This paper presents the effect of self-consistent plasma backgrounds including plasma-neutral interactions, on the dynamics of filament propagation. The principle focus is on the influence of the neutrals on the filament through both direct interactions and through their influence on the plasma background. Both direct and indirect interactions influence the motion of filaments. A monotonic increase of filament peak velocity with upstream electron temperature is observed, while a decrease with increasing electron density is observed. If ordered by the target temperature, the density dependence disappears and the filament velocity is only a function of the target temperature. Smaller filaments keep a density dependence, as a result of the density dependence of the plasma viscosity. The critical size δ^*, where filaments are fastest, is shifted to larger sizes for higher densities, due to the plasma viscosity. If the density dependence of the plasma viscosity is removed, δ^* has no temperature dependence, but rather a density dependence.

We describe a quantum limit to measurement of classical spacetimes. Specifically, we formulate a quantum Cramér-Rao lower bound for estimating the single parameter in any one-parameter family of spacetime metrics. We employ the locally covariant formulation of quantum field theory in curved spacetime, which allows for a manifestly background-independent derivation. The result is an uncertainty relation that applies to all globally hyperbolic spacetimes. Among other examples, we apply our method to detection of gravitational waves with the electromagnetic field as a probe, as in laser-interferometric gravitational-wave detectors. Other applications are discussed, from terrestrial gravimetry to cosmology.

This paper presents the effect of self-consistent plasma backgrounds, on the dynamics of filament propagation. The critical size δ ∗, is an important scaling parameter for filaments. It is here defined as the perpendicular size, where filaments are fastest and is shifted to larger sizes for higher densities, due to the plasma viscosity. If the density dependency of the plasma viscosity is included, δ ∗ does not show a temperature dependency, but instead a density dependency is observed.

An unsolved problem in relativistic quantum information research is how to model efficient, directional quantum communication between localized parties in a fully quantum field-theoretical framework. We propose a tractable approach to this problem based on calculating expectation values of localized field observables in the Heisenberg picture. We illustrate our approach by analyzing, and obtaining approximate analytical solutions to, the problem of communicating coherent states between an inertial sender, Alice, and an accelerated receiver, Rob. We use these results to determine the efficiency with which continuous variable quantum key distribution could be carried out over such a communication channel. DOI: 10.1103/PhysRevA.87.012327

Introduction: Intelligence, surveillance, and reconnaissance (ISR) sensors are becoming ubiquitous in military operations. In fact, many people refer to a condition known as “ISR saturation,” in which the volume of still imagery and video becomes so great that it cannot be efficiently processed by decision makers on the battlefield. Hyperspectral imagers, such as the MX-20SW developed at NRL, are powerful because they collect and analyze detailed spectroscopic information for each pixel in the image and automatically cue operators to areas of interest. This avoids requiring the operator to view the entire image to identify the very small fraction that is relevant to Department of Defense operations, thereby helping to solve the problem of ISR saturation. The MX-20SW is particularly valuable because it operates in the shortwave infrared (SWIR) spectral region that yields much lower atmospheric scattering and, hence, longer range than sensors operating in the visible spectrum. In addition, many militarily relevant materials are more spectrally distinct in the SWIR than in the visible.

Relativistic quantum information combines the informational approach to understanding and using quantum mechanics systems -quantum information -with the relativistic view of the universe.In this introductory review we examine key results to emerge from this new field of research in physics and discuss future directions.A particularly active area recently has been the question of what happens when quantum systems interact with general relativistic closed timelike curves -effectively time machines.We discuss two different approaches that have been suggested for modelling such situations.It is argued that the approach based on matching the density operator of the quantum state between the future and past most consistently avoids the paradoxes usually associated with time travel.

We present APEX SABOCA 350 μm and LABOCA 870 μm observations of 11 representative examples of the rare, extremely bright (S1.4 mm > 15 mJy), dust-dominated millimeter-selected galaxies recently discovered by the South Pole Telescope. All 11 sources are robustly detected with LABOCA with 40 mJy < S870 μm < 130 mJy, approximately an order of magnitude higher than the canonical submillimeter galaxy (SMG) population. Six of the sources are also detected by SABOCA at >3σ, with the detections or upper limits providing a key constraint on the shape of the spectral energy distribution (SED) near its peak. We model the SEDs of these galaxies using a simple modified blackbody and perform the same analysis on samples of SMGs of known redshift from the literature. These calibration samples inform the distribution of dust temperature for similar SMG populations, and this dust temperature prior allows us to derive photometric redshift estimates and far-infrared luminosities for the sources. We find a median redshift of , higher than the inferred for the normal SMG population. We also derive the apparent size of the sources from the temperature and apparent luminosity, finding them to appear larger than our unlensed calibration sample, which supports the idea that these sources are gravitationally magnified by massive structures along the line of sight.

The geometry of space-time is determined by physical measurements made with clocks and rulers. In so far as these are physical systems, the ultimate accuracy achievable is determined by quantummechanics. In this paper we use methods from quantum parameter estimation theory to obtain uncertainty principles constraining how well we can estimate the components of a metric tensor using quantum field states propagating in curved space-time, which is treated entirely classically.

Here we describe the quantum limit to measurement of the classical gravitational field. Specifically, we write down the optimal quantum Cramer-Rao lower bound, for any single parameter describing a metric for spacetime. The standard time-energy and Heisenberg uncertainty relations are shown to be special cases of the uncertainty relation for the spacetime metric. Four key examples are given, describing quantum limited estimation for: acceleration, black holes, gravitational waves and cosmology. We employ the locally covariant formulation of quantum field theory in curved spacetime, which allows for a manifestly spacetime independent derivation. The result is an uncertainty relation applicable to all causal spacetime manifolds.

An open question in the field of relativistic quantum information is how parties in arbitrary motion may distribute and store quantum entanglement. We propose a scheme for storing quantum information in the field modes of cavities moving in flat space-time and analyze it in a quantum field theoretical framework. In contrast with previous work that found entanglement degradation between observers moving with uniform acceleration, we find the quantum information in such systems is protected. We further discuss a method for establishing the entanglement in the first place and show that in principle it is always possible to produce maximally entangled states between the cavities.

Using experimental thermal conductivity and volume heat capacity of narrow silicon nitride beams obtained from thermal test structures and a boundary limited phonon scattering model, as well as the heat conduction equation, we analyze the thermal performance of an absorber‐coupled TES polarimeter with finite element method. The polarimeter’s temperature distribution, thermal power readout efficiency, and time constant are calculated. The thermal power readout efficiency of the polarimeter is up to 87% at a low signal modulation frequency, and has a 0.5 dB attenuation at 120 Hz. We also compare a preliminary optical testing result with theoretical expectation.

This contribution reviews recent results on the dynamics of YSO jets obtained by the JETSET network using theoretical MHD models, numerical simulations, and laboratory experiments. Topics include pressure-driven stellar winds, magnetospheric ejections, disk winds, MRI and KH instabilities, turbulence injection, molecular outflow formation, and MHD code development and testing.

We discuss an alternative formulation of the problem of quantum optical fields in a curved space-time using localized operators. We contrast this formulation with the standard approach and find observable differences for entangled states. We propose an experiment in which an entangled pair of optical pulses are propagated through nonuniform gravitational fields and find that the alternative formulation predicts decorrelation of the optical entanglement under experimentally realistic conditions.

We propose an experiment in which an entangled pair of optical pulses follow different paths through a gravitational field.,W use a non-standard technique based on localized operators to analyze this situation. The calculation predicts decorrelation of the optical entanglement under experimentally realistic conditions.

We propose an experiment in which an entangled pair of optical pulses are propagated through non-uniform gravitational fields. A field operator calculation of this situation predicts decoherence of the optical entanglement under experimentally realistic conditions.

Discarding the canonical magnetohydrodynarnic approximation frees the magnetic field to diffuse with respect to the bulk velocity field. As a consequence the induction equation becomes problematic to solve numerically via standard explicit techniques. In particular, the Hall diffusion term can impose vanishing timestep limits on conventional explicit schemes. We present two complementary techniques to alleviate the problems of a diffusion-like stability limit from within an explicit differencing framework.

The Spectral Energy Distribution (SPEED) Camera is being developed to study the spectral energy distributions of high redshift galaxies. Its initial use will be on the Heinrich Hertz Telescope and eventually on the Large Millimeter Telescope. SPEED requires a small cryogenic detector array of 2×2 pixels with each pixel having four frequency bands in the 150–375GHz range. Here we describe the development of the detector array of these high-efficiency Frequency Selective Bolometers (FSB). The FSB design provides the multi-pixel, multi-spectral band capability required for SPEED in a compact stackable array. The SPEED bolometers will use proximity effect superconducting transition edge sensors as their temperature-sensing element, allowing for higher levels of electronic multiplexing in future applications.