Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Domain Wall Problem of Axion and Isocurvature Fluctuations in Chaotic
  Inflation Models   We study the domain wall problem of an axion in chaotic inflation models. We
show that the production of domain walls does not occurs if the Peccei-Quinn
scalar has a flat potential and its breaking $F_{a}$ is larger than $\sim
10^{15}$GeV. We find that too large isocurvature fluctuations are produced for
such high $F_{a}$. In order for those isocurvature fluctuations to be
consistent with observations of the large scale structure of the universe, the
self-coupling constant $g$ and the breaking scale of the Peccei-Quinn scalar
should be $g \simeq (1-2.8)\times 10^{-13}$ and $F_{a} \simeq (0.6-1.5)\times
10^{15}$GeV, respectively. In particular the value of self-coupling constant is
almost the same as that required for a chaotic inflation, which strongly
suggests that the Peccei-Quinn scalar itself is an inflaton.

16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc