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I would like to know, whether the following quotient construction has been considered, or whether it makes sense:

One way to think of toric varieties is as a quotient of $\mathbb{C}^n$ (minus exceptional set) by a product of $\mathbb{C}^*$'s, giving different projective weights to the $n$ complex coordinates. Choosing the weights amounts to setting the representation of $\mathbb{C}^*$ under which a homogeneous coordinate transforms. In the quiver GIT constructions, one also considers quotients by products of $GL$ groups. However, in that case the representations are always the trivial, fundamental or anti-fundamental representations, since quiver arrows don't allow for more.

Are there constructions where one uses more general representations of $GL$ to create such quotients?

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  • $\begingroup$ Sure: for any complex reductive group G and any linear representation V of G, you can consider the GIT quotient G//V (which in general can be twisted by a choice of character of G). Toric varieties are obtained for G a torus (product of $\mathbb{C}^{*}$) and quiver varieties for G a product of linear groups and V made of fundamentals and anti-fundamentals. $\endgroup$
    – user25309
    Jan 23, 2017 at 11:11
  • $\begingroup$ Has this been used explicitly for the resolved du Val singularities? I have seen those described via quiver GIT, but then those spaces require preprojective algebras of quadratic relations. I always suspected this was due to the limitation in representations used in quivers. For instance, the A series can be treated torically, without resort to relations if one allows for more general reps. Could the D and E series be treated as "appropriate" (meaning not using the (anti-)fundamental)) quotients of GL groups? $\endgroup$ Jan 23, 2017 at 11:37

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