Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First-order aggregation models with alignment   We include alignment interactions in a well-studied first-order
attractive-repulsive macroscopic model for aggregation. The distinctive feature
of the extended model is that the equation that specifies the velocity in terms
of the population density, becomes {\em implicit}, and can have non-unique
solutions. We investigate the well-posedness of the model and show rigorously
how it can be obtained as a macroscopic limit of a second-order kinetic
equation. We work within the space of probability measures with compact support
and use mass transportation ideas and the characteristic method as essential
tools in the analysis. A discretization procedure that parallels the analysis
is formulated and implemented numerically in one and two dimensions.

19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph