Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quark-cluster Stars: hints from the surface   The matter inside pulsar-like compact stars could be in a quark-cluster phase
since in cold dense matter at a few nuclear densities (2 to 10 times), quarks
could be coupled still very strongly and condensate in position space to form
quark clusters. Quark-cluster stars are chromatically confined and could
initially be bare, therefore the surface properties of quark-cluster stars
would be quite different from that of conventional neutron stars. Some facts
indicate that a bare and self-confined surface of pulsar-like compact stars
might be necessary in order to naturally understand different observational
manifestations. On one hand, as for explaining the drifting sub-pulse
phenomena, the binding energy of particles on pulsar surface should be high
enough to produce vacuum gaps, which indicates that pulsar's surface might be
strongly self-confined. On the other hand, a bare surface of quark-cluster star
can overcome the baryon contamination problem of Gamma-ray burst as well as
promote a successful core-collapse supernova. What is more, the non-atomic
thermal spectra of dead pulsars may indicate also a bare surface without
atmosphere, and the hydrocyclotron oscillation of the electron sea above the
quark-cluster star surface could be responsible for those absorption features
detected. These hints could reflect the property of compact star's surface and
possibly the state of condensed matter inside, and then might finally result in
identifying quark-cluster stars.

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The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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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: hep-th
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph
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The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg