Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Potential. Solution of Poisson's Equation, Equations of Continuity and
  Elasticity   The modern theory of the potential does not give a solution of Poisson's
equation. In the present work its solution has been found via generalized
functions and a nonpotential solution of the continuity equation has been
obtained. The method is demonstrated by the solution of elasticity equations
using the example of a crack in the infinite specimen and a surface crack.
Their elastic energies have been calculated. In has been shown that there is no
critical condition for a crack in the infinite specimen and the crack always
closes. Only the surface crack possesses the critical condition.

25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin