Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Propagation of ultra-high energy protons in the nearby universe   We present a new calculation of the propagation of protons with energies
above $10^{19}$ eV over distances of up to several hundred Mpc. The calculation
is based on a Monte Carlo approach using the event generator
  SOPHIA for the simulation of hadronic nucleon-photon interactions and a
realistic integration of the particle trajectories in a random extragalactic
magnetic field. Accounting for the proton scattering in the magnetic field
affects noticeably the nucleon energy as a function of the distance to their
source and allows us to give realistic predictions on arrival energy, time
delay, and arrival angle distributions and correlations as well as secondary
particle production spectra.

8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat