Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lanczos's functional theory of electrodynamics: A commentary on
  Lanczos's PhD dissertation   Lanczos's idea of classical electrodynamics as a biquaternionic field theory
in which point singularities are interpreted as electrons is reevaluated. Using
covariant quaternionic integration techniques developed by Paul Weiss in 1941,
we show that the Lagrangian suggested by Lanczos in his thesis of 1919 is
equivalent to the standard Lagrangian of classical electrodynamics. On the
mathematical side, Lanczos's thesis contains the correct generalizations of the
Cauchy-Riemann regularity conditions, and of Cauchy's formula, from complex
numbers to quaternions. Lanczos therefore anticipated Moisil-Fueter's discovery
of 1931 by more than 12 years.

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The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
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The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg