44 research outputs found
Pair Events in Superluminal Optics
When an object moves faster than emissions it creates, it may appear at two
positions simultaneously. The appearance or disappearance of this bifurcation
is referred to as a pair event. Inherently convolved with superluminal motion,
pair events have no subluminal counterparts. Common examples of superluminal
motions that exhibit pair events include Cherenkov radiation, sonic booms,
illumination fronts from variable light sources, and rotating beams. The
minimally simple case of pair events from a single massive object is explored
here: uniform linear motion. A pair event is perceived when the radial
component of the object's speed toward the observer drops from superluminal to
subluminal. Emission from the pair creation event will reach the observer
before emission from either of the two images created. Potentially observable
image pair events are described for sonic booms and Cherenkov light. To date,
no detection of discrete images following a projectile pair event have ever
been reported, and so the pair event nature of sonic booms and Cherenkov
radiation, for example, remains unconfirmed. Recent advances in modern
technology have made such pair event tracking feasible. If measured, pair
events could provide important information about object distance and history.Comment: 13 pages, 3 figures. in press: Annalen der Physi
Vacuum Cherenkov radiation
Within the classical Maxwell-Chern-Simons limit of the Standard-Model
Extension (SME), the emission of light by uniformly moving charges is studied
confirming the possibility of a Cherenkov-type effect. In this context, the
exact radiation rate for charged magnetic point dipoles is determined and found
in agreement with a phase-space estimate under certain assumptions.Comment: 4 pages, REVTeX
Quantum Properties of Cavity Cerenkov Radiation
Cerenkov radiation from cavities have been analyzed by quantum electrodynamic
theory. Analytical expressions of some basic radiation properties including
Einstein's and coefficients are derived and shown to be directly
modified by the cavities. Coherent and incoherent radiations are analyzed with
the aim of generating THz radiation from the devices.Comment: 6 pages 5 figure
Interaction of a moving charged particle with a spatially dispersive medium. I. Structure of the electromagnetic field
Řešení stability důlních děl v podmínkách velkých hloubek v OKR a Donbasse
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