Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Products of harmonic forms and rational curves   In general, the product of harmonic forms is not harmonic. We study the top
exterior power of harmonic two-forms on compact Kaehler manifolds. Often, it is
not harmonic. This phenomenon is related to the geometry of the manifold and to
the existence of rational curves in particular. K3 surfaces and hyperkaehler
manifolds are discussed in detail.

34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess