Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Subnormal weighted shifts on directed trees whose nth powers have
  trivial domain   It is shown that for any positive integer n there exists a subnormal weighted
shift on a directed tree whose nth power is closed and densely defined while
its (n + 1)th power has trivial domain. Similar result for composition
operators in L2-spaces is established.

22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ