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Related papers: Superradiance from a Relativistic Source

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We present a didactic derivation of the special theory of relativity in which Lorentz transformations are `discovered' as symmetry transformations of the Klein-Gordon equation. The interpretation of Lorentz boosts as transformations to…

Classical Physics · Physics 2014-08-01 H. Arodź

The possibility of forming gravitational-wave sources with high center-of-mass (c.m.) velocities in the vicinity of supermassive black holes requires us to develop a method of deriving the waveform in the observer's frame. Here we show that…

General Relativity and Quantum Cosmology · Physics 2023-07-07 Han Yan , Xian Chen , Alejandro Torres-Orjuela

We analytically derive a relativistic variable Eddington factor in the relativistic radiative flow, and found that the Eddington factor depends on the {\it velocity gradient} as well as the flow velocity. When the gaseous flow is…

High Energy Astrophysical Phenomena · Physics 2015-05-13 J. Fukue

We develop a time-dependent multi-group multidimensional relativistic radiative transfer code, which is required to numerically investigate radiation from relativistic fluids involved in, e.g., gamma-ray bursts and active galactic nuclei.…

Instrumentation and Methods for Astrophysics · Physics 2015-09-09 Nozomu Tominaga , Sanshiro Shibata , Sergei I. Blinnikov

This paper is a review of the canonical proper-time approach to relativistic mechanics and classical electrodynamics. The purpose is to provide a physically complete classical background for a new approach to relativistic quantum theory.…

Mathematical Physics · Physics 2010-09-17 Tepper L. Gill , Woodford W. Zachary

In the pilot-wave theory of quantum mechanics particles have definite positions and velocities and the system evolves deterministically. The velocity of a particle is determined by the wave function of the system (the guidance equation) and…

Quantum Physics · Physics 2021-02-03 Dan N. Vollick

Since Dicke's seminal paper on coherence in spontaneous radiation by atomic ensembles, superradiance has been extensively studied. Subradiance, on the contrary, has remained elusive, mainly because subradiant states are weakly coupled to…

Atomic Physics · Physics 2016-03-24 William Guerin , Michelle O. Araújo , Robin Kaiser

Multiple scattering of light by resonant vapor is characterized by Levy-type superdiffusion with a step size distribution $P(x) \propto 1/x^{1+{\alpha}}$, with $0 < {\alpha} < 2$. The Levy parameter ${\alpha}$ was measured from $P(x)$,…

We show that the relativistic energy-momentum relation can emerge as an effective ensemble-averaged structure from a multiplicative Hamiltonian when fluctuations of an auxiliary parameter are treated using maximum entropy inference. The…

Mathematical Physics · Physics 2026-05-08 Sikarin Yoo-Kong

Admitting the validity of Lorentz transformations for the space as time coordinates of the same event we derive their differential form in order to underline the correct prerequisites for the application of time and length contraction or…

General Physics · Physics 2008-12-02 Stefan Popescu , Bernhard Rothenstein

Soon available multi petawatt ultra-high-intensity (UHI) lasers will allow us to probe high-amplitude electromagnetic fields interacting with either ultra-relativistic electron beams or hot plasmas in the so-called moderately quantum…

Plasma Physics · Physics 2018-08-01 F. Niel , C. Riconda , F. Amiranoff , M. Lobet , J. Derouillat , F. Pérez , T. Vinci , M. Grech

This paper introduces some general properties of the gravitational metric and the natural basis of vectors and covectors in 4-dimensional emission coordinates. Emission coordinates are a class of space-time coordinates defined and generated…

General Relativity and Quantum Cosmology · Physics 2016-08-16 Bartolomé Coll , José María Pozo

A synthesis of the present knowledge on gamma-ray emission from the magnetosphere of a rapidly rotating neutron star is presented, focusing on the electrodynamics of particle accelerators. The combined curvature, synchrotron, and…

Astrophysics · Physics 2009-11-11 Kouichi Hirotani

We describe a new hybrid framework to model non-thermal spectral signatures from highly energetic particles embedded in a large-scale classical or relativistic MHD flow. Our method makes use of \textit{Lagrangian} particles moving through…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Bhargav Vaidya , Andrea Mignone , Gianluigi Bodo , Paola Rossi , Silvano Massaglia

The inability of otherwise successful dynamical models to reproduce the ``HBT radii'' extracted from two-particle correlations measured at the Relativistic Heavy Ion Collider (RHIC) is known as the ``RHIC HBT Puzzle.'' Most comparisons…

Nuclear Theory · Physics 2008-11-26 Evan Frodermann , Ulrich Heinz , Michael Annan Lisa

A relativistic collapse model for distinguishable particles is presented. Position and time, for each particle, are the fundamental operators of the theory. The Schr\"odinger equation is of the CSL form, with a Hermitian Hamiltonian and an…

Quantum Physics · Physics 2025-06-10 Daniel J. Bedingham , Philip Pearle

A new relativistic transformation in the velocity space (here named the differential Lorentz transformation) is formulated solely from the principle of relativity and the invariance of the speed of light. The differential Lorentz…

Classical Physics · Physics 2008-12-31 Young-Sea Huang

Fully-excited two-level atoms separated by less than the transition wavelength cooperatively emit light in a short burst, a phenomenon called superradiance by R. Dicke in 1954. The burst is characterized by a maximum intensity scaling with…

Quantum Physics · Physics 2022-06-30 M. Bojer , J. von Zanthier

A Lorenz-covariant system of wave equations is formulated for a quantum-mechanical two-body system in one space dimension, comprised of one electron and one photon. Manifest Lorentz covariance is achieved using Dirac's formalism of…

Mathematical Physics · Physics 2020-12-02 Michael K. -H. Kiessling , Matthias Lienert , A. Shadi Tahvildar-Zadeh

Analytical solutions are presented for the electromagnetic radiation by an arbitrary pulsed source into a homogeneous time-varying background medium. In the constant-impedance case an explicit radiation formula is obtained for the…

Classical Physics · Physics 2009-11-16 Neil V. Budko