Results for "Philipp Bender"

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Supraferromagnetic correlations in clusters of magnetic nanoflowersJul 05 2019Magnetic nanoflowers are densely packed aggregates of superferromagnetically coupled iron oxide nanocrystallites, which excel during magnetic hyperthermia experiments. Here, we investigate the nature of the moment coupling within a powder of such nanoflowers ... More
The magnetic structure factor of correlated nanoparticle moments in small-angle neutron scatteringApr 12 2019Here, we derive expressions for the magnetic small-angle neutron scattering (SANS) cross section of magnetic nanoparticle ensembles under consideration of a magnetic structure factor. We show that for structurally disordered ensembles with correlated ... More
Dipolar-coupled moment correlations in clusters of magnetic nanoparticlesMar 05 2018Oct 30 2018Here, we investigate the nature of the moment coupling between 10-nm DMSA-coated magnetic nanoparticles, in both colloidal dispersion and in powder form. The individual iron oxide cores were composed of > 95% maghemite and agglomerated to clusters. At ... More
Evolutionary Mechanics: new engineering principles for the emergence of flexibility in a dynamic and uncertain worldJan 21 2011Engineered systems are designed to deftly operate under predetermined conditions yet are notoriously fragile when unexpected perturbations arise. In contrast, biological systems operate in a highly flexible manner; learn quickly adequate responses to ... More
Time discretization and Markovian iteration for coupled FBSDEsJan 21 2008In this paper we lay the foundation for a numerical algorithm to simulate high-dimensional coupled FBSDEs under weak coupling or monotonicity conditions. In particular, we prove convergence of a time discretization and a Markovian iteration. The iteration ... More
A Revised Parallel-Sequence Morphological Classification of Galaxies: Structure and Formation of S0 and Spheroidal GalaxiesOct 19 2011We update van den Bergh's parallel sequence galaxy classification in which S0 galaxies form a sequence S0a-S0b-S0c that parallels the sequence Sa-Sb-Sc of spiral galaxies. The ratio B/T of bulge to total light defines the position of a galaxy in each ... More
A general non-existence result for linear BSDEs driven by Gaussian processesSep 08 2015Jan 19 2016In this paper, we study linear backward stochastic differential equations driven by a class of centered Gaussian non-martingales, including fractional Brownian motion with Hurst parameter $H\in (0,1)\setminus \{\frac12\}$. We show that, for every choice ... More
Measurable cardinals and good $Σ_1(κ)$-wellorderingsApr 03 2017We study the influence of the existence of large cardinals on the existence of wellorderings of power sets of infinite cardinals $\kappa$ with the property that the collection of all initial segments of the wellordering is definable by a $\Sigma_1$-formula ... More
Asymptotic enumeration of labelled graphs with a given genusDec 23 2009Mar 14 2010We enumerate rooted 2-connected and 3-connected surface maps with respect to vertices and edges. We also derive the bivariate version of the large face-width result for random 3-connected maps. These results are then used to derive asymptotic formulas ... More
Calculation of the Hidden Symmetry Operator for a $\cP\cT$-Symmetric Square WellJan 18 2006It has been shown that a Hamiltonian with an unbroken $\cP\cT$ symmetry also possesses a hidden symmetry that is represented by the linear operator $\cC$. This symmetry operator $\cC$ guarantees that the Hamiltonian acts on a Hilbert space with an inner ... More
Locally Restricted Sequential Structures and Runs of a Subcomposition in Integer CompositionsMay 13 2016We study part sizes of supercritical locally restricted sequential structures. This extends previous results about locally restricted integer compositions and part sizes in smooth supercritical compositional structures. Applications are given for runs ... More
Unbounded C-symmetries and their nonuniquenessJul 05 2012Aug 14 2012It is shown that if the C operator for a PT-symmetric Hamiltonian with simple eigenvalues is not unique, then it is unbounded. Apart from the special cases of finite-matrix Hamiltonians and Hamiltonians generated by differential expressions with PT-symmetric ... More
Quantum disorder in the spatially completely anisotropic triangular lattice I: Heisenberg $S=1/2$ antiferromagnetMay 09 2012Jan 29 2013Spin liquids occuring in 2D frustrated spin systems were initially assumed to appear at strongest frustration, but evidence grows that they more likely intervene at transitions between two different types of order. To identify if this is more general, ... More
Proceedings of the Data For Good Exchange 2016Sep 30 2016Oct 28 2016These are the proceedings of the Data For Good Exchange 2016, which was held in New York, NY, on September 26th 2016.
Three-loop corrections to the mass of the light Higgs boson in the MSSMJul 30 2010The Minimal Supersymmetric extension of the Standard Model (MSSM) predicts the existence of a light neutral Higgs boson. Once found at the LHC, its mass will immediately become a precision observable. The theoretical value of the Higgs mass Mh is subject ... More
Absorption Line Studies in the HaloSep 25 2003Significant progress has been made over the last few years to explore the gaseous halo of the Milky Way by way of absorption spectroscopy. I review recent results on absorption line studies in the halo using various instruments, such as the Far Ultraviolet ... More
On the Evolution and Appearance of a Surviving Companion after a Type Ia Supernova ExplosionMar 31 2003One promising method to test progenitor models for Type Ia supernovae is to identify surviving companion stars in historical supernova remnants. A surviving companion will have been strongly affected by its interaction with the supernova ejecta. Here ... More
Relevance distributions across Bradford Zones: Can Bradfordizing improve search?May 02 2013The purpose of this paper is to describe the evaluation of the effectiveness of the bibliometric technique Bradfordizing in an information retrieval (IR) scenario. Bradfordizing is used to re-rank topical document sets from conventional abstracting & ... More
Harmonics Generation in Ultra-Thin Nanofilms Irradiated by Intense Nonrelativistic Short Laser PulseFeb 08 2014The problem of harmonics generation in nanotargets is considered at the range of parameters (a nanotarget diameter and a pump laser intensity) when the oscillation amplitude of an electron in a target is much larger than the target width. Electron motion ... More
When is scalar multiplication decidable?May 29 2015Mar 21 2019Let $K$ be a subfield of $\mathbb{R}$. The theory of $\mathbb{R}$ viewed as an ordered $K$-vector space and expanded by a predicate for $\mathbb{Z}$ is decidable if and only if $K$ is a real quadratic field.
Continuous Shearlet Tight FramesJan 10 2010Based on the shearlet transform we present a general construction of continuous tight frames for $L^2(\mathbb{R}^2)$ from any sufficiently smooth function with anisotropic moments. This includes for example compactly supported systems, piecewise polynomial ... More
Notes on socio-economic transparency mechanismsJun 15 2016Clearly, socio-economic freedom requires some extent of transparency regarding the implications of choices. In this paper, we review some established mechanisms for achieving such transparency, without any claim to completeness, and briefly discuss potential ... More
Relatively bounded perturbations of J-non-negative operatorsMar 10 2019We improve known perturbation results for self-adjoint operators in Hilbert spaces and use these to prove spectral enclosures for $J$-self-adjoint operator matrices and perturbation theorems for $J$-non-negative operators. The results are applied to singular ... More
Algorithms for Convex Quadratic ProgrammingSep 18 2014The main contribution of this thesis is the development of a new algorithm for solving convex quadratic programs. It consists in combining the method of multipliers with an infeasible active-set method. Our approach is iterative. In each step we calculate ... More
The Mg-sigma Relation of Elliptical Galaxies at Various RedshiftsJan 15 1997The correlation between the Mg absorption index and the velocity dispersion (sigma) of local elliptical galaxies is very tight. Because the Mg absorption depends on both metallicity and age of the underlying stellar population the observed Mg-sigma relation ... More
Axiomatic Description of Lefschetz Type Equivariant Homotopy InvariantsJan 30 2013We describe generators of universal Lefschetz groups consisting of self-maps of equivariant 1-spheres. This allows to formulate a normalization axiom which, together with the usual axioms, determines an equivariant Lefschetz number uniquely. We apply ... More
Are topic-specific search term, journal name and author name recommendations relevant for researchers?Aug 19 2014Aug 31 2014In this paper we describe a case study where researchers in the social sciences (n=19) assess topical relevance for controlled search terms, journal names and author names which have been compiled automatically by bibliometric-enhanced information retrieval ... More
Proceedings of the Data For Good Exchange 2016Sep 30 2016Oct 10 2016These are the proceedings of the Data For Good Exchange 2016, which was held in New York, NY, on September 26th 2016.
Molecular Gas in the Galactic Halo and BeyondSep 12 2001I review recent observations of molecular gas in the halo of the Milky Way and in the Magellanic Clouds. Far-ultraviolet absorption line studies of molecular hydrogen (H_2) with ORFEUS and FUSE have unveiled the presence of a diffuse molecular hydrogen ... More
ORFEUS II echelle spectra : H_2 measurements in the Magellanic CloudsMay 12 2000More than 20 years after the Copernicus satellite, ORFEUS allows the investigation of molecular hydrogen (H_2) in the diffuse interstellar medium by way of FUV absorption spectroscopy once again. This time, targets in the Magellanic Clouds were also observed, ... More
Updated estimate of the number of edges in induced subgraphs of a special distance graphFeb 06 2018In this article, the author proposes a new approach for the estimating of the number of edges in induced subgraphs of a special distance graph. Author significantly improves previous estimates and suggests a new approach to obtaining better ones.
Constructing smooth and fully faithful tropicalizations for Mumford curvesMay 29 2018The tropicalization of an algebraic variety X is a combinatorial shadow of X, which is sensitive to a closed embedding of X into a toric variety. Given a good embedding, the tropicalization can provide a lot of information about X. We construct two types ... More
Updated estimate of the number of edges in induced subgraphs of a special distance graphFeb 06 2018Feb 15 2018In this article, the author proposes a new approach for the estimating of the number of edges in induced subgraphs of a special distance graph. Author significantly improves previous estimates and suggests a new approach to obtaining better ones.
Perfect subsets of generalized Baire spaces and long gamesMar 29 2017Jun 13 2017We extend Solovay's theorem about definable subsets of the Baire space to the generalized Baire space ${}^\lambda\lambda$, where $\lambda$ is an uncountable cardinal with $\lambda^{<\lambda}=\lambda$. In the first main theorem, we show that that the perfect ... More
Continuous reducibility and dimension of metric spacesMar 29 2017Jun 13 2017If $(X,d)$ is a Polish metric space of dimension $0$, then by Wadge's lemma, no more than two Borel subsets of $X$ can be incomparable with respect to continuous reducibility. In contrast, our main result shows that for any metric space $(X,d)$ of positive ... More
A characterization of arithmetical invariants by the monoid of relationsFeb 22 2010Mar 03 2010The investigation and classification of non-unique factorization phenomena have attracted some interest in recent literature. For finitely generated monoids, S.T. Chapman and P. Garcia-Sanchez, together with several co-authors, derived a method to calculate ... More
A characterization of arithmetical invariants by the monoid of relations II: The monotone catenary degree and applications to semigroup ringsApr 02 2011The investigation and classification of non-unique factorization phenomena has attracted some interest in recent literature. For finitely generated monoids, S.T. Chapman and P.A. Garc\'ia-S\'anchez, together with several co-authors, derived a method to ... More
Cosmological perturbation theory with York timeNov 10 2015One method to overcome the notorious problem of time in the quantisation of gravity is the identification of a physically preferred time parameter, a promising candidate being so-called `York time'. The dynamical equations for matter and spatial geometry ... More
Expansions of the ordered additive group of real numbers by two discrete subgroupsJul 25 2014May 26 2015The theory of $(\mathbb{R},<,+,\mathbb{Z},\mathbb{Z} a)$ is decidable if $a$ is quadratic. If $a$ is the golden ratio, $(\mathbb{R},<,+,\mathbb{Z},\mathbb{Z} a)$ defines multiplication by $a$. The results are established by using the Ostrowski numeration ... More
Eigenvalues in gaps of selfadjoint operators in Pontryagin spacesNov 13 2011Given an open real interval \Delta\ and two selfadjoint operators A_1, A_2 in a \Pi_\kappa-space with n-dimensional resolvent difference we show that the difference of the total multiplicities of the eigenvalues of A_1 and A_2 in \Delta\ is at most n+2\kappa. ... More
The Tate-Voloch Conjecture in a Power of a Modular CurveOct 11 2012Jan 29 2013Let $p$ be a prime. Tate and Voloch proved that a point of finite order in the algebraic torus cannot be $p$-adically too close to a fixed subvariety without lying on it. The current work is motivated by the analogy between torsion points on semi-abelian ... More
Torsion Points on Elliptic Curves in Weierstrass FormMay 23 2011We prove that there are only finitely many complex numbers $a$ and $b$ with $4a^3+27b^2\not=0$ such that the three points $(1,*),(2,*),$ and $(3,*)$ are simultaneously torsion on the elliptic curve defined in Weierstrass form by $y^2=x^3+ax+b$. This gives ... More
Expansions of subfields of the real field by a discrete setDec 16 2010Aug 16 2011Let K be a subfield of the real field, D be a discrete subset of K and f : D^n -> K be a function such that f(D^n) is somewhere dense. Then (K,f) defines the set of integers. We present several applications of this result. We show that K expanded by predicates ... More
Cold gas accretion by high-velocity clouds and their connection to QSO absorption-line systemsNov 07 2011Mar 13 2012We combine HI 21cm observations of the Milky Way, M31, and the local galaxy population with QSO absorption-line measurements to geometrically model the three-dimensional distribution of infalling neutral gas clouds (HVCs) in the extended halos of low-redshift ... More
Dimensional Reduction Applied to Non-Supersymmetric TheoriesOct 12 2007We consider regularisation of a Yang-Mills theory by Dimensional Reduction (DRED). In particular, the anomalous dimensions of fermion masses and gauge coupling are computed to four-loop order. We put special emphasis on the treatment of evanescent couplings ... More
F_2^bbbar measurement at ZEUSJul 05 2010Two recent measurements of beauty production in deep inelastic scattering based on data collected by the ZEUS detector are summarised. In the first one, the beauty fraction in the data was obtained from events with a muon and a jet. In the second one, ... More
Classification of materials with divergent magnetic Grüneisen parameterSep 07 2016At any quantum critical point (QCP) with a critical magnetic field $H_c$, the magnetic Gr\"uneisen parameter $\Gamma_{\rm H}$, which equals the adiabatic magnetocaloric effect, is predicted to show characteristic signatures such as a divergence, sign ... More
Grüneisen parameter studies on heavy fermion quantum criticalityAug 17 2016The Gr\"uneisen parameter, experimentally determined from the ratio of thermal expansion to specific heat, quantifies the pressure dependence of characteristic energy scales of matter. It is highly enhanced for Kondo lattice systems, whose properties ... More
Phase Retrieval from 4N-4 MeasurementsMar 19 2014We prove by means of elementary methods that phase retrieval of complex polynomials p of degree less than N is possible with 4N-4 phaseless Fourier measurements of p and p'. In addition, we provide an associated algorithm and prove that it recovers p ... More
Finding Linear Dependencies in Integration-By-Parts Equations: A Monte Carlo ApproachSep 27 2013Feb 11 2014The reduction of a large number of scalar integrals to a small set of master integrals via Laporta's algorithm is common practice in multi-loop calculations. It is also a major bottleneck in terms of running time and memory consumption. It involves solving ... More
Constructing experimental indicators for Open Access documentsOct 11 2006The ongoing paradigm change in the scholarly publication system ('science is turning to e-science') makes it necessary to construct alternative evaluation criteria/metrics which appropriately take into account the unique characteristics of electronic ... More
Gas Accretion onto the Milky WayDec 01 2016The Milky Way is surrounded by large amounts of gaseous matter that are slowly being accreted over cosmic timescales to support star formation in the disk. The corresponding gas-accretion rate represents a key parameter for the past, present, and future ... More
Ultrafast infrared spectroscopy with single molecular ionsSep 18 2018We propose a method to investigate the vibrational dynamics of a single polyatomic molecular ion that is co-trapped with an atomic ion. Quantum logic techniques will be used to detect the recoil of a single photon absorption event in the molecule on the ... More
Discrete-Time Dynamic Noncooperative Game TheorySep 18 2014Dynamic noncooperative game theory is a field of mathematics and economics in which a lot of research is being carried out at present featuring a great number of applications in many different areas of economics and management science like capital accumulation ... More
Stochastic cosmic ray sources and the TeV break in the all-electron spectrumSep 13 2018Nov 22 2018Despite significant progress over more than 100 years, no accelerator has been unambiguously identified as the source of the locally measured flux of cosmic rays. High-energy electrons and positrons are of particular importance in the search for nearby ... More
Tropical Hodge numbers of non-archimedean curvesJun 19 2017Mar 26 2018We study the tropical Dolbeault cohomology of non-archimedean curves as defined by Chambert-Loir and Ducros. We give a precise condition for when this cohomology satisfies Poincar\'e duality. The condition is always satisfied when the residue field of ... More
Torsion-free, divisible, and Mittag-Leffler modulesJan 06 2013We study (relative) K-Mittag-Leffler modules, with emphasis on the class K of absolutely pure modules. A final goal is to describe the K-Mittag-Leffler abelian groups as those that are, modulo their torsion part, aleph_1-free, Cor.6.12. Several more general ... More
Continuous Shearlet Frames and Resolution of the Wavefront SetSep 21 2009Dec 13 2009In recent years directional multiscale transformations like the curvelet- or shearlet transformation have gained considerable attention. The reason for this is that these transforms are - unlike more traditional transforms like wavelets - able to efficiently ... More
Implications of positive formulas in modules (RIMS)Apr 12 2019In this survey the role of implications of positive formulas -- finitary and infinitary -- is dicussed, in general and in module categories, where they seem of particular importance. A list of algebraic examples is given, some old, some rather new, and ... More
Entropy production as change in observational entropyJun 24 2019The second law of nonequilibrium thermodynamics within the open system paradigm (a small system coupled to one or multiple baths) is derived. This is done by showing positivity of entropy production for arbitrary Hamiltonian dynamics for a large class ... More
Detection of Geometric Structures by an Optimally Subsampled Shearlet System in Noisy Digital ImagesMar 30 2015Apr 23 2015We provide a statistical analysis of the ability of digitized continuous shearlet systems to detect objects embedded in white noise. We analyze the possibility to subsample the shearlet transform and obtain a subset of significantly reduced cardinality ... More
Shearlet approximation of functions with discontinuous derivativesAug 03 2015Jan 12 2016We demonstrate that shearlet systems yield superior $N$-term approximation rates compared with wavelet systems of functions whose first or higher order derivatives are smooth away from smooth discontinuity curves. We will also provide an improved estimate ... More
Small Height and Infinite Non-Abelian ExtensionsSep 27 2011Jan 29 2013Let $E$ be an elliptic curve defined over the rationals without complex multiplication. The field $F$ generated by all torsion points of $E$ is an infinite, non-abelian Galois extension of the rationals which has unbounded, wild ramification above all ... More
Effective Height Upper Bounds on Algebraic ToriJan 16 2012The main emphasis will be on height upper bounds in the algebraic torus G^{n}_{m}. By height we will mean the absolute logarithmic Weil height. Section 3.2 contains a precise definition of this and other more general height functions. The first appendix ... More
Constructing smooth and fully faithful tropicalizations for Mumford curvesMay 29 2018Apr 03 2019The tropicalization of an algebraic variety X is a combinatorial shadow of X, which is sensitive to a closed embedding of X into a toric variety. Given a good embedding, the tropicalization can provide a lot of information about X. We construct two types ... More
End spaces of graphs are normalNov 20 2009We show that the topological space of any infinite graph and its ends is normal. In particular, end spaces themselves are normal.
Error boundedness of Correction Procedure via Reconstruction / Flux ReconstructionJun 05 2018We study the long time error behaviour of correction procedure via reconstruction / flux reconstruction methods to hyperbolic conservation laws. We show that not only the choice of the numerical flux (upwind or central) affects the growth rate and asymptotic ... More
Using the singular value decomposition to extract 2D correlation functions from scattering patternsMar 26 2019Jun 21 2019We apply the truncated singular value decomposition (SVD) to extract the underlying 2D correlation functions from small-angle scattering patterns. We test the approach by transforming the simulated data of ellipsoidal particles and show that also in case ... More
A novel processing pipeline for optical multi-touch surfacesJan 08 2013In this thesis a new approach for touch detection on optical multi-touch devices is proposed that exploits the fact that the camera images reveal not only the actual touch points but also objects above the screen such as the hand or arm of a user. The ... More
Measurement of VZ production cross sections in Z -> bb decay channels in pp collisions at 8 TeVAug 21 2014We present a measurement of the WZ and ZZ production cross sections in proton-proton collisions at 8 TeV in final states where one Z boson decays to b-tagged jets, while the other gauge boson, either W or Z, is detected through its leptonic decay. The ... More
Dynamic criticality far-from-equilibrium: one-loop flow of Burgers-Kardar-Parisi-Zhang systems with broken Galilean invarianceAug 06 2014Mar 22 2015Burgers-Kardar-Parisi-Zhang (KPZ) scaling has recently (re-) surfaced in a variety of physical contexts, ranging from anharmonic chains to quantum systems such as open superfluids, in which a variety of random forces may be encountered and/or engineered. ... More
Quantum Mechanics: Bell and Quantum Entropy for the ClassroomJan 10 2007In this article we are willing to give some first steps to quantum mechanics and a motivation of quantum mechanics and its interpretation for undergraduate students not from physics. After a short historical review in the development we discuss philosophical, ... More
Optimal Reinforcement Learning for Gaussian SystemsJun 04 2011Oct 14 2011The exploration-exploitation trade-off is among the central challenges of reinforcement learning. The optimal Bayesian solution is intractable in general. This paper studies to what extent analytic statements about optimal learning are possible if all ... More
Three-Loop Calculation of the Higgs Boson Mass in SupersymmetryNov 30 2011A Key feature of the minimal supersymmetric extension of the Standard Model (MSSM) is the existence of a light Higgs boson, the mass of which is not a free parameter but an observable that can be predicted from the theory. Given that the LHC is able to ... More
Three-Loop Predictions for the Light Higgs Mass in the MSSMAug 02 2010The Minimal Supersymmetric Extension of the Standard Model (MSSM) features a light Higgs boson, the mass Mh of which is predicted by the theory. Given that the LHC will be able to measure the mass of a light Higgs with great accuracy, a precise theoretical ... More
AU Scale Structures in Extra-planar GasSep 15 2004Recent spectroscopic observations of intermediate- and high-velocity clouds (IVCs and HVCs) in the Milky Way halo have unveiled the presence of diffuse interstellar molecular hydrogen (H_2) several kpc away from the Galactic disk. Most of this H_2 gas ... More
Binary Evolution and the Progenitor of SN 1987AFeb 13 2017Since the majority of massive stars are members of binary systems, an understanding of the intricacies of binary interactions is essential for understanding the large variety of supernova types and sub-types. I therefore briefly review the basic elements ... More
Vector boson fusion and scattering results from CMSOct 27 2017Measurements on vector boson scattering in the same-sign WW and fully leptonic ZZ channel, and a measurement of vector boson fusion of a Z boson are summarized. The three measurements are based on a dataset of proton--proton collisions at $\sqrt{s}=13\,\mathrm{Te\hspace{-.08em}V}$ ... More
An approach to Griffiths conjectureOct 27 2017The Griffiths conjecture asserts that every ample vector bundle $E$ over a compact complex manifold $S$ admits a hermitian metric with positive curvature in the sense of Griffiths. In this article we give a sufficient condition for a positive hermitian ... More
Neural Machine TranslationSep 22 2017Draft of textbook chapter on neural machine translation. a comprehensive treatment of the topic, ranging from introduction to neural networks, computation graphs, description of the currently dominant attentional sequence-to-sequence model, recent refinements, ... More
Detecting cities in aerial night-time images by learning structural invariants using single reference augmentationOct 19 2018This paper examines, if it is possible to learn structural invariants of city images by using only a single reference picture when producing transformations along the variants in the dataset. Previous work explored the problem of learning from only a ... More
Ultrafast infrared spectroscopy with single molecular ionsSep 18 2018May 28 2019We propose a method to investigate the vibrational dynamics of single polyatomic molecular ions confined in a Paul trap. Quantum logic techniques are employed to detect the recoil of single photon absorption events in the molecule via a co-trapped atomic ... More
Living Labs - An Ethical Challenge for Researchers and Platform ProvidersJun 22 2017The infamous Facebook emotion contagion experiment is one of the most prominent and best-known online experiments based on the concept of what we here call "living labs". In these kinds of experiments, real-world applications such as social web platforms ... More
An analogue of the Baire Category TheoremJan 06 2011May 23 2012Every definably complete expansion of an ordered field satisfies an analogue of the Baire Category Theorem.
Defining the set of integers in expansions of the real field by a closed discrete setJun 26 2009Oct 22 2009Let D\subseteq \mathbb{R} be closed and discrete and f:D^n \to \mathbb{R} be such that f(D^n) is somewhere dense. We show that (\mathbb{R},+,\cdot,f) defines the set of integers. As an application, we get that for every a,b \in \mathbb{R} with \log_{a}(b)\notin ... More
Semigroup Splitting And Cubature Approximations For The Stochastic Navier-Stokes EquationsMay 12 2011Approximation of the marginal distribution of the solution of the stochastic Navier-Stokes equations on the two-dimensional torus by high order numerical methods is considered. The corresponding rates of convergence are obtained for a splitting scheme ... More
Quantum disorder in the spatially completely anisotropic triangular lattice II: frustrated hard-core bosonsMay 09 2012Jan 29 2013Spin liquids occuring in 2D frustrated spin systems were initially assumed to appear at strongest frustration, but evidence grows that they more likely intervene at transitions between two different types of order. To identify if this is more general, ... More
Bessel sequences from iterated operator actionsMay 24 2016May 30 2016Given a bounded normal operator $A$ in a Hilbert space and a fixed vector $x$, we elaborate on the problem of finding necessary and sufficient conditions under which $(A^kx)_{k\in\mathbb N}$ constitutes a Bessel sequence. We provide a characterization ... More
Renormalization group theory for fermions and order parameter fluctuations in interacting Fermi systemsSep 08 2011In this thesis, we perform a comprehensive renormalization group analysis of two- and three-dimensional Fermi systems at low and zero temperature. We examine systems with spontaneous symmetry-breaking and quantum critical behavior by deriving and solving ... More
Expectation Propagation on the Maximum of Correlated Normal VariablesOct 01 2009Many inference problems involving questions of optimality ask for the maximum or the minimum of a finite set of unknown quantities. This technical report derives the first two posterior moments of the maximum of two correlated Gaussian variables and the ... More
High-Velocity Clouds and the Local Intergalactic MediumFeb 15 2006In this article I review recent observations of the gaseous halos of galaxies and the intergalactic medium at low redshift. In the first part I discuss distribution, metal content, and physical properties of the Galactic intermediate- and high-velocity ... More
Tensor generators on schemes and stacksJun 23 2013Jul 19 2015We show that an algebraic stack with affine stabilizer groups satisfies the resolution property if and only if it is a quotient of a quasi-affine scheme by the action of the general linear group, or equivalently, if there exists a vector bundle whose ... More
Nielsen-Schreier implies the finite Axiom of ChoiceJun 10 2015Oct 12 2015We present a new proof that the statement 'every subgroup of a free group is free' implies the Axiom of Choice for finite sets.
D^{+}, D^{0} and Lambda_{c}^{+} production in deep inelastic scattering at HERADec 06 2010Several recent measurements of charmed hadron production in deep inelastic scattering at HERA are reviewed. Cross sections for the production of D mesons were measured and compared to NLO QCD predictions. The charm contribution to the inclusive structure ... More
Equivariant Lefschetz and Fuller indices via topological intersection theoryJul 22 2013For a compact Lie group G, we use G-equivariant Poincar\'e duality for ordinary RO(G)-graded homology to define an equivariant intersection product, the dual of the equivariant cup product. Using this, we give a homological construction of the equivariant ... More
Genericity in equivariant dynamical systems and equivariant Fuller index theoryJan 30 2013We define a notion of equivariant non-degeneracy of $G$-maps to introduce the class of equivariantly non-degenerate flows on smooth compact manifolds with compact Lie group action. We prove genericity of this class and use this result to construct an ... More
Quantum mechanics on York slicesJul 06 2015Jul 13 2015For some time the York time parameter has been identified as a candidate for a physically meaningful time in cosmology. An associated Hamiltonian may be found by solving the Hamiltonian constraint for the momentum conjugate to the York time variable, ... More
Quantum mechanics as the dynamical geometry of trajectoriesJul 31 2015We illustrate how non-relativistic quantum mechanics may be recovered from a dynamical Weyl geometry on configuration space and an `ensemble' of trajectories (or `worlds'). The theory, which is free of a physical wavefunction, is presented starting from ... More
Investigating the Intersection of Science Fiction, Human-Computer Interaction and Computer Science ResearchJul 25 2018This paper outlines ongoing dissertation research located in the intersection of science fiction, human-computer interaction and computer science. Through an interdisciplinary perspective, drawing from fields such as human-computer interaction, film theory ... More
High-Fidelity Solar Power Income Modeling for Solar-Electric UAVs: Development and Flight Test Based VerificationMar 21 2017Solar power models are a crucial element of solar-powered UAV design and performance analysis. During the conceptual design phase, their accuracy directly relates to the accuracy of the predicted performance metrics and thus the final design characteristics ... More