Representations of Lie algebras arising from polytopes

We present an extremely elementary construction of the simple Lie algebras over the complex numbers in all of their minuscule representations, using the vertices of various polytopes. The construction itself requires no complicated combinatorics and essentially no Lie theory other than the definition of a Lie algebra; in fact, the Lie algebras themselves appear as by-products of the construction.Comment: Approximately 32 pages, AMSTe

On triangles with a minuscule side

Let $W\subset O(V)$ be the Weyl group of a root system $R\subset V$. If $a+b+c=0=a'+b'+c'$ with $a$, $b$ and $c$ respectively conjugated to $a'$, $b'$ and $c'$ in V , then $(a,b,c)$ is conjugated to $(a',b',c')$ in $V^3$ when each projection of $a$ to an irreducible component of $V$ is co-linear to a minuscule coweight.Comment: in Frenc

Exceptional Theta-correspondences I

Let $G$ be a split simply laced group defined over a $p$-adic field $F$. In this paper we study the restriction of the minimal representation of $G$ to various dual pairs in $G$. For example, the restriction of the minimal representation of $E_7$ to the dual pair $G_2 \times{}$Sp(6) gives the non-endoscopic Langlands lift of irreducible representations of $G_2$ to Sp(6)