Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Alternative Structures and Bihamiltonian Systems   In the study of bi-Hamiltonian systems (both classical and quantum) one
starts with a given dynamics and looks for all alternative Hamiltonian
descriptions it admits.In this paper we start with two compatible Hermitian
structures (the quantum analog of two compatible classical Poisson brackets)
and look for all the dynamical systems which turn out to be bi-Hamiltonian with
respect to them.

35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph