Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variational Problems in Elastic Theory of Biomembranes, Smectic-a Liquid
  Crystals, and Carbon Related Structures   After a brief introduction to several variational problems in the study of
shapes of thin thickness structures, we deal with variational problems on
2-dimensional surface in 3-dimensional Euclidian space by using exterior
differential forms. The morphological problems of lipid bilayers and
stabilities of cell membranes are also discussed. The key point is that the
first and the second order variations of the free energy determine equilibrium
shapes and mechanical stabilities of structures.

16
The categories of this paper are: stat
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph