Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Confluences of exceptional points and a systematic classification of
  quantum catastrophes   Specific quantum phase transitions of our interest are assumed associated
with the fall of a closed, unitary quantum system into its exceptional-point
(EP) singularity. The physical realization of such a "quantum catastrophe"
(connected, typically, with an instantaneous loss of the diagonalizability of
the corresponding parameter-dependent Hamiltonian $H(g)$) depends, naturally,
on the formal mathematical characteristics of the EP, i.e., in essence, on its
so called algebraic multiplicity $N$ and geometric multiplicity $K$. In our
paper we assume that both of them are finite, and we illustrate and discuss,
using several solvable toy models, some of the most elementary mechanisms of
the EP-merger realization of the process of the transition $g \to g^{(EP)}$.

33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio