Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reconstructing the Primordial Spectrum from WMAP Data by the Cosmic
  Inversion Method   We reconstruct the primordial spectrum of the curvature perturbation, $P(k)$,
from the observational data of the Wilkinson Microwave Anisotropy Probe (WMAP)
by the cosmic inversion method developed recently. In contrast to conventional
parameter-fitting methods, our method can potentially reproduce small features
in $P(k)$ with good accuracy. As a result, we obtain a complicated oscillatory
$P(k)$. We confirm that this reconstructed $P(k)$ recovers the WMAP angular
power spectrum with resolution up to $\Delta \ell \simeq 5$. Similar
oscillatory features are found, however, in simulations using artificial cosmic
microwave background data generated from a scale-invariant $P(k)$ with random
errors that mimic observation. In order to examine the statistical significance
of the nontrivial features, including the oscillatory behaviors, therefore, we
consider a method to quantify the deviation from scale-invariance and apply it
to the $P(k)$ reconstructed from the WMAP data. We find that there are possible
deviations from scale-invariance around $k \simeq 1.5\times10^{-2}$ and
$2.6\times10^{-2}{\rm Mpc}^{-1}$.

26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph