Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Realizing Enveloping Algebras via Varieties of Modules   By using the Ringel-Hall algebra approach, we investigate the structure of
the Lie algebra $L(\Lambda)$ generated by indecomposable constructible sets in
the varieties of modules for any finite dimensional $\mathbb{C}$-algebra
$\Lambda.$ We obtain a geometric realization of the universal enveloping
algebra $R(\Lambda)$ of $L(\Lambda).$ This generalizes the main result of
Riedtmann in \cite{R}. We also obtain Green's theorem in \cite{G} in a
geometric form for any finite dimensional $\mathbb{C}$-algebra $\Lambda$ and
use it to give the comultiplication formula in $R(\Lambda).$

19
The categories of this paper are: eess
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
16
The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph