Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Poincare' invariance for continuous-time histories   We show that the relativistic analogue of the two types of time translation
in a non-relativistic history theory is the existence of two distinct
Poincar\'{e} groups. The `internal' Poincar\'{e} group is analogous to the one
that arises in the standard canonical quantisation scheme; the `external'
Poincar\'{e} group is similar to the group that arises in a Lagrangian
description of the standard theory. In particular, it performs explicit changes
of the spacetime foliation that is implicitly assumed in standard canonical
field theory.

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The categories of this paper are: eess
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex