Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A polynomial f(R) inflation model   Motivated by the ultraviolet complete theory of quantum gravity, for example
the string theory, we investigate a polynomial $f(R )$ inflation model in
detail. We calculate the spectral index and tensor-to-scalar ratio in the $f(R
)$ inflation model with the form of $f(R )=R+{R^2\over 6M^2}+{\lambda_n\over
2n}{R^n\over (3M^2)^{n-1}}$. Compared to Planck 2013, we find that $R^n$ term
should be exponentially suppressed, i.e. $|\lambda_n|\lesssim 10^{-2n+2.6}$.

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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom