Hindawi Publishing Corporation ISRN High Energy Physics Volume 2013, Article ID 374612, 21 pages http://dx.doi.org/10.1155/2013/374612 Research Article From Generalized Dirac Equations to a Candidate for Dark Energy U. D. Jentschura and B. J. Wundt Department of Physics, Missouri University of Science and Technology, Rolla, MO 65409, USA Correspondence should be addressed to U. D. Jentschura;
[email protected] Received 12 November 2012; Accepted 1 December 2012 Academic Editors: G. A. Alves, C. A. D. S. Pires, and F.-H. Liu Copyright © 2013 U. D. Jentschura and B. J. Wundt. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 5 5 We consider extensions of the Dirac equation with mass terms 1 + i 2 and i1 +2. The corresponding Hamiltonians 5 are Hermitian and pseudo-Hermitian ( Hermitian), respectively. The fundamental spinor solutions for all generalized Dirac equations are found in the helicity basis and brought into concise analytic form. We postulate that the time-ordered product of field operators should yield the Feynman propagator (i prescription), and we also postulate that the tardyonic as well as tachyonic Dirac equations should have a smooth massless limit. These postulates lead to sum rules that connect the form of the fundamental field anticommutators with the tensor sums of the fundamental plane-wave eigenspinors and the projectors over positive-energy and negative-energy states. In the massless case, the sum rules are fulfilled by two egregiously simple, distinguished functional forms.