Results for "Christopher T. Reinhard"

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Earth as an ExoplanetApr 11 2018The search for habitable and inhabited environments beyond our planet commonly focuses on analogs to Earth, especially in the case of exoplanets. Observations from ground-based facilities, satellites, and spacecraft have yielded a rich collection of data ... More
A limited habitable zone for complex lifeFeb 13 2019The habitable zone (HZ) is defined as the range of distances from a host star within which liquid water, a key requirement for life, may exist at a planet's surface. Substantially more CO2 than present in Earth's modern atmosphere is required to maintain ... More
Qualitative shape representation based on the qualitative relative direction and distance calculus eOPRAmDec 20 2014This document serves as a brief technical report, detailing the processes used to represent and reconstruct simplified polygons using qualitative spatial descriptions, as defined by the eOPRAm qualitative spatial calculus.
Earth: Atmospheric Evolution of a Habitable PlanetMar 15 2018Our present-day atmosphere is often used as an analog for potentially habitable exoplanets, but Earth's atmosphere has changed dramatically throughout its 4.5 billion year history. For example, molecular oxygen is abundant in the atmosphere today but ... More
Atmospheric Seasonality as an Exoplanet BiosignatureJun 12 2018Current investigations of exoplanet biosignatures have focused on static evidence of life, such as the presence of biogenic gases like O2 or CH4. However, the expected diversity of terrestrial planet atmospheres and the likelihood of both false positives ... More
Rethinking CO Antibiosignatures in the Search for Life Beyond the Solar SystemMar 18 2019Some atmospheric gases have been proposed as counter indicators to the presence of life on an exoplanet if remotely detectable at sufficient abundance (i.e., antibiosignatures), informing the search for biosignatures and potentially fingerprinting uninhabited ... More
F-statistic search for white-dwarf binaries in the first Mock LISA Data ChallengeJul 01 2007The F-statistic is an optimal detection statistic for continuous gravitational waves, i.e., long-duration (quasi-)monochromatic signals with slowly-varying intrinsic frequency. This method was originally developed in the context of ground-based detectors, ... More
The Importance of UV Capabilities for Identifying Inhabited Exoplanets with Next Generation Space TelescopesJan 09 2018The strongest remotely detectable signature of life on our planet today is the photosynthetically produced oxygen (O2) in our atmosphere. However, recent studies of Earth's geochemical proxy record suggest that for all but the last ~500 million years, ... More
Unsupervised Learning with Stein's Unbiased Risk EstimatorMay 26 2018Learning from unlabeled and noisy data is one of the grand challenges of machine learning. As such, it has seen a flurry of research with new ideas proposed continuously. In this work, we revisit a classical idea: Stein's Unbiased Risk Estimator (SURE). ... More
Searching for Galactic White Dwarf Binaries in Mock LISA Data using an F-Statistic Template BankAug 26 2009Jan 07 2010We describe an F-statistic search for continuous gravitational waves from galactic white-dwarf binaries in simulated LISA Data. Our search method employs a hierarchical template-grid based exploration of the parameter space. In the first stage, candidate ... More
Improved search for galactic white dwarf binaries in Mock LISA Data Challenge 1B using an F-statistic template bankMay 14 2008Jun 27 2008We report on our F-statistic search for white-dwarf binary signals in the Mock LISA Data Challenge 1B (MLDC1B). We focus in particular on the improvements in our search pipeline since MLDC1, namely refinements in the search pipeline and the use of a more ... More
Towards femtosecond on-chip electronicsAug 01 2017To combine the advantages of ultrafast femtosecond optics with an on-chip communcation scheme, optical signals with a frequency of several hundreds of THz need to be down-converted to coherent electronic signals of GHz or less. So far, this has not been ... More
Exoplanet Biosignatures: Future DirectionsMay 23 2017Aug 08 2017Exoplanet science promises a continued rapid accumulation of new observations in the near future, energizing a drive to understand and interpret the forthcoming wealth of data to identify signs of life beyond our Solar System. The large statistics of ... More
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
"Super"-Dilatation Symmetry of the Top-Higgs SystemNov 12 2012Feb 06 2013The top-Higgs system, consisting of top quark (LH doublet, RH singlet), and Higgs boson kinetic terms, with gauge fields set to zero, has an exact (modulo total divergences) symmetry where both fermion and Higgs fields are shifted and mixed in a supersymmetric ... More
Conjecture on the Physical Implications of the Scale AnomalyOct 20 2005Oct 21 2005Murray Gell-Mann, after co-inventing QCD, recognized the interplay of the scale anomaly, the renormalization group, and the origin of the strong scale, Lambda_{QCD}. I tell a story, then elaborate this concept, and for the sake of discussion, propose ... More
Topcolor and the First Muon Collider (Talk presented at the Workshop on Physics at the First Muon Collider and at the Front End of the Muon Collider, Nov. 1997)Feb 02 1998We describe a class of models of electroweak symmetry breaking that involves strong dynamics and top quark condensation. A new scheme based upon a seesaw mechanism appears particularly promising. Various implications for the first-stage muon collider ... More
The Diffractive Quantum Limits of Particle CollidersFeb 22 2000Feb 23 2000Quantum Mechanics places limits on achievable transverse beam spot sizes of particle accelerators. We estimate this limit for a linear collider to be \Delta x > \hbar c f/E\delta_0 where f is the final focal length, E the beam energy, and \delta_0 the ... More
``Topcolor''; Invited talk presented at "Strongly Coupled Gauge Theories, 1996", Nagoya, Japan, Nov. 1996Feb 12 1997We review a class of dynamical models in which top condensation occurs at the weak scale, giving rise to the large top quark mass and other phenomena. This typically requires a color embedding, $SU(3)_c \rightarrow SU(3)_1\times SU(3)_2$. These models ... More
Dirac Branes and Anomalies/Chern-Simons terms in any DJul 07 2009Jul 14 2009The Dirac quantization procedure of a magnetic monopole can be used to derive the coefficient of the D=3 Chern-Simons term through a self-consistency argument, which can be readily generalized to any odd D. This yields consistent and covariant axial anomaly ... More
Topcolor Assisted TechnicolorNov 29 1994Dec 02 1994A condensate, $\overline{t}t$, arising from $O(TeV)$ scale ``topcolor,'' in addition to technicolor (and ETC) may naturally explain the gauge hierarchy, the large top quark mass, and contains a rich system of testable consequences. A triplet of strongly ... More
B--Physics in Hadron CollidersSep 21 1993The possibility of exploring the systematics of the spectroscopy, strong dynamics, and the weak and rare decay modes of b--quark systems at hadron colliders such as Fermilab, LHC and SSC, is discussed. A copious yield of $10^{10}$ detected $B$--mesons ... More
On D. Peterson's comparison formula for Gromov-Witten invariantsJun 07 2002Oct 13 2004We prove a formula of Dale Peterson comparing genus zero Gromov-Witten invariants of $G/P$ to those of $G/B$ using results of Atiyah-Bott and Ramanathan on canonical reductions of principal bundles.
Axion Induced Oscillating Electric Dipole Moment of the ElectronAug 17 2015Jan 20 2016A cosmic axion, via the electromagnetic anomaly, induces an oscillating electric dipole for the electron of frequency $m_a$ and strength $\sim$(few)$\times 10^{-32}$ e-cm, two orders of magnitude above the nucleon, and within a few orders of magnitude ... More
Axion Induced Oscillating Electric Dipole MomentsApr 06 2015Apr 10 2015The axion electromagnetic anomaly induces an oscillating electric dipole for {\em any} static magnetic dipole. Static electric dipoles do not produce oscillating magnetic moments. This is a low energy theorem which is a consequence of the space-time dependent ... More
Geometrical Renormalization Groups: Perfect Deconstruction ActionsMar 31 2003Apr 04 2003By combining two distinct renormalization group transformations, opposing scale transformations, we obtain a composite transformation which does not rescale the system, and drives it to a "geometrical" fixed point, controlling the effective geometry and ... More
Fractal Theory Space: Spacetime of Noninteger DimensionalityOct 08 2002Oct 29 2002We construct matter field theories in ``theory space'' that are fractal, and invariant under geometrical renormalization group (RG) transformations. We treat in detail complex scalars, and discuss issues related to fermions, chirality, and Yang-Mills ... More
Topological Solitons from DeConstructed Extra DimensionsSep 07 2001Dec 04 2001A topological monopole-like field configuration exists for Yang-Mills gauge fields in a 4+1 dimensions. When the extra dimension is compactified to 3+1 dimensions with periodic lattice boundary conditions, these objects reappear in the low energy effective ... More
Moment maps and geometric invariant theoryDec 06 2009Jun 29 2011These lectures centered around the Kempf-Ness theorem, which describes the equivalence between notions of quotient in symplectic and algebraic geometry. The text also describes connections to invariant theory, such existence of invariants in tensor products ... More
Bipolar jets produced by a spectroscopic binaryDec 09 2009We present evidence that the spectroscopically identified bipolar jets of the pre-main sequence binary KH 15D are a common product of the whole binary system, rather than being launched from either star individually. They may be launched from the innermost ... More
Natural Coronagraphic Observations of the Eclipsing T Tauri System KH 15D: Evidence for Accretion and Bipolar Outflow in a WTTSMay 24 2003We present high resolution (R $\sim$ 44,000) UVES spectra of the eclipsing pre-main sequence star KH 15D covering the wavelength range 4780 to 6810 {\AA} obtained at three phases: out of eclipse, near minimum light and during egress. The system evidently ... More
Theorem: A Static Magnetic N-pole Becomes an Oscillating Electric N-pole in a Cosmic Axion FieldJun 15 2016Jul 14 2016We show for the classical Maxwell equations, including the axion electromagnetic anomaly source term, that a cosmic axion field induces an oscillating electric N-moment for any static magnetic N-moment. This is a straightforward result, accessible to ... More
Complex Variability of the H$α$ Emission Line Profile of the T Tauri Binary System KH 15D: The Influence of Orbital Phase, Occultation by the Circumbinary Disk, and Accretion PhenomenaeApr 05 2012We have obtained 48 high resolution echelle spectra of the pre-main sequence eclipsing binary system KH~15D (V582 Mon, P = 48.37 d, $e$ $\sim$ 0.6, M$_{A}$ = 0.6 M$_{\odot}$, M$_{B}$ = 0.7 M$_{\odot}$). The eclipses are caused by a circumbinary disk seen ... More
Reply to "Comment on `Axion induced oscillating electric dipole moments' " [1]Oct 19 2015A recent paper of Flambaum, Roberts and Stadnik, [1], claims there is no induced oscillating electric dipole moment (OEDM), eg, for the electron, arising from the oscillating cosmic axion background via the anomaly. This claim is based upon the assumption ... More
The Yang-Mills heat flow on the moduli space of framed bundles on a surfaceNov 15 2002Feb 24 2004We study the analog of the Yang-Mills heat flow on the moduli space of framed bundles on a cut surface. Existence and convergence of the heat flow give a stratification of Morse type invariant under the action of the loop group. We use the stratification ... More
Exact Equivalence of the D=4 Gauged Wess-Zumino-Witten Term and the D=5 Yang-Mills Chern-Simons TermMar 08 2006Mar 10 2006We derive the full Wess-Zumino-Witten term of a gauged chiral lagrangian in D=4 by starting from a pure Yang-Mills theory of gauged quark flavor in a flat, compactified D=5. The theory is compactified such that there exists a B_5 zero mode, and supplemented ... More
Is the Higgs Boson Associated with Coleman-Weinberg Dynamical Symmetry Breaking?Jan 16 2014Jan 27 2014The Higgs mechanism may be a quantum phenomenon, i.e., a Coleman-Weinberg potential generated by the explicit breaking of scale symmetry in Feynman loops. We review the relationship of scale symmetry, trace anomalies, and emphasize the role of the renormalization ... More
"Super"-Dilatation Symmetry of the Top-Higgs SystemFeb 06 2013Feb 12 2013The top-Higgs system, consisting of top quark (LH doublet, RH singlet) and Higgs boson kinetic terms, with gauge fields set to zero, has an exact (modulo total divergences) symmetry where both fermion and Higgs fields are shifted and mixed in a supersymmetric ... More
Asymptotic behavior of quantum walks with spatio-temporal coin fluctuationsJan 23 2012Quantum walks subject to decoherence generically suffer the loss of their genuine quantum feature, a quadratically faster spreading compared to classical random walks. This intuitive statement has been verified analytically for certain models and is also ... More
Static Electric Dipole Polarizabilities of Na ClustersDec 22 1999The static electric dipole polarizability of $\mathrm{Na_N}$ clusters with even N has been calculated in a collective, axially averaged and a three-dimensional, finite-field approach for $2\le N \le 20$, including the ionic structure of the clusters. ... More
Addressing current challenges in cancer immunotherapy with mathematical and computational modelingJun 06 2017The goal of cancer immunotherapy is to boost a patient's immune response to a tumor. Yet, the design of an effective immunotherapy is complicated by various factors, including a potentially immunosuppressive tumor microenvironment, immune-modulating effects ... More
Practical adaptive quantum tomographyMay 17 2016We introduce a fast and accurate heuristic for adaptive tomography that addresses many of the limitations of prior methods. Previous approaches were either too computationally intensive or tailored to handle special cases such as single qubits or pure ... More
The Importance of 3D General Circulation Models for Characterizing the Climate and Habitability of Terrestrial Extrasolar PlanetsMar 12 2019While recently discovered exotic new planet-types have both challenged our imaginations and broadened our knowledge of planetary system workings, perhaps the most compelling objective of exoplanet science is to detect and characterize habitable and possibly ... More
Topology in the Bulk: Gauge Field Solitons in Extra DimensionsJul 27 2000Jul 28 2000Certain static soliton configurations of gauge fields in 4+1 dimensions correspond to the instanton in 4-Euclidean dimensions ``turned on its side,'' becoming a monopole in 4+1. The periodic instanton solution can be used with the method of images to ... More
Classification of affine vorticesJan 29 2013Jul 07 2015We prove a Hitchin-Kobayashi correspondence for affine vortices generalizing a result of Jaffe-Taubes for the action of the circle on the affine line. Namely, suppose a compact Lie group K has a Hamiltonian action on a Kaehler manifold X which is either ... More
Is the Higgs Boson Composed of Neutrinos?Jun 09 2015We show that conventional Higgs compositeness conditions can be achieved by the running of large Higgs-Yukawa couplings involving right-handed neutrinos that become active at $\sim 10^{13}- 10^{14}$ GeV. Together with a somewhat enhanced quartic coupling, ... More
The Index Formula on the Moduli of G-bundlesDec 08 2003Sep 05 2007We prove the formulae conjectured by the first author for the index of K-theory classes over the moduli stack of algebraic G-bundles on a smooth projective curve. The formulae generalise Verlinde's for line bundles and have Witten's integrals over the ... More
The Light Curve of the Weakly-Accreting T Tauri Binary KH 15D from 2005-10: Insights into the Nature of its Protoplanetary DiskJul 23 2010Photometry of the unique pre-main sequence binary system KH 15D is presented, spanning the years 2005-2010. This system has exhibited photometric variations and eclipses over the last 50 years caused by a precessing circumbinary disk. Advancement of the ... More
Eigenvalue Measurement of Topologically Protected Edge states in Split-Step Quantum WalksNov 23 2018We study topological phenomena of quantum walks by implementing a novel protocol that extends the range of accessible properties to the eigenvalues of the walk operator. To this end, we experimentally realise for the first time a split-step quantum walk ... More
Current-phase relation for Josephson effect through helical metalJul 31 2012Josephson junctions fabricated on the surface of three-dimensional topological insulators (TI) show a few unusual properties distinct from conventional Josephson junctions. In these devices, the Josephson coupling and the supercurrent are mediated by ... More
Derivatives of spin dynamics simulationsOct 19 2009We report analytical equations for the derivatives of spin dynamics simulations with respect to pulse sequence and spin system parameters. The methods described are significantly faster, more accurate and more reliable than the finite difference approximations ... More
The Newstead-Ramanan conjecture for Chern classesDec 21 2005Newstead and Ramanan conjectured the vanishing of the top (2g-1) Chern classes of the moduli space of stable, odd degree vector bundles of rank 2 on a Riemann surface of genus g. This was proved by Gieseker [G], while an analogue in rank 3 was recently ... More
Evolutionary Events in a Mathematical Sciences Research Collaboration NetworkMar 23 2012Feb 04 2015This study examines long-term trends and shifting behavior in the collaboration network of mathematics literature, using a subset of data from Mathematical Reviews spanning 1985-2009. Rather than modeling the network cumulatively, this study traces the ... More
Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its EnvironmentMay 22 2017Here we review how environmental context can be used to interpret whether O2 is a biosignature in extrasolar planetary observations. This paper builds on the overview of current biosignature research discussed in Schwieterman et al. (2017), and provides ... More
Exoplanet Biosignatures: A Review of Remotely Detectable Signs of LifeMay 16 2017Jun 25 2018In the coming years and decades, advanced space- and ground-based observatories will allow an unprecedented opportunity to probe the atmospheres and surfaces of potentially habitable exoplanets for signatures of life. Life on Earth, through its gaseous ... More
Computing the Degenerate Ground Space of Gapped Spin Chains in Polynomial TimeFeb 24 2015May 11 2016Given a gapped Hamiltonian of a spin chain, we give a polynomial-time algorithm for finding the degenerate ground space projector. The output is an orthonormal set of matrix product states that approximate the true ground space projector up to an inverse ... More
Superheavy nuclei in selfconsistent nuclear calculationsOct 23 1996The shell structure of superheavy nuclei is investigated within various parametrizations of relativistic and nonrelativistic nuclear mean field models. The heaviest known even-even nucleus 264Hs is used as a benchmark to estimate the predictive value ... More
Shell Corrections of Superheavy Nuclei in Self-Consistent CalculationsOct 15 1999Shell corrections to the nuclear binding energy as a measure of shell effects in superheavy nuclei are studied within the self-consistent Skyrme-Hartree-Fock and Relativistic Mean-Field theories. Due to the presence of low-lying proton continuum resulting ... More
False negatives for remote life detection on ocean-bearing planets: Lessons from the early EarthFeb 03 2017Ocean-atmosphere chemistry on Earth has undergone dramatic evolutionary changes through its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures. Though a great deal of work has ... More
Dispersion Relations in Gauge Theories with ConfinementNov 01 1995The analytic structure of {\it physical} amplitudes is considered for gauge theories with confinement of excitations corresponding to the elementary fields. Confinement is defined in terms of the BRST algebra. BRST-invariant, local, composite fields are ... More
A physical derivation of the Kerr-Newman black hole solutionOct 02 2013According to the no-hair theorem, the Kerr-Newman black hole solution represents the most general asymptotically flat, stationary (electro-) vacuum black hole solution in general relativity. The procedure described here shows how this solution can indeed ... More
Ends and TanglesOct 14 2015Dec 09 2015We show that an arbitrary infinite graph can be compactified by its ${\aleph_0}$-tangles in much the same way as the ends of a locally finite graph compactify it in its Freudenthal compactification. In general, the ends then appear as a subset of its ... More
Bringing the LHC and ATLAS to a regional planetariumSep 13 2011An outreach effort has started at Michigan State University to bring particle physics, the Large Hadron Collider, and the ATLAS experiment to a general audience at the Abrams planetarium on the MSU campus. A team of undergraduate students majoring in ... More
Relativistic Nucleus-Nucleus Collisions: A Connection between the Strangeness-Maximum at $\sqrt{s} \approx$ 7 GeV and the QCD Critical Endpoint from Lattice StudiesApr 15 2004A steep maximum occurs in the Wroblewski ratio between strange and non-strange quarks created in central nucleus-nucleus collisions, of about A=200, at the lower SPS energy $\sqrt{s} \approx$ 7 GeV. By analyzing hadronic multiplicities within the grand ... More
Relativistic Nucleus-Nucleus Collisions: from the BEVALAC to RHICMay 12 2004I briefly describe the initial goals of relativistic nuclear collisions research, focusing on the LBL Bevatron/Bevalac facility in the 1970's. An early concept of high hadronic density fireball formation, and subsequent isentropic decay (preserving information ... More
Gravitational fields of rotating disks and black holesDec 14 1999The two known exact solutions of Einstein's field equations describing rotating objects of physical significance - a black hole and a rigidly rotating disk of dust - are discussed using a single mathematical framework related to Jacobi's inversion problem. ... More
The Parton-Hadron Phase Transition in Central Nuclear Collisions at the CERN SPSJan 26 1999Jan 27 1999A selection of recent data referring to Pb+Pb collisions at the SPS CERN energy of 158 GeV per nucleon is presented which might describe the state of highly excited strongly interacting matter both above and below the deconfinement to hadronization (phase) ... More
Existence of solutions for semilinear elliptic boundary value problems on arbitrary open setsJul 31 2015We show the existence of a weak solution of a semilinear elliptic Dirichlet problem on an arbitrary open set. We make no assumptions about the open set, very mild regularity assumptions on the semilinearity, plus a coerciveness assumption which depends ... More
Reduction of Coupling ParametersNov 01 1995The general theory of the reduction in the number of coupling parameters is discussed. The method involves renormalization group invariant relations between couplings. It is more general than the imposition of symmetries. There are reduced theories with ... More
On the Analytic Structure of Hadronic Amplitudes in QCDDec 21 1992Analytic properties of hadronic amplitudes are discussed within the framework of QCD as formulated on the basis of the BRST algebra. Local, composite fields are introduced for hadrons. Given confinement, it is shown that hadronic amplitudes have no thresholds ... More
Isovariant mappings of degree 1 and the Gap HypothesisApr 03 2009Unpublished results of S Straus and W Browder state that two notions of homotopy equivalence for manifolds with smooth group actions - isovariant and equivariant - often coincide under a condition called the Gap Hypothesis; the proofs use deep results ... More
Intensional Models for the Theory of TypesAug 23 2006In this paper we define intensional models for the classical theory of types, thus arriving at an intensional type logic ITL. Intensional models generalize Henkin's general models and have a natural definition. As a class they do not validate the axiom ... More
Tree setsDec 11 2015Feb 27 2017We study an abstract notion of tree structure which lies at the common core of various tree-like discrete structures commonly used in combinatorics: trees in graphs, order trees, nested subsets of a set, tree-decompositions of graphs and matroids etc. ... More
Variational description of multi-fluid hydrodynamics: Coupling to gauge fieldsMar 29 2005In this work we extend our previously developed formalism of Newtonian multi-fluid hydrodynamics to allow for coupling between the fluids and the electromagnetic and gravitational field. This is achieved within the convective variational principle by ... More
Quasistationary collapse to the extreme Kerr black holeMay 14 2004It is shown that the extreme Kerr black hole is the only candidate for a black hole limit of rotating fluid bodies in equilibrium.
On Confinement, Chiral Symmetry Breaking, and the UA(1) anomaly in Functional ApproachesFeb 15 2011The so-called decoupling and scaling solutions of functional equations of Landau gauge Yang-Mills theory are briefly reviewed. In both types of solutions the positivity violation seen in the gluon propagator is taken as an indication of gluon confinement. ... More
On the gap of finite metric spaces of p-negative typeAug 05 2010Let (X,d) be a metric space of p-negative type. Recently I. Doust and A. Weston introduced a quantification of the p-negative type property, the so called gap {\Gamma} of X. This talk introduces some formulas for the gap {\Gamma} of a finite metric space ... More
Quasi-stationary routes to the Kerr black holeDec 01 2006Quasi-stationary (i.e. parametric) transitions from rotating equilibrium configurations of fluid bodies to rotating black holes are discussed. For the idealized model of a rotating disc of dust, analytical results derived by means of the "inverse scattering ... More
QCD Green Functions and their Application to Hadron PhysicsNov 07 2006Apr 20 2007In a functional approach to QCD the infrared behaviour of Landau gauge Green functions is investigated. It can be proven that the ghost Dyson-Schwinger equation implies the Gribov-Zwanziger horizon condition. Its relation to the Kugo-Ojima confinement ... More
The search for continuous gravitational waves: metric of the multi-detector F-statisticJun 20 2006Oct 09 2006We develop a general formalism for the parameter-space metric of the multi-detector F-statistic, which is a matched-filtering detection statistic for continuous gravitational waves. We find that there exists a whole family of F-statistic metrics, parametrized ... More
Forcing finite minors in sparse infinite graphs by large-degree assumptionsSep 24 2012Developing further Stein's recent notion of relative end degrees in infinite graphs, we investigate which degree assumptions can force a locally finite graph to contain a given finite minor, or a finite subgraph of given minimum degree. This is part of ... More
Massive Black Holes: Evidence, Demographics and Cosmic EvolutionOct 31 2014The article summarizes the observational evidence for the existence of massive black holes, as well as the current knowledge about their abundance, their mass and spin distributions, and their cosmic evolution within and together with their galactic hosts. ... More
Slowly Rotating Two-Fluid Neutron Star ModelOct 15 1999We study stationary axisymmetric configurations of a star model consisting of two barotropic fluids, which are uniformly rotating at two different rotation rates. Analytic approximate solutions in the limit of slow rotation are obtained with the classical ... More
The parton to hadron phase transition observed in Pb+Pb collisions at 158 GeV per nucleonMay 05 1999Hadronic yields and yield ratios observed in Pb+Pb collisions at the SPS energy of 158 GeV per nucleon are known to resemble a thermal equilibrium population at T=180 +/- 10 MeV, also observed in elementary e+ + e- to hadron data at LEP. We argue that ... More
Confinement & Chiral Symmetry Breaking: The fundamental problems of hadron physicsJul 30 2009Some of the difficulties arising when one tries to understand confinement as well as dynamical and anomalous chiral symmetry breaking are reviewed. Criteria to be fulfilled by a successful and complete picture of these phenomena are presented, and a few ... More
Reduction of Dual TheoriesAug 10 1998Sep 10 1998In view of the presence of a superpotential, the dual of a gauge theory like SQCD contains two coupling parameters. The method of the Reduction of Couplings is used in order to express the parameter of the superpotential in terms of the dual gauge coupling. ... More
The rigidly rotating disk of dust and its black hole limitMar 26 1997The exact global solution of the Einstein equations [Neugebauer & Meinel, Phys. Rev. Lett. 75 (1995) 3046] describing a rigidly rotating, self-gravitating disk is discussed. The underlying matter model is a perfect fluid in the limit of vanishing pressure. ... More
Polarization in Hyperon Photo- and Electro- ProductionFeb 07 2008Multiple polarization observables must be measured to access the amplitude structure of pseudoscalar meson photoproduction off the proton. The hyperon-producing reactions are especially attractive to study, since the weak decays allow straightforward ... More
Selected Topics from Top Mass Measurements at the TevatronDec 07 2016The most recent results of the top-quark mass measurements at the Tevatron at Fermilab are presented. Data were collected in proton-antiproton collisions at sqrt{s}=1.96 TeV by the CDF and D0 experiments. Top quark mass measurements in the lepton+jets, ... More
Superconvergence, Confinement and DualityNov 02 1995Arguments for the confinement of transverse gauge field excitations, which are based upon superconvergence relations of the propagator, and upon the BRST algebra, are reviewed and applied to supersymmetric models. They are shown to be in agreement with ... More
Analytic Structure of Amplitudes in Gauge Theories with ConfinementDec 05 1994For gauge theories with confinement, the analytic structure of amplitudes is explored. It is shown that the analytic properties of physical amplitudes are the same as those obtained on the basis of an effective theory involving only the composite, physical ... More
A Survey on Migration-Selection Models in Population GeneticsSep 10 2013This survey focuses on the most important aspects of the mathematical theory of population genetic models of selection and migration between discrete niches. Such models are most appropriate if the dispersal distance is short compared to the scale at ... More
Locally finite graphs with ends: a topological approachDec 21 2009Jul 10 2012This paper is intended as an introductory survey of a newly emerging field: a topological approach to the study of locally finite graphs that crucially incorporates their ends. Topological arcs and circles, which may pass through ends, assume the role ... More
To which extent is the membrane potential in a neuron between successive spikes adequately modelled by a (continuous) semimartingale?Aug 25 2010We consider $p$-variations in some membrane potential data --viewed as a function of the step size in case where $p$ is fixed, or viewed as a function of $p$ in case where the step size is fixed-- and compare their shape with results in Ait-Sahalia and ... More
Abstract Separation SystemsJun 15 2014Apr 17 2017Abstract separation systems provide a simple general framework in which both tree-shape and high cohesion of many combinatorial structures can be expressed, and their duality proved. Applications range from tangle-type duality and tree structure theorems ... More
Local decay of $C_0$-semigroups with a possible singularity of logarithmic type at zeroOct 29 2017We prove decay rates for a vector-valued function $f$ of a non-negative real variable with bounded weak derivative, under rather general conditions on the Laplace transform $\hat{f}$. This generalizes results of Batty-Duyckaerts (2008) and other authors ... More
The Z=82 shell closure in neutron-deficient Pb isotopesOct 23 2001Recent mass measurements show a substantial weakening of the binding energy difference delta_{2p} (Z,N) = E(Z-2,N) - 2 E(Z,N) + E(Z+2,N) in the neutron-deficient Pb isotopes. As delta_{2p} is often attributed to the size of the proton magic gap, it might ... More
Mapping exchange in relativistic Hartree-FockJan 23 2003We show that formally for the standard ansatz relativistic point-coupling mean-field (RMF-PC) model a lagrangian density L is not equivalent in Hartree and Hartree-Fock approximations. The equivalency can be achieved only if we use a ``complete'' ansatz ... More
Identifying Word Translations in Non-Parallel TextsMay 22 1995Common algorithms for sentence and word-alignment allow the automatic identification of word translations from parallel texts. This study suggests that the identification of word translations should also be possible with non-parallel and even unrelated ... More
A norm - inequality related to affine regular hexagonsJun 30 2011Let $(E, \lVert . \rVert)$ be a two-dimensional real normed space with unit sphere $S = \{x \in E, \lVert x \rVert = 1\}$. The main result of this paper is the following: Consider an affine regular hexagon with vertex set $H = \{\pm v_1, \pm v_2, \pm ... More