Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Montevideo Interpretation: How the inclusion of a Quantum
  Gravitational Notion of Time Solves the Measurement Problem   We review the Montevideo Interpretation of quantum mechanics, which is based
on the use of real clocks to describe physics, using the framework recently
introduced by Hoehn, Smith and Lock to treat the problem of time in generally
covariant systems. The use of the new formalism makes the whole construction
more accessible to readers without familiarity with totally constrained
systems. We find that as in the original formulation, a fundamental mechanism
of decoherence emerges that allows to supplement ordinary environmental
decoherence and avoid its criticisms. Recent results on quantum complexity
provide additional support to the type of global protocols used to prove that
within ordinary -- unitary -- quantum mechanics no definite event -- an outcome
to which a probability can be associated -- occurs. In lieu of this, states
that start in a coherent superposition of possible outcomes always remain as a
superposition. We show that, if one takes into account fundamental inescapable
uncertainties in measuring length and time intervals due to general relativity
and quantum mechanics, the previously mentioned global protocols no longer
allow to distinguish whether the state is in a superposition or not. One is
left with a formulation of quantum mechanics purely defined in quantum
mechanical terms without any reference to the classical world and with an
intrinsic operational definition of quantum events that does not need external
observers.

19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph