Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Chaos and Quantum Randomness - Paradigms of Entropy Production
  on the Smallest Scales   Quantum chaos is presented as a paradigm of information processing by
dynamical systems at the bottom of the range of phase-space scales. Starting
with a brief review of classical chaos as entropy flow from micro- to
macro-scales, I argue that quantum chaos came as an indispensable
rectification, removing inconsistencies related to entropy in classical chaos:
Bottom-up information currents require an inexhaustible entropy production and
a diverging information density in phase space, reminiscent of Gibbs' paradox
in Statistical Mechanics. It is shown how a mere discretization of the state
space of classical models already entails phenomena similar to hallmarks of
quantum chaos, and how the unitary time evolution in a closed system directly
implies the ''quantum death'' of classical chaos. As complementary evidence, I
discuss quantum chaos under continuous measurement. Here, the two-way exchange
of information with a macroscopic apparatus opens an inexhaustible source of
entropy and lifts the limitations implied by unitary quantum dynamics in closed
systems. The infiltration of fresh entropy restores permanent chaotic dynamics
in observed quantum systems. Could other instances of stochasticity in quantum
mechanics be interpreted in a similar guise? Where observed quantum systems
generate randomness, that is, produce entropy without discernible source, could
it have infiltrated from the macroscopic meter? This speculation is worked out
for the case of spin measurement.

22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
19
The categories of this paper are: eess
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
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The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math