Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A note on positive definite, symplectic four-manifolds   We prove that a positive definite smooth four-manifold with $b_2^+ \geq 2$
and having either no 1-handles or no 3-handles cannot admit a symplectic
structure.

27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an