Higher Noncommutative Motives and Higher K-theory

We construct higher additive noncommutative motives of stable (∞,n)-categories, extending the additive motives of Blumberg, Gepner, and Tabuada and the secondary theory of Mazel-Gee and Stern. We formulate a notion of exact sequences and establish the universal property of the resulting additive motives. We give two equivalent constructions: a localization of enriched presheaves and a weighted Waldhausen S-construction on complete exact flags. We then compute their Hom objects, obtaining ordinary K-theory at the first level and lower additive motives recursively at higher levels. Our results recover the classical and secondary theories, provide coherent multiplicative structures, and yield an endofunctor on the category of Stefanich rings. In short, higher motives are higher K-theory.