4,208 research outputs found
Slicing the Vacuum: New Accelerating Mirror Solutions of the Dynamical Casimir Effect
Radiation from accelerating mirrors in a Minkowski spacetime provides
insights into the nature of horizons, black holes, and entanglement entropy. We
introduce new, simple, symmetric and analytic moving mirror solutions and study
their particle, energy, and entropy production. This includes an asymptotically
static case with finite emission that is the black hole analog of complete
evaporation. The total energy, total entropy, total particles, and spectrum are
the same on both sides of the mirror. We also study its asymptotically
inertial, drifting analog (which gives a black hole remnant) to explore
differences in finite and infinite production.Comment: 8 pages, 10 figure
Eternal and Evanescent Black Holes: It's All Done With Mirrors
The analogy between black hole radiation and accelerating mirror radiation
(the dynamical Casimir effect) is particularly strong for mirror trajectories
giving rise to a constant thermal flux of particles. We present new ways to
achieve such thermal plateaus, and customize their finite, semi-infinite, and
eternal presence, corresponding to forming/collapsing,
complete-evaporation/remnants, and eternal black holes. We find simple
expressions for the energy flux in terms of the mirror rapidity as a function
of proper time and null time.Comment: 13 pages, 11 figure
Finite Energy but Infinite Entropy Production from Moving Mirrors
Accelerating mirrors provide a simple conceptual laboratory for studying
particle production and the relation between trajectory and particle, energy,
and entropy fluxes. We focus on the relation between energy and entropy,
studying some special cases with finite total energy but infinite integrated
entropy (though the entropy flux may be finite at any particular moment). We
present a new asymptotically static moving mirror trajectory with solvable beta
Bogolyubov coefficients, total energy and fully relativistic particle count.
The integrated entropy diverges despite finite global radiative particle and
energy emission. Another class of models includes exponentially accelerated
mirrors in proper time; one of its unexpected behaviors is finite energy
emission but divergent entropy. We compare mirrors exponentially accelerated in
other coordinates as well, showing their close relation and an interesting
duality property.Comment: 10 pages, 8 figures, 2 table
The mirror at the edge of the universe: Reflections on an accelerated boundary correspondence with de Sitter cosmology
An accelerated boundary correspondence (ABC) is solved for the de Sitter
moving mirror cosmology. The beta Bogoliubov coefficients reveal the particle
spectrum is a Planck distribution with temperature inversely proportional to
horizon radius. The quantum stress-tensor indicates a constant emission of
energy flux consistent with eternal equilibrium, while the total energy carried
by the particles remains finite. The curved spacetime transformation to flat
spacetime with an accelerated boundary is illustrated, and also shown for
Anti-de Sitter (AdS) spacetime.Comment: 4 pages, 5 figure
The mazEF toxin-antitoxin system as a novel antibacterial target in Acinetobacter baumannii
Although analysis of toxin-antitoxin (TA) systems can be instructive, to date, there is no information on the prevalence and identity of TA systems based on a large panel of Acinetobacter baumannii clinical isolates. The aim of the current study was to screen for functional TA systems among clinical isolates of A. baumannii and to identify the systems' locations. For this purpose, we screened 85 A. baumannii isolates collected from different clinical sources for the presence of the mazEF, relBE and higBA TA genes. The results revealed that the genes coding for the mazEF TA system were commonly present in all clinical isolates of A. baumannii. Reverse transcriptase-polymerase chain reaction analysis showed that transcripts were produced in the clinical isolates. Our findings showed that TA genes are prevalent, harboured by chromosomes and transcribed within A. baumannii. Hence, activation of the toxin proteins in the mazEF TA system should be investigated further as an effective antibacterial strategy against this bacterium
Crystal structure of the catalytic fragment of murine poly(ADP-ribose) polymerase-2.
Poly(ADP-ribose) polymerase-1 (PARP-1) has become an important pharmacological target in the treatment of cancer due to its cellular role as a 'DNA-strand break sensor', which leads in part to resistance to some existing chemo- and radiological treatments. Inhibitors have now been developed which prevent PARP-1 from synthesizing poly(ADP-ribose) in response to DNA-breaks and potentiate the cytotoxicity of DNA damaging agents. However, with the recent discoveries of PARP-2, which has a similar DNA-damage dependent catalytic activity, and additional members containing the 'PARP catalytic' signature, the isoform selectivity and resultant pharmacological effects of existing inhibitors are brought into question. We present here the crystal structure of the catalytic fragment of murine PARP-2, at 2.8 A resolution, and compare this to the catalytic fragment of PARP-1, with an emphasis on providing a possible framework for rational drug design in order to develop future isoform-specific inhibitors
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.Comment: 8 pages, 9 figure
Light and Airy: a simple solution for relativistic quantum acceleration radiation
We study the quantum radiation of particle production by vacuum from an
ultra-relativistic moving mirror (dynamical Casimir effect) solution that
allows (possibly for the first time) analytically calculable time evolution of
particle creation and an Airy particle spectral distribution. The reality of
the beta Bogoliubov coefficients is responsible for the simplicity, and the
mirror is asymptotically inertial at the speed of light, with finite energy
production. We also discuss general relations regarding negative energy flux,
the transformation to the 1-D Schr{\"o}dinger equation, and the incompleteness
of entanglement entropy.Comment: 10 pages, 9 figure
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