Evolution Dynamics and Cauchy Problems with Quaternionic Variables and Lifting to Banach Bilateral $\mathbb{A}$-Algebras

Abstract

In this paper, we develop a theory of evolution dynamics in a Banach bilateral $\mathbb{H}$-algebra and establish a well-posedness theory for the Cauchy problem of evolution equations with quaternionic variables. First, we study the geometric properties of slice structures of Banach bilateral $\mathbb{H}$-modules. By employing different slice structures, we construct some noncommutative Banach bilateral $\mathbb{H}$-subalgebras which are compatible with the slice regularity of the functions involved. Moreover, through the quaternionic sliced geometric path integral over Banach bilateral $\mathbb{A}$-module, an integral representation of the solution to the homogeneous Cauchy problem with quaternionic variables is obtained in a quaternionic $σ$-ball, and for the first time, a local existence and uniqueness theorem is established for $σ$-analytic solutions. Then the local $σ$-analytic solution is extended to the entire quaternionic spherical sectorial region, thereby proving a global existence and uniqueness theorem for the Cauchy problem. Based on it, the notion of an evolution system in a quaternionic $\mathbb{H}$-algebra is introduced and its core properties are established. In addition, the global existence and uniqueness theorems are obtained under hyperbolic-like and parabolic-like conditions. Finally, the structure of Banach bilateral $\mathbb{H}$-modules and $\mathbb{H}$-algebras is lifted to Banach bilateral $\mathbb{A}$-modules and $\mathbb{A}$-algebras, and a well-posedness theory for evolution equations in this setting is developed. This reveals, from a new perspective, the universality of well-posedness for the Cauchy problem under the generic noncommutative $\mathbb{A}$-algebraic structures.