Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Birth of de Sitter Universe from time crystal   We show that a simple sub-class of Horndeski theory can describe a time
crystal Universe. The time crystal Universe can be regarded as a baby Universe
nucleated from a flat space, which is mediated by an extension of
Giddings-Strominger instanton in a 2-form theory dual to the Horndeski theory.
Remarkably, when a cosmological constant is included, de Sitter Universe can be
created by tunneling from the time crystal Universe. It gives rise to a past
completion of an inflationary Universe.

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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
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The categories of this paper are: stat
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The categories of this paper are: mtrl-th
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
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The categories of this paper are: comp-gas
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: funct-an