Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pre-inflationary genesis with CMB B-mode polarization   Recent B-mode polarization observation seems to imply the tensor tilt
$n_T\gtrsim 1$ at large angular scale, if the primordial signal is dominated.
We show that for a primordial universe, which is in a slowly expanding genesis
phase before the slow-roll inflation, the primordial tensor spectrum will get a
large-scale cutoff, i.e. $n_T\gtrsim 1$ at large scales while $n_T\simeq 0$ at
small scale. We find that this inflationary scenario not only may be consistent
with the observation, but also predicts a large-scale anomaly in BB power
spectrum, i.e. due to the large suppression of tensor perturbation amplitude we
will hardly see the reionization bump at low-$l$, which may be falsified by the
Planck polarization data.

12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex