English

Projective Geometry and $\cal PT$-Symmetric Dirac Hamiltonian

High Energy Physics - Theory 2009-03-16 v2 Quantum Physics

Abstract

The (3+1)(3 + 1)-dimensional (generalized) Dirac equation is shown to have the same form as the equation expressing the condition that a given point lies on a given line in 3-dimensional projective space. The resulting Hamiltonian with a γ5\gamma_5 mass term is not Hermitian, but is invariant under the combined transformation of parity reflection P\cal P and time reversal T\cal T. When the PT\cal PT symmetry is unbroken, the energy spectrum of the free spin-12\frac {1}{2} theory is real, with an appropriately shifted mass.

Keywords

Cite

@article{arxiv.0901.2579,
  title  = {Projective Geometry and $\cal PT$-Symmetric Dirac Hamiltonian},
  author = {Y. Jack Ng and H. van Dam},
  journal= {arXiv preprint arXiv:0901.2579},
  year   = {2009}
}

Comments

7 pages, LaTeX; version accepted for publication in Phys. Lett. B; revised version incorporates useful suggestions from an anonymous referee

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