Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analytic infinite derivative gravity, $R^2$-like inflation, quantum
  gravity and CMB   Emergence of $R^2$ inflation which is the best fit framework for CMB
observations till date comes from the attempts to attack the problem of
quantization of gravity which in turn have resulted in the trace anomaly
discovery. Further developments in trace anomaly and different frameworks
aiming to construct quantum gravity indicate an inevitability of non-locality
in fundamental physics at small time and length scales. A natural question
would be to employ the $R^2$ inflation as a probe for signatures of
non-locality in the early Universe physics. Recent advances of embedding $R^2$
inflation in a string theory inspired non-local gravity modification provides
very promising theoretical predictions connecting the non-local physics in the
early Universe and the forthcoming CMB observations.

15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci