On octonionic Monge-Ampère equation and pluripotential theory associated to octonionic plurisubharmonic functions of two variables
Wei Wang
TL;DR
This work extends pluripotential theory to octonionic plurisubharmonic functions of two variables, navigating non-associativity by exploiting a weak associativity framework. It develops a full toolkit: an integration-by-parts formula for the mixed octonionic Monge-Ampère operator, uniform estimates, and a comparison principle; identifies a fundamental solution and Lelong numbers, and studies the Dirichlet problem with $C_{loc}^{1,1}$ regularity via Bedford–Taylor methods augmented by weighted automorphism transformations. The paper also defines octonionic relative extremal functions and capacity, establishing their basic properties and connections to regular compact sets; finally, it proves quasicontinuity for locally bounded OPSH functions. Together, these results lay a robust octonionic pluripotential framework with parallels to complex and quaternionic theories, enabling further development of octonionic potential theory and its geometric applications.
Abstract
Several aspects of pluripotential theory are generalized to octonionic plurisubharmonic (OPSH) functions of two variables. We prove the comparison principle for continuous OPSH functions and the quasicontinuity of locally bounded ones. An important tool is a formula of integration by parts for mixed octonionic Monge-Ampère operator. Various useful properties of octonionic relative extremal functions and octonionic capacity are established. The main difficulty is the non-associativity of octonions. However, some weak form of associativity can be used to covercome this difficulty. Another important ingredient in pluripotential theory is the solution to the Dirichlet problem for the homogeneous octonionic Monge-Ampère equation on the unit ball, for which we show the $C_{loc}^{1,1}$-regularity by applying Bedford-Taylor's method. The obstacle to do so is that an OPSH function is usually not OPSH under automorphisms of the unit ball. This issue can be solved by finding a weighted transformation formula of OPSH functions.
