Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutrinos from SN 1987A: Can they tell even more ?   The neutrino signal from SN~1987A provides an excellent opportunity to
constrain physical theories for matter at extreme conditions and properties of
particles that are produced in supernova (SN) cores. Phase transitions in the
supranuclear equation of state (EOS) may change the cooling history of the
collapsed stellar core and may even lead to a collapse of the protoneutron star
to a black hole on a time scale of several seconds. The implications of such a
scenario for the characteristics of the neutrino emission are tested. Moreover,
the consequences of a reduction of the neutrino opacities by a possible
suppression of the axial-vector interaction in a dense medium (Raffelt and
Seckel 1994) are investigated. Since the strongest constraints from SN~1987A
for the considered theories rely on the signal duration marked by the last
three events in Kamiokande, we also discuss attempts to explain these events
different from the standard protoneutron star cooling scenario. In particular,
attention is focussed on the scenario of a rapid cooling of the protoneutron
star within the time interval of the first 8 Kamiokande events or the IMB
signal which is only about 2--$5\,{\rm s}$. Such a short neutrino emission
could be the consequence of low neutrino opacities or convectively enhanced
neutrino transport. Since the driving force of neutrino heating around the
protoneutron star diminishes, the pressure support of the overlying material
decreases and some matter might fall back to the neutron star. However,
analytical estimates and numerical simulations indicate that the neutrino
emission associated with the accretion of this material is hardly energetic
enough to account for the last bunch of neutrinos at Kamiokande.

16
The categories of this paper are: stat
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph