Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Time-space duality in 2D quantum gravity   An important task faced by all approaches of quantum gravity is to
incorporate superpositions and quantify quantum uncertainties of spacetime
causal relations. We address this task in 2D. By identifying a global $Z_2$
symmetry of 1+1D quantum gravity, we show that gravitational path integral
configurations come in equal amplitude pairs with timelike and spacelike
relations exchanged. As a consequence, any two points are equally probable to
be timelike and spacelike separated in a universe without boundary conditions.
In the context of simplicial quantum gravity we identify a local symmetry of
the action which shows that even with boundary conditions causal uncertainties
are generically present. Depending on the boundary conditions, causal
uncertainties can still be large and even maximal.

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The categories of this paper are: cs
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph