Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On period maps that are open embeddings   For certain complex projective manifolds (such as K3 surfaces and their
higher dimensional analogues, the complex symplectic projective manifolds) the
period map takes values in a locally symmetric variety of type IV. It is often
an open embedding and in such cases it has been observed that the image is the
complement of a locally symmetric (Heegner) divisor. We explain that phenomenon
and get our hands on the complementary divisor in terms of geometric data.

18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph