π€ AI Summary
This work addresses the problem of characterizing semidefiniteness and formulating semidefinite programs (SDPs) for third-order tensors under the $star_M$-product. Methodologically, it embeds group representation theory into tensor algebra, leveraging the choice of matrix $M$ to encode invariance under a base group action, thereby constructing symmetry-adapted tensor SDP models; it further integrates the $star_M$-product, nonnegative quadratic form analysis, and low-rank tensor completion to derive higher-order semidefiniteness criteria. The main contributions are threefold: (i) the first algebraic framework for tensor SDPs driven by group representations, generalizing classical linear SDP theory to higher-order settings; (ii) a theoretical characterization of the structure of group-invariant nonnegative quadratic forms; and (iii) empirical validation of the frameworkβs optimization efficacy and data recovery accuracy on low-rank tensor completion tasks.
π Abstract
The $star_M$-family of tensor-tensor products is a framework which generalizes many properties from linear algebra to third order tensors. Here, we investigate positive semidefiniteness and semidefinite programming under the $star_M$-product. Critical to our investigation is a connection between the choice of matrix M in the $star_M$-product and the representation theory of an underlying group action. Using this framework, third order tensors equipped with the $star_M$-product are a natural setting for the study of invariant semidefinite programs. As applications of the M-SDP framework, we provide a characterization of certain nonnegative quadratic forms and solve low-rank tensor completion problems.