Results for "N. Mathews"

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Source region of the 2003 November 18 CME that led to the strongest magnetic storm of cycle 23Dec 30 2008The super-storm of November 20, 2003 was associated with a high speed coronal mass ejection which originated in the NOAA AR 10501 on November 18. This coronal mass ejection had severe terrestrial consequences leading to a geomagnetic storm with DST index ... More
Narrow-Band Imaging System for the Multi-application Solar Telescope at Udaipur Solar Observatory: Characterization of Lithium Niobate EtalonsJul 29 2014Multi-application Solar Telescope is a 50 cm off-axis Gregorian telescope that has been installed at the lake site of Udaipur Solar Observatory. For quasi-simultaneous photospheric and chromospheric observations, a narrow-band imager has been developed ... More
Bulk viscous matter and recent acceleration of the universe based on causal viscous theoryAug 08 2017Apr 20 2018Evolution of the bulk viscous matter dominated universe has been analysed using the full causal, Israel-Stewart theory for the evolution of bulk viscous pressure in the context of recent acceleration of the universe. The form of bulk viscosity is taken ... More
The homology of $\mathrm{tmf}$May 27 2013Dec 18 2015We compute the mod $2$ homology of the spectrum $\mathrm{tmf}$ of topological modular forms by proving a 2-local equivalence $\mathrm{tmf} \wedge DA(1) \simeq \mathrm{tmf}_1(3) \simeq BP\left \langle 2\right\rangle$, where $DA(1)$ is an eight cell complex ... More
Multi-focal tensors as invariant differential formsOct 13 2016For each relative $\operatorname{GL}(V)$-invariant tensor $I\in \Lambda^{p_1+1}V^{\vee}\otimes .. \otimes \Lambda^{p_n+1}V^{\vee}$ we construct a $\operatorname{GL}(V)$-invariant weighted differential form $\eta$ on $(\mathbb{P} V)^{n}$. Then $\eta$ is ... More
Categories parametrized by schemes and representation theory in complex rankJun 07 2010Many key invariants in the representation theory of classical groups (symmetric groups $S_n$, matrix groups $GL_n$, $O_n$, $Sp_{2n}$) are polynomials in $n$ (e.g., dimensions of irreducible representations). This allowed Deligne to extend the representation ... More
Residue fields for a class of rational $\mathbf{E}_\infty$-rings and applicationsJun 19 2014Jul 18 2016Let $A$ be an $\mathbf{E}_{\infty}$-ring spectrum over the rational numbers. If $A$ satisfies a noetherian condition on its homotopy groups $\pi_*(A)$, we construct a collection of $\mathbf{E}_{\infty}$-$A$-algebras that realize on homotopy the residue ... More
A Schur transform for spatial stochastic processesNov 15 2018Nov 16 2018The variance, higher order moments, covariance, and joint moments or cumulants are shown to be special cases of a certain tensor in $V^{\otimes n}$ defined in terms of a collection $X_1,...,X_n$ of $V$-valued random variables, for an appropriate finite-dimensional ... More
An invariance principle for the stochastic heat equationJun 17 2017We approximate the white-noise driven stochastic heat equation by replacing the fractional Laplacian by the generator of a discrete time random walk on the one dimensional lattice, and approximating white noise by a collection of i.i.d. mean zero random ... More
Kaledin's degeneration theorem and topological Hochschild homologyOct 25 2017Nov 12 2017We give a short proof of Kaledin's theorem on the degeneration of the noncommutative Hodge-to-de Rham spectral sequence. Our approach is based on topological Hochschild homology and the theory of cyclotomic spectra. As a consequence, we also obtain relative ... More
Magnetism in C60 Films Induced by Proton IrradiationMar 13 2005Mar 22 2005It is shown that polycrystalline fullerene thin films on hydrogen passivated Si(111) substrates irradiated by 2 MeV protons displays ferromagnetic-like behavior at 5 K. At 300 K both the pristine and the irradiated film show diamagnetic behavior. Magnetization ... More
Data-Optimized Coronal Field Model: I. Proof of ConceptApr 12 2019Deriving the strength and direction of the three-dimensional (3D) magnetic field in the solar atmosphere is fundamental for understanding its dynamics. Volume information on the magnetic field mostly relies on coupling 3D reconstruction methods with photospheric ... More
Origin and Evolution of Structure and Nucleosynthesis for Galaxies in the Local GroupMar 07 2014May 03 2014The Milky Way is the product of a complex evolution of generations of mergers, collapse, star formation, supernova and collisional heating, radiative and collisional cooling, and ejected nucleosynthesis. Moreover, all of this occurs in the context of ... More
α^{m}}(A)$, $C_{α^{m}}(A)$ and $α^{m}$-open and closed FunctionsJan 14 2016In this paper, we derive more on $\alpha^{m}$-continuous functions and $\alpha^{m}$-irresolute functions with $\alpha^{m}$-open maps and $\alpha^{m}$-closed maps in topological spaces also we introduce $I_{\alpha^{m}}(A)$ and $C_{\alpha^{m}}(A)$ by using ... More
Separation axioms of $α^{m}$-open setsJan 14 2016In this paper, we introduce $T_{\alpha^{m}}$-Spaces, $\alpha^{m}$-closed maps and $\alpha^{m}$-open maps and studied some of their properties.
Contact topology and holomorphic invariants via elementary combinatoricsDec 08 2012In recent times a great amount of progress has been achieved in symplectic and contact geometry, leading to the development of powerful invariants of 3-manifolds such as Heegaard Floer homology and embedded contact homology. These invariants are based ... More
Continuum AB percolation and AB random geometric graphsMay 12 2014Consider a bipartite random geometric graph on the union of two independent homogeneous Poisson point processes in $d$-space, with distance parameter $r$ and intensities $\lambda,\mu$. We show for $d \geq 2$ that if $\lambda$ is supercritical for the ... More
Non-triviality of the vacancy phase transition for the Boolean modelJun 07 2017Jul 23 2018In the spherical Poisson Boolean model, one takes the union of random balls centred on the points of a Poisson process in Euclidean $d$-space with $d \geq 2$. We prove that whenever the radius distribution has a finite $d$-th moment, there exists a strictly ... More
Strand algebras and contact categoriesAug 09 2016Oct 08 2016We demonstrate an isomorphism between the homology of the strand algebra of bordered Floer homology, and the category algebra of the contact category introduced by Honda. This isomorphism provides a direct correspondence between various notions of Floer ... More
Variations of the Ramanujan polynomials and remarks on $ζ(2j+1)/π^{2j+1}$Jun 06 2011We observe that five polynomial families have all of their zeros on the unit circle. We prove the statements explicitly for four of the polynomial families. The polynomials have coefficients which involve Bernoulli numbers, Euler numbers, and the odd ... More
Nonlinear stability of spatially-periodic traveling-wave solutions of systems of reaction diffusion equationsApr 06 2010Nov 18 2010Using spatial domain techniques developed by the authors and Myunghyun Oh in the context of parabolic conservation laws, we establish under a natural set of spectral stability conditions nonlinear asymptotic stability with decay at Gaussian rate of spatially ... More
Inhomogeneous random graphs, isolated vertices, and Poisson approximationJul 25 2015Sep 20 2017Consider a graph on randomly scattered points in an arbitrary space, with two points $x,y$ connected with probability $\phi(x,y)$. Suppose the number of points is large but the mean number of isolated points is $O(1)$. We give general criteria for the ... More
Leaves on the line and in the planeJun 10 2018Jul 21 2018The Dead Leaves Model (DLM) provides a random tessellation of $d$-space, representing the visible portions of fallen leaves on the ground when $d=2$. For $d=1$, we establish formulae for the intensity, two-point correlations, and asymptotic covariances ... More
A-infinity algebras, strand algebras, and contact categoriesMar 17 2018Jun 03 2018In previous work we showed that the contact category algebra of a quadrangulated surface is isomorphic to the homology of a strand algebra from bordered sutured Floer theory. Being isomorphic to the homology of a differential graded algebra, this contact ... More
Relaxing the $W'$ constraint on compactified extra-dimensionApr 17 2019It has been known for some time that the inclusion of brane fluctuations, namely branons, helps in the suppression of KK-mode couplings to brane localised matter fields. In this paper we study the constraint on brane tension and compactification scale ... More
Sutured Floer homology, sutured TQFT and non-commutative QFTJun 28 2010Feb 16 2011We define a "sutured topological quantum field theory", motivated by the study of sutured Floer homology of product 3-manifolds, and contact elements. We study a rich algebraic structure of suture elements in sutured TQFT, showing that it corresponds ... More
Solving Hodgkin-Huxley equations using the compact difference scheme -tapering dendriteAug 08 2013Sep 27 2013Dendritic processing is now considered to be important in pre-processing of signals coming into a cell. Dendrites are involved in both propagation and backpropagation of signals. In a cylindrical dendrite, signals moving in either direction will be similar. ... More
An extension of Boyd's $p$-adic algorithm for the harmonic seriesAug 17 2007In this paper we will extend a $p$-adic algorithm of Boyd in order to study the size of the set: \[J_p(y)=\left\{n :\sum_{j=1}^{n}\frac{y^j}{j}\equiv 0(\mod p)\right\}.\] Suppose that $p$ is one of the first 100 odd primes and $y\in\{1,2,...,p-1\}$, then ... More
Unparticle physics at hadron collider via dilepton productionMay 31 2007Oct 24 2007The scale invariant unparticle physics recently proposed by Georgi could manifest at low energies as non integral number d_U of invisible particles. Unparticles if existing, could couple to the Standard Model fields and consequently affect the collider ... More
Angular distribution of Drell-Yan process at hadron colliders to NLO-QCD in models of TeV scale gravityJul 21 2005Jul 19 2006In TeV scale gravity models, for dilepton production at hadron colliders, we present the NLO-QCD corrections for the double differential cross section in the invariant mass and scattering angle. For both ADD and RS models, the quantitative impact of QCD ... More
Hierarchical Partition-Based Anonymous Routing Protocol(HPAR) in Manet for Efficient and Secure TransmissionMay 10 2016Anonymous routing protocols are used in MANET's to hide the nodes from outsiders in order to protect from various attacks. HPAR partitions the network area dynamically into zones and chooses nodes in zones randomly as intermediate relay nodes .This relay ... More
Polarised and Unpolarised Charmonium Production at Higher Orders in vAug 28 1997We study the unpolarised and polarised hadro-production of charmonium in non-relativistic QCD (NRQCD) at low transverse momentum, including sufficiently higher orders in the relative velocity, $v$, so as to study the ratio of $\chi_{c1}$ and $\chi_{c2}$ ... More
Can Image Retrieval help Visual Saliency Detection?Sep 24 2017We propose a novel image retrieval framework for visual saliency detection using information about salient objects contained within bounding box annotations for similar images. For each test image, we train a customized SVM from similar example images ... More
Comments on the ERA-2005 numerical theory of Earth rotationSep 30 2007Two papers recently published in Celestial Mechanics (Krasinsky 2006, and Krasinsky and Vasilyev 2006) have presented a model for Earth-rotation variations, called ERA-2005, based on numerical integration of a new set of equations for the rotation of ... More
Functional equations for Mahler measures of genus-one curvesDec 01 2006Feb 09 2007In this paper we will establish functional equations for Mahler measures of families of genus-one two-variable polynomials. These families were previously studied by Beauville, and their Mahler measures were considered by Boyd, Rodriguez-Villegas, Bertin, ... More
Estimate of the total mechanical feedback energy from galaxy cluster-centered black holes: implications for black hole evolution, cluster gas fraction and entropyMay 30 2011Jun 22 2011The total feedback energy injected into hot gas in galaxy clusters by central black holes can be estimated by comparing the potential energy of observed cluster gas profiles with the potential energy of non-radiating, feedback-free hot gas atmospheres ... More
Removing Cool Cores and Central Metallicity Peaks in Galaxy Clusters with Powerful AGN OutburstsApr 13 2010May 20 2010Recent X-ray observations of galaxy clusters suggest that cluster populations are bimodally distributed according to central gas entropy and are separated into two distinct classes: cool core (CC) and non-cool core (NCC) clusters. While it is widely accepted ... More
Simulating X-ray Supercavities and Their Impact on Galaxy ClustersNov 19 2009Feb 23 2010Recent X-ray observations of hot gas in the galaxy cluster MS 0735.6+7421 reveal huge radio-bright, quasi-bipolar X-ray cavities having a total energy ~10^{62} ergs, the most energetic AGN outburst currently known. We investigate the evolution of this ... More
A2-Planar Algebras IJun 23 2009Apr 14 2011We give a diagrammatic presentation of the A_2-Temperley-Lieb algebra. Generalizing Jones' notion of a planar algebra, we formulate an A_2-planar algebra motivated by Kuperberg's A_2-spider. This A_2-planar algebra contains a subfamily of vector spaces ... More
Tunneling in energy eigenstates and complex quantum trajectoriesDec 18 2015Complex quantum trajectory approach, which arose from a modified de Broglie-Bohm interpretation of quantum mechanics, has attracted much attention in recent years. The exact complex trajectories for the Eckart potential barrier and the soft potential ... More
Percolation and limit theory for the Poisson lilypond modelAug 04 2010The lilypond model on a point process in $d$-space is a growth-maximal system of non-overlapping balls centred at the points. We establish central limit theorems for the total volume and the number of components of the lilypond model on a sequence of ... More
Asymptotic normality of maximum likelihood estimator for cooperative sequential adsorptionMay 06 2010We have shown in previous work that statistical inference for cooperative sequential adsorption model can be based on maximum likelihood estimation. In this paper we continue this research and establish asymptotic normality of the maximum likelihood estimator ... More
Nonlinear stability of periodic traveling wave solutions of viscous conservation laws in dimensions one and twoDec 30 2009Jan 07 2010Extending results of Oh and Zumbrun in dimensions $d\ge 3$, we establish nonlinear stability and asymptotic behavior of spatially-periodic traveling-wave solutions of viscous systems of conservation laws in critical dimensions $d=1,2$, under a natural ... More
Overcoming model simplifications when quantifying predictive uncertaintyMar 21 2017It is generally accepted that all models are wrong -- the difficulty is determining which are useful. Here, a useful model is considered as one that is capable of combining data and expert knowledge, through an inversion or calibration process, to adequately ... More
Effects of structure formation on the expansion rate of the Universe: An estimate from numerical simulationsDec 24 2009Jan 28 2011General relativistic corrections to the expansion rate of the Universe arise when the Einstein equations are averaged over a spatial volume in a locally inhomogeneous cosmology. It has been suggested that they may contribute to the observed cosmic acceleration. ... More
Entropy Evolution in Galaxy Groups and Clusters; A Comparison of External and Internal HeatingJan 29 2001X-ray observations of hot gas in galaxy groups indicate higher entropies than can be achieved in the accretion shocks as it fell into the dark halos. It has been proposed that this entropy excess results from some universal external heating process in ... More
Energetics of X-ray Cavities and Radio Lobes in Galaxy ClustersMay 16 2008We describe the formation and evolution of X-ray cavities in the hot gas of galaxy clusters. The cavities are formed only with relativistic cosmic rays that eventually diffuse into the surrounding gas. We explore the evolution of cavities formed with ... More
Creation of the X-ray Cavity Jet and its Radio Lobe in M87/Virgo with Cosmic Rays; Relevance to Relic Radio SourcesNov 27 2007Dec 06 2007Young cavities in the X-ray emitting hot gas in galaxy clusters are often filled with radio synchrotron emission and it is widely thought that the cavities are inflated by these cosmic rays. At a later stage of its evolution, when the cavity becomes buoyant, ... More
Heated Cooling FlowsMar 22 2002In conventional models of galactic and cluster cooling flows widespread cooling (mass dropout) is assumed to avoid accumulation of unacceptably large central masses. However, recent XMM observations have failed to find spectral evidence for locally cooling ... More
Where Do Cooling Flows Cool?Feb 21 2000Although only about 5 percent of the total baryonic mass in luminous elliptical galaxies is in the form of cooled interstellar gas, it is concentrated within the optical effective radius r_e where it influences the local dynamical mass. The mass of cooled ... More
Chandra Detection of Massive Black Holes in Galactic Cooling FlowsOct 31 1999Anticipating forthcoming observations with the Chandra X-ray telescope, we describe the continuation of interstellar cooling flows deep into the cores of elliptical galaxies. Interstellar gas within about r = 50 parsecs from the massive black hole is ... More
Bulk gauge and matter fields in nested warping: I. the formalismJan 25 2015Oct 01 2015The lack of evidence for a TeV-mass graviton has been construed as constricting the Randall-Sundrum model. However, a doubly-warped generalization naturally avoids such restrictions. We develop, here, the formalism for extension of the Standard Model ... More
Poisson process Fock space representation, chaos expansion and covariance inequalitiesSep 17 2009We consider a Poisson process $\eta$ on an arbitrary measurable space with an arbitrary sigma-finite intensity measure. We establish an explicit Fock space representation of square integrable functions of $\eta$. As a consequence we identify explicitly, ... More
On the critical threshold for continuum AB percolationDec 13 2017Consider a bipartite random geometric graph on the union of two independent homogeneous Poisson point processes in $d$-space, with distance parameter $r$ and intensities $\lambda,\mu$. For any $\lambda>0$ we consider the percolation threshold $\mu_c(\lambda)$ ... More
Optimal Cheeger cuts and bisections of random geometric graphsMay 22 2018Let $d \geq 2$. The Cheeger constant of a graph is the minimum surface-to-volume ratio of all subsets of the vertex set with relative volume at most 1/2. There are several ways to define surface and volume here: the simplest method is to count boundary ... More
A Dirac-type Characterization of k-chordal GraphsJun 23 2012Dec 31 2012Characterization of k-chordal graphs based on the existence of a "simplicial path" was shown in [Chv{\'a}tal et al. Note: Dirac-type characterizations of graphs without long chordless cycles. Discrete Mathematics, 256, 445-448, 2002]. We give a characterization ... More
A Merger Model and Globular Cluster FormationAug 17 1994We propose a self-consistent model for globular cluster formation in, but not limited to, our Galaxy, based on the merger model of Mathews and Schramm (1993). Stars and star clusters form in bursts at the merging interfaces as protogalactic clouds collide. ... More
Late Decaying Dark Matter, Bulk Viscosity and the Cosmic AccelerationJan 06 2008We discuss a cosmology in which cold dark matter begins to decay into relativistic particles at a recent epoch (z < 1). We show that the large entropy production and associated bulk viscosity from such decays leads to an accelerating cosmology as required ... More
Universal Lepton Asymmetry: New Constraints from the Cosmic Microwave Background and Primordial NucleosynthesisFeb 06 2002We study the primordial nucleosynthesis and cosmic age in the presence of a net lepton asymmetry as well as baryon asymmetry. We explore a previously unnoted region of the parameter space in which very large baryon densities $0.1 \le \Omega_b \le 1$ can ... More
Neutrino Degeneracy and Decoupling: New Limits from Primordial Nucleosynthesis and the Cosmic Microwave BackgroundMay 23 2000Feb 22 2001We reanalyze the cosmological constraints on the existence of a net universal lepton asymmetry and neutrino degeneracy. We show that neutrinos can begin to decouple at higher temperatures than previous estimates due to several corrections which diminish ... More
Geometrical Effects of Baryon Density Inhomogeneities on Primordial NucleosynthesisSep 19 1996We discuss effects of fluctuation geometry on primordial nucleosynthesis. For the first time we consider condensed cylinder and cylindrical-shell fluctuation geometries in addition to condensed spheres and spherical shells. We find that a cylindrical ... More
Extending some results on the second neighborhood conjectureAug 07 2018Jan 10 2019A vertex in a directed graph is said to have a large second neighborhood if it has at least as many second out-neighbors as out-neighbors. The Second Neighborhood Conjecture, first stated by Seymour, asserts that there is a vertex having a large second ... More
Halo White Dwarfs and the Hot Intergalactic MediumApr 17 1996Oct 07 1996We present a schematic model for the formation of baryonic galactic halos and hot gas in the Local Group and the intergalactic medium. We follow the dynamics, chemical evolution, heat flow and gas flows of a hierarchy of scales, including: protogalactic ... More
Domination in designsMay 14 2014We commence the study of domination in the incidence graphs of combinatorial designs. Let $D$ be a combinatorial design and denote by $\gamma(D)$ the domination number of the incidence (Levy) graph of $D$. We obtain a number of results about the domination ... More
An approximation result for a class of stochastic heat equations with colored noiseNov 21 2016We show that a large class of stochastic heat equations can be approximated by systems of interacting stochastic differential equations. As a consequence, we prove various comparison principles extending earlier results. Among other things, our results ... More
Finding Trends in Software ResearchAug 29 2016Oct 03 2018This paper explores the structure of research papers in software engineering. Using text mining, we study 35,391 software engineering (SE) papers from 34 leading SE venues over the last 25 years. These venues were divided, nearly evenly, between conferences ... More
A Supersymmetric Model with Dirac Neutrino MassesDec 08 2009Mar 18 2010New models have recently been proposed in which a second Higgs doublet couples only to the lepton doublets and right-handed neutrinos, yielding Dirac neutrino masses. The vacuum value of this second "nu-Higgs" doublet is made very small by means of a ... More
Morse structures on partial open books with extendable monodromyFeb 24 2017The first author in recent work with D. Gay developed the notion of a Morse structure on an open book as a tool for studying closed contact 3-manifolds. We extend the notion of Morse structure to extendable partial open books in order to study contact ... More
Transverse structure function in the factorisation methodJul 22 1996Aug 08 1996Deep Inelastic scattering experiments using transversely polarised targets yield information on the structure function $g_2$. By means of a free-field analysis, we study the operator structure of $g_2$ and demonstrate the need for retaining the twist ... More
Oscillatory relaxation of a merging galaxy clusterSep 21 2006Nov 13 2006Within the cosmic framework clusters of galaxies are relatively young objects. Many of them have recently experienced major mergers. Here we investigate an equal mass merging event at z = ~0.6 resulting in a dark matter haloe of ~2.2 times 10^{14} Msol/h ... More
Uniquely Restricted Matchings in Interval GraphsApr 24 2016May 10 2016A matching $M$ in a graph $G$ is said to be uniquely restricted if there is no other matching in $G$ that matches the same set of vertices as $M$. We describe a polynomial-time algorithm to compute a maximum cardinality uniquely restricted matching in ... More
Multivariate normal approximation in geometric probabilityJul 26 2007Consider a measure $\mu_\lambda = \sum_x \xi_x \delta_x$ where the sum is over points $x$ of a Poisson point process of intensity $\lambda$ on a bounded region in $d$-space, and $\xi_x$ is a functional determined by the Poisson points near to $x$, i.e. ... More
Strict inequalities of critical values in continuum percolationJul 20 2010We consider the supercritical finite-range random connection model where the points $x,y$ of a homogeneous planar Poisson process are connected with probability $f(|y-x|)$ for a given $f$. Performing percolation on the resulting graph, we show that the ... More
Independent Particles in a Dynamical Random EnvironmentOct 09 2011Sep 19 2018We study the motion of independent particles in a dynamical random environment on the integer lattice. The environment has a product distribution. For the multidimensional case, we characterize the class of spatially ergodic invariant measures. These ... More
On the Blumberg-Mandell Künneth theorem for TPOct 16 2017Jul 31 2018We give a new proof of the recent K\"unneth theorem for periodic topological cyclic homology (TP) of smooth and proper dg categories over perfect fields of characteristic p>0 due to Blumberg and Mandell. Our result is slightly stronger and implies a finiteness ... More
Negative Results for Software Effort EstimationSep 18 2016Sep 22 2016Context:More than half the literature on software effort estimation (SEE) focuses on comparisons of new estimation methods. Surprisingly, there are no studies comparing state of the art latest methods with decades-old approaches. Objective:To check if ... More
Pairwise Suitable Family of Permutations and BoxicityDec 30 2012A family F of permutations of the vertices of a hypergraph H is called "pairwise suitable" for H if, for every pair of disjoint edges in H, there exists a permutation in F in which all the vertices in one edge precede those in the other. The cardinality ... More
NeuralHydrology - Interpreting LSTMs in HydrologyMar 19 2019Despite the huge success of Long Short-Term Memory networks, their applications in environmental sciences are scarce. We argue that one reason is the difficulty to interpret the internals of trained networks. In this study, we look at the application ... More
Synthetic gauge fields for phonon transport in a nano-optomechanical systemDec 21 2018Jan 17 2019Gauge fields play important roles in condensed matter, explaining for example nonreciprocal and topological transport phenomena. Establishing gauge potentials for phonon transport in nanomechanical systems would bring quantum Hall physics to a new domain, ... More
Boundaries, Mirror Symmetry, and Symplectic Duality in 3d $\mathcal{N}=4$ Gauge TheoryMar 28 2016Aug 04 2016We introduce several families of $\mathcal{N}=(2,2)$ UV boundary conditions in 3d $\mathcal N=4$ gauge theories and study their IR images in sigma-models to the Higgs and Coulomb branches. In the presence of Omega deformations, a UV boundary condition ... More
Graph-theoretic perspective on a special class of Steiner SystemsOct 21 2014Oct 23 2014We study $S(t-1,t,2t)$, which is a special class of Steiner systems. Explicit constructions for designing such systems are developed under a graph-theoretic platform where Steiner systems are represented in the form of uniform hypergraphs. The constructions ... More
A lagrangian description of elastic motion in riemannian manifolds and an angular invariant of axially-symmetric elasticity tensorsDec 24 2013This article is a description of elasticity theory for readers with mathematical background. The first sections are an abridgment of parts of the book by Marsden and Hughes, including a compact identification of the equations of motion as the Euler-Lagrange ... More
Why Software Effort Estimation Needs SBSEApr 02 2018Industrial practitioners now face a bewildering array of possible configurations for effort estimation. How to select the best one for a particular dataset? This paper introduces OIL (short for optimized learning), a novel configuration tool for effort ... More
Fluctuations of the quenched mean of a planar random walk in an i.i.d. random environment with forbidden directionSep 01 2008We consider an i.i.d. random environment with a strong form of transience on the two dimensional integer lattice. Namely, the walk always moves forward in the y-direction. We prove a functional CLT for the quenched expected position of the random walk ... More
Federated Learning Of Out-Of-Vocabulary WordsMar 26 2019We demonstrate that a character-level recurrent neural network is able to learn out-of-vocabulary (OOV) words under federated learning settings, for the purpose of expanding the vocabulary of a virtual keyboard for smartphones without exporting sensitive ... More
Environmental Dependence of Type Ia Supernova Luminosities from a Sample without a Local-Global Difference in Host Star FormationDec 11 2017It is now established that there is a dependence of the luminosity of type Ia supernovae (SNe Ia) on environment: SNe Ia in young, star-forming, metal-poor stellar populations appear fainter after light-curve shape corrections than those in older, passive, ... More
Infrared studies of the Be star X PerApr 06 2012Photometric and spectroscopic results are presented for the Be star X Per/HD 24534 from near-infrared monitoring in 2010-2011. The star is one of a sample of selected Be/X-ray binaries being monitored by us in the near-IR to study correlations between ... More
Studies of a possible new Herbig Ae/Be star in the open cluster NGC 7380Jan 24 2012We present a study of the star 2MASS J22472238+5801214 with the aim of identifying its true nature which has hitherto been uncertain. This object, which is a member of the young cluster NGC 7380, has been variously proposed to be a Be star, a D-type symbiotic ... More
The X-ray Ribs Within the Cocoon Shock of Cygnus AFeb 26 2018We use new and archival Chandra observations of Cygnus A, totalling $\sim$1.9 Ms, to investigate the distribution and temperature structure of gas lying within the projected extent of the cocoon shock and exhibiting a rib-like structure. We confirm that ... More
Torus actions on stable module categories, Picard groups, and localizing subcategoriesDec 06 2015Given an abelian $p$-group $G$ of rank $n$, we construct an action of the torus $\mathbb{T}^n$ on the stable module $\infty$-category of $G$-representations over a field of characteristic $p$. The homotopy fixed points are given by the $\infty$-category ... More
$THH$ and base-change for Galois extensions of ring spectraJan 26 2015Jul 18 2016We treat the question of base-change in $THH$ for faithful Galois extensions of ring spectra in the sense of Rognes. Given a faithful Galois extension $A \to B$ of ring spectra, we consider whether the map $THH(A) \otimes_A B \to THH(B)$ is an equivalence. ... More
The Galois group of a stable homotopy theoryApr 08 2014Jan 07 2016To a "stable homotopy theory" (a presentable, symmetric monoidal stable $\infty$-category), we naturally associate a category of finite \'etale algebra objects and, using Grothendieck's categorical machine, a profinite group that we call the Galois group. ... More
A thick subcategory theorem for modules over certain ring spectraNov 15 2013Nov 22 2014We classify thick subcategories of the $\infty$-categories of perfect modules over ring spectra which arise as functions on even periodic derived stacks satisfying affineness and regularity conditions. For example, we show that the thick subcategories ... More
Torsion exponents in stable homotopy and the Hurewicz homomorphismJan 29 2015Aug 05 2015We give estimates for the torsion in the Postnikov sections $\tau_{[1, n]} S^0$ of the sphere spectrum, and show that the $p$-localization is annihilated by $p^{n/(2p-2) + O(1)}$. This leads to explicit bounds on the exponents of the kernel and cokernel ... More
New Formulae for Gravity Amplitudes: Parity Invariance and Soft LimitsJul 17 2012Cachazo and Skinner have recently conjectured a new formula for the complete tree-level S-matrix of N = 8 supergravity. The formula is an integral over the moduli space of rational curves in supertwistor space, and remarkably, manifests the full permutation ... More
Explicit filtering for large eddy simulation as use of a spectral bufferOct 06 2016The explicit filtering method for large eddy simulation (LES,) which comprises integration of the governing equations without any added terms for sub-grid-scale modeling and the application of a low-pass filter to transported fields, is discussed. The ... More
"SHORT"er Reasoning About Larger Requirements ModelsFeb 18 2017Aug 22 2017When Requirements Engineering(RE) models are unreasonably complex, they cannot support efficient decision making. SHORT is a tool to simplify that reasoning by exploiting the "key" decisions within RE models. These "keys" have the property that once values ... More
Memristive System Design for Variable Pixel G-Neighbor Denoising FilterSep 24 2017Image blurring artifact is the main challenge to any spatial, denoising filters. This artifact is contributed by the heterogeneous intensities within the given neighborhood or window of fixed size. Selection of most similar intensities (G-Neighbors) helps ... More
On the Modulation Equations and Stability of Periodic GKdV Waves via Bloch DecompositionsMar 17 2010In this paper, we complement recent results of Bronski and Johnson and of Johnson and Zumbrun concerning the modulational stability of spatially periodic traveling wave solutions of the generalized Korteweg-de Vries equation. In this previous work it ... More
Spectroscopic study of Be-shell stars: 4 Her and 88 HerFeb 09 2016We present the optical spectroscopic study based on 41 spectra of 4 Her and 32 spectra of 88 Her, obtained over a period of 6 months. We estimate the rotational velocity of these stars from He{\sc i} lines in the blue spectral region (4000--4500 \AA). ... More