Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectral transition for Dirac operators with electrostatic
  $\delta$-shell potentials supported on the straight line   In this note the two dimensional Dirac operator $A_\eta$ with an
electrostatic $\delta$-shell interaction of strength $\eta\in\mathbb R$
supported on a straight line is studied. We observe a spectral transition in
the sense that for the critical interaction strengths $\eta=\pm 2$ the
continuous spectrum of $A_\eta$ inside the spectral gap of the free Dirac
operator $A_0$ collapses abruptly to a single point.

4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th