Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An extremal effective survey about extremal effective cycles in moduli
  spaces of curves   We survey recent developments and open problems about extremal effective
divisors and higher codimension cycles in moduli spaces of curves.

21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci