arXiv subjects

Michael R. R. Good

Publications and source records attributed to Michael R. R. Good.

At least 37 records · Page 2Linked to original sources

arXiv2023

Non-thermal photons and a Fermi-Dirac spectral distribution

Although non-intuitive, an accelerated electron along a particular trajectory can be shown to emit classical electromagnetic radiation in the form of a Fermi-Dirac spectral distribution when observed in a particular angular regime. We investigate the relationship between the distribution, spectrum, and particle count. The result for the moving point charge is classical, as it accelerates along an exactly known trajectory. We map to the semi-classical regime of the moving mirror model with a quantized spin-0 field. The scalars also possess a $β$ Bogoliubov coefficient distribution with Fermi-Dirac form in the respective frequency regime.

quant-ph↗

arXiv2023

Larmor Temperature, Casimir Dynamics, and Planck's Law

Classical radiation from a single relativistically accelerating electron is investigated where the temperature characterizing the system highlights the dependence on acceleration. In the context of the dynamic Casimir effect with Planck-distributed photons and thermal black hole evaporation, we demonstrate analytic consistency between the ideas of constant acceleration and equilibrium thermal radiation. For ultra-relativistic speeds, we demonstrate a long-lasting constant peel acceleration and constant power emission, which is consistent with the idea of balanced equilibrium of Planck-distributed particle radiation.

gr-qc↗

arXiv2023

Thermal Larmor radiation

Thermal radiation from a moving point charge is found. The calculation is entirely from a classical point of view, but is shown to have an immediate connection to quantum field theory.

gr-qc↗

arXiv2023

Stopping to Reflect: Asymptotic Static Moving Mirrors as Quantum Analogs of Classical Radiation

Radiation from an accelerating charge is a basic process that can serve as an intersection between classical and quantum physics. We present two exactly soluble electron trajectories that permit analysis of the radiation emitted, exploring its time evolution and spectrum by analogy with the moving mirror model of the dynamic Casimir effect. These classical solutions are finite energy, rectilinear (nonperiodic), asymptotically zero velocity worldlines with corresponding quantum analog beta Bogolyubov coefficients. One of them has an interesting connection to uniform acceleration and Leonardo da Vinci's water pitcher experiment.

quant-ph↗

arXiv2023

Electron as a Tiny Mirror: Radiation From a Worldline With Asymptotic Inertia

We present a moving mirror analog of the electron, whose worldline possesses asymptotic constant velocity with corresponding beta Bogolubov coefficients that are consistent with finite total emitted energy. Furthermore, the quantum analog model is in agreement with the total energy obtained by integrating the classical Larmor power.

gr-qc↗

arXiv2022

Upon the horizon's verge: Thermal particle creation between and approaching horizons

Quantum particle creation from spacetime horizons, or accelerating boundaries in the dynamical Casimir effect, can have an equilibrium, or thermal, distribution. Using an accelerating boundary in flat spacetime (moving mirror), we investigate the production of thermal energy flux despite non-equilibrium accelerations, the evolution between equilibrium states, and the "interference" between horizons. In particular, this allows us to give a complete solution to the particle spectrum of the accelerated boundary correspondence with Schwarzschild-de Sitter spacetime.

gr-qc↗

arXiv2022

Spacetime continuity and quantum information loss

Continuity across the shock wave of two regions in the metric during the formation of a black hole can be relaxed in order to achieve information preservation. A Planck scale sized spacetime discontinuity leads to unitarity (a constant asymptotic entanglement entropy) by restricting the origin of coordinates (moving mirror) to be timelike. Moreover, thermal equilibration occurs and total evaporation energy emitted is finite.

gr-qc↗

arXiv2022

Extreme electron acceleration with fixed radiation energy

We examine the extreme situation of radiation from an electron that is asymptotically accelerated to the speed of light, resulting in finite emission energy. The analytic solution explicitly demonstrates the difference between radiation power loss and kinetic power loss (null).

gr-qc↗

arXiv2022

Modeling black hole evaporative mass evolution via radiation from moving mirrors

We investigate the evaporation of an uncharged and non-rotating black hole (BH) in vacuum, by taking into account the effects given by the shrinking of the horizon area. These include the back-reaction on the metric and other smaller contributions arising from quantum fields in curved spacetime. Our approach is facilitated by the use of an analog accelerating moving mirror. We study the consequences of this modified evaporation on the BH entropy. Insights are provided on the amount of information obtained from a BH by considering non-equilibrium thermodynamics and the non-thermal part of Hawking radiation.

gr-qc↗

arXiv2022

Infrared acceleration radiation

We present an exactly soluble electron trajectory that permits an analysis of the soft (deep infrared) radiation emitted, the existence of which has been experimentally observed during beta decay via lowest order inner bremsstrahlung. Our treatment also predicts the time evolution and temperature of the emission, and possibly the spectrum, by analogy with the closely related phenomenon of the dynamic Casimir effect.

gr-qc↗

arXiv2022

The Hookean Law of Black Holes and Fragmentation: Insights from Maximum Force Conjecture and Ruppeiner Geometry

We show that the notion of "Hookean law" $F=kx$, suitably defined in asymptotically flat singly spinning Myers-Perry black hole spacetimes in dimensions $d\geqslant 5$, is related to the Emparan-Myers fragmentation (splitting of a black hole into two becomes thermodynamically preferable). Specifically, the values of black hole parameters when fragmentation occurs correspond to the maximal value of $F$. Furthermore this always happens before $F$ reaches $1/4$ in Planck units. These results suggest that a version of "maximum force conjecture" may be relevant for black hole thermodynamics. We also relate these findings to the Ruppeiner thermodynamic geometry of these black holes and speculate on the implications for the underlying microstructures of black hole horizons.

gr-qc↗

arXiv2022

On the duality of Schwarzschild-de Sitter spacetime and moving mirror

The Schwarzschild-de Sitter (SdS) metric is the simplest spacetime solution in general relativity with both a black hole event horizon and a cosmological event horizon. Since the Schwarzschild metric is the most simple solution of Einstein's equations with spherical symmetry and the de Sitter metric is the most simple solution of Einstein's equations with a positive cosmological constant, the combination in the SdS metric defines an appropriate background geometry for semi-classical investigation of Hawking radiation with respect to past and future horizons. Generally, the black hole temperature is larger than that of the cosmological horizon, so there is heat flow from the smaller black hole horizon to the larger cosmological horizon, despite questions concerning the definition of the relative temperature of the black hole without a measurement by an observer sitting in an asymptotically flat spacetime. Here we investigate the accelerating boundary correspondence (ABC) of the radiation in SdS spacetime without such a problem. We have solved for the boundary dynamics, energy flux and asymptotic particle spectrum. The distribution of particles is globally non-thermal while asymptotically the radiation reaches equilibrium.

gr-qc↗

arXiv2022

Quantum communication through a partially reflecting accelerating mirror

Motivated by the fact that the null-shell of a collapsing black hole can be described by a perfectly reflecting accelerating mirror, we investigate an extension of this model to mirror semi-transparency and derive a general implicit expression for the corresponding Bogoliubov coefficients. Then, we turn this into an explicit analytical form by focusing on mirrors that are accelerated via an impulsive force. From the so-obtained Bogoliubov coefficients we derive the particle production. Finally, we realize the field coming from left-past spacetime region, passing through the semitransparent moving mirror and ending up to right-future spacetime region as undergoing the action of a Gaussian quantum channel. We study the transmission and noisy generation properties of this channel, relating them to the Bogoliubov coefficients of the mirror's motion, through which we evaluate capacities in transmitting classical and quantum information.

gr-qc↗

arXiv2021

Quantum power: a Lorentz invariant approach to Hawking radiation

Particle radiation from black holes has an observed emission power depending on the surface gravity $κ= c^4/(4GM)$ as \begin{equation}\nonumber P_{\textrm{black hole}} \sim \frac{\hbar κ^2}{6πc^2} = \frac{\hbar c^6}{96πG^2 M^2}\,,\end{equation} while both the radiation from accelerating particles and moving mirrors (accelerating boundaries) obey similar relativistic Larmor powers, \begin{equation}\nonumber P_{\textrm{electron}}= \frac{q^2α^2}{6πε_0 c^3}\,, \quad P_{\textrm{mirror}} =\frac{\hbar α^2}{6πc^2}\,, \end{equation} where $α$ is the Lorentz invariant proper acceleration. This equivalence between the Lorentz invariant powers suggests a close relation that could be used to understand black hole radiation. We show that an accelerating mirror with a prolonged metastable acceleration plateau can provide a unitary, thermal, energy-conserved analog model for black hole decay.

gr-qc↗

arXiv2021

Analog Particle Production Model for General Classes of Taub-NUT Black Holes

We derive a correspondence between the Hawking radiation spectra emitted from general classes of Taub-NUT black holes with that induced by the relativistic motion of an accelerated Dirichlet boundary condition (i.e.\ a perfectly reflecting mirror) in (1+1)-dimensional flat spacetime. We demonstrate that the particle and energy spectra is thermal at late-times and that particle production is suppressed by the NUT parameter. We also compute the radiation spectrum in the rotating, electrically charged (Kerr-Newman) Taub-NUT scenario, and the extremal case, showing explicitly how these parameters affect the outgoing particle and energy fluxes.

gr-qc↗

arXiv2021

Finite thermal particle creation of Casimir light

A new solution for an analytic spectrum of particle creation by an accelerating mirror (dynamical Casimir effect) is given. It is the first model to simultaneously radiate thermally and emit a finite number of particles.

quant-ph↗

arXiv2021

Möbius Mirrors

An accelerating boundary (mirror) acts as a horizon and black hole analog, radiating energy with some particle spectrum. We demonstrate that a Möbius transformation on the null coordinate advanced time mirror trajectory uniquely keeps invariant not only the energy flux but the particle spectrum. We clarify how the geometric entanglement entropy is also invariant. The transform allows generation of families of dynamically distinct trajectories, including $\mathcal{PT}$-symmetric ones, mapping from the eternally thermal mirror to the de Sitter horizon, and different boundary motions corresponding to Kerr or Schwarzschild black holes.

gr-qc↗

arXiv2021

Dual-temperature acceleration radiation

We solve for a system that emits acceleration radiation at two different temperatures. The equilibrium states occur asymptotically in Planck distributions and transition non-thermally. The model is simple enough to obtain a global solution for the radiation spectrum analytically. We present it as a potentially useful model for investigation of non-thermal vacuum acceleration radiation in the presence of final(initial) asymptotic thermodynamic horizon(less) states in equilibrium.

gr-qc↗