Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Conservation laws, uncertainty relations, and quantum limits of
  measurements   The uncertainty relation between the noise operator and the conserved
quantity leads to a bound for the accuracy of general measurements. The bound
extends the assertion by Wigner, Araki, and Yanase that conservation laws limit
the accuracy of ``repeatable'', or ``nondisturbing'', measurements to general
measurements, and improves the one previously obtained by Yanase for spin
measurements. The bound also sets an obstacle to making a small quantum
computer.

2
The categories of this paper are: math
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph