Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Assessing the collision nature of coronal mass ejections in the inner
  heliosphere   There have been few attempts in the past to understand the collision of
individual cases of interacting Coronal Mass Ejections (CMEs). We selected 8
cases of interacting CMEs and estimated their propagation and expansion speeds,
direction of impact and masses exploiting coronagraphic and heliospheric
imaging observations. Using these estimates with ignoring the errors therein,
we find that the nature of collision is perfectly inelastic for 2 cases (e.g.,
2012 March and November), inelastic for 2 cases (e.g., 2012 June and 2011
August), elastic for 1 case (e.g., 2013 October) and super-elastic for 3 cases
(e.g., 2011 February, 2010 May and 2012 September). Admitting large
uncertainties in the estimated directions, angular widths and pre-collision
speeds; the probability of perfectly inelastic collision for 2012 March and
November cases diverge from 98%-60% and 100%-40%, respectively, reserving some
probability for other nature of collision. Similarly, the probability of
inelastic collision diverge from 95%-50% for 2012 June case, 85%-50% for 2011
August case, and 75%-15% for 2013 October case. We note that probability of
super-elastic collision for 2011 February, 2010 May and 2012 September CMEs
diverge from 90%-75%, 60%-45% and 90%-50%, respectively. Although the sample
size is small, we find a good dependence of nature of collision on CMEs
parameters. The crucial pre-collision parameters of the CMEs responsible for
increasing the probability of super-elastic collision, in descending order of
priority, are their lower approaching speed, higher expansion speed of the
following CME over the preceding one, and longer duration of collision phase.

2
The categories of this paper are: math
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int