Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unified formal reduction for fluid models of free-surface shallow
  gravity-flows   We propose a unified approach to the formal long-wave reduction of several
fluid models for thin-layer incompressible homogeneous flows driven by a
constant external force like gravity. The procedure is based on a mathematical
coherence property that univoquely defines one reduced model given one rheology
and one thin-layer regime. For the first time, as far as we know, various known
reduced models can thus be investigated within a single mathematical framework,
for various rheologies (viscous and viscoelastic) and various limit regimes
(fast inertial flows and slow viscous flows). Furthermore, our systematic
procedure also produces new reduced models for viscoelastic non-Newtonian
fluids and improves on our previous work [Bouchut & Boyaval, M3AS (23) 8,
2013].

17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg