Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Branching rules of semi-simple Lie algebras using affine extensions   We present a closed formula for the branching coefficients of an embedding p
in g of two finite-dimensional semi-simple Lie algebras. The formula is based
on the untwisted affine extension of p. It leads to an alternative proof of a
simple algorithm for the computation of branching rules which is an analog of
the Racah-Speiser algorithm for tensor products. We present some simple
applications and describe how integral representations for branching
coefficients can be obtained. In the last part we comment on the relation of
our approach to the theory of NIM-reps of the fusion rings of WZW models with
chiral algebra g_k. In fact, it turns out that for these models each embedding
p in g induces a NIM-rep at level k to infinity. In cases where these NIM-reps
can be be extended to finite level, we obtain a Verlinde-like formula for
branching coefficients.

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The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: cs
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: q-bio
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
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The categories of this paper are: plasm-ph
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The categories of this paper are: physics