Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bertrand Partner D-Curves in Euclidean 3-space   In this paper we consider the idea of Bertrand curves for curves lying on
surfaces and by considering the Darboux frames of them we define these curves
as Bertrand D-curves and give the characterizations for these curves. We also
find the relations between the geodesic curvatures, the normal curvatures and
the geodesic torsions of these associated curves. Furthermore, we show that the
definition and the characterizations of Bertrand D-curves include those of
Bertrand curves in some special cases.

21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg