Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On rotations in front form dynamics   Quantum field theories in front-form dynamics are not manifestly rotationally
invariant. We study a model bound-state equation in 3+1 dimensional front-form
dynamics, which was shown earlier to reproduce the Bohr and hyperfine structure
of positronium. We test this model with regard to its rotational symmetry and
find that rotational invariance is preserved to a high degree. Also, we find
and quantify the expected dependence on the cut-off.

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
1
The categories of this paper are: cs
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga