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Propagating Uncertainty in Multi-Stage Bayesian Convolutional Neural Networks with Application to Pulmonary Nodule DetectionDec 01 2017Motivated by the problem of computer-aided detection (CAD) of pulmonary nodules, we introduce methods to propagate and fuse uncertainty information in a multi-stage Bayesian convolutional neural network (CNN) architecture. The question we seek to answer ... More

A 3D Probabilistic Deep Learning System for Detection and Diagnosis of Lung Cancer Using Low-Dose CT ScansFeb 08 2019We introduce a new end-to-end computer aided detection and diagnosis system for lung cancer screening using low-dose CT scans. Our system is based on 3D convolutional neural networks and achieves state-of-the-art performance for both lung nodule detection ... More

Monte Carlo Simulations of Higgs-Fermion SystemsApr 08 1992To gain understanding of the Higgs-fermion sector of the standard model, we study the one-component $Z_2$ symmetric and the four-component O(4) symmetric scalar models coupled to staggered fermions using the hybrid Monte Carlo algorithm. We map out the ... More

Performance of a GPU-based Direct Summation Algorithm for Computation of Small Angle Scattering ProfileJun 10 2013Small Angle Scattering (SAS) of X-rays or neutrons is an experimental technique that provides valuable structural information for biological macromolecules under physiological conditions and with no limitation on the molecular size. In order to refine ... More

The Diphoton and Diboson Excesses in a Left-Right Symmetric Theory of Dark MatterJan 07 2016We explore the possibility that the recently reported diphoton excess at ATLAS and CMS can be accommodated within a minimal extension of a left-right symmetric model. Our setup is able to simultaneously explain the Run 2 diphoton and Run 1 diboson excesses, ... More

Neutrino Oscillations as a Probe of Light Scalar Dark MatterAug 03 2016We consider a class of models involving interactions between ultra-light scalar dark matter and Standard Model neutrinos. Such couplings modify the neutrino mass splittings and mixing angles to include additional components that vary in time periodically ... More

Neutrino Oscillations as a Probe of Light Scalar Dark MatterAug 03 2016Dec 01 2016We consider a class of models involving interactions between ultra-light scalar dark matter and Standard Model neutrinos. Such couplings modify the neutrino mass splittings and mixing angles to include additional components that vary in time periodically ... More

WIMPs with GUTs: Dark Matter Coannihilation with a Lighter SpeciesApr 26 2017We propose a new thermal freeze-out mechanism for ultra-heavy dark matter. Dark matter coannihilates with a lighter unstable species, leading to an annihilation rate that is exponentially enhanced relative to standard WIMPs. This scenario destabilizes ... More

Physics of Proteins at Low TemperatureJul 15 2004We present results of a hole burning study with thermal cycling and waiting time spectral diffusion experiments on a modified cytochrome - c protein in its native as well as in its denatured state. The experiments show features which seem to be characteristic ... More

Flipping quantum coinsApr 27 2009May 01 2009Coin flipping is a cryptographic primitive in which two distrustful parties wish to generate a random bit in order to choose between two alternatives. This task is impossible to realize when it relies solely on the asynchronous exchange of classical bits: ... More

Quantum dynamical properties of a two-photon non-linear Jaynes-Cummings modelOct 31 2000In this paper we study a two-photon time-dependent Jaynes-Cummings model interacting with a Kerr-like medium. We assumed that the electromagnetic field is in different states such as coherent, squeezed vacuum and pair coherent, and that the atom is initially ... More

Improving Zero-Day Malware Testing Methodology Using Statistically Significant Time-Lagged Test SamplesAug 02 2016Enterprise networks are in constant danger of being breached by cyber-attackers, but making the decision about what security tools to deploy to mitigate this risk requires carefully designed evaluation of security products. One of the most important metrics ... More

A Thermal Neutrino Portal to Sub-MeV Dark MatterJul 11 2018Thermal relics lighter than an MeV contribute to the energy density of the universe at the time of nucleosynthesis and recombination. Constraints on extra radiation degrees of freedom typically exclude even the simplest of such dark sectors. We explore ... More

Axion-Assisted Production of Sterile Neutrino Dark MatterOct 12 2016Sterile neutrinos can be generated in the early universe through oscillations with active neutrinos and represent a popular and well-studied candidate for our universe's dark matter. Stringent constraints from X-ray and gamma-ray line searches, however, ... More

Stringent Constraints On The Dark Matter Annihilation Cross Section From Subhalo Searches With The Fermi Gamma-Ray Space TelescopeSep 02 2013The dark matter halo of the Milky Way is predicted to contain a very large number of smaller subhalos. As a result of the dark matter annihilations taking place within such objects, the most nearby and massive subhalos could appear as point-like or spatially ... More

Inelastic Dark Matter at the LHC Lifetime Frontier: ATLAS, CMS, LHCb, CODEX-b, FASER, and MATHUSLAOct 03 2018Visible signals from the decays of light long-lived hidden sector particles have been extensively searched for at beam dump, fixed-target, and collider experiments. If such hidden sectors couple to the Standard Model through mediators heavier than $\sim ... More

Some Useful Properties of Rotational Gibbs States In Chiral Conformal QFTMay 17 1994We derive the Kac Wakimoto formula in the algebraic framework of chiral conformal QFT s a consequence of the universal behaviour of high-temperature Gibbs-states on intertwiner subalgebras. By studying selfintertwiners in the presence of other charges, ... More

Deep Neural Network Based Malware Detection Using Two Dimensional Binary Program FeaturesAug 13 2015Sep 03 2015Malware remains a serious problem for corporations, government agencies, and individuals, as attackers continue to use it as a tool to effect frequent and costly network intrusions. Machine learning holds the promise of automating the work required to ... More

Thermal Dark Matter Below an MeVJun 21 2017Mar 02 2018We consider a class of models in which thermal dark matter is lighter than an MeV. If dark matter thermalizes with the Standard Model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cools and heats the Standard Model ... More

Survey of Instantaneous 1-22 GHz Spectra of 550 Compact Extragalactic Objects with Declinations from -30deg to +43degAug 16 2004We present observational results for extragalactic radio sources with milliarcsecond components, obtained with the 600 meter ring radio telescope RATAN-600 from 1st to 22nd December, 1997. For each source, a six frequency broad band radio spectrum was ... More

RATAN-600 new zenith field survey and CMB problemsAug 02 2005We present new RATAN-600 data on the synchrotron Galaxy radiation at the PLANCK Mission and WMAP frequencies at high Galactic latitudes upto l=3000. The difference between the standard synchrotron template (l<50) of the WMAP group and RATAN-600 data was ... More

PeV-Scale Dark Matter as a Thermal Relic of a Decoupled SectorFeb 26 2016In this letter, we consider a class of scenarios in which the dark matter is part of a heavy hidden sector that is thermally decoupled from the Standard Model in the early universe. The dark matter freezes-out by annihilating to a lighter, metastable ... More

A 3.55 keV Line from Exciting Dark Matter without a Hidden SectorJan 14 2015Models in which dark matter particles can scatter into a slightly heavier state which promptly decays to the lighter state and a photon (known as eXciting Dark Matter, or XDM) have been shown to be capable of generating the 3.55 keV line observed from ... More

Thermal Dark Matter From A Highly Decoupled SectorSep 08 2016It has recently been shown that if the dark matter is in thermal equilibrium with a sector that is highly decoupled from the Standard Model, it can freeze-out with an acceptable relic abundance, even if the dark matter is as heavy as ~1-100 PeV. In such ... More

Testing mixed action approaches to meson spectroscopy with twisted mass sea quarksAug 22 2013We explore and compare three mixed action setups with Wilson twisted mass sea quarks and different valence quark actions: (1) Wilson twisted mass, (2) Wilson twisted mass + clover and (3) Wilson + clover. Our main goal is to reduce lattice discretization ... More

Everything You Always Wanted to Know About Dark Matter Elastic Scattering Through Higgs Loops But Were Afraid to AskAug 21 2015We consider a complete list of simplified models in which Majorana dark matter particles annihilate at tree level to $hh$ or $hZ$ final states, and calculate the loop-induced elastic scattering cross section with nuclei in each case. Expressions for these ... More

Epidemiology of Latency and Relapse in Plasmodium vivax MalariaMay 08 2015Malaria is a major contributor to health burdens throughout the regions where it is endemic. Historically, it was believed that there was limited morbidity and essentially no mortality associated with Plasmodium vivax; however, evidence from diverse settings ... More

Mean curvature blow up in mean curvature flowFeb 25 2009May 24 2010In this note we establish that finite-time singularities of the mean curvature flow of compact Riemannian submanifolds are characterised by the blow up of the mean curvature.

Observing Long Cosmic Strings Through Gravitational LensingMay 28 1997We consider the gravitational lensing produced by long cosmic strings formed in a GUT scale phase transition. We derive a formula for the deflection of photons which pass near the strings that reduces to an integral over the light cone projection of the ... More

Short Report: Study variability in recent human challenge experiments with Plasmodium falciparum sporozoites (PfSPZ Challenge)May 06 2015There has been renewed interest in the use of sporozoite-based approaches for malaria vaccination and controlled human infections, and several sets of human challenge studies have recently completed. A study undertaken in Tanzania and published in 2014 ... More

Age, Metallicity, and the Distance to the Magellanic Clouds From Red Clump StarsApr 10 1998We show that the luminosity dependence of the red clump stars on age and metallicity can cause a difference of up to < ~0.6 mag in the mean absolute I magnitude of the red clump between different stellar populations. We show that this effect may resolve ... More

A Characterization of the Singular Time of the Mean Curvature FlowMay 24 2010In this note we investigate the behaviour at finite-time singularities of the mean curvature flow of compact Riemannian submanifolds M^m_t\hookrightarrow (N^{m+n}, h). We show that they are characterized by the blow-up of a trace A = H \cdot II of the ... More

Singularities of the Lagrangian Mean Curvature FlowMay 07 2015In this paper we investigate the singularities of Lagrangian mean curvature flows in $\mathbf{C}^m$ by means of smooth singularity models. Type I singularities can only occur at certain times determined by invariants in the cohomology of the initial data. ... More

Fractal Location and Anomalous Diffusion Dynamics for Oil Wells from the KY Geological SurveyDec 13 2009Utilizing data available from the Kentucky Geonet (KYGeonet.ky.gov) the fossil fuel mining locations created by the Kentucky Geological Survey geo-locating oil and gas wells are mapped using ESRI ArcGIS in Kentucky single plain 1602 ft projection. This ... More

A quantum group version of quantum gauge theories in two dimensionsJul 09 1992For the special case of the quantum group $SL_q (2,{\bf C})\ (q= \exp \pi i/r,\ r\ge 3)$ we present an alternative approach to quantum gauge theories in two dimensions. We exhibit the similarities to Witten's combinatorial approach which is based on ideas ... More

Malicious Behavior Detection using Windows Audit LogsJun 13 2015Aug 25 2015As antivirus and network intrusion detection systems have increasingly proven insufficient to detect advanced threats, large security operations centers have moved to deploy endpoint-based sensors that provide deeper visibility into low-level events across ... More

Simplified Dark Matter Models for the Galactic Center Gamma-Ray ExcessMar 31 2014Jun 02 2015Motivated by the gamma-ray excess observed from the region surrounding the Galactic Center, we explore particle dark matter models that could potentially account for the spectrum and normalization of this signal. Taking a model-independent approach, we ... More

Mono-Higgs Detection of Dark Matter at the LHCFeb 27 2014Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators where a Higgs ... More

Thermal Dark Matter From A Highly Decoupled SectorSep 08 2016Dec 01 2016It has recently been shown that if the dark matter is in thermal equilibrium with a sector that is highly decoupled from the Standard Model, it can freeze-out with an acceptable relic abundance, even if the dark matter is as heavy as ~1-100 PeV. In such ... More

Booms and Busts: the Burstiness of Star Formation in Nearby Dwarf GalaxiesNov 19 2009In this review I summarise recent advances in our understanding of the importance of starburst events to the evolutionary histories of nearby galaxies. Ongoing bursts are easily diagnosed in emission-line surveys, but assessing the timing and intensity ... More

Performance of the NuTeV Fe-Scintillator Sampling Calorimeter and Implications for Thin CalorimetersJan 20 2000NuTeV is a neutrino-nucleon deep inelastic scattering experiment at Fermilab. The NuTeV detector is a traditional heavy target neutrino detector which consists of an iron/liquid scintillator sampling calorimeter followed by a muon spectrometer. The calorimeter ... More

A Compactness Theorem for the Second Fundamental FormJun 29 2010Apr 25 2011In this note we establish several versions of a compactness theorem for submanifolds. In particular we require only bounds on the second fundamental form and do not assume volume or diameter bounds. As an application we prove a compactness theorem for ... More

A Simple Converse of Burnashev's ReliabilityOct 25 2006Sep 23 2008In a remarkable paper published in 1976, Burnashev determined the reliability function of variable-length block codes over discrete memoryless channels with feedback. Subsequently, an alternative achievability proof was obtained by Yamamoto and Itoh via ... More

Charge migration in organic materials: Can propagating charges affect the key physical quantities controlling their motion?Jan 23 2012Charge migration is a ubiquitous phenomenon with profound implications throughout many areas of chemistry, physics, biology and materials science. The long-term vision of designing functional materials with tailored molecular scale properties has triggered ... More

Generalising the Willmore equation: submanifold conformal invariants from a boundary Yamabe problemJul 24 2014The Willmore energy, alias bending energy or rigid string action, and its variation-the Willmore invariant-are important surface conformal invariants with applications ranging from cell membranes to the entanglement entropy in quantum gravity. In work ... More

Where are the Old-Population High Velocity Stars?Jan 11 2007To date, all of the reported high velocity stars (HVSs), which are believed to be ejected from the Galactic center, are blue and therefore almost certainly young. Old-population HVSs could be much more numerous than the young ones that have been discovered, ... More

No Death Star -- For NowJan 07 1998Mar 30 1998A star passing within $\sim 10^4 \au$ of the Sun would trigger a comet shower that would reach the inner solar system about 0.18 Myr later. We calculate a prior probability of ~0.4% that a star has passed this close to the Sun but that the comet shower ... More

Rotation and Activity in Late-type M DwarfsOct 01 2008We have examined the relationship between rotation and activity in 14 late-type (M6-M7) M dwarfs, using high resolution spectra taken at the Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey. Most are inactive at a spectral ... More

On The Origin Of The Mass-Metallicity Relation For GRB Host GalaxiesNov 17 2010We investigate the nature of the mass-metallicity (M-Z) relation for long gamma-ray burst (LGRB) host galaxies. Recent studies suggest that the M-Z relation for local LGRB host galaxies may be systematically offset towards lower metallicities relative ... More

Active Semi-Supervised Learning using Submodular FunctionsFeb 14 2012We consider active, semi-supervised learning in an offline transductive setting. We show that a previously proposed error bound for active learning on undirected weighted graphs can be generalized by replacing graph cut with an arbitrary symmetric submodular ... More

Globular Cluster Abundances from High-Resolution Integrated Light Spectra, I: 47 TucSep 12 2007May 06 2008We describe the detailed chemical abundance analysis of a high-resolution (R~35,000), integrated-light (IL), spectrum of the core of the Galactic globular cluster 47 Tuc, obtained using the du Pont echelle at Las Campanas. We develop an abundance analysis ... More

Sensitivity of atom interferometry to ultralight scalar field dark matterMay 13 2016Sep 24 2016We discuss the use of atom interferometry as a tool to search for Dark Matter (DM) composed of ultra-light scalar fields. Previous work on ultra-light DM detection using accelerometers has considered the possibility of equivalence principle violating ... More

Predicted Information Content of Gaia-HipparcosSep 09 2016Sep 13 2016The Gaia-Tycho release, scheduled for 14 September, is forecast to yield parallax errors of $\sigma(\pi)\sim 300\,\mu$as for about 2 million Tycho stars. We show analytically that the actual performance should be $$ \sigma(\pi) = {\rm max}(\sigma_{1991}/96,20\,\mu{\rm ... More

Conformal hypersurface geometry via a boundary Loewner-Nirenberg-Yamabe problemJun 08 2015Nov 12 2016We develop a new approach to the conformal geometry of embedded hypersurfaces by treating them as conformal infinities of conformally compact manifolds. This involves the Loewner--Nirenberg-type problem of finding on the interior a metric that is both ... More

On Closed Graphs IJun 21 2013Dec 31 2014A graph is closed when its vertices have a labeling by [n] with a certain property first discovered in the study of binomial edge ideals. In this article, we prove that a connected graph has a closed labeling if and only if it is chordal, claw-free, and ... More

Boundary quasi-orthogonality and sharp inclusion bounds for large Dirichlet eigenvaluesJun 18 2010We study eigenfunctions and eigenvalues of the Dirichlet Laplacian on a bounded domain $\Omega\subset\RR^n$ with piecewise smooth boundary. We bound the distance between an arbitrary parameter $E > 0$ and the spectrum $\{E_j \}$ in terms of the boundary ... More

Maps admitting trialities but not dualitiesNov 13 2009We use group theory to construct infinite families of maps on surfaces which are invariant under Wilson's map operations of order 3 but not under the operations of order 2, such as duality and Petrie duality.

Boundary calculus for conformally compact manifoldsApr 15 2011May 17 2012On conformally compact manifolds of arbitrary signature, we use conformal geometry to identify a natural (and very general) class of canonical boundary problems. It turns out that these encompass and extend aspects of already known holographic bulk-boundary ... More

Dynamics of the forward vortex cascade in two-dimensional quantum turbulenceNov 19 2014The dynamics of the forward vortex cascade in 2D turbulence in a superfluid film is investigated using analytic techniques. The cascade is formed by injecting pairs with the same initial separation (the stirring scale) at a constant rate. They move to ... More

Resonant detection of axion mediated forces with Nuclear Magnetic ResonanceMar 05 2014We describe a method based on precision magnetometry that can extend the search for axion-mediated spin-dependent forces by several orders of magnitude. By combining techniques used in nuclear magnetic resonance and short-distance tests of gravity, our ... More

Multiple-scales analysis of cosmological perturbations in brane-worldsAug 12 2004We present a new approximation method for solving the equations of motion for cosmological tensor perturbations in a Randall-Sundrum brane-world model of the type with one brane in a five-dimensional anti-de Sitter spacetime. This method avoids the problem ... More

Estimates on Neumann eigenfunctions at the boundary, and the "Method of Particular Solutions" for computing themJul 12 2011We consider the "Method of particular solutions" for numerically computing eigenvalues and eigenfunctions of the Laplacian $\Delta$ on a smooth, bounded domain Omega in RR^n with either Dirichlet or Neumann boundary conditions. This method constructs ... More

A Quadruple or Triple Origin For Tycho B and SN 1572Oct 22 2012Kerzendorf et al. (2012) recently reported the startling discovery of a metal-poor ([Fe/H]=-1 +/- 0.4) A-type star near the center of the Tycho supernova remnant. We propose two possible explanations. In the first, Tycho B is a blue straggler, formed ... More

Investigations of Higher Order LinksFeb 20 2016The following is an amalgamation of four preprints and some computer programs which together represent the current state of our investigations of higher order links. This investigation was motivated by questions discussed and raised in the first author's ... More

Gaia Parallax Zero Point From RR Lyrae StarsSep 02 2016Like Hipparcos, Gaia is designed to give absolute parallaxes, independent of any astrophysical reference system. And indeed, Gaia's internal zero-point error for parallaxes is likely to be smaller than any individual parallax error. Nevertheless, due ... More

Lagrangian Flows, Maslov Index Zero and Special LagrangiansJun 08 2016Sep 15 2016We introduce a notion of vanishing Maslov index for lagrangian varifolds and lagrangian integral cycles in a Calabi-Yau manifold. We construct mass-decreasing flows of lagrangian varifolds and lagrangian cycles which satisfy this condition. The flow of ... More

Renormalized Volumes with BoundaryNov 25 2016We develop a general regulated volume expansion for the volume of a manifold with boundary whose measure is suitably singular along a separating hypersurface. The expansion is shown to have a regulator independent anomaly term and a renormalized volume ... More

Renormalized VolumeMar 23 2016For any conformally compact manifold with hypersurface boundary we define a canonical renormalized volume functional and compute an explicit, holographic formula for the corresponding anomaly. For the special case of asymptotically Einstein manifolds, ... More

Conformal hypersurface geometry via a boundary Loewner-Nirenberg-Yamabe problemJun 08 2015Aug 26 2015We develop an approach to the conformal geometry of embedded hypersurfaces by treating them as conformal infinities of conformally compact manifolds. The central tool is the Loewner-Nirenberg-type problem of finding on the interior a metric that is conformally ... More

Ultra-cold mechanical resonators coupled to atoms in an optical latticeJun 25 2009We propose an experiment utilizing an array of cooled micro-cantilevers coupled to a sample of ultra-cold atoms trapped near a micro-fabricated surface. The cantilevers allow individual lattice site addressing for atomic state control and readout, and ... More

Holomorphic factorization of determinants of laplacians on Riemann surfaces and a higher genus generalization of Kronecker's first limit formulaOct 12 2004Sep 29 2006For a family of compact Riemann surfaces X_t of genus g>1 parametrized by the Schottky space S_g, we define a natural basis for the holomorphic n-differentials on X_t which varies holomorphically with t and generalizes the basis of normalized abelian ... More

Proper Motion Catalog From SDSS \intersect USNO-BOct 29 2003We present a catalog of 345,000 stars with proper motions \mu > 20 mas/yr and magnitudes r' <20, drawn from the intersection of the SDSS Data Release One and USNO-B. We first use SDSS quasars to correct the proper motions in each of the two source catalogs, ... More

Renormalized VolumeMar 23 2016Oct 19 2016We develop a universal distributional calculus for regulated volumes of metrics that are singular along hypersurfaces. When the hypersurface is a conformal infinity we give simple integrated distribution expressions for the divergences and anomaly of ... More

Decoupled limbs yield differentiable trajectory outcomes through intermittent contact in locomotion and manipulationSep 13 2016When limbs are decoupled, we find that trajectory outcomes in mechanical systems subject to unilateral constraints vary differentiably with respect to initial conditions, even as the contact mode sequence varies.

The evolution of Kerr discs and late-time tidal disruption event light curvesSep 06 2018An encounter between a passing star and a massive black hole at the centre of a galaxy, a so-called tidal disruption event or TDE, may leave a debris disc that subsequently accretes onto the hole. We solve for the time evolution of such a TDE disc, making ... More

Light Dark Matter eXperiment (LDMX)Aug 15 2018We present an initial design study for LDMX, the Light Dark Matter Experiment, a small-scale accelerator experiment having broad sensitivity to both direct dark matter and mediator particle production in the sub-GeV mass region. LDMX employs missing momentum ... More

Detecting high-frequency gravitational waves with optically-levitated sensorsJul 23 2012Jan 02 2013We propose a tunable resonant sensor to detect gravitational waves in the frequency range of 50-300 kHz using optically trapped and cooled dielectric microspheres or micro-discs. The technique we describe can exceed the sensitivity of laser-based gravitational ... More

A Trinomial Analogue of Bailey's Lemma and N=2 Superconformal InvarianceFeb 03 1997Mar 05 1997We propose and prove a trinomial version of the celebrated Bailey's lemma. As an application we obtain new fermionic representations for characters of some unitary as well as nonunitary models of N = 2 superconformal field theory (SCFT). We also establish ... More

Probing Sub-Micron Forces by Interferometry of Bose-Einstein Condensed AtomsJun 18 2003Oct 16 2003We propose a technique, using interferometry of Bose-Einstein condensed alkali atoms, for the detection of sub-micron-range forces. It may extend present searches at 1 micron by 6 to 9 orders of magnitude, deep into the theoretically interesting regime ... More

Exact Four-Dimensional Dyonic Black Holes and Bertotti-Robinson Spacetimes in String TheoryMar 30 1994Mar 31 1994Conformal field theories corresponding to two-dimensional electrically charged black holes and to two-dimensional anti-de Sitter space with a covariantly constant electric field are simply constructed as $SL(2,R)/Z$ WZW coset models. The two-dimensional ... More

The star formation history of the Sculptor Dwarf Irregular GalaxyNov 01 2012[abridged] We study the resolved stellar populations and derive the SFH of the SDIG, a gas-rich dwarf galaxy member of the NGC7793 subgroup in the Sculptor group. We construct a CMD using archival HST observations and examine its stellar content. We derive ... More

A First Look at Rotation in Inactive Late-Type M DwarfsDec 05 2008We have examined the relationship between rotation and activity in 14 late-type (M6-M7) M dwarfs, using high resolution spectra taken at the W.M. Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey. Most were selected to be ... More

General triple charged black ring solution in supergravityJun 18 2014We present the general black ring solution in $U(1)^{3}$ supergravity in 5 dimensions with three independent dipole and electric charges. This immediately gives the general black ring solution in the minimal 5D supergravity as well.

Quantum electrodynamics near a photonic band-gapMar 09 2016Apr 06 2016Photonic crystals provide an extremely powerful toolset for manipulation of optical dispersion and density of states, and have thus been employed for applications from photon generation to quantum sensing with NVs and atoms. The unique control afforded ... More

Extreme Scaling of Supercomputing with Stranded Power: Costs and CapabilitiesJul 07 2016Power consumption (supply, heat, cost) and associated carbon emissions (environmental impact) are increasingly critical challenges in scaling supercomputing to Exascale and beyond. We proposes to exploit stranded power, renewable energy that has no value ... More

On closed graphs IIDec 31 2014Apr 22 2015A graph is closed when its vertices have a labeling by [n] with a certain property first discovered in the study of binomial edge ideals. In this article, we explore various aspects of closed graphs, including the number of closed labelings and clustering ... More

Dirac-Fermionic Dark Matter in $U(1)_X$ ModelsJun 22 2015Sep 28 2015We study a number of $U(1)_X$ models featuring a Dirac fermion dark matter particle. We perform a comprehensive analysis which includes the study of corrections to the muon magnetic moment, dilepton searches with LHC data, as well as direct and indirect ... More

Severely Constraining Dark Matter Interpretations of the 21-cm AnomalyMar 07 2018The EDGES Collaboration has recently reported the detection of a stronger-than-expected absorption feature in the global 21-cm spectrum, centered at a frequency corresponding to a redshift of z ~ 17. This observation has been interpreted as evidence that ... More

Communication and Synchronization of Distributed Medical Models: Design, Development, and Performance AnalysisNov 25 2017Jan 22 2018Model-based development is a widely-used method to describe complex systems that enables the rapid prototyping. Advances in the science of distributed systems has led to the development of large scale statechart models which are distributed among multiple ... More

Fair Loss-Tolerant Quantum Coin FlippingApr 27 2009May 04 2009Coin flipping is a cryptographic primitive in which two spatially separated players, who in principle do not trust each other, wish to establish a common random bit. If we limit ourselves to classical communication, this task requires either assumptions ... More

Dark Matter, Millicharges, Axion and Scalar Particles, Gauge Bosons, and Other New Physics with LDMXJul 04 2018The proposed LDMX experiment would provide roughly a meter-long region of instrumented tracking and calorimetry that acts as a beam stop for multi-GeV electrons in which each electron is tagged and its evolution measured. This would offer an unprecedented ... More

Using Close White Dwarf + M Dwarf Stellar Pairs to Constrain the Flare Rates in Close Stellar BinariesFeb 19 2016We present a study of the statistical flare rates of M dwarfs (dMs) with close white dwarf (WD) companions (WD+dM; typical separations < 1 au). Our previous analysis demonstrated that dMs with close WD companions are more magnetically active than their ... More

Manipulating time-bin qubits with fiber optics componentsMay 06 2006We propose two experimental schemes to implement arbitrary unitary single qubit operations on single photons encoded in time-bin qubits. Both schemes require fiber optics components that are available with current technology.

Deterministic unitary operations on time-bin qudits for quantum communicationAug 23 2006Aug 23 2006We show for the first time how deterministic unitary operations on time-bin qubits encoded in single photon pulses can be realized using fiber optics components that are available with current technology. We also generalize this result to operations on ... More

Toward (Finally!) Ruling Out Z and Higgs Mediated Dark Matter ModelsSep 28 2016In recent years, direct detection, indirect detection, and collider experiments have placed increasingly stringent constraints on particle dark matter, exploring much of the parameter space associated with the WIMP paradigm. In this paper, we focus on ... More

Dark Matter Complementarity and the Z$^\prime$ PortalJan 14 2015Sep 28 2015Z' gauge bosons arise in many particle physics models as mediators between the dark and visible sectors. We exploit dark matter complementarity and derive stringent and robust collider, direct and indirect constraints, as well as limits from the muon ... More

Pseudoscalar Portal Dark MatterFeb 20 2015Aug 13 2015A fermion dark matter candidate with a relic abundance set by annihilation through a pseudoscalar can evade constraints from direct detection experiments. We present simplified models that realize this fact by coupling a fermion dark sector to a two-Higgs ... More

Neutralinos in Vector Boson Fusion at High Energy CollidersFeb 17 2015Jun 17 2015Discovering dark matter at high energy colliders continues to be a compelling and well-motivated possibility. Weakly interacting massive particles are a particularly interesting class in which the dark matter particles interact with the standard model ... More

Strings Near a Rindler Or Black Hole HorizonOct 28 1994Nov 07 1994Orbifold techniques are used to study bosonic, type II and heterotic strings in Rindler space at integer multiples N of the Rindler temperature, and near a black hole horizon at integer multiples of the Hawking temperature, extending earlier results of ... More

Early-type Stars: Most Favorable Targets for Astrometrically Detectable Planets in the Habitable ZoneFeb 26 2003Early-type stars appear to be a difficult place to look for planets astrometrically. First, they are relatively heavy, and for fixed planetary mass the astrometric signal falls inversely as the stellar mass. Second, they are relatively rare (and so tend ... More