Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrahigh energy cosmic rays from a nearby extragalactic source in the
  diffusive regime   We study the effects that the diffusion of the cosmic rays in the magnetic
field of the Local Supercluster can have on the spectrum of a nearby
extragalactic source at ultrahigh energies. We find that the strong enhancement
of the flux below the energy at which the transition between the diffusive and
quasirectilinear regimes takes place, as well as the suppression at lower
energies associated with a finite source age, can help to explain the observed
features of the cosmic-ray spectrum and the composition. Scenarios are
discussed in which a nearby extragalactic source with mixed composition and
rigidity-dependent spectrum accounts for most of the observed cosmic rays at
energies above a few EeV while the rest of the extragalactic sources lead to a
diffuse flux that dominates at lower energies and down to $\sim 0.1$~EeV. The
nearby source can also naturally account for the dipolar anisotropy
measurements above 4~EeV, and these measurements can also help to constrain its
evolution with redshift.

17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
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The categories of this paper are: econ
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int