and swimmers, where thermal forces are often
important and inertia is negligible, our macroscopic particles exhibit complex
dynamics due expressly to active non-thermal noise combined with inertial
effects. Strong confinement induces accumulation at a finite distance within
the boundary and gives rise to three distinguishable dynamical states; both
depending on activity and inertia. These surprisingly complex dynamics arise
already at the single particle level -- highlighting the importance of inertia
in macroscopic active matter.

17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys