Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analytic Approaches to the Evolution of Polarised Parton Distributions
  at Small $x$   The $Q^2$ evolution of polarised parton distributions at small $x$ is
studied. Various analytic approximations are critically discussed. We compare
the full evolution with that obtained from the leading-pole approximation to
the splitting functions, and show that the validity of this approximation
depends critically on the $x \to 0$ behaviour of the starting distributions. A
new analytic solution which is valid at small $x$ is obtained, and its domain
of applicability is discussed.

21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg