Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: From Hardy Spaces to Quantum Jumps: A Quantum Mechanical Beginning of
  Time   In quantum mechanical experiments one distinguishes between the state of an
experimental system and an observable measured in it. Heuristically, the
distinction between states and observables is also suggested in scattering
theory or when one expresses causality. We explain how this distinction can be
made also mathematically. The result is a theory with asymmetric time evolution
and for which decaying states are exactly unified with resonances. A
consequence of the asymmetric time evolution is a beginning of time. The
meaning of this beginning of time can be understood by identifying it in data
from quantum jumps experiments.

0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex