Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A nucleation and growth model for COVID-19 epidemic in Japan   COVID-19 epidemics in Japan and Tokyo were analyzed by a fundamental equation
of the dynamic phase transition. As a result, the epidemic was found to be in
good agreement with the random nucleation and linear growth model suggesting
that the epidemic between March 13, 2020 and May 22, 2020 was simply
rate-limited by the three constant-parameters: the initial susceptible, domain
growth rate, and nucleation decay constant. This model provides a good
predictor of the epidemic because it consists of one equation and the initial
specific plot is linear.

11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
18
The categories of this paper are: econ
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn