Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constraining the double gluon distribution by the single gluon
  distribution   We show how to consistently construct initial conditions for the QCD
evolution equations for double parton distribution functions in the pure gluon
case. We use to momentum sum rule for this purpose and a specific form of the
known single gluon distribution function in the MSTW parameterization. The
resulting double gluon distribution satisfies exactly the momentum sum rule and
is parameter free. We also study numerically its evolution with a hard scale
and show the approximate factorization into product of two single gluon
distributions at small values of x, whereas at large values of x the
factorization is always violated in agreement with the sum rule.

35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math