Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Four Lectures on the Physics of Crystal Growth   Several aspects of the theory of epitaxial crystal growth from atomic or
molecular beams are developed from the perspective of statistical physics.
Lectures are devoted to the rate equation theory of two-dimensional nucleation
and its limitations; the growth of multilayer wedding cakes in the presence of
strong step edge barriers; the continuum theory of mound coarsening; and
growth-induced step meandering on vicinal surfaces.

27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
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The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin