Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Maxwell Matters   Charges are everywhere because most atoms are charged. Chemical bonds are
formed by electrons with their charge. Charges move and interact according to
Maxwell's equations in space and in atoms where the equations of
electrodynamics are embedded in Schroedinger's equation as the potential.
Maxwell's equations are universal, valid inside atoms and between stars from
times much shorter than those of atomic motion (0.1 femtoseconds) to years (32
mega-seconds). Maxwell's equations enforce the conservation of current.
Analysis shows that the electric field can take on whatever value is needed to
ensure conservation of current. The properties of matter rearrange themselves
to satisfy Maxwell's equations and conservation of current. Conservation of
current is as universal as Maxwell's equations themselves. Yet equations of
electrodynamics find little place in the literature of material physics,
chemistry, or biochemistry. Kinetic models of chemistry and Markov treatments
of atomic motion are ordinary differential equations in time and do not satisfy
conservation of current unless modified significantly. Systems at equilibrium,
without macroscopic flow, have thermal fluctuating currents that are conserved
according to the Maxwell equations although their macroscopic averages are
zero. The macroscopic consequences of atomic scale fluctuating thermal currents
are not known but are likely to be substantial because of the nonlinear
interactions in systems like these, in which 'everything interacts with
everything else'.
  Conclusion: current needs to be conserved in models of material systems, even
in simplified versions.

16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol