Drinfeld's quantization conjecture for Lie bialgebras

A Lie bialgebra is a vector space with a Lie bracket and a compatible Lie cobracket. Drinfeld's quantization conjecture. Any Lie bialgebra can be quantized. This conjecture asks whether every classical Lie bialgebra structure arises as the semiclassical limit of a quantum group; its resolution is a foundational result in the theory of quantum groups.