Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Calculations of scattering lengths in four-nucleon system on the basis
  of cluster reduction method for Yakubovsky equations   The cluster reduction method for the Yakubovsky equations in configuration
space is used for calculations of zero-energy scattering in four-nucleon
system. The main idea of the method consists in making use of expansions for
the Yakubovsky amplitudes onto the basis of the Faddeev components for the
two-cluster sub-Hamiltonian eigenfunctions. The expansions reduce the original
equations to ones for the functions depending on the relative coordinates
between the clusters. On the basis of the resulting equations the N-(NNN)
zero-energy scattering problems are solved numerically with the MT I-III model
for N-N forces and neglecting the Coulomb interaction between protons.

35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex