Results for "Morgan W. Mitchell"

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Sensor self-interaction, scale-invariant spin dynamics, and the $\hbar$ limit of field sensingApr 02 2019We describe quantum limits to field sensing that relate noise, geometry and measurement duration to fundamental constants, with no reference to particle number. We cast the Tesche and Clarke (TC) bound on dc-SQUID sensitivity as such a limit, and find ... More
NOON states from cavity-enhanced down-conversion: High quality and super-resolutionNov 27 2009Indistinguishable photons play a key role in quantum optical information technologies. We characterize the output of an ultra-bright photon-pair source using multi-particle tomography [R. B. A. Adamson et al., Phys. Rev. Lett. 98, 043601 (2007)] and separately ... More
A self-tuning optical resonatorJul 28 2017Jan 06 2018We demonstrate a nonlinear optical resonator that tunes itself onto resonance with an input beam. In a monolithic Fabry-Perot cavity implemented in rubidium-doped periodically-poled potassium titanyl phosphate, an intensity-dependent refractive index ... More
Atom-resonant squeezed light from a tunable monolithic ppRKTP parametric amplifierJan 06 2018We demonstrate vacuum squeezing at the D1 line of atomic rubidium (795 nm) with a tunable, doubly-resonant, monolithic sub-threshold optical parametric oscillator in periodically-poled Rb-doped potassium titanyl phosphate. The squeezing appears to be ... More
A passive transmitter for quantum key distribution with coherent lightAug 03 2011Signal state preparation in quantum key distribution schemes can be realized using either an active or a passive source. Passive sources might be valuable in some scenarios; for instance, in those experimental setups operating at high transmission rates, ... More
Shot-noise-limited magnetometer with sub-pT sensitivity at room temperatureMar 30 2014Nov 20 2014We report a photon shot-noise-limited (SNL) optical magnetometer based on amplitude modulated optical rotation using a room-temperature $^{85}$Rb vapor in a cell with anti-relaxation coating. The instrument achieves a room-temperature sensitivity of $70$ ... More
Simultaneous tracking of spin angle and amplitude beyond classical limitsFeb 28 2017We show how simultaneous, back-action evading tracking of non-commuting observables can be achieved in a widely-used sensing technology, atomic interferometry. Using high-dynamic-range dynamically-decoupled quantum non-demolition (QND) measurements on ... More
Precision measurement of spin-dependent inter-hyperfine scattering lengths in $^{87}$RbApr 16 2019We present precision measurements of the $f=1$ to $f=2$ inter-hyperfine scattering lengths in a single-domain $^{87}$Rb spinor Bose-Einstein condensate. The inter-hyperfine interaction leads to a strong and state-dependent modification of the spin-mixing ... More
Phase diffusion quantum entropy source on a silicon chipApr 12 2018We report an accelerated laser phase diffusion quantum entropy source with all non-laser optical and optoelectronic elements implemented in silicon photonics. The device uses efficient and robust single-laser accelerated phase diffusion methods, and implements ... More
Atomic filtering for hybrid continuous-variable/discrete-variable quantum opticsJun 16 2014Sep 04 2014We demonstrate atomic filtering of frequency-degenerate photon pairs from a sub-threshold optical parametric oscillator (OPO). The filter, a modified Faraday anomalous dispersion optical filter (FADOF), achieves 70% peak transmission simultaneous with ... More
Ultra-Narrow Faraday Rotation Filter at the Rb D1 LineOct 11 2011Jul 14 2016We present a theoretical and experimental study of the ultra-narrow bandwidth Faraday anomalous dispersion optical filter (FADOF) operating at the rubidium D1 line (795 nm). This atomic line gives better performance than other lines for the main FADOF ... More
Precision measurement of spin-dependent inter-hyperfine scattering lengths in $^{87}$RbApr 16 2019Apr 17 2019We present precision measurements of the $f=1$ to $f=2$ inter-hyperfine scattering lengths in a single-domain $^{87}$Rb spinor Bose-Einstein condensate. The inter-hyperfine interaction leads to a strong and state-dependent modification of the spin-mixing ... More
Long-term laser frequency stabilization using fiber interferometersOct 13 2014Jul 03 2015We report long-term laser frequency stabilization using only the target laser and a pair of 5 m fiber interferometers, one as a frequency reference and the second as a sensitive thermometer to stabilize the frequency reference. When used to stabilize ... More
Quantum enhanced measurements without entanglementJan 18 2017Apr 16 2018Quantum-enhanced measurements exploit quantum mechanical effects for increasing the sensitivity of measurements of certain physical parameters and have great potential for both fundamental science and concrete applications. Most of the research has so ... More
Certified quantum non-demolition measurement of material systemsMar 29 2012An extensive debate on quantum non-demolition (QND) measurement, reviewed in Grangier et al. [Nature, {\bf 396}, 537 (1998)], finds that true QND measurements must have both non-classical state-preparation capability and non-classical information-damage ... More
Signal tracking beyond the time resolution of an atomic sensor by Kalman filteringJul 25 2017Feb 21 2018We study causal waveform estimation (tracking) of time-varying signals in a paradigmatic atomic sensor, an alkali vapor monitored by Faraday rotation probing. We use Kalman filtering, which optimally tracks known linear Gaussian stochastic processes, ... More
Sensitivity, quantum limits, and quantum enhancement of noise spectroscopiesOct 07 2016May 15 2018We study the fundamental limits of noise spectroscopy using estimation theory, Faraday rotation probing of an atomic spin system, and squeezed light. We find a simple and general expression for the Fisher information, which quantifies the sensitivity ... More
Interferometric measurement of the biphoton wave functionJul 29 2014Interference between an unknown two-photon state (a "biphoton") and the two-photon component of a reference state gives a phase-sensitive arrival-time distribution containing full information about the biphoton temporal wave function. Using a coherent ... More
A macroscopic quantum state analysed particle by particleOct 26 2014Explaining how microscopic entities collectively produce macroscopic phenomena is a fundamental goal of many-body physics. Theory predicts that large-scale entanglement is responsible for exotic macroscopic phenomena, but observation of entangled particles ... More
A nonlocal classical perspective on quantum electrodynamicsSep 05 2001The ideas behind the nonlocal classical statistical field theory model for the quantized Klein-Gordon field introduced in Morgan(2001, quant-ph/0106141) are extended to accommodate quantum electrodynamics. The anticommutation rules for the quantized Dirac ... More
A high-brightness source of polarization-entangled photons optimized for applications in free spaceApr 24 2012We present a simple but highly efficient source of polarization-entangled photons based on spontaneous parametric down-conversion (SPDC) in bulk periodically poled potassium titanyl phosphate crystals (PPKTP) pumped by a 405 nm laser diode. Utilizing ... More
Holomorphic Principal Bundles Over Elliptic Curves II: The Parabolic ConstructionJun 22 2000Mar 14 2001This paper continues the study of holomorphic semistable principal G-bundles over an elliptic curve. In this paper, the moduli space of all such bundles is constructed by considering deformations of a minimally unstable G-bundle. The set of all such deformations ... More
Mathematics Underlying the F-Theory/Heterotic String Duality in Eight DimensionsAug 11 2003One of the dualities in string theory, the F-theory/heterotic string duality in eight dimensions, predicts an interesting correspondence between two seemingly disparate geometrical objects. On one side of the duality there are elliptically fibered K3 ... More
Automorphism sheaves, spectral covers, and the Kostant and Steinberg sectionsSep 05 2002Kostant constructed a section from the adjoint quotient morphism of a simple Lie algebra to the open set of regular elements, and Steinberg constructed such a section for the adjoint quotient of a simply connected and simple algebraic group. In this paper, ... More
Holomorphic principal bundles over elliptic curvesNov 22 1998In this paper, the first of a series of three, we classify holomorphic principal G-bundles over an elliptic curve, where G is a reductive group. We also study the local and global properties of the moduli space of semistable G-bundles. We identify canonical ... More
Generation, characterization and use of atom-resonant indistinguishable photon pairsFeb 26 2015We describe the generation of atom-resonant indistinguishable photon pairs using nonlinear optical techniques, their spectral purification using atomic filters, characterization using multi-photon interference, and application to quantum-enhanced sensing ... More
Parametric down-conversion from a wave-equations approach: geometry and absolute brightnessJul 22 2008Jan 25 2009Using the approach of coupled wave equations, we consider spontaneous parametric down-conversion (SPDC) in the narrow-band regime and its relationship to classical nonlinear processes such as sum-frequency generation. We find simple expressions in terms ... More
Experimental test of measurement dependent local Bell inequality with human free willJul 02 2018A Bell test can rule out local realistic models, and has potential applications in communications and information tasks. For example, a Bell inequality violation can certify the presence of intrinsic randomness in measurement outcomes, which then can ... More
Experimental Low-Latency Device-Independent Quantum RandomnessDec 19 2018Applications of randomness such as private key generation and public randomness beacons require small blocks of certified random bits on demand. Device-independent quantum random number generators can produce such random bits, but existing quantum-proof ... More
Entangled photon apparatus for the undergraduate laboratoryMay 27 2002We present detailed instructions for constructing and operating an apparatus to produce and detect polarization-entangled photons. The source operates by type-I spontaneous parametric downconversion in a two-crystal geometry. Photons are detected in coincidence ... More
Entangled photons, nonlocality and Bell inequalities in the undergraduate laboratoryMay 27 2002We use polarization-entangled photon pairs to demonstrate quantum nonlocality in an experiment suitable for advanced undergraduates. The photons are produced by spontaneous parametric downconversion using a violet diode laser and two nonlinear crystals. ... More
Mirror Symmetry and Integral Variations of Hodge Structure Underlying One Parameter Families of Calabi-Yau ThreefoldsMay 12 2005This proceedings note introduces aspects of the authors' work relating mirror symmetry and integral variations of Hodge structure. The emphasis is on their classification of the integral variations of Hodge structure which can underly families of Calabi-Yau ... More
An Outbreak Vector-host Epidemic Model with Spatial Structure: The 2015 Zika Outbreak in Rio de JaneiroMay 27 2016Jun 22 2016Background: A deterministic model is developed for the spatial spread of an epidemic disease in a geographical setting. The disease is borne by vectors to susceptible hosts through criss-cross dynamics. The model is focused on an epidemic outbreak that ... More
Spontaneous PT symmetry breaking of a ferromagnetic superfluid in a gradient fieldJan 27 2015Sep 24 2015We consider the interaction of a ferromagnetic spinor Bose-Einstein condensate with a magnetic field gradient. The magnetic field gradient realizes a spin-position coupling that explicitly breaks time-reversal symmetry T and space parity P, but preserves ... More
A magneto-optical trap created by the 2nd-order external cavity diode lasersDec 03 2018In this article, we report on a magneto-optical trap (MOT) created by the 2nd-order external cavity diode lasers (ECDLs). The lasers were characterized. We have observed the non-continuous changes of the wavelength as a function of the laser diode current. ... More
Generation of macroscopic singlet states in atomic ensemblesJan 27 2009May 19 2010We study squeezing of the spin uncertainties by quantum non-demolition (QND) measurement in non-polarized spin ensembles. Unlike the case of polarized ensembles, the QND measurements can be performed with negligible back-action, which allows, in principle, ... More
Randomness in Quantum Mechanics: Philosophy, Physics and TechnologyNov 07 2016Aug 17 2017This progress report covers recent developments in the area of quantum randomness, which is an extraordinarily interdisciplinary area that belongs not only to physics, but also to philosophy, mathematics, computer science, and technology. For this reason ... More
The Potential of Spaced-based High-Energy Neutrino Measurements via the Airshower Cherenkov SignalSep 29 2011Future space-based experiments, such as OWL and JEM-EUSO, view large atmospheric and terrestrial neutrino targets. With energy thresholds slightly above 10^19 eV for observing airshowers via air fluorescence, the potential for observing the cosmogenic ... More
A partition theorem for a large dense linear orderJun 07 2005Let Q_K=(Q,<_Q)$ be a strongly K-dense linear order of size K for a suitable cardinal K. We prove, for all integers m > 1 that there is a finite value t_m^+ such that the set of all m-tuples from Q can be divided into t_m^+ many classes, such that whenever ... More
Strong experimental guarantees in ultrafast quantum random number generationJan 13 2015We describe a methodology and standard of proof for experimental claims of quantum random number generation (QRNG), analogous to well-established methods from precision measurement. For appropriately constructed physical implementations, lower bounds ... More
Theory of high gain cavity-enhanced spontaneous parametric down-conversionSep 03 2014Jan 08 2015We compute the output of multimode cavity-enhanced spontaneous parametric down-conversion (SPDC) for sub-threshold, but otherwise arbitrary, gain. We find analytic Bogoliubov transformations that allow us to calculate arbitrary field correlation functions, ... More
Extreme spin squeezing for photonsApr 09 2013Jun 10 2014We apply spin-squeezing techniques to identify and quantify highly multi-partite photonic entanglement in polarization-squeezed light. We consider a practical single-mode scenario, and find that Wineland-criterion polarization squeezing implies entanglement ... More
Optical spin squeezing: bright beams as high-flux entangled photon sourcesMar 21 2013Oct 09 2013In analogy with the spin-squeezing inequality of Wang and Sanders [Physical Review A 68, 012101 (2003)], we find inequalities describing macroscopic polarization correlations that are obeyed by all classical fields, and whose violation implies entanglement ... More
Real-time imaging of density ducts between the plasmasphere and ionosphereApr 24 2015Ionization of the Earth's atmosphere by sunlight forms a complex, multi-layered plasma environment within the Earth's magnetosphere, the innermost layers being the ionosphere and plasmasphere. The plasmasphere is believed to be embedded with cylindrical ... More
Rubidium resonant squeezed light from a diode-pumped optical-parametric oscillatorJul 27 2008We demonstrate a diode-laser-pumped system for generation of quadrature squeezing and polarization squeezing. Due to their excess phase noise, diode lasers are challenging to use in phase-sensitive quantum optics experiments such as quadrature squeezing. ... More
Potential for measuring the longitudinal and lateral profile of muons in TeV air showers with IACTsMar 28 2019Muons are copiously produced within hadronic extensive air showers (EAS) occurring in the Earth's atmosphere, and are used by particle air shower detectors as a means of identifying the primary cosmic ray which initiated the EAS. Imaging Atmospheric Cherenkov ... More
The Panchromatic STARBurst IRregular Dwarf Survey (STARBIRDS) DataNov 15 2016Understanding star formation in resolved low mass systems requires the integration of information obtained from observations at different wavelengths. We have combined new and archival multi-wavelength observations on a set of 20 nearby starburst and ... More
Revealing a new region of gamma-ray emission in the vicinity of HESS J1825-137Feb 20 2019HESS J1825-137 is a bright very-high-energy (VHE) gamma-ray source that has been firmly established as a pulsar wind nebula (PWN), and one of the most extended gamma-ray objects within this category. The progenitor supernova remnant (SNR) for this PWN ... More
Optimization of the Orbiting Wide-angle Light Collectors (OWL) Mission for Charged-Particle and Neutrino AstronomyJul 15 2013OWL uses the Earth's atmosphere as a vast calorimeter to fully enable the emerging field of charged-particle astronomy with high-statistics measurements of ultra-high-energy cosmic rays (UHECR) and a search for sources of UHE neutrinos and photons. Confirmation ... More
Dynamics of Atom-Mediated Photon-Photon Scattering II: ExperimentFeb 06 2000Temporal and angular correlations in atom-mediated photon-photon scattering are measured. Good agreement is found with the theory presented in Part~I.
Computing maximal subsemigroups of a finite semigroupJun 17 2016Jul 06 2018A proper subsemigroup of a semigroup is maximal if it is not contained in any other proper subsemigroup. A maximal subsemigroup of a finite semigroup has one of a small number of forms, as described in a paper of Graham, Graham, and Rhodes. Determining ... More
A robust algorithm for $k$-point grid generation and symmetry reductionSep 26 2018Feb 12 2019We develop an algorithm for computing generalized regular $k$-point grids and a related algorithm for symmetry-reducing a grid to its symmetrically distinct points. The algorithm exploits the connection between integer matrices and finite groups to achieve ... More
A tunable narrowband entangled photon pair source for resonant single-photon single-atom interactionAug 14 2008Aug 28 2008We present a tunable, frequency-stabilized, narrow-bandwidth source of frequency-degenerate, entangled photon pairs. The source is based on spontaneous parametric downconversion (SPDC) in periodically-poled KTiOPO4 (PPKTP). Its wavelength can be stabilized ... More
Requirements for a loophole-free photonic Bell test using imperfect setting generatorsNov 18 2014Mar 10 2016Experimental violations of Bell inequalities are in general vulnerable to so-called "loopholes." In this work, we analyse the characteristics of a loophole-free Bell test with photons, closing simultaneously the locality, freedom-of-choice, fair-sampling ... More
Planar squeezing by quantum non-demolition measurement in cold atomic ensemblesNov 20 2012May 05 2013Planar squeezed states, i.e. quantum states which are squeezed in two orthogonal spin components, have recently attracted attention due to their applications in atomic interferometry and quantum information [Q. Y. He et al, New J. Phys. 14, 093012 (2012)]. ... More
Rapid, Machine-Learned Resource Allocation: Application to High-redshift GRB Follow-upDec 15 2011As the number of observed Gamma-Ray Bursts (GRBs) continues to grow, follow-up resources need to be used more efficiently in order to maximize science output from limited telescope time. As such, it is becoming increasingly important to rapidly identify ... More
X-ray Monitoring of Gravitational Lenses With ChandraFeb 23 2012We present \emph{Chandra} monitoring data for six gravitationally lensed quasars: QJ 0158$-$4325, HE 0435$-$1223, HE 1104$-$1805, SDSS 0924+0219, SDSS 1004+4112, and Q 2237+0305. We detect X-ray microlensing variability in all six lenses with high confidence. ... More
A Traveling Feature in Saturn's RingsJul 18 2016The co-orbital satellites of Saturn, Janus and Epimetheus, swap radial positions every 4.0 years. Since \textit{Cassini} has been in orbit about Saturn, this has occurred on 21 January in 2006, 2010, and 2014. We describe the effects of this radial migration ... More
Insulating transition in the flux-flow resistivity of a high temperature superconductorDec 19 2005Measurements of the DC resistivity of under-doped cuprate superconductors have revealed a metal--insulator transition at low temperatures when superconductivity is suppressed by a very large magnetic field, with the resistivity growing logarithmically ... More
The Sizes of the X-ray and Optical Emission Regions of RXJ1131-1231Jun 23 2009We use gravitational microlensing of the four images of the z=0.658 quasar RXJ1131-1231 to measure the sizes of the optical and X-ray emission regions of the quasar. The (face-on) scale length of the optical disk at rest frame 400 nm is 1.3 10^15cm, while ... More
The Relativistic Astrophysics Explorer: A New Mission for X-Ray TimingNov 11 1999The great success of the Rossi X-Ray Timing Explorer (RXTE) has given us a new probe to study strong gravitational fields and to measure the physical properties of black holes and neutron stars. Here, we describe a "next-generation" x-ray timing mission, ... More
X-Ray Observations of GRS 1915+105Sep 16 1996A comparison of ROSAT observations with simultaneous BATSE monitoring data shows a different intensity evolution in the soft and hard X-ray band of GRS 1915+105 since 1992. In addition, fits of simultaneous ROSAT/BATSE spectra require more than one spectral ... More
Measuring the Innermost Stable Circular Orbits of Supermassive Black HolesSep 29 2016Feb 01 2017We present a promising new technique, the g-distribution method, for measuring the inclination angle (i), the innermost stable circular orbit (ISCO), and the spin of a supermassive black hole. The g-distribution method uses measurements of the energy ... More
Efficiency of Generalized Regular k-point GridsApr 12 2018Jun 25 2018Most DFT practitioners use regular grids (Monkhorst-Pack, MP) for integrations in the Brillioun zone. Although regular grids are the natural choice and easy to generate, more general grids whose generating vectors are not merely integer divisions of the ... More
Spatial Models of Vector-Host Epidemics with Directed Movement of Vectors Over Long DistancesSep 10 2018We investigate a time-dependent spatial vector-host epidemic model with non-coincident domains for the vector and host populations. The host population resides in small non-overlapping sub-regions, while the vector population resides throughout a much ... More
Constraining Quasar Relativistic Reflection Regions and Spins with MicrolensingJan 17 2019We present an analysis of Chandra X-ray spectra of the gravitationally lensed active galactic nuclei Q J0158-4325, HE 0435-1223, SDSS J1004+4112, HE 1104-1805, and Q 2237+0305. We confirm the previous detections of FeK\alpha\ emission lines in most images ... More
Multi-particle quantum fields for bound states and interactionsJul 29 2015Mar 01 2017The Fock-Hilbert space generated by a single-particle interaction-free Wightman field is augmented by introducing non-trivial multi-particle (that is, multi-point, multilinear) quantum fields, which is justified insofar as Haag's theorem establishes that ... More
The Space of Planar Soap Bubble ClustersMay 24 2016Soap bubbles and foams have been extensively studied by scientists, engineers, and mathematicians as models for organisms and materials, with applications ranging from extinguishing fires to mining to baking bread. Here we provide some basic results on ... More
Regularization by Test FunctionJun 22 2014Quantum fields are generally taken to be operator-valued distributions, linear functionals of test functions into an algebra of operators; here the effective dynamics of an interacting quantum field is taken to be nonlinearly modified by properties of ... More
A succinct presentation of the quantized Klein-Gordon field, and a similar quantum presentation of the classical Klein-Gordon random fieldNov 21 2004Mar 22 2005A succinct presentation of the algebraic structure of the quantized Klein-Gordon field can be given in terms of a Lorentz invariant inner product. A presentation of a classical Klein-Gordon \emph{random} field at non-zero temperature can be given in the ... More
A geometry for the electroweak fieldFeb 07 2003The structure of the electroweak theory is suggested by classical geometrical ideas. A nonlinear map is constructed, from a 12-dimensional linear space of three Weyl spinors onto the 12-dimensional tangent bundle of the Stiefel manifold of orthonormal ... More
The derivation of Bell inequalities for beablesSep 21 2000Jul 17 2003The derivation of Bell inequalities for beables is well-known to require a "no-conspiracy" assumption. This assumption is widely accepted, the alternative being correlations between instrument settings and hidden beables. Two further assumptions are identified ... More
Unary Classical MechanicsJan 02 2019Mar 20 2019Classical mechanics is presented here in a unary operator form, constructed using the binary multiplication and Poisson bracket operations that are given in a phase space formalism, then a Gibbs equilibrium state over this unary operator algebra is introduced, ... More
In orbifolds, small isoperimetric regions are small ballsDec 23 2006Jun 28 2008In a compact orbifold, for small prescribed volume, an isoperimetric region is close to a small metric ball; in a Euclidean orbifold, it is a small metric ball.
Regularity of area-minimizing surfaces in 3D polytopes and of invariant hypersurfaces in R^nApr 27 2004In (the surface of) a convex polytope P^3 in R^4, an area-minimizing surface avoids the vertices of P and crosses the edges orthogonally. In a smooth Riemannian manifold M with a group of isometries G, an area-minimizing G-invariant oriented hypersurface ... More
Classical states, quantum field measurementSep 20 2017Mar 06 2019Classical Koopman--von Neumann Hilbert spaces of states are constructed here by the action of classical random fields on a vacuum state in ways that support an action of the quantized electromagnetic field and of the $U(1)$--invariant observables of the ... More
A graphical presentation of signal delays in the datasets of Weihs et alJul 24 2012A graphical presentation of the timing of avalanche photodiode events in the datasets from the experiment of Weihs et al. [Phys. Rev. Lett. 81, 5039 (1998)] makes manifest the existence of two types of signal delay: (1) The introduction of rapid switching ... More
Lie fields revisitedApr 25 2007Nov 27 2007A class of interacting classical random fields is constructed using deformed *-algebras of creation and annihilation operators. The fields constructed are classical random field versions of "Lie fields". A vacuum vector is used to construct linear forms ... More
A relativistic variant of the Wigner functionApr 28 2003Dec 17 2003The conventional Wigner function is inappropriate in a quantum field theory setting because, as a quasiprobability density over phase space, it is not manifestly Lorentz covariant. A manifestly relativistic variant is constructed as a quasiprobability ... More
Models of measurement for quantum fields and for classical continuous random fieldsJul 24 2006A quantum field model for an experiment describes thermal fluctuations explicitly and quantum fluctuations implicitly, whereas a comparable continuous random field model would describe both thermal and quantum fluctuations explicitly. An ideal classical ... More
Bell inequalities for random fieldsMar 29 2004May 24 2006The assumptions required for the derivation of Bell inequalities are not usually satisfied for random fields in which there are any thermal or quantum fluctuations, in contrast to the general satisfaction of the assumptions for classical two point particle ... More
Bell inequalities and incompatible measurementsJul 17 2003Bell inequalities are a consequence of measurement incompatibility (not, as generally thought, of nonlocality). In classical terms, this is equivalent to contextuality -- measurement devices do have a significant effect. Contextual models are reasonable ... More
A classical perspective on nonlocality in quantum field theoryJun 25 2001Nov 07 2001A classical statistical field theory hidden variable model for the quantized Klein-Gordon model is constructed that preserves relativistic signal locality and is relativistically covariant, but is at the same time relativistically nonlocal, paralleling ... More
Existence of Least-perimeter PartitionsNov 27 2007Feb 19 2008We prove the existence of a perimeter-minimizing partition of R^n into regions of unit volume. We conclude with a short tribute to the late Manuel A. Fortes.
Nonlinear Wightman fieldsNov 12 2012Dec 06 2012A nonlinear Wightman field is taken to be a nonlinear map from a linear space of test functions to a linear space of Hilbert space operators, with inessential modifications to other axioms only to the extent dictated by the introduction of nonlinearity. ... More
Embedding quantum and random optics in a larger field theoryJun 09 2008Introducing creation and annihilation operators for negative frequency components extends the algebra of smeared local observables of quantum optics to include an associated classical random field optics.
Nonlinear dependence of the renormalization scale on test functionsSep 19 2013Quantum electrodynamics exhibits an informal nonlinear dependence on Lorentz invariant test function properties that determine the renormalization scale, such as Mandelstam variables, contrary to the linear dependence on test functions that is required ... More
Equivalence of the Klein-Gordon random field and the complex Klein-Gordon quantum fieldMay 08 2009Aug 29 2009The difference between a Klein-Gordon random field and the complex Klein-Gordon quantum field is characterized, explicitly comparing the roles played by negative frequency modes of test functions in creation and annihilation operator presentations of ... More
Weakened linearity for quantum fieldsDec 22 2005Oct 10 2006There are still no interacting models of the Wightman axioms, suggesting that the axioms are too tightly drawn. Here a weakening of linearity for quantum fields is proposed, with the algebra still linear but with the quantum fields no longer required ... More
Mitchell-style forcing, with small working parts and collections of models as side conditions, and gap-one simplified morassesNov 22 2014We give a modification of Mitchell's technique for adding objects of size $\omega_2$ with conditions with finite working parts in which the collections of models used as side conditions are very highly structured, arguably making them more wieldy. We ... More
Near-resonant optical forces beyond the two-level approximation for a continuous source of spin-polarized cold atomsJan 18 2013Mar 14 2013We propose a method to generate a source of spin-polarized cold atoms which are continuously extracted and guided from a magneto-optical trap using an atom-diode effect. We show that it is possible to create a pipe-like potential by overlapping two optical ... More
An atlas of coronal electron density at 5Rs I: Data processing and calibrationSep 10 2015Tomography of the solar corona can provide cruicial constraints for models of the low corona, unique information on changes in coronal structure and rotation rates, and a valuable boundary condition for models of the heliospheric solar wind. This is the ... More
Registering large volume serial-section electron microscopy image sets for neural circuit reconstruction using FFT signal whiteningDec 14 2016The detailed reconstruction of neural anatomy for connectomics studies requires a combination of resolution and large three-dimensional data capture provided by serial section electron microscopy (ssEM). The convergence of high throughput ssEM imaging ... More
Simultaneous Observations of Giant Pulses from the Crab Pulsar, with the Murchison Widefield Array and Parkes Radio Telescope: Implications for the Giant Pulse Emission MechanismJul 17 2015We report on observations of giant pulses from the Crab pulsar performed simultaneously with the Parkes radio telescope and the incoherent combination of the Murchison Widefield Array (MWA) antenna tiles. The observations were performed over a duration ... More
The low-frequency characteristics of PSR J0437-4715 observed with the Murchison Widefield ArrayJul 17 2014We report on the detection of the millisecond pulsar PSR J0437-4715 with the Murchison Widefield Array (MWA) at a frequency of 192 MHz. Our observations show rapid modulations of pulse intensity in time and frequency that arise from diffractive scintillation ... More
Low Frequency Imaging of Fields at High Galactic Latitude with the Murchison Widefield Array 32-Element PrototypeMar 26 2012The Murchison Widefield Array (MWA) is a new low-frequency, wide field-of-view radio interferometer under development at the Murchison Radio-astronomy Observatory (MRO) in Western Australia. We have used a 32-element MWA prototype interferometer (MWA-32T) ... More
Human language reveals a universal positivity biasJun 15 2014Using human evaluation of 100,000 words spread across 24 corpora in 10 languages diverse in origin and culture, we present evidence of a deep imprint of human sociality in language, observing that (1) the words of natural human language possess a universal ... More
On the 14C(alpha,gamma) reaction rateOct 02 2009The 14C(alpha,gamma) reaction rate at temperatures below 0.3 GK depends on the properties of two near threshold resonances in 18O, the 1- at 6.198 MeV and the 3- at 6.404 MeV. The alpha+14C Asymptotic Normalization Coefficients (ANCs) for these resonances ... More
Classical dispersion-cancellation interferometryApr 30 2007Even-order dispersion cancellation, an effect previously identified with frequency-entangled photons, is demonstrated experimentally for the first time with a linear, classical interferometer. A combination of a broad bandwidth laser and a high resolution ... More
Calibrating UV Star Formation Rates for Dwarf Galaxies from STARBIRDSMay 04 2015May 17 2015Integrating our knowledge of star formation traced by observations at different wavelengths is essential for correctly interpreting and comparing star formation activity in a variety of systems and environments. This study compares extinction corrected ... More