Related papers: Faster-than-light signalling in the rotating-wave …
Photons propagating in curved spacetime may, depending on their direction and polarisation, have velocities exceeding the ``speed of light'' c. This phenomenon arises through vacuum polarisation in QED and is a tidal gravitational effect…
We distinguish between the notions of asymptotic causality and infrared causality for gravitational effective field theories, and show that the latter gives constraints consistent with gravitational positivity bounds. We re-explore the…
A number of general issues relating to superluminal photon propagation in gravitational fields are explored. The possibility of superluminal, yet causal, photon propagation arises because of Equivalence Principle violating interactions…
It has been found in several papers that, because of quantum corrections, light front can propagate with superluminal velocity in gravitational fields and even in flat space-time across two conducting plates. We show that, if this is the…
Relativistic causality constrains the $S$-matrix both through its analyticity, and by imposing lower bounds on the scattering time delay. These bounds are easiest to determine for spacetimes which admit either a timelike or null Killing…
Recently, there has been increased interest in understanding entanglement and quantum communication in black hole spacetimes and in using quantum information techniques to address questions in gravity. Studies on relativistic entanglement…
We investigate the Cherenkov radiation triggered by qubit acceleration simulated by superconducting circuit. By analyzing the radiation probability, we confirm the existence of Cherenkov speed threshold, implying that simulating…
We showed in a previous paper that a wide class of nonmetric theories of gravity encompassed by the $\chi g$ formalism predict that the speed of light rays depends on the their polarization direction relative to directions singled out by…
The existence of a faster-than-light particle is in direct opposition to Einstein's relativity and the principle of causality. However, we show that the theory of classical relativistic fields is not inherently inconsistent with the…
The light-rays and wave fronts in a flat class of Godel-type metric are examined to reveal the causality violating features of the space-time. Non-causal features demonstrated by the development of unusual wave front singularities are shown…
The analysis of a general multibody physical system governed by Einstein's equations in quite difficult, even if numerical methods (on a computer) are used. Some of the difficulties -- many coupled degrees of freedom, dynamic instability --…
A classic problem in physics is the origin of fat tailed distributions generated by complex systems. We study the distributions of stock returns measured over different time lags $\tau.$ We find that destroying all correlations without…
It has been advocated by Bell and Bohm that the Einstein-Podolsky-Rosen (EPR) correlations are mediated through faster-than-light (FTL) interactions. In a previous paper a way to avoid causal paradoxes derived from this FTL hypothesis (via…
Physical phenomena caused by particle's moving faster than light in a space with multifractal time with dimension close to integer ($d_{t}=1+\epsilon(r(t),t), |\epsilon| \ll 1$ - time is almost homogeneous and almost isotropic) are…
Rotating wave approximation in a quantum spin system driven by a linearly polarized alternating magnetic field with quadrupole interaction presents is investigated in detail in this paper. The conventional way to employ the rotating wave…
We investigate the phenomenon of "faster than light" photons in a family of dilaton black hole spacetimes. For radially directed photons, we find that their light-cone condition is modified even though the spacetimes are spherically…
In numerical computations of Einstein's equations for black hole spacetimes, it will be necessary to use approximate boundary conditions at a finite distance from the holes. We point out here that ``tails,'' the inverse power-law decrease…
In the wave equation obeyed by electromagnetic fields in curved spacetime there are Riemann and Ricci curvature coupling terms to the photon polarisation, which result in a polarisation dependent deviation of the photon trajectories from…
In this note I introduce a mysterious approximation called the rotating wave approximation (RWA) to undergraduates or non-experts who are interested in both Mathematics and Quantum Optics. In Quantum Optics it plays a very important role in…
A violation of the distance-duality relation is directly linked with a temporal variation of the electromagnetic fine-structure constant. We consider a number of well-studied $f(T)$ gravity models and we revise the theoretical prediction of…