Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radially Self-Accelerating Beams   We report on optical non-paraxial beams that exhibit a self-accelerating
behavior in radial direction. Our theory shows that those beams are solutions
to the full scalar Helmholtz equation and that they continuously evolve on
spiraling trajectories. We provide a detailed insight into the theoretical
origin of the beams and verify our findings on an experimental basis.

4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs