Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A new possibility of the fast neutrino-flavor conversion in the
  pre-shock region of core-collapse supernova   We make a strong case that the fast neutrino-flavor conversion, one of the
collective flavor oscillation modes, commonly occurs in core-collapse
supernovae (CCSNe). It is confirmed in the numerical data obtained in realistic
simulations of CCSNe but the argument is much more generic and applicable
universally: the coherent neutrino-nucleus scattering makes the electron lepton
number (ELN) change signs at some inward direction and trigger the flavor
conversion in the outward direction in the pre-shock region. Although the ELN
crossing is tiny and that is why it has eluded recognition so far, it is still
large enough to induce the flavor conversion. Our findings will have an
important observational consequences for CCSNe neutrinos.

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The categories of this paper are: hep-ph
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn