Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A singular Coxeter presentation   We enlarge a Coxeter group into a category, with one object for each finite
parabolic subgroup, encoding the combinatorics of double cosets. This category,
the singular Coxeter monoid, is connected to the geometry of partial flag
varieties. Our main result is a presentation of this category by generators and
relations. We also provide a new description of reduced expressions for double
cosets. We describe all the braid relations between such reduced expressions,
and prove an analogue of Matsumoto's theorem. This gives a proper development
of ideas first introduced by Geordie Williamson. In type A we also equip the
singular Coxeter monoid with a diagrammatic presentation using webs.

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The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: physics
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The categories of this paper are: adap-org
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The categories of this paper are: q-bio
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The categories of this paper are: cmp-lg
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The categories of this paper are: alg-geom