Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Types of Observables in Constrained Theories   The Kuchar observables notion is shown to apply only to a limited range of
theories. Relational mechanics, slightly inhomogeneous cosmology and
supergravity are used as examples that require further notions of observables.
A suitably general notion of A-observables is then given to cover all of these
cases. `A' here stands for `algebraic substructure'; A-observables can be
defined by association with each closed algebraic substructure of a theory's
constraints. Both constrained algebraic structures and associated notions of
A-observables form bounded lattices.

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The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
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The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
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The categories of this paper are: astro-ph
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
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The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
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The categories of this paper are: adap-org