Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lorentzian $CR$ structures and nonembeddability   In this paper we construct examples of $CR$ deformations of Lorentzian
hypersurfaces which are $CR$ embeddable at all points outside an arbitrarily
small compact set whose interior contains a point where $CR$ embeddablity is
not possible.

34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn