Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tree-level Scattering Amplitude in de Sitter Space   In previous papers [1,2], it was proved that a covariant quantization of the
minimally coupled scalar field in de Sitter space is achieved through addition
of the negative norm states. This causal approach which eliminates the infrared
divergence, was generalized further to the calculation of the graviton
propagator in de Sitter space [3] and one-loop effective action for scalar
field in a general curved space-time [4]. This method gives a natural
renormalization of the above problems. Pursuing this approach, in the present
paper the tree-level scattering amplitudes of the scalar field, with one
graviton exchange, has been calculated in de Sitter space. It is shown that the
infrared divergence disappears and the theory automatically reaches a
renormalized solution of the problem.

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The categories of this paper are: math-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: econ
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
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The categories of this paper are: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-th