Suppose a finite group acts on a scheme X and a finite-dimensional Lie
algebra g. The corresponding equivariant map algebra is the Lie algebra M of
equivariant regular maps from X to g. We classify the irreducible
finite-dimensional representations of these algebras. In particular, we show
that all such representations are tensor products of evaluation representations
and one-dimensional representations, and we establish conditions ensuring that
they are all evaluation representations. For example, this is always the case
if M is perfect.
Suppose a finite group acts on a scheme X and a finite-dimensional Lie
algebra g. The corresponding equivariant map algebra is the Lie algebra M of
equivariant regular maps from X to g. We classify the irreducible
finite-dimensional representations of these algebras. In particular, we show
that all such representations are tensor products of evaluation representations
and one-dimensional representations, and we establish conditions ensuring that
they are all evaluation representations. For example, this is always the case
if M is perfect.
In this paper we consider the category of F^\sigma of finite-dimensional
representations of a twisted loop algebra corresponding to a finite-dimensional
Lie algebra with non-trivial diagram automorphism. Although F^\sigma is not
semisimple, it can be written as a sum of indecomposable subcategories (the
blocks of the category). To describe these summands, we introduce the twisted
spectral characters for the twisted loop algebra.
We survey some important results concerning the finite--dimensional
representations of the loop algebra of a simple complex Lie algebra, and their
twisted loop subalgebras. In particular, we review the parametrization and
description of the Weyl modules and of the irreducible finite--dimensional
representations of such algebras, describe a block decomposition of the
(non--semisimple) category of their finite--dimensional representations, and
conclude with recent developments in the representation theory of multiloop
algebras.