Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What is the Magnetic Moment of the Electron?   A direct definition of the intrinsic magnetic moment of the electron is
given, which does not use infrared regularizations and interactions with
external fields. The expression does not depend on the unavoidable ambiguities
of the definition of a 1-electron state (exact form of its soft photon cloud).
The method leads to the same analytic expression as the conventional approach,
thus preserving the excellent agreement between theory and experiment.

8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys