Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discrete field theory: symmetries and conservation laws   We present a general algorithm constructing a discretization of a classical
field theory from a Lagrangian. We prove a new discrete Noether theorem
relating symmetries to conservation laws and an energy conservation theorem not
based on any symmetry. This gives exact conservation laws for several discrete
field theories: electrodynamics, gauge theory, Klein-Gordon and Dirac ones. In
particular, we construct a conserved discrete energy-momentum tensor,
approximating the continuum one at least for free fields. The theory is stated
in topological terms, such as coboundary and products of cochains.

22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int