Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamical effects of self-generated magnetic fields in cosmic ray
  modified shocks   Recent observations of greatly amplified magnetic fields ($\delta B/B\sim
100$) around supernova shocks are consistent with the predictions of the
non-linear theory of particle acceleration (NLT), if the field is generated
upstream of the shock by cosmic ray induced streaming instability. The high
acceleration efficiencies and large shock modifications predicted by NLT need
however to be mitigated to confront observations, and this is usually assumed
to be accomplished by some form of turbulent heating. We show here that
magnetic fields with the strength inferred from observations have an important
dynamical role on the shock, and imply a shock modification substantially
reduced with respect to the naive unmagnetized case. The effect appears as soon
as the pressure in the turbulent magnetic field becomes comparable with the
pressure of the thermal gas. The relative importance of this unavoidable effect
and of the poorly known turbulent heating is assessed. More specifically we
conclude that even in the cases in which turbulent heating may be of some
importance, the dynamical reaction of the field cannot be neglected, as instead
is usually done in most current calculations.

26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol