Remark: Family 292. A counterexample to Kirchberg's norm-ultrapower embedding problem

Constructs an explicit separable unital full group $C^{\ast }$-algebra that cannot embed unitally into the norm ultrapower of any fixed nonzero unital nuclear $C^{\ast }$-algebra, for any free ultrafilter on the natural numbers. Taking the target to be ${\mathcal{O}}_2$ answers Kirchberg's norm-ultrapower embedding problem negatively.

The authors are OpenAI. This companion does not verify the proof. The claim is not a theorem of the Enter series and not a premise of any registered sheet. It does not close O.1. O.1 stays NOT_CLOSED. It is not a de Sitter state and not the QdS external-leg scheme. No quantum coefficient is admitted. No compilation is asserted.