Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutrino mean free path and in-medium nuclear interaction   Neutrinos produced during the collapse of a massive star are trapped in a
nuclear medium (the proto-neutron star). Typically, neutrino energies (10-100
MeV) are of the order of nuclear giant resonances energies. Hence, neutrino
propagation is modified by the possibility of coherent scattering on nucleons.
We have compared the predictions of different nuclear interaction models. It
turns out that their main discrepancies are related to the density dependence
of the k-effective mass as well as to the onset of instabilities as density
increases. This last point had led us to a systematic study of instabilities of
infinite matter with effective Skyrme-type interactions. We have shown that for
such interactions there is always a critical density, above which the system
becomes unstable.

5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int