Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Novel Asymptotic Solution to the Sommerfeld Radiation Problem:
  Analytic field expressions and the emergence of the Surface Waves   The well-known "Sommerfeld radiation problem" of a small -Hertzian- vertical
dipole above flat lossy ground is reconsidered. The problem is examined in the
spectral domain, through which it is proved to yield relatively simple integral
expressions for the received Electromagnetic (EM) field. Then, using the Saddle
Point method, novel analytical expressions for the scattered EM field are
obtained, including sliding observation angles. As a result, a closed form
solution for the subject matter is provided. Also, the necessary conditions for
the emergence of the so-called Surface Wave are discussed as well. A complete
mathematical formulation is presented, with detailed derivations where
necessary.

30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph