Results for "William Borucki"

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Characteristics of Kepler Planetary Candidates Based on the First Data Set: The Majority are Found to be Neptune-Size and SmallerJun 14 2010Jul 23 2010In the spring of 2009, the Kepler Mission commenced high-precision photometry on nearly 156,000 stars to determine the frequency and characteristics of small exoplanets, conduct a guest observer program, and obtain asteroseismic data on a wide variety ... More
Kepler-62f: Kepler's First Small Planet in the Habitable Zone, but Is It Real?May 14 2019Kepler-62f is the first exoplanet small enough to plausibly have a rocky composition orbiting within the habitable zone (HZ) discovered by the Kepler Mission. The planet is 1.4 times the size of the Earth and has an orbital period of 267 days. At the ... More
White-light flares on cool stars in the Kepler Quarter 1 DataAug 04 2010Oct 20 2010We present the results of a search for white light flares on the ~23,000 cool dwarfs in the Kepler Quarter 1 long cadence data. We have identified 373 flaring stars, some of which flare multiple times during the observation period. We calculate relative ... More
Photometric Variability in Kepler Target Stars: The Sun Among Stars -- A First LookJan 03 2010The Kepler mission provides an exciting opportunity to study the lightcurves of stars with unprecedented precision and continuity of coverage. This is the first look at a large sample of stars with photometric data of a quality that has heretofore been ... More
Kepler-62f: Kepler's First Small Planet in the Habitable Zone, but Is It Real?May 14 2019May 15 2019Kepler-62f is the first exoplanet small enough to plausibly have a rocky composition orbiting within the habitable zone (HZ) discovered by the Kepler Mission. The planet is 1.4 times the size of the Earth and has an orbital period of 267 days. At the ... More
KIC 9632895 - The 10th Kepler Transiting Circumbinary PlanetSep 04 2014We present the discovery of KIC 9632895b, a 6.2 Earth-radius planet in a low-eccentricity, 240.5-day orbit about an eclipsing binary. The binary itself consists of a 0.93 and 0.194 solar mass pair of stars with an orbital period of 27.3 days. The plane ... More
KOI-54: The Kepler Discovery of Tidally-Excited Pulsations and Brightenings in a Highly Eccentric BinaryFeb 08 2011Sep 01 2011Kepler observations of the star HD 187091 (KID 8112039, hereafter KOI-54) revealed a remarkable light curve exhibiting sharp periodic brightening events every 41.8 days with a superimposed set of oscillations forming a beating pattern in phase with the ... More
The Frequency of Giant impacts on Earth-like WorldsNov 11 2015Mar 10 2016The late stages of terrestrial planet formation are dominated by giant impacts that collectively influence the growth, composition and habitability of any planets that form. Hitherto, numerical models designed to explore these late stage collisions have ... More
Validation of small Kepler transiting planet candidates in or near the habitable zoneNov 03 2017A main goal of NASA's Kepler Mission is to establish the frequency of potentially habitable Earth-size planets (eta Earth). Relatively few such candidates identified by the mission can be confirmed to be rocky via dynamical measurement of their mass. ... More
The atmospheres of the hot-Jupiters Kepler-5b and Kepler-6b observed during occultations with Warm-Spitzer and KeplerFeb 02 2011Feb 03 2011This paper reports the detection and the measurements of occultations of the two transiting hot giant exoplanets Kepler-5b and Kepler-6b by their parent stars. The observations are obtained in the near infrared with Spitzer Space Telescope and at optical ... More
Discovery and Validation of Kepler-452b: A 1.6-Re Super Earth Exoplanet in the Habitable Zone of a G2 StarJul 24 2015We report on the discovery and validation of Kepler-452b, a transiting planet identified by a search through the 4 years of data collected by NASA's Kepler Mission. This possibly rocky 1.63$^{+0.23}_{-0.20}$ R$_\oplus$ planet orbits its G2 host star every ... More
A Transiting Hot Jupiter Orbiting a Metal-Rich StarJan 02 2010We announce the discovery of Kepler-6b, a transiting hot Jupiter orbiting a star with unusually high metallicity, [Fe/H] = +0.34 +/- 0.04. The planet's mass is about 2/3 that of Jupiter, Mp = 0.67 Mj, and the radius is thirty percent larger than that ... More
The Discovery of Ellipsoidal Variations in the Kepler Light Curve of HAT-P-7Jan 03 2010Feb 05 2010We present an analysis of the early Kepler observations of the previously discovered transiting planet HAT-P-7b. The light curve shows the transit of the star, the occultation of the planet, and the orbit phase-dependent light from the planet. In addition, ... More
Kepler-10c, a 2.2-Earth radius transiting planet in a multiple systemMay 23 2011The Kepler Mission has recently announced the discovery of Kepler-10 b, the smallest exoplanet discovered to date and the first rocky planet found by the spacecraft. A second, 45-day period transit-like signal present in the photometry from the first ... More
Characteristics of planetary candidates observed by Kepler, II: Analysis of the first four months of dataFeb 02 2011Mar 12 2011On 1 February 2011 the Kepler Mission released data for 156,453 stars observed from the beginning of the science observations on 2 May through 16 September 2009. There are 1235 planetary candidates with transit like signatures detected in this period. ... More
Preliminary Astrometric Results from KeplerJan 02 2010Although not designed as an astrometric instrument, Kepler is expected to produce astrometric results of a quality appropriate to support many of the astrophysical investigations enabled by its photometric results. On the basis of data collected during ... More
Kepler observations of a roAp star: delta Scuti and gamma Doradus pulsations in Ap starsJun 21 2010Observations of the A5p star KIC 8677585 obtained during the Kepler 10-d commissioning run with 1-min time resolution show that it is a roAp star with several frequencies with periods near 10 min. In addition, a low frequency at 3.142 cycles/day is also ... More
Discovery and Rossiter-McLaughlin Effect of Exoplanet Kepler-8bJan 04 2010We report the discovery and the Rossiter-McLaughlin effect of Kepler-8b, a transiting planet identified by the NASA Kepler Mission. Kepler photometry and Keck-HIRES radial velocities yield the radius and mass of the planet around this F8IV subgiant host ... More
Kepler-16: A Transiting Circumbinary PlanetSep 15 2011We report the detection of a planet whose orbit surrounds a pair of low-mass stars. Data from the Kepler spacecraft reveal transits of the planet across both stars, in addition to the mutual eclipses of the stars, giving precise constraints on the absolute ... More
The high albedo of the hot Jupiter Kepler-7bMay 25 2011Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric precision at visible wavelengths ... More
Kepler constraints on planets near hot JupitersMay 10 2012We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 days) identified in the Kepler data through its sixth quarter of science operations. Special emphasis ... More
Kepler Eclipsing Binary Stars. I. Catalog and Principal Characterization of 1879 Eclipsing Binaries in the First Data ReleaseJun 14 2010Jan 21 2011The Kepler space mission is devoted to finding Earth-size planets in habitable zones orbiting other stars. Its large, 105-deg field-of-view features over 156,000 stars that are observed continuously to detect and characterize planet transits. Yet this ... More
Planetary Candidates Observed by Kepler VI: Planet Sample from Q1-Q16 (47 Months)Feb 06 2015\We present the sixth catalog of Kepler candidate planets based on nearly 4 years of high precision photometry. This catalog builds on the legacy of previous catalogs released by the Kepler project and includes 1493 new Kepler Objects of Interest (KOIs) ... More
Kepler-14b: A massive hot Jupiter transiting an F star in a close visual binaryJun 27 2011We present the discovery of a hot Jupiter transiting an F star in a close visual (0.3" sky projected angular separation) binary system. The dilution of the host star's light by the nearly equal magnitude stellar companion (~ 0.5 magnitudes fainter) significantly ... More
Detection of solar-like oscillations from Kepler photometry of the open cluster NGC 6819Dec 30 2009Asteroseismology of stars in clusters has been a long-sought goal because the assumption of a common age, distance and initial chemical composition allows strong tests of the theory of stellar evolution. We report results from the first 34 days of science ... More
Photometric Variability in Kepler Target Stars. II. An Overview of Amplitude, Periodicity, and Rotation in First Quarter DataAug 05 2010Nov 02 2010We provide an overview of stellar variability in the first quarter of data from the Kepler mission. The intent of this paper is to examine the entire sample of over 150,000 target stars for periodic behavior in their lightcurves, and relate this to stellar ... More
A Catalog of Kepler Habitable Zone Exoplanet CandidatesAug 01 2016Sep 02 2016The NASA Kepler mission has discovered thousands of new planetary candidates, many of which have been confirmed through follow-up observations. A primary goal of the mission is to determine the occurrance rate of terrestrial-size planets within the Habitable ... More
The Kepler Pixel Response FunctionJan 02 2010Mar 24 2010Kepler seeks to detect sequences of transits of Earth-size exoplanets orbiting Solar-like stars. Such transit signals are on the order of 100 ppm. The high photometric precision demanded by Kepler requires detailed knowledge of how the Kepler pixels respond ... More
Validation of Kepler's Multiple Planet Candidates. II: Refined Statistical Framework and Descriptions of Systems of Special InterestFeb 25 2014We extend the statistical analysis of Lissauer et al. (2012, ApJ 750, 112), which demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) represent true transiting planets, and develop therefrom a procedure ... More
On the Provenance of Linked Data StatisticsOct 19 2014As the amount of linked data published on the web grows, attempts are being made to describe and measure it. However even basic statistics about a graph, such as its size, are difficult to express in a uniform and predictable way. In order to be able ... More
On the structure of virtually nilpotent compact $p$-adic analytic groupsAug 10 2016Let $G$ be a compact $p$-adic analytic group. We recall the well-understood finite radical $\Delta^+$ and FC-centre $\Delta$, and introduce a $p$-adic analogue of Roseblade's subgroup $\mathrm{nio}(G)$, the unique largest orbitally sound open normal subgroup ... More
Fast Algorithms for Finding Pattern Avoiders and Counting Pattern Occurrences in PermutationsSep 28 2015Oct 30 2016Given a set $\Pi$ of permutation patterns of length at most $k$, we present an algorithm for building $S_{\le n}(\Pi)$, the set of permutations of length at most $n$ avoiding the patterns in $\Pi$, in time $O(|S_{\le n - 1}(\Pi)| \cdot k + |S_{n}(\Pi)|)$. ... More
Novae Ejecta as Discrete Adiabatically Expanding GlobulesJun 26 2013Available data for novae show that the X-ray and visible spectral regions correlate with each other as they evolve. Large differences in ionization exist simultaneously in the two wavelength regimes, and a straightforward model is proposed that explains ... More
Third Parameter Classification of Transients and Novae Ejecta as Ballistically Ejected GlobulesJan 03 2016Feb 03 2016A third parameter, in addition to luminosity and rate of brightness decline, derived from the spectra of transients is suggested as a means of more accurately classifying objects in outburst. Principal component analysis of the spectra of transients is ... More
QCD inequalities for hadron interactionsAug 29 2014We derive generalisations of the Weingarten--Witten QCD mass inequalities for particular multi-hadron systems. For systems of any number of identical pseudo-scalar mesons of maximal isospin, these inequalities prove that interactions between the constituent ... More
The domain algebra of a CP semigroupMay 24 2000A CP semigroup is a semigroup of normal unit-preserving completely positive maps acting on the algebra B(H) of all operators on a separable Hilbert space H. Such a semigroup has a natural generator L; since the individual maps of the semigroup need not ... More
On the index and dilations of completely positive semigroupsMay 25 1997It is known that every semigroup of normal completely positive maps $P = {P_t: t\geq 0}$ of $B(H)$, satisfying $P_t(1) = 1$ for every $t\geq 0$, has a minimal dilation to an E_0-semigroup acting on $B(K)$ for some Hilbert space K containing H. The minimal ... More
Multilinear Embedding -- convolution estimates on smooth submanifoldsApr 25 2012Multilinear embedding estimates for the fractional Laplacian are obtained in terms of functionals defined over a hyperbolic surface. Convolution estimates used in the proof enlarge the classical framework of the convolution algebra for Riesz potentials ... More
The Two Extended Bodies Problem in General Relativity within the post-Newtonian ApproximationApr 02 2014The dynamics of extended bodies is a fundamental problem in any gravitational theory. In the case of General Relativity, this problem is under study since the theory was published. Several methods have been developed and different approaches are avalaible ... More
Approximate Recall Confidence IntervalsFeb 13 2012Oct 23 2012Recall, the proportion of relevant documents retrieved, is an important measure of effectiveness in information retrieval, particularly in the legal, patent, and medical domains. Where document sets are too large for exhaustive relevance assessment, recall ... More
Comments on "Increasing destructiveness of tropical cyclones over the past 30 years" by Kerry Emanuel, Nature, 31 July 2005, Vol. 436, pp. 686-688Jan 09 2006The near universal references to the above paper by most of the major US media outlets and blogs since Katrina and Rita made US landfall requires a response from a few of us who study hurricanes. Having been involved with hurricane research and forecasting ... More
First Run of the LArIAT Testbeam ExperimentNov 01 2015LArIAT (Liquid Argon In A Testbeam) aims to characterize the response of a liquid argon time projection chamber (LArTPC) to the particles often seen as final-state products of ~1 GeV neutrino interactions in existing and planned detectors. The experiment ... More
The Dimension of the Space of Cusp Forms of Weight OneNov 09 1994A new upper bound is given for the dimension of the space of holomorphic cusp forms of weight one and prime level $q$: $$ \hbox{dim}\, S_1(q) << q^{11/12} \log^4{q} $$ with an absolute implied constant.
The Combinatorics of Occam's RazorApr 28 2015Occam's Razor tells us to pick the simplest model that fits our observations. In order to make sense of his process mathematically, we interpret it in the context of posets of functions. Our approach leads to some unusual new combinatorial problems concerning ... More
Do Type-Ia Supernovae Constrain the Total Equation of State?Nov 28 2005Feb 01 2007In this paper, we consider a couple of alternative dark energy models using the total equation of state of the cosmological fluid, $\wt$. These models are fit to the recent type-Ia supernovae data and are compared to previously considered models. The ... More
Embeddings of Iteration TreesApr 17 1992This paper, dating from May 1991, contains preliminary (and unpublishable) notes on investigations about iteration trees. They will be of interest only to the specialist. In the first two sections I define notions of support and embeddings for tree iterations, ... More
Higgs + 2 jets: Compact Analytic ResultsJan 12 2010This report describes the recent efforts to compute analytic formulae for the Next-to-Leading-Order (NLO) QCD corrections to Higgs plus two jet production at hadron colliders. In these calculations the Higgs boson couples to gluons via a top-quark loop ... More
$P$-adic $L$-functions of Bianchi modular formsApr 08 2014Jan 22 2015The theory of overconvergent modular symbols, developed by Rob Pollack and Glenn Stevens, gives a beautiful and effective construction of the $p$-adic $L$-function of a modular form. In this paper, we give an analogue of their results for Bianchi modular ... More
Exciton Transfer Integrals Between Polymer ChainsMar 26 2007The line-dipole approximation for the evaluation of the exciton transfer integral, $J$, between conjugated polymer chains is rigorously justified. Using this approximation, as well as the plane-wave approximation for the exciton center-of-mass wavefunction, ... More
Theory of the singlet exciton yield in light-emitting polymersOct 26 2004This paper presents a possible explanation for the enhanced singlet exciton yield in light emitting polymers. We propose a theory of electron-hole recombination via inter-molecular inter-conversion from inter-molecular weakly bound polaron pairs (or charge-transfer ... More
Asymptotic Behavior of Spherically Symmetric Marginally Trapped TubesFeb 19 2007Jan 14 2009We give conditions on a general stress-energy tensor T_{\alpha \beta} in a spherically symmetric black hole spacetime which are sufficient to guarantee that the black hole will contain a (spherically symmetric) marginally trapped tube which is eventually ... More
A Comment on Black Hole Entropy in String TheoryJun 03 1994Jun 12 1994In this note, we extend the string theoretic calculation of the black hole entropy, first performed by Susskind and Uglum, away from the infinite mass limit. It is shown that the result agrees with that obtained from the classical action of string theory, ... More
Kaluza-Klein Black Holes in String TheoryDec 08 1993Exact solutions of heterotic string theory corresponding to four-dimensional magnetic black holes in $N=4$ supergravity are described. The solutions describe the black holes in the throat limit, and consist of a tensor product of an $SU(2)$ WZW orbifold ... More
LHC Higgs Boson searchesJan 22 2012A summary of the Higgs boson searches by the ATLAS and CMS collabrations using 1 f b-1 of LHC data is presented, concentrating on the Standard Model Higgs boson. Both experiments have the sensitivity to exclude at 95% CL a Standard Model Higgs boson in ... More
The sensitivity of the Higgs boson branching ratios to the W boson widthApr 06 2016The Higgs boson branching ratio into vector bosons is sensitive to the decay widths of those vector bosons because they are produced with at least one boson significantly off-shell. Gamma(H to V V ) is approximately proportional to the product of the ... More
Effects of the circularly polarized beam of linearized gravitational wavesDec 03 2016Solutions of the linearized Einstein equations are found that describe a transversely confined beam of circularly polarized gravitational waves on a Minkowski backdrop. By evaluating the cycle-averaged stress-energy-momentum pseudotensor of Landau & Lifshitz ... More
Weakly localized states for nonlinear Dirac equationsFeb 15 2018Jul 30 2018We prove the existence of infinitely many non square-integrable stationary solutions for a family of massless Dirac equations in 2D. They appear as effective equations in two dimensional honeycomb structures. We give a direct existence proof thanks to ... More
Quasi-stationarity for one-dimensional renormalized Brownian motionSep 20 2018We are interested in the quasi-stationarity of the time-inhomogeneous Markov process X t = B t (t + 1) $\kappa$ where (B t) t$\ge$0 is a one-dimensional Brownian motion and $\kappa$ $\in$ (0, $\infty$). We first show that the law of X t conditioned not ... More
D-branes and Cosmological SingularitiesJul 25 2001Jul 27 2001The motion of a test Dq-brane in a Dp-brane background is studied. The induced metric on the test brane is then interpreted as the cosmology of the test brane universe. One is then able to resolve the resulting cosmological singularities. In particular, ... More
Low, Superlow, and Superduperlow Sets: An Exposition of a Known But Not Well-Known ResultJan 10 2015A set is low if A' \le_T HALT. A set is superlow if A' \le_tt HALT. A set is superduperlow if A' \le_btt HALT. While it was known that any superduperlow is decidable it does not seem to be well known. We include two unpublished proofs of this result: ... More
Dilation theory yesterday and todayFeb 23 2009Feb 23 2009Paul Halmos' work in dilation theory began with a question and its answer: Which operators on a Hilbert space can be extended to normal operators on a larger Hilbert space? The answer is interesting and subtle. The idea of representing operator-theoretic ... More
Evaluating the boundary and Stieltjes transform of limiting spectral distributions for random matrices with a separable variance profileApr 26 2019We present numerical algorithms for solving two problems encountered in random matrix theory and its applications. First, we compute the boundary of the limiting spectral distribution for random matrices with a separable variance profile. Second, we evaluate ... More
A dynamical-system picture of a simple branching-process phase transitionNov 30 2010This paper develops ideas from a previous paper described as `an appetizer for non-linear Wiener--Hopf theory', but is completely independent of that paper. It again considers only the simplest possible case in which the underlying motion of the branching ... More
Nonperturbative QCD Vacuum Effects in Nonlocal Quark DynamicsJan 30 1997A straightforward calculation reveals the essentially nonlocal character of the leading heavy $Q\bar{Q}$ interaction arising from nonperturbative gluon field correlations in the model of a fluctuating QCD vacuum. In light of this quarkonium spin splitting ... More
Pitt's inequality with sharp convolution estimatesDec 18 2006Jan 03 2007Sharp $L^p$ extensions of Pitt's inequality expressed as a weighted Sobolev inequality are obtained using convolution estimates and Stein-Weiss potentials. More generally, optimal constants are obtained for the full Stein-Weiss potential as a map from ... More
Quotients of Standard Hilbert ModulesFeb 17 2005Jul 14 2005We initiate a study of Hilbert modules over the polynomial algebra A=C[z_1,...,z_d] that are obtained by completing A with respect to an inner product having certain natural properties. A standard Hilbert module is a finite multiplicity version of one ... More
Doubled Khovanov HomologyApr 24 2017May 30 2017We define a homology theory of virtual links built out of the direct sum of the standard Khovanov complex with itself, motivating the name doubled Khovanov homology. We demonstrate that it can be used to show that some virtual links are non-classical, ... More
On the virtual Rasmussen invariantMar 09 2016Jun 26 2017We produce chain-level generators of the virtual Lee complex $ Kh ' (V ) $ and use them to convert the computable bounds on the Rasmussen invariant of classical knots due to Kawamura and Lobb into bounds on the virtual Rasmussen invariant as defined by ... More
A parity for 2-colourable linksJan 22 2019We introduce the 2-colour parity. It is a theory of parity for a large class of virtual links, defined using the interaction between orientations of the link components and a certain type of colouring. The 2-colour parity is an extension of the Gaussian ... More
Generalized Fibonacci groups H(r,n,s) that are connected Labelled Oriented Graph groupsMay 16 2017Nov 07 2017The class of connected LOG (Labelled Oriented Graph) groups coincides with the class of fundamental groups of complements of closed, orientable 2-manifolds embedded in S^4, and so contains all knot groups. We investigate when Campbell and Robertson's ... More
Mace4 Reference Manual and GuideOct 28 2003Mace4 is a program that searches for finite models of first-order formulas. For a given domain size, all instances of the formulas over the domain are constructed. The result is a set of ground clauses with equality. Then, a decision procedure based on ... More
Natural Proofs Versus DerandomizationDec 09 2012Jul 21 2015We study connections between Natural Proofs, derandomization, and the problem of proving "weak" circuit lower bounds such as ${\sf NEXP} \not\subset {\sf TC^0}$. Natural Proofs have three properties: they are constructive (an efficient algorithm $A$ is ... More
Origin of the `He/N' and `Fe II' Spectral Classes of NovaeAug 02 2012The spectra of postoutburst novae display either He+N or Fe II lines as the most prominent non-Balmer lines at maximum light. Spectral diagnostics indicate physical conditions for 'He/N' spectra that are consistent with their origin in the white dwarf ... More
A Casual Tour Around a Circuit Complexity BoundNov 04 2011I will discuss the recent proof that the complexity class NEXP (nondeterministic exponential time) lacks nonuniform ACC circuits of polynomial size. The proof will be described from the perspective of someone trying to discover it.
Alternation-Trading Proofs, Linear Programming, and Lower BoundsJan 05 2010Feb 03 2010A fertile area of recent research has demonstrated concrete polynomial time lower bounds for solving natural hard problems on restricted computational models. Among these problems are Satisfiability, Vertex Cover, Hamilton Path, Mod6-SAT, Majority-of-Majority-SAT, ... More
Applying Practice to TheoryNov 09 2008How can complexity theory and algorithms benefit from practical advances in computing? We give a short overview of some prior work using practical computing to attack problems in computational complexity and algorithms, informally describe how linear ... More
Strong ETH Breaks With Merlin and Arthur: Short Non-Interactive Proofs of Batch EvaluationJan 18 2016We present an efficient proof system for Multipoint Arithmetic Circuit Evaluation: for every arithmetic circuit $C(x_1,\ldots,x_n)$ of size $s$ and degree $d$ over a field ${\mathbb F}$, and any inputs $a_1,\ldots,a_K \in {\mathbb F}^n$, $\bullet$ the ... More
Embedding estimates and fractional smoothnessJun 19 2012Aug 01 2012A short intrinsic proof is given for the Bourgain-Brezis-Mironescu theorem with an extension for higher-order gradient forms. This argument illustrates the role of functional geometry and Fourier analysis for obtaining embedding estimates. New Hausdorff-Young ... More
Target mass effects in deep-inelastic scattering on the deuteronSep 01 2005We calculate the effects of the target mass on deep-inelastic electron scattering on targets of spin one such as the deuteron, focusing on the novel structure functions that enter. It is important to understand these effects given the recent HERMES measurements ... More
Pure E_0-semigroups and absorbing statesMay 25 1997An E_0-semigroup acting on B(H) is called pure if the intersection of the ranges $\alpha_t(B(H))$, $t>0$, is the algebra of scalars. We determine all pure E_0-semigroups which have a weakly continuous invariant state $\omega$ and which are minimal in ... More
Path spaces, continuous tensor products, and E_0 semigroupsNov 20 1994Nov 21 1994We classify all continuous tensor product systems of Hilbert spaces which are ``infinitely divisible" in the sense that they have an associated logarithmic structure. These results are applied to the theory of E_0 semigroups to deduce that every E_0 semigroup ... More
The role of C*-algebras in infinite dimensional numerical linear algebraJun 08 1993This is a survey of four recent papers which deal with the relationship of simple C*-algebras to the problem of computing the spectra of self-adjoint operators in the general case, especially when the spectrum is not discrete. It is an expanded version ... More
Four Lectures on Noncommutative DynamicsJul 29 2002These lectures concern basic aspects of the theory of semigroups of endomorphisms of type $I$ factors that relate to causal dynamics, dilation theory, and the problem of classifying $E_0$-semigroups up to cocycle conjugacy. We give only a few proofs here; ... More
Discretized CCR algebrasNov 30 1992Jan 18 1993We discuss how the canonical commutation relations must be modified in order to make appropriate numerical models of quantum systems. The C*-algebras associated with the discretized CCRs are the non-commutative spheres of Bratteli, Elliott, Evans and ... More
Perspectives on theory at the interface of physics and biologyDec 30 2015Theoretical physics is the search for simple and universal mathematical descriptions of the natural world. In contrast, much of modern biology is an exploration of the complexity and diversity of life. For many, this contrast is prima facie evidence that ... More
Thinking about the brainMay 10 2002Jul 09 2002We all are fascinated by the phenomena of intelligent behavior, as generated both by our own brains and by the brains of other animals. As physicists we would like to understand if there are some general principles that govern the structure and dynamics ... More
Martian Methyl Chloride. A lesson in uncertaintyApr 16 2013The MSL Lander Curiosity has recently detected methyl halides coming from heated samples of Martian soil. This is reminiscent of similar findings in the Viking Lander spacecraft. In the 1970s a consensus developed quickly explaining the methyl halides ... More
Jonsson Cardinals, Erdős Cardinals, and the Core ModelJun 20 1997We show that every Jonsson cardinal is Ramsey in the Steel core model, provided that this model exists and there is no model with a Woodin cardinal. This basic result is improved in two directions. First, we prove the same result for delta-Jonsson and ... More
Language Support for Declarative Future CommitmentsAug 23 2011Sequential programming and work-flow programming are two useful, but radically different, ways of describing computational processing. Of the two, it is sequential programming that we teach all programmers and support by programming languages, whether ... More
Strongly maximal intersection-complete neural codes on grids are convexOct 19 2016The brain encodes spacial structure through a combinatorial code of neural activity. Experiments suggest such codes correspond to convex areas of the subject's environment. We present an intrinsic condition that implies a neural code may correspond to ... More
Overcoming FragilityOct 06 2006We examine the sensitivity and surface bias of convolved DGLV radiative and elastic loss in a realistic geometry including Bjorken expansion. We find that this more faithful treatment of the medium density is not a priori reproducible via fixed length ... More
Conclusions from a NAIVE Bayes Operator Predicting the Medicare 2011 Transaction Data SetFeb 20 2014Introduction: The United States Federal Government operates one of the worlds largest medical insurance programs, Medicare, to ensure payment for clinical services for the elderly, illegal aliens and those without the ability to pay for their care directly. ... More
Marginally trapped tubes generated from nonlinear scalar field initial dataJan 14 2009Dec 18 2009We show that the maximal future development of asymptotically flat spherically symmetric black hole initial data for a self-gravitating nonlinear scalar field, also called a Higgs field, contains a connected, achronal marginally trapped tube which is ... More
The Knotting-Unknotting Game played on Sums of Rational ShadowsJul 13 2011Jul 22 2011We consider the recently introduced knotting-unknotting game, in which two players take turns resolving crossings in a knot diagram which initially is missing all its crossing information. Once the knot is fully resolved, the winner is decided by whether ... More
A black hole with no marginally trapped tube asymptotic to its event horizonMay 28 2010We construct an example of a spherically symmetric black hole interior in which there is NO (spherically symmetric) marginally trapped tube asymptotic to the event horizon. The construction uses a self-gravitating massive scalar field matter model, and ... More
Zero Sets of H^p Functions in Convex Domains of Finite TypeFeb 11 2016We give a condition under which a divisor X in a bounded convex domain of finite type D in C^n is the zero set of a function in a Hardy space H^p(D) for some p \textgreater{} 0. This generalizes Varopoulos' result [Zero sets of H^p functions in several ... More
Measures and dynamics on Noetherian spacesFeb 03 2012Dec 20 2012We give an explicit description of all finite Borel measures on Noetherian topological spaces X, and characterize them as objects dual to a space of functions on X. We use these results to study the asymptotic behavior of continuous dynamical systems ... More
Bounding the minimal number of generators of an Azumaya algebraOct 08 2018A paper of U. First & Z. Reichstein proves that if $R$ is a commutative ring of dimension $d$, then any Azumaya algebra $A$ over $R$ can be generated as an algebra by $d+2$ elements, by constructing such a generating set, but they do not prove that this ... More
Asymptotic Stability I: Completely Positive MapsApr 30 2003Jan 26 2004We show that for every "locally finite" unit-preserving completely positive map P acting on a C*-algebra, there is a corresponding *-automorphism \alpha of another unital C*-algebra such that the two sequences P, P^2,P^3,... and \alpha, \alpha^2,\alpha^3,... ... More
Contextual Value-definiteness and the Kochen-Specker ParadoxDec 06 2005Compatibility between the realist tenants of value-definiteness and causality is called into question by several realism impossibility proofs in which their formal elements are shown to conflict. We review how this comes about in the Kochen-Specker and ... More