Frobenius Profiles of Polynomial-Multiple MRD Codes

Overview & Synopsis

We study Frobenius intersection profiles of maximum rank distance (MRD) codes arising from ordinary polynomial multiples over finite fields. We prove that every numerically admissible profile is realized within this family over every sufficiently large extension, using a root-exponent pattern independent of the extension degree. A factor-orbit gap formula provides the underlying structural description, while effective extension-degree bounds guarantee realization. We also establish a lower bound valid for all polynomial generators and show that the upper and lower bounds differ by only $O_q(\log n)$ along an infinite family of parameters. Finally, we characterize the generalized Gabidulin members and obtain non-generalized-Gabidulin realizations of every profile with initial loss at least two over infinitely many extensions.