Pérez Teruel, Ginés R. New wave equation for ultrarelativistic matter. (English) Zbl 1389.81024 Palest. J. Math. 4, No. 2, 301-312 (2015). Summary: Starting from first principles and general assumptions based on the energy-momentum relation of the Special Theory of Relativity, we present a novel wave equation for ultrarelativistic matter. This wave equation arises when particles satisfy the condition, \(p \gg m\), i.e, when the energy-momentum relation can be approximated by, \(E\simeq p + \frac{m^2}{2p}\). Interestingly enough, such as the Dirac equation, it is found that this wave equation includes spin in a natural way. Furthermore, the free solutions of this wave equation contain plane waves that are completely equivalent to those of the theory of neutrino oscillations. Therefore, the theory reproduces some standard results of the Dirac theory in the limit \(p \gg m\), but offers the possibility of an explicit Lorentz Invariance Violation of order, \(\mathcal O((mc)^4/p^2)\). As a result, the theory could be useful to test small departures from Dirac equation and Lorentz Invariance at very high energies. On the other hand, the wave equation can also describe particles of spin 1 by a simple substitution of the spin operators, \(\sigma \to \alpha\). In addition, it naturally admits a Lagrangian formulation and a Hamiltonian formalism. We also discuss the associated conservation laws that arise through the symmetry transformations of the Lagrangian. MSC: 81T99 Quantum field theory; related classical field theories 70S05 Lagrangian formalism and Hamiltonian formalism in mechanics of particles and systems 70S10 Symmetries and conservation laws in mechanics of particles and systems Keywords:matter wave equations; ultra-high energy cosmic rays; Dirac equation; Lorentz invariance violations; classical field theory; Pauli matrices; Majorana-Oppenheimer matrices; Lagrangian formalism PDFBibTeX XMLCite \textit{G. R. Pérez Teruel}, Palest. J. Math. 4, No. 2, 301--312 (2015; Zbl 1389.81024) Full Text: arXiv Link