**
Takashi Kimura
**

**On stringy algebraic operations in
equivariant K-theory
**

**Abstract
**

We will introduce and explain some new algebraic structures associated to a smooth variety with a proper action of an algebraic group that are invariants of the associated quotient orbifold. Such algebraic structures arise from their orbifold K-theory ring, a K-theoretic variant of Chen-Ruan orbifold cohomology, and generalize more familiar operations in ordinary K-theory.