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Results for "Noah J. Planavsky"

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The remote detectability of Earth's biosphere through time and the importance of UV capability for characterizing habitable exoplanetsMar 13 2019Thousands of planets beyond our solar system have been discovered to date, dozens of which are rocky in composition and are orbiting within the circumstellar habitable zone of their host star. The next frontier in life detection beyond our solar system ... More
The Super-Earth Opportunity - Search for Habitable Exoplanets in the 2020sMar 12 2019The recent discovery of a staggering diversity of planets beyond the Solar System has brought with it a greatly expanded search space for habitable worlds. The Kepler exoplanet survey has revealed that most planets in our interstellar neighborhood are ... More
Continual Prediction from EHR Data for Inpatient Acute Kidney InjuryFeb 26 2019Acute kidney injury (AKI) commonly occurs in hospitalized patients and can lead to serious medical complications. In order to optimally predict AKI before it develops at any time during a hospital stay, we present a novel framework in which AKI is continually ... More
An epistemology and expectations survey about experimental physics: Development and initial resultsOct 03 2013May 02 2014In response to national calls to better align physics laboratory courses with the way physicists engage in research, we have developed an epistemology and expectations survey to assess how students perceive the nature of physics experiments in the contexts ... More
Incorporating learning goals about modeling into an upper-division physics laboratory experimentJan 18 2013Nov 14 2013Implementing a laboratory activity involves a complex interplay among learning goals, available resources, feedback about the existing course, best practices for teaching, and an overall philosophy about teaching labs. Building on our previous work, which ... More
Development and Validation of the Colorado Learning Attitudes about Science Survey for Experimental PhysicsJul 10 2012As part of a comprehensive effort to transform our undergraduate physics laboratories and evaluate the impacts of these efforts, we have developed the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS). The E-CLASS assesses ... More
The Process of Transforming an Advanced Lab Course: Goals, Curriculum, and AssessmentsJul 09 2012A thoughtful approach to designing and improving labs, particularly at the advanced level, is critical for the effective preparation of physics majors for professional work in industry or graduate school. With that in mind, physics education researchers ... More
Development and results from a survey on students views of experiments in lab classes and researchJul 22 2013The Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS) was developed as a broadly applicable assessment tool for undergraduate physics lab courses. At the beginning and end of the semester, the E-CLASS assesses students ... More
Mednykh's Formula via Lattice Topological Quantum Field TheoriesMar 05 2007Aug 28 2008Mednykh proved that for any finite group G and any orientable surface S, there is a formula for #Hom(pi_1(S), G) in terms of the Euler characteristic of S and the dimensions of the irreducible representations of G. A similar formula in the nonorientable ... More
The dual complex of $\bar{M}_{0,n}$ via phylogeneticsDec 01 2015May 09 2016The moduli space $\bar{M}_{0,n}$ of stable rational n-pointed curves has divisorial boundary with simple normal crossings. In this brief note I observe that the dual complex is a flag complex; that is, a collection of irreducible boundary divisors has ... More
Resolving a Conjecture on Degree of Regularity of Linear Homogeneous EquationsApr 13 2014A linear equation is $r$-regular, if, for every $r$-coloring of the positive integers, there exist positive integers of the same color which satisfy the equation. In 2005, Fox and Radoicic conjectured that the equation $x_1 + 2x_2 + \cdots + 2^{n-2}x_{n-1} ... More
Conformal blocks and rational normal curvesDec 21 2010Jan 11 2015We prove that the Chow quotient parametrizing configurations of n points in $\mathbb{P}^d$ which generically lie on a rational normal curve is isomorphic to $\overline{M}_{0,n}$, generalizing the well-known $d = 1$ result of Kapranov. In particular, $\overline{M}_{0,n}$ ... More
Strong rules for discarding predictors in lasso-type problemsNov 09 2010Nov 24 2010We consider rules for discarding predictors in lasso regression and related problems, for computational efficiency. El Ghaoui et al (2010) propose "SAFE" rules that guarantee that a coefficient will be zero in the solution, based on the inner products ... More
Evaluating Compositionality in Sentence EmbeddingsFeb 12 2018May 17 2018An important challenge for human-like AI is compositional semantics. Recent research has attempted to address this by using deep neural networks to learn vector space embeddings of sentences, which then serve as input to other tasks. We present a new ... More
A time-distance trade-off for GDD with preprocessing---Instantiating the DLW heuristicFeb 22 2019Feb 25 2019For $0 \leq \alpha \leq 1/2$, we show an algorithm that does the following. Given appropriate preprocessing $P(\mathcal{L})$ consisting of $N_\alpha := 2^{O(n^{1-2\alpha} + \log n)}$ vectors in some lattice $\mathcal{L} \subset \mathbb{R}^n$ and a target ... More
Quantum subgroups of the Haagerup fusion categoriesFeb 13 2011Sep 01 2011We answer three related questions concerning the Haagerup subfactor and its even parts, the Haagerup fusion categories. Namely we find all simple module categories over each of the Haagerup fusion categories (in other words, we find the `"quantum subgroups" ... More
Neural Discourse Structure for Text CategorizationFeb 07 2017May 06 2017We show that discourse structure, as defined by Rhetorical Structure Theory and provided by an existing discourse parser, benefits text categorization. Our approach uses a recursive neural network and a newly proposed attention mechanism to compute a ... More
The cone of type A, level one conformal blocks divisorsMay 16 2011May 17 2011We prove that the type A, level one, conformal blocks divisors on $\bar{M}_{0,n}$ span a finitely generated, full-dimensional subcone of the nef cone. Each such divisor induces a morphism from $\bar{M}_{0,n}$, and we identify its image as a GIT quotient ... More
Projective linear configurations via non-reductive actionsJan 03 2014We study the iterated blow-up X of projective space along an arbitrary collection of linear subspaces. By replacing the universal torsor with an $\mathbb{A}^1$-homotopy equivalent model, built from $\mathbb{A}^1$-fiber bundles not just algebraic line ... More
GIT Compactifications of $M_{0,n}$ from ConicsJan 16 2010Jan 11 2015We study GIT quotients parametrizing n-pointed conics that generalize the GIT quotients $(\mathbb{P}^1)^n//SL2$. Our main result is that $\overline{M}_{0,n}$ admits a morphism to each such GIT quotient, analogous to the well-known result of Kapranov for ... More
Multimodal Generative Models for Scalable Weakly-Supervised LearningFeb 14 2018Nov 12 2018Multiple modalities often co-occur when describing natural phenomena. Learning a joint representation of these modalities should yield deeper and more useful representations. Previous generative approaches to multi-modal input either do not learn a joint ... More
A Grassmann algebra for matroidsOct 15 2015Sep 14 2017We introduce an idempotent analogue of the exterior algebra for which the theory of tropical linear spaces (and valuated matroids) can be seen in close analogy with the classical Grassmann algebra formalism for linear spaces. The top wedge power of a ... More
Teaching Quantum Interpretations: Revisiting the goals and practices of introductory quantum physics coursesSep 30 2014Jan 31 2015Most introductory quantum physics instructors would agree that transitioning students from classical to quantum thinking is an important learning goal, but may disagree on whether or how this can be accomplished. Although (and perhaps because) physicists ... More
Development of quantum perspectives in modern physicsSep 03 2012Introductory undergraduate courses in classical physics stress a perspective that can be characterized as realist; from this perspective, all physical properties of a classical system can be simultaneously specified and thus determined at all future times. ... More
On Kapranov's description of $\overline{M}_{0,n}$ as a Chow quotientMar 24 2011Jan 11 2015We provide a direct proof, valid in arbitrary characteristic, of the result originally proven by Kapranov over $\mathbb{C}$, that the Hilbert and Chow quotients $(\mathbb{P}^1)^n//PGL2$ are isomorphic to $\overline{M}_{0,n}$. In both cases this is done ... More
Lost in Machine Translation: A Method to Reduce Meaning LossFeb 25 2019A desideratum of high-quality translation systems is that they preserve meaning, in the sense that two sentences with different meanings should not translate to one and the same sentence in another language. However, state-of-the-art systems often fail ... More
Roadblocked monotonic paths and the enumeration of coalescent histories for non-matching caterpillar gene trees and species treesJan 14 2019Given a gene tree topology and a species tree topology, a coalescent history represents a possible mapping of the list of gene tree coalescences to associated branches of a species tree on which those coalescences take place. Enumerative properties of ... More
Differentiable Antithetic Sampling for Variance Reduction in Stochastic Variational InferenceOct 05 2018Stochastic optimization techniques are standard in variational inference algorithms. These methods estimate gradients by approximating expectations with independent Monte Carlo samples. In this paper, we explore a technique that uses correlated, but more ... More
A simplicial approach to effective divisors in $\overline{M}_{0,n}$Jan 02 2014Mar 08 2016We study the Cox ring and monoid of effective divisor classes of $\overline{M}_{0,n} = Bl\mathbb{P}^{n-3}$, over a ring R. We provide a bijection between elements of the Cox ring, not divisible by any exceptional divisor section, and pure-dimensional ... More
Degree of Regularity of Linear Homogeneous EquationsSep 27 2013Jan 27 2014We define a linear homogeneous equation to be strongly r-regular if, when a finite number of inequalities is added to the equation, the system of the equation and inequalities is still r-regular. In this paper, we show that, if a linear homogeneous equation ... More
GIT Compactifications of M_{0,n} and FlipsDec 01 2011Feb 05 2016We use geometric invariant theory (GIT) to construct a large class of compactifications of the moduli space M_{0,n}. These compactifications include many previously known examples, as well as many new ones. As a consequence of our GIT approach, we exhibit ... More
The Smith and Critical Groups of the Square Rook's Graph and its ComplementJul 23 2015Let $R_{n}$ denote the graph with vertex set consisting of the squares of an $n \times n$ grid, with two squares of the grid adjacent when they lie in the same row or column. This is the square rook's graph, and can also be thought of as the Cartesian ... More
On dualizability of braided tensor categoriesApr 20 2018Aug 15 2018We study the question of dualizability in higher Morita categories of locally presentable tensor categories and braided tensor categories. Our main results are that the 3-category of rigid tensor categories with enough compact projectives is 2-dualizable, ... More
Wavelet regression and additive models for irregularly spaced dataMar 11 2019We present a novel approach for nonparametric regression using wavelet basis functions. Our proposal, $\texttt{waveMesh}$, can be applied to non-equispaced data with sample size not necessarily a power of 2. We develop an efficient proximal gradient descent ... More
Generalized Sparse Additive ModelsMar 11 2019We present a unified framework for estimation and analysis of generalized additive models in high dimensions. The framework defines a large class of penalized regression estimators, encompassing many existing methods. An efficient computational algorithm ... More
To Tune or Not to Tune? Adapting Pretrained Representations to Diverse TasksMar 14 2019While most previous work has focused on different pretraining objectives and architectures for transfer learning, we ask how to best adapt the pretrained model to a given target task. We focus on the two most common forms of adaptation, feature extraction ... More
Gate-tunable high mobility remote-doped InSb/In_{1-x}Al_{x}Sb quantum well heterostructuresMar 23 2015Gate-tunable high-mobility InSb/In_{1-x}Al_{x}Sb quantum wells (QWs) grown on GaAs substrates are reported. The QW two-dimensional electron gas (2DEG) channel mobility in excess of 200,000 cm^{2}/Vs is measured at T=1.8K. In asymmetrically remote-doped ... More
Plastic scintillator detector with the readout based on an array of large-area SiPMs for the ND280/T2K upgrade and SHiP experimentsJan 23 2019Plastic scintillator detectors have been extensively used in particle physics experiments for decades. A large-scale detector is typically arranged as an array of staggered long bars which provide a fast trigger signal and/or particle identification via ... More
Redesigning a junior-level electronics course to support engagement in scientific practicesJul 14 2015Building on successful work on studying and transforming our senior-level Advanced Lab course, we have transformed our junior-level Electronics course to engage students in a variety of authentic scientific practices, including constructing, testing, ... More
Optimal Control with Noisy TimeDec 31 2013This paper examines stochastic optimal control problems in which the state is perfectly known, but the controller's measure of time is a stochastic process derived from a strictly increasing L\'evy process. We provide dynamic programming results for continuous-time ... More
The Propagation of Quantum Information Through a Spin SystemDec 16 2003It has been recently suggested that the dynamics of a quantum spin system may provide a natural mechanism for transporting quantum information. We show that one dimensional rings of qubits with fixed (time-independent) interactions, constant around the ... More
Neurally-Guided Procedural Models: Amortized Inference for Procedural Graphics Programs using Neural NetworksMar 19 2016Oct 13 2016Probabilistic inference algorithms such as Sequential Monte Carlo (SMC) provide powerful tools for constraining procedural models in computer graphics, but they require many samples to produce desirable results. In this paper, we show how to create procedural ... More
Applying Probabilistic Programming to Affective ComputingMar 15 2019Affective Computing is a rapidly growing field spurred by advancements in artificial intelligence, but often, held back by the inability to translate psychological theories of emotion into tractable computational models. To address this, we propose a ... More
Magic of high order van Hove singularityJan 16 2019Feb 03 2019We introduce a new type of van Hove singularity in two dimensions, where a saddle point in momentum space is changed from second-order to high-order. Correspondingly, the density of states near such ``high-order van Hove singularity'' is significantly ... More
Uniform control of local times of spectrally positive stable processesSep 21 2016We establish two results about local times of spectrally positive stable processes. The first is a general approximation result, uniform in space and on compact time intervals, in a model where each jump of the stable process may be marked by a random ... More
Aldous diffusion I: a projective system of continuum $k$-tree evolutionsSep 20 2018The Aldous diffusion is a conjectured Markov process on the space of real trees that is the continuum analogue of discrete Markov chains on binary trees. We construct this conjectured process via a consistent system of stationary evolutions of binary ... More
Interval partition evolutions with emigration related to the Aldous diffusionApr 04 2018We construct a stationary Markov process corresponding to the evolution of masses and distances of subtrees along the spine from the root to a branch point in a conjectured stationary, continuum random tree-valued diffusion that was proposed by David ... More
Greedy, Joint Syntactic-Semantic Parsing with Stack LSTMsJun 29 2016We present a transition-based parser that jointly produces syntactic and semantic dependencies. It learns a representation of the entire algorithm state, using stack long short-term memories. Our greedy inference algorithm has linear time, including feature ... More
Touchdown: Natural Language Navigation and Spatial Reasoning in Visual Street EnvironmentsNov 29 2018Feb 25 2019We study the problem of jointly reasoning about language and vision through a navigation and spatial reasoning task. We introduce the Touchdown task and dataset, where an agent must first follow navigation instructions in a real-life visual urban environment ... More
A probabilistic heuristic for counting components of functional graphs of polynomials over finite fieldsSep 24 2016In 2014, Flynn and the second author bounded the average number of components of the functional graphs of polynomials of fixed degree over a finite field. When the fixed degree was large (relative to the size of the finite field), their lower bound matched ... More
Compaction and Melt Transport in Ammonia-Rich Ice Shells: Implications for the Evolution of TritonNov 27 2018Ammonia, if present in the ice shells of icy satellites, could lower the temperature for the onset of melting to 176 K and create a large temperature range where partial melt is thermally stable. The evolution of regions of ammonia-rich partial melt could ... More
Projections of the Aldous chain on binary trees: Intertwining and consistencyFeb 02 2018Consider the Aldous Markov chain on the space of rooted binary trees with $n$ labeled leaves in which at each transition a uniform random leaf is deleted and reattached to a uniform random edge. Now, fix $1\le k < n$ and project the leaf mass onto the ... More
Pragmatic inference and visual abstraction enable contextual flexibility during visual communicationMar 11 2019Visual modes of communication are ubiquitous in modern life. Here we investigate drawing, the most basic form of visual communication. Communicative drawing poses a core challenge for theories of how vision and social cognition interact, requiring a detailed ... More
Hairy binary black holes in Einstein-Maxwell-dilaton theory and their effective-one-body descriptionSep 03 2018Nov 14 2018In General Relativity and many modified theories of gravity, isolated black holes (BHs) cannot source massless scalar fields. Einstein-Maxwell-dilaton (EMd) theory is an exception: through couplings both to electromagnetism and (non-minimally) to gravity, ... More
Discovery of Latent 3D Keypoints via End-to-end Geometric ReasoningJul 05 2018Nov 23 2018This paper presents KeypointNet, an end-to-end geometric reasoning framework to learn an optimal set of category-specific 3D keypoints, along with their detectors. Given a single image, KeypointNet extracts 3D keypoints that are optimized for a downstream ... More
Simulating Vehicle Movement and Multi-Hop Connectivity from Basic Safety MessagesMay 05 2018The Basic Safety Message (BSM) is a standardized communication packet that is sent every tenth of a second between connected vehicles using Dedicated Short Range Communication (DSRC). BSMs contain data about the sending vehicle's state, such as speed, ... More
Diffusions on a space of interval partitions with Poisson-Dirichlet stationary distributionsSep 21 2016Mar 21 2017We construct a pair of related diffusions on a space of interval partitions of the unit interval $[0,1]$ that are stationary with the Poisson-Dirichlet laws with parameters (1/2,0) and (1/2,1/2) respectively. These are two particular cases of a general ... More
Meta-Amortized Variational Inference and LearningFeb 05 2019How can we learn to do probabilistic inference in a way that generalizes between models? Amortized variational inference learns for a single model, sharing statistical strength across observations. This benefits scalability and model learning, but does ... More
Zero Shot Learning for Code Education: Rubric Sampling with Deep Learning InferenceSep 05 2018Dec 17 2018In modern computer science education, massive open online courses (MOOCs) log thousands of hours of data about how students solve coding challenges. Being so rich in data, these platforms have garnered the interest of the machine learning community, with ... More
Studying Expert Practices to Create Learning Goals for Electronics LabsJul 11 2014Laboratory courses for upper-division undergraduates often involve sophisticated equipment, relatively small class sizes, and extended hands-on projects. These courses present distinct challenges and opportunities for the physics education research community ... More
Sustaining Educational Reforms in Introductory PhysicsMay 02 2008While it is well known which curricular practices can improve student performance on measures of conceptual understanding, the sustaining of these practices and the role of faculty members in implementing these practices are less well understood. We present ... More
Dimension of posets with planar cover graphs excluding two long incomparable chainsAug 31 2016Dec 19 2018It has been known for more than 40 years that there are posets with planar cover graphs and arbitrarily large dimension. Recently, Streib and Trotter proved that such posets must have large height. In fact, all known constructions of such posets have ... More
When redundancy is rational: A Bayesian approach to 'overinformative' referring expressionsMar 19 2019Referring is one of the most basic and prevalent uses of language. How do speakers choose from the wealth of referring expressions at their disposal? Rational theories of language use have come under attack for decades for not being able to account for ... More
Entropy-scaling search of massive biological dataMar 19 2015Sep 21 2015Many datasets exhibit a well-defined structure that can be exploited to design faster search tools, but it is not always clear when such acceleration is possible. Here, we introduce a framework for similarity search based on characterizing a dataset's ... More
LSTMs Exploit Linguistic Attributes of DataMay 29 2018While recurrent neural networks have found success in a variety of natural language processing applications, they are general models of sequential data. We investigate how the properties of natural language data affect an LSTM's ability to learn a nonlinguistic ... More
Segmental Recurrent Neural Networks for End-to-end Speech RecognitionMar 01 2016Jun 20 2016We study the segmental recurrent neural network for end-to-end acoustic modelling. This model connects the segmental conditional random field (CRF) with a recurrent neural network (RNN) used for feature extraction. Compared to most previous CRF-based ... More
Theory of Deep Learning IIb: Optimization Properties of SGDJan 07 2018In Theory IIb we characterize with a mix of theory and experiments the optimization of deep convolutional networks by Stochastic Gradient Descent. The main new result in this paper is theoretical and experimental evidence for the following conjecture ... More
Dynamic Social Balance and Convergent Appraisals via Homophily and Influence MechanismsOct 26 2017Feb 05 2019Social balance theory describes allowable and forbidden configurations of the topologies of signed directed social appraisal networks. In this paper, we propose two discrete-time dynamical systems that explain how an appraisal network \textcolor{blue}{converges ... More
Rapid spatial equilibration of a particle in a boxJun 11 2015Jun 29 2015We study the equilibration behaviour of a quantum particle in a one-dimensional box, with respect to a coarse grained position measurement (whether it lies in a certain spatial window or not). We show that equilibration in this context indeed takes place ... More
Quantum mechanical evolution towards thermal equilibriumDec 12 2008The circumstances under which a system reaches thermal equilibrium, and how to derive this from basic dynamical laws, has been a major question from the very beginning of thermodynamics and statistical mechanics. Despite considerable progress, it remains ... More
Products of Weighted Logic ProgramsJun 15 2010Weighted logic programming, a generalization of bottom-up logic programming, is a well-suited framework for specifying dynamic programming algorithms. In this setting, proofs correspond to the algorithm's output space, such as a path through a graph or ... More
Infinite Families of Partitions into MSTD SubsetsAug 16 2018A set $A$ is MSTD (more-sum-than-difference) if $|A+A|>|A-A|$. Though MSTD sets are rare, Martin and O'Bryant proved that there exists a positive constant lower bound for the proportion of MSTD subsets of $\{1,2,\ldots ,r\}$ as $r\rightarrow\infty$. Asada ... More
No quantum advantage for nonlocal computationOct 12 2006We investigate the problem of "nonlocal" computation, in which separated parties must compute a function with nonlocally encoded inputs and output, such that each party individually learns nothing, yet together they compute the correct function output. ... More
Model-Based Reasoning in the Upper-Division Physics Laboratory: Framework and Initial ResultsOct 03 2014Feb 23 2015We review and extend existing frameworks on modeling to develop a new framework that describes model-based reasoning in upper-division physics labs. Constructing and using models are core scientific practices that have gained significant attention within ... More
Generalizations of a Curious Family of MSTD Sets Hidden By Interior BlocksAug 16 2018A set $A$ is MSTD (more-sum-than-difference) or sum-dominant if $|A+A|>|A-A|$ and is RSD (restricted-sum dominant) if $|A\hat{+}A|>|A-A|$, where $A\hat{+}A$ is the sumset of $A$ without a number added to itself. We study an interesting family of MSTD ... More
44 New & Known M Dwarf Multiples In The SDSS-III/APOGEE M Dwarf Ancillary Science SampleJun 06 2018Jun 29 2018Binary stars make up a significant portion of all stellar systems. Consequently, an understanding of the bulk properties of binary stars is necessary for a full picture of star formation. Binary surveys indicate that both multiplicity fraction and typical ... More
SAT Modulo Monotonic TheoriesMay 31 2014We define the concept of a monotonic theory and show how to build efficient SMT (SAT Modulo Theory) solvers, including effective theory propagation and clause learning, for such theories. We present examples showing that monotonic theories arise from ... More
Polar Ring Galaxies in the Galaxy ZooFeb 22 2012Mar 08 2012We report observations of 16 candidate polar ring galaxies (PRGs) identified by the Galaxy Zoo project in the Sloan Digital Sky Survey (SDSS) database. Deep images of five galaxies are available in the SDSS Stripe82 database, while to reach similar depth ... More
On the speed of fluctuations around thermodynamic equilibriumJul 07 2009We study the speed of fluctuation of a quantum system around its thermodynamic equilibrium state, and show that the speed will be extremely small for almost all times in typical thermodynamic cases. The setting considered here is that of a quantum system ... More
Developing Mobility and Traffic Visualization Applications for Connected VehiclesNov 25 2018This technical report is a catalog of two applications that have been enhanced and developed to augment vehicular networking research. The first application is already described in our previous work [21], while the second one is a desktop application ... More
Thinking about ArcheoastronomyMar 29 2011I discuss various aspects of archeoastronomy concentrating on physical artifacts (i.e., not including ethno-archeoastronomy) focusing on the period that ended about 2000 years ago. I present examples of artifacts interpreted as showing the interest of ... More
Quest for truly isolated galaxiesJun 23 2009I describe attempts to identify and understand the most isolated galaxies starting from my 1983 Leiden PhD thesis, continuing through a string of graduate theses on various aspects of this topic, and concluding with an up-to-date account of the difficulty ... More
The TAUVEX UV ImagerSep 30 1996I present an up-to-date description of the TAUVEX UV imager, constructed to operate on the Spectrum X-Gamma international space observatory. The projected performance and the expected scientific yield of TAUVEX are described.
Casimir Energies of Periodic Dielectric GratingsJul 17 2014Sep 23 2014Reflection of electromagnetic waves from a periodic grating can be described in terms of a discrete coupled multichannel scattering problem. By modeling the grating as a space- and frequency-dependent dielectric, it is possible to use a variable phase ... More
Brownian bricklayer: a random space-filling curveAug 23 2017Let $(B(t),\,t\ge0)$ denote the standard, one-dimensional Wiener process and $(\ell(y,t);\, y\in\mathbb{R},\, t\ge0)$ its local time at level $y$ up to time $t$. Then $\big( (B(t),\, \ell(B(t),t)),\; t\ge0 \big)$ is a random path that fills the upper ... More
Transfinite Recursion in Higher Reverse MathematicsOct 22 2013In this paper we investigate the reverse mathematics of higher-order analogues of the theory \ATRz{} within the framework of higher order reverse mathematics developed by Kohlenbach \cite{Koh01}. We define a theory \RCAzthr, a close higher-type analogue ... More
Ultraviolet Sky SurveysSep 29 1996Sep 30 1996I review the development of UV and EUV astronomy, covering the spectral range from 5 to 300 nm, with emphasis on sky surveys for discrete sources. I discuss studies which resulted in lists of sources observed by imaging. The missions are compared in terms ... More
A rotational approach to triple point obstructionsJul 21 2012Subfactors where the initial branching point of the principal graph is 3-valent are subject to strong constraints called triple point obstructions. Since more complicated initial branches increase the index of the subfactor, triple point obstructions ... More
The Liouville phenomenon in the deformation problem of coisotropicsMay 16 2008The work of Oh and Park ([OP]) on the deformation problem of coisotropic submanifolds opened the possibility of studying a large and interesting class of foliations with some explicit geometric tools. These tools assemble into the structure of an L-infinity ... More
The m-Degenerate Chromatic Number of a DigraphSep 26 2014Dec 04 2018The digraph chromatic number of a directed graph $D$, denoted $\chi_A(D)$, is the minimum positive integer $k$ such that there exists a partition of the vertices of $D$ into $k$ disjoint sets, each of which induces an acyclic subgraph. For any $m \geq ... More
The dwarf galaxy population of the Virgo ClusterJun 13 2002Jul 07 2002I review the status of knowledge about the dwarf galaxies in the Virgo Cluster (VC) concentrating on work published after 1995. I explain the present ideas about the nature and history of the dwarf elliptical galaxies and emphasize the major increments ... More
Groups with a Character of Large DegreeMar 10 2006Aug 28 2008Let G be a finite group of order n and V an irreducible representation over the complex numbers of dimension d. For some nonnegative number e, we have n=d(d+e). If e is small, then the character of V has unusually large degree. We fix e and attempt to ... More
Galaxy interactions in the Hickson Compact Group 88Sep 21 2015I present observations of the Hickson Compact Group 88 (HCG88) obtained during the commissioning of a new 28-inch telescope at the Wise Observatory. This galaxy group was advertised to be non-interacting, or to be in a very early interaction stage, but ... More
Dwarf Irregular Galaxies and the Intergalactic MediumOct 20 1998Dwarf galaxies (DGs) are more numerous than large galaxies. Most dwarfs in clusters are dEs, but in the field they belong mostly to late types. The importance of late-type DGs in the context of the intergalactic medium (IGM) lies in the fact that (at ... More
Electromagnetic Casimir Forces in Elliptic Cylinder GeometriesMar 26 2013The scattering theory approach makes it possible to carry out exact calculations of Casimir energies in any geometry for which the scattering T-matrix and a partial wave expansion of the free Green's function are available. We implement this program for ... More
Schwarzschild Quantum Fluctuations from Regge-Wheeler ScatteringOct 17 2018Jan 08 2019We apply a multichannel variable phase method to scattering from Regge-Wheeler potentials. Using a reduced version of the WKB subtraction developed by Candelas and Howard, this approach allows for efficient numerical calculations of scattering data for ... More
UV sky surveysJul 26 1998I review the development of UV and EUV astronomy, covering the spectral range from 5 to 300 nm, with emphasis on sky surveys for discrete sources. I discuss studies which resulted in lists of sources observed by imaging and deliberately omit most spectroscopic ... More
Modeling and Particle Tracking through Longitudinal Gradient Bending MagnetsOct 26 2015This report documents the development of a versatile model for longitudinal gradient bending magnets (LGB's) and its implementation in particle tracking simulations. The model presented below may be used to represent an arbitrary magnetic field profile, ... More
Intentional Design for EmpowermentAug 27 2013I argue for empowering education, adapting Marx's idea of ownership of the means of production, and discuss interactive simulations as one example of a tool in which intentional design can support student ownership of learning. I propose a model that ... More
Acyclic Colorings of Directed GraphsSep 26 2014The acyclic chromatic number of a directed graph $D$, denoted $\chi_A(D)$, is the minimum positive integer $k$ such that there exists a decomposition of the vertices of $D$ into $k$ disjoint sets, each of which induces an acyclic subgraph. For any $m ... More