Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Note on Local Ultrametricity in Text   High dimensional, sparsely populated data spaces have been characterized in
terms of ultrametric topology. This implies that there are natural, not
necessarily unique, tree or hierarchy structures defined by the ultrametric
topology. In this note we study the extent of local ultrametric topology in
texts, with the aim of finding unique ``fingerprints'' for a text or corpus,
discriminating between texts from different domains, and opening up the
possibility of exploiting hierarchical structures in the data. We use coherent
and meaningful collections of over 1000 texts, comprising over 1.3 million
words.

36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
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The categories of this paper are: astro-ph
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The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom