Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Common Origin of Quantum Regression and Quantum Fluctuation Dissipation
  Theorems   It is shown that the quantum fluctuation dissipation theorem can be
considered as a mathematical formulation in the spectral representation of
Onsager hypothesis on the regression of fluctuations in physical systems. It is
shown that the quantum fluctuation dissipation theorem can be generalized to an
arbitrary stationary state.

22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th