Complex Numbers for Relativistic Operations

When presenting special relativity, it is customary to single out the so-called paradoxes. One of these paradoxes is the formal occurrence of speeds exceeding the speed of light. An essential part of such paradoxes arises from the incompleteness of the relativistic calculus of velocities. In special relativity, the additive group is used for velocities. However, the use of only group operations imposes artificial restrictions on possible computations. Naive expansion to vector space is usually done by using non-relativistic operations. We propose to consider arithmetic operations in the special theory of relativity in the framework of the Cayley–Klein model for projective spaces. We show that such paradoxes do not arise in the framework of the proposed relativistic extension of algebraic operations.

Particle Trajectories For Compton Scattering in One Space Dimension

Using a relativistic extension of Bohmian Me-chanics known as Multi-Time Wave Function formula-tion, we examine a two-body, one-dimensional sys-tem consisting of one photon and one electron that interact only upon contact. We investigate the effects that various parameters in this theory including mo-mentum of the incoming photon and mass of the electron have on the dynamics of the two interact-ing bodies with the goal of understanding conser-vation of momentum and energy in the system. We show that the core principles of Compton scattering remain when we use this alternative formulation of quantum mechanics. Although a complete relativ-istic theory of Bohmian mechanics has yet to be de-veloped, our work aims to make the ideas in this the-ory more accessible to a wider audience.

Relativistic Ermakov–Milne–Pinney Systems and First Integrals

The Ermakov–Milne–Pinney equation is ubiquitous in many areas of physics that have an explicit time-dependence, including quantum systems with time-dependent Hamiltonian, cosmology, time-dependent harmonic oscillators, accelerator dynamics, etc. The Eliezer and Gray physical interpretation of the Ermakov–Lewis invariant is applied as a guiding principle for the derivation of the special relativistic analog of the Ermakov–Milne–Pinney equation and associated first integral. The special relativistic extension of the Ray–Reid system and invariant is obtained. General properties of the relativistic Ermakov–Milne–Pinney are analyzed. The conservative case of the relativistic Ermakov–Milne–Pinney equation is described in terms of a pseudo-potential, reducing the problem to an effective Newtonian form. The non-relativistic limit is considered to be well. A relativistic nonlinear superposition law for relativistic Ermakov systems is identified. The generalized Ermakov–Milne–Pinney equation has additional nonlinearities, due to the relativistic effects.

Direct Relativistic Extension of the Madelung-de-Broglie-Bohm Reformulations of Quantum Mechanics and Quantum Hydrodynamics

Using a Schrödinger-like equation, which describes a particle with mass and spin-0 and with the correct relativistic relation between its linear momentum and kinetic energy, the basic equations of the non-relativistic quantum mechanics with trajectories and quantum hydrodynamics are extended to the relativistic domain. Some simple but instructive free particle examples are discussed.

Relativistic Ermakov-Milne-Pinney Systems and First Integrals

The Eliezer and Gray physical interpretation of the Ermakov-Lewis invariant is applied as a guiding principle for the derivation of the special relativistic analog of the Ermakov-Milne-Pinney equation and associated first integral. The special relativistic extension of the Ray-Reid system and invariant is obtained. General properties of the relativistic Ermakov-Milne-Pinney are analyzed. The conservative case of the relativistic Ermakov-Milne-Pinney equation is described in terms of a pseudo-potential, reducing the problem to an effective Newtonian form. The non-relativistic limit is considered as well. A relativistic nonlinear superposition law for relativistic Ermakov systems is identified. The generalized Ermakov-Milne-Pinney equation has additional nonlinearities, due to the relativistic effects.

Zero-point energy and photon spin-induced diffraction phenomena

A brief review of our previously introduced forward and backward in time formalism for non-relativistic electron diffraction and its relativistic extension to study photons in time and space is presented. The zero-point energy in the Planck black body spectrum emerges naturally once time-symmetric motion — inherent in Maxwell equations — is invoked for photons. A study of two-slit experiments for slits smaller than the wavelength of the photon unravels novel phenomena due to the spin of the photon. Our proposed experiments are within reach of present technology and could be of interest for modern imaging and quantum optics.

Does GW170817 falsify MOND?

The gravitational-wave event GW170817 and the near-simultaneous corresponding gamma-ray burst (GRB 170817 A) falsify modified gravity theories in which the gravitational geometry differs non-conformally from physical geometry. Thus, the observations of this event definitively rule out theories, such as TeVeS, a suggested relativistic extension of Milgrom’s modified Newtonian dynamics (MOND), that predict a significantly different Shapiro delay for electromagnetic and gravitational radiation. While not falsifying MOND per se, GW170817 severely constrains relativistic extensions of MOND to theories that do not rely on additional matter-coupling fields but rather upon modified field equations for one universal gravitational and physical metric. Here, I mention a simple preferred-frame theory as an example.