Two-Component Spinorial Formalism using Quaternions for Six-dimensional Spacetimes

TL;DR

This paper develops a two-component quaternionic spinorial formalism for six-dimensional spacetimes, connecting quaternionic representations with the Lorentz group and complexified spacetime structures.

Contribution

It introduces a novel quaternionic spinorial framework for 6D spacetimes and explores its algebraic and geometric properties, linking it to existing formalisms.

Findings

Representation of vectors, bivectors, and 3-vectors in quaternionic spinors

Connection between quaternionic spin group and SO(5,1) Lie algebra

Bridge between quaternionic and complex spinorial formalisms

Abstract

In this article we construct and discuss several aspects of the two-component spinorial formalism for six-dimensional spacetimes, in which chiral spinors are represented by objects with two quaternionic components and the spin group is identified with $SL(2;\mathbb{H})$, which is a double covering for the Lorentz group in six dimensions. We present the fundamental representations of this group and show how vectors, bivectors, and 3-vectors are represented in such spinorial formalism. We also complexify the spacetime, so that other signatures can be tackled. We argue that, in general, objects built from the tensor products of the fundamental representations of $SL(2;\mathbb{H})$ do not carry a representation of the group, due to the non-commutativity of the quaternions. The Lie algebra of the spin group is obtained and its connection with the Lie algebra of $SO(5,1)$ is presented, providing a physical interpretation for the elements of $SL(2;\mathbb{H})$. Finally, we present a bridge between this quaternionic spinorial formalism for six-dimensional spacetimes and the four-component spinorial formalism over the complex field that comes from the fact that the spin group in six-dimensional Euclidean spaces is given by $SU(4)$.