Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analytical operator solution of master equations describing
  phase-sensitive processes   We present a method of solving master equations which may describe, in their
most general form, phase sensitive processes such as decay and amplification.
We make use of the superoperator technique.

18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph