Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: KPII: Cauchy-Jost function, Darboux transformations and totally
  nonnegative matrices   Direct definition of the Cauchy-Jost (known also as Cauchy-Baker-Akhiezer)
function in the case of pure solitonic solution is given and properties of this
function are discussed in detail using the Kadomtsev-Petviashvili II equation
as example. This enables formulation of the Darboux transformations in terms of
the Cauchy-Jost function and classification of these transformations. Action of
Darboux transformations on Grassmanians-i.e., on the space of soliton
parameters-is derived and relation of the Darboux transformations with property
of total nonnegativity of elements of corresponding Grassmanians is discussed.

22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph