Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Conformal Field Theory Approach to Quantum Impurity Problems   A brief review is given of a new method for studying the critical behavior of
quantum impurity problems, based on conformal field theory techniques, which I
developed with Andreas Ludwig. Some results on the overscreened Kondo problem
are reviewed. It is shown that the simple open and periodic fixed points, which
occur in quantum spin chain impurity models, are related to each other by
fusion.

11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
3
The categories of this paper are: physics
2
The categories of this paper are: math