Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A tight Cram\'er-Rao bound for joint parameter estimation with a pure
  two-mode squeezed probe   We calculate the Holevo Cram\'er-Rao bound for estimation of the displacement
experienced by one mode of an two-mode squeezed vacuum state with squeezing r
and find that it is equal to 4exp(-2r). This equals the sum of the mean squared
error obtained from a dual homodyne measurement, indicating that the bound is
tight and that the dual homodyne measurement is optimal.

3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin