We consider four subsets of the complexified spacetime algebra, namely the real even part, the real odd part, the imaginary even part and the imaginary odd part. This naturally leads to the four connected components of the Lorentz group, supplemented each time by an additional symmetry. We then examine how these four parts impact the Dirac equation and show that four types of matter arise with positive and negative masses as well as positive and negative charges.

中文翻译：

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论时空代数及其与负质量的关系

我们考虑复时空代数的四个子集，即实偶部分、实奇部分、虚偶部分和虚奇部分。这自然导致了洛伦兹群的四个连通分量，每次都补充了一个额外的对称性。然后，我们研究这四个部分如何影响狄拉克方程，并表明四种类型的物质会产生正负质量以及正电荷和负电荷。