Asenjo, F. A., & Hojman, S. A. (2023). Timedomain supersymmetry for massless scalar and electromagnetic fields in anisotropic cosmologies. Phys. Scr., 98(10), 105302.
Abstract: It is shown that any cosmological anisotropic model produces supersymmetric theories for both massless scalar and electromagnetic (abelian) fields. This supersymmetric theory is the timedomain analogue of a supersymmetric quantum mechanics algebra theory. In this case, the variations of the anisotropic scale factors of the Universe are responsible for triggering the supersymmetry. For scalar fields, the superpartner fields evolve in two different cosmological scenarios (Universes). On the other hand, for propagating electromagnetic fields, supersymmetry is manifested through its polarization degrees of freedom in one Universe. In this case, polarization degrees of freedom of electromagnetic waves, which are orthogonal to its propagation direction, become superpartners from each other. This behavior can be measured, for example, through the rotation of the plane of polarization of cosmological light.

Asenjo, F. A., Hojman, S. A., MoyaCessa, H. M., & SotoEguibar, F. (2022). Supersymmetric relativistic quantum mechanics in timedomain. Phys. Lett. A, 450, 128371.
Abstract: A supersymmetric relativistic quantum theory in the temporal domain is developed for bispinor fields satisfying the Dirac equation. The simplest timedomain supersymmetric theory can be postulated for fields with timedependent mass, showing an equivalence with the bosonic supersymmetric theory in timedomain. Solutions are presented and they are used to produce probability oscillations between mass states. As an application of this idea, we study the twoneutrino oscillation problem, showing that flavour state oscillations may emerge from the supersymmetry originated by the timedependence of the unique mass of the neutrino.(c) 2022 Elsevier B.V. All rights reserved.

Asenjo, F. A., Hojman, S. A., VillegasMartinez, B. M., MoyaCessa, H. M., & SotoEguibar, F. (2024). Supersymmetric behavior of polarized electromagnetic waves in anisotropic media. Mod. Phys. Lett. A, 39(06), 2450013.
Abstract: A medium with specific anisotropic refractive indices can induce a supersymmetric behavior in the propagation of polarized electromagnetic waves, in an analog fashion to a quantum mechanical system. The polarizations of the wave are the ones which behave as superpartners from each other. For this to happen, the anisotropy of the medium must be transverse to the direction of propagation of the wave, with different refractive indices along the direction of each polarization, being in this way a biaxial medium. These refractive indices must be complex and follow a very specific relation in order to trigger the supersymetric response of the electromagnetic wave, each of them with spatial dependence on the longitudinal (propagation) direction of the wave. In this form, in these materials, different polarized light can be used to test supersymmetry in an optical fashion.
