Results for "Daniel Hader"

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Geometric Tiles and Powers and Limitations of Geometric Hindrance in Self-AssemblyMar 14 2019Tile-based self-assembly systems are capable of universal computation and algorithmically-directed growth. Systems capable of such behavior typically make use of "glue cooperation" in which the glues on at least $2$ sides of a tile must match and bind ... More
Alternating quaternary algebra structures on irreducible representations of sl(2,C)Aug 11 2010We determine the multiplicity of the irreducible representation V(n) of the simple Lie algebra sl(2,C) as a direct summand of its fourth exterior power $\Lambda^4 V(n)$. The multiplicity is 1 (resp. 2) if and only if n = 4, 6 (resp. n = 8, 10). For these ... More
Mode-locking in vertical external-cavity surface-emitting lasers with type-II quantum-well configurationsApr 02 2019A microscopic study of mode-locked pulse generation is presented for vertical external-cavity surface-emitting lasers utilizing type-II quantum well configurations. The coupled Maxwell semiconductor Bloch equations are solved numerically where the type-II ... More
Universal associative envelopes of nonassociative triple systemsNov 18 2012We construct universal associative envelopes for the nonassociative triple systems arising from the trilinear operations of Bremner and Peresi applied to the 2-dimensional simple associative triple system. We use noncommutative Gr\"obner bases to determine ... More
The universal Associative envelope of the anti-Jordan triple system of $n \times n$ matricesMar 01 2013We show that the universal associative enveloping algebra of the simple anti-Jordan triple system of all $n \times n$ matrices $(n \ge 2)$ over an algebraically closed field of characteristic 0 is finite dimensional. We investigate the structure of the ... More
Universal associative envelopes of (n+1)-dimensional n-Lie algebrasAug 11 2010For n even, we prove Pozhidaev's conjecture on the existence of associative enveloping algebras for simple n-Lie algebras. More generally, for n even and any (n+1)-dimensional n-Lie algebra L, we construct a universal associative enveloping algebra U(L) ... More
Special Identities for Comtrans AlgebrasJun 26 2018Oct 08 2018Comtrans algebras, arising in web geometry, have two trilinear operations, commutator and translator. We determine a Gr\"obner basis for the comtrans operad, and state a conjecture on its dimension formula. We study multilinear polynomial identities for ... More
High Performance GNR Power Gating for Low-Voltage CMOS CircuitsJan 01 2019A robust power gating design using Graphene Nano-Ribbon Field Effect Transistors (GNRFET) is proposed using 16nm technology. The Power Gating (PG) structure is composed of GNRFET as a power switch and MOS power gated module. The proposed structure resolves ... More
Microscopic calculation of the optical properties and intrinsic losses in the methylammonium lead iodide perovskite systemOct 26 2018For opto-electronic and photo-voltaic applications of perovskites, it is essential to know the optical properties and intrinsic losses of the used materials. A systematic microscopic analysis is presented for the example of methylammonium lead iodide ... More
Five basic lemmas for symmetric tensor products of normed spacesMay 18 2011We give the symmetric version of five lemmas which are essential for the theory of tensor products (and norms). These are: the approximation, extension, embedding, density and local technique lemmas. Some application of these tools to the metric theory ... More
Scaling Laws in Self-Gravitating DisksApr 16 1999The interstellar medium (ISM) reveals strongly inhomogeneous structures at every scale. These structures do not seem completely random since they obey certain power laws. Larson's law (\citeyear{Larson81}) $\sigma \propto R^{\delta}$ and the plausible ... More
Supergravity for Effective TheoriesSep 01 2011Higher-derivative operators are central elements of any effective field theory. In supersymmetric theories, these operators include terms with derivatives in the K\"ahler potential. We develop a toolkit for coupling such supersymmetric effective field ... More
Inflating with BaryonsSep 15 2010We present a field theory solution to the eta problem. By making the inflaton field the phase of a baryon of SU(N_c) supersymmetric Yang-Mills theory we show that all operators that usually spoil the flatness of the inflationary potential are absent. ... More
Formalizing and Checking Thread Refinement for Data-Race-Free Execution Models (Extended Version)Oct 24 2015When optimizing a thread in a concurrent program (either done manually or by the compiler), it must be guaranteed that the resulting thread is a refinement of the original thread. Most theories of valid optimizations are formulated in terms of valid syntactic ... More
Desensitizing Inflation from the Planck ScaleApr 21 2010A new mechanism to control Planck-scale corrections to the inflationary eta parameter is proposed. A common approach to the eta problem is to impose a shift symmetry on the inflaton field. However, this symmetry has to remain unbroken by Planck-scale ... More
Signatures of Supersymmetry from the Early UniverseSep 01 2011Oct 11 2011Supersymmetry plays a fundamental role in the radiative stability of many inflationary models. Spontaneous breaking of the symmetry inevitably leads to fields with masses of order the Hubble scale during inflation. When these fields couple to the inflaton ... More
The symmetric Radon-Nikodým property for tensor normsMay 15 2010We introduce the symmetric-Radon-Nikod\'ym property (sRN property) for finitely generated s-tensor norms $\beta$ of order $n$ and prove a Lewis type theorem for s-tensor norms with this property. As a consequence, if $\beta$ is a projective s-tensor norm ... More
Ultrafast band-gap renormalization and build-up of optical gain in monolayer MoTe$_2$Mar 20 2019The dynamics of the band-gap renormalization and gain build-up in monolayer MoTe$_2$ is investigated by solving the non-equilibrium Dirac-Bloch equations where the incoherent carrier-carrier and carrier-phonon scattering is treated via quantum-Boltzmann ... More
Valence band splitting in bulk dilute bismidesSep 28 2017The electronic structure of bulk GaAs$_{1-x}$Bi$_x$ systems for different atomic configurations and Bi concentrations is calculated using density functional theory. The results show a Bi-induced splitting between the light-hole and heavy-hole bands at ... More
Configuration Dependence of Band Gap Narrowing and Localization in Dilute GaAs_{1-x} Bi_x AlloysFeb 05 2016Anion substitution with bismuth (Bi) in III-V semiconductors is an effective method for experimental engineering of the band gap Eg at low Bi concentrations, in particular in gallium arsenide (GaAs). The inverse Bi-concentration dependence of Eg has been ... More
Long-Range Correlations in Self-Gravitating N-Body SystemsJan 29 2002Observed self-gravitating systems reveal often fragmented non-equilibrium structures that feature characteristic long-range correlations. However, models accounting for non-linear structure growth are not always consistent with observations and a better ... More
Lumpy Structures in Self-Gravitating DisksMay 29 2001Following Toomre & Kalnajs (1991), local models of slightly dissipative self-gravitating disks show how inhomogeneous structures can be maintained over several galaxy rotations. Their basic physical ingredients are self-gravity, dissipation and differential ... More
Equilateral Non-Gaussianity and New Physics on the HorizonFeb 25 2011Mar 23 2011We examine the effective theory of single-field inflation in the limit where the scalar perturbations propagate with a small speed of sound. In this case the non-linearly realized time-translation symmetry of the Lagrangian implies large interactions, ... More
Natural symmetric tensor normsFeb 22 2010Dec 14 2010In the spirit of the work of Grothendieck, we introduce and study natural symmetric n-fold tensor norms. We prove that there are exactly six natural symmetric tensor norms for $n\ge 3$, a noteworthy difference with the 2-fold case in which there are four. ... More
Casimir force in O(n) lattice models with a diffuse interfaceJun 23 2008On the example of the spherical model we study, as a function of the temperature $T$, the behavior of the Casimir force in O(n) systems with a diffuse interface and slab geometry $\infty^{d-1}\times L$, where $2<d<4$ is the dimensionality of the system. ... More
Fragmentation in Kinematically Cold DisksJan 16 2001Gravity is scale free. Thus gravity may form similar structures in self-gravitating systems on different scales. Indeed, observations of the interstellar medium, spiral disks and cosmic structures, reveal similar characteristics. The structures in these ... More
A Field Range Bound for General Single-Field InflationNov 13 2011We explore the consequences of a detection of primordial tensor fluctuations for general single-field models of inflation. Using the effective theory of inflation, we propose a generalization of the Lyth bound. Our bound applies to all single-field models ... More
Extending polynomials in maximal and minimal idealsOct 20 2009Feb 08 2010Given an homogeneous polynomial on a Banach space $E$ belonging to some maximal or minimal polynomial ideal, we consider its iterated extension to an ultrapower of $E$ and prove that this extension remains in the ideal and has the same ideal norm. As ... More
Unconditionality in tensor products and ideals of polynomials, multilinear forms and operatorsJun 17 2009Feb 08 2010We study tensor norms that destroy unconditionality in the following sense: for every Banach space $E$ with unconditional basis, the $n$-fold tensor product of $E$ (with the corresponding tensor norm) does not have unconditional basis. We establish an ... More
Mutation and Gauge Theory I: Yang-Mills InvariantsOct 29 1997Mutation is an operation on 3-manifolds containing an embedded surface of genus 2. It is defined by cutting along the surface and regluing using the `hyperelliptic' involution, and is known to preserve many 3-manifold invariants. I show that mutation ... More
Embedding tangles in linksJan 25 2000We reprove and extend a result of David Krebes (J. Knot Theory Ramif. 8 (1999), 321-352) giving an obstruction to embedding a tangle T into a link L. Closing the tangle up in the two obvious ways gives rise to two links, the numerator and denominator ... More
Fault-Tolerant Quantum Computation with Constant OverheadOct 10 2013Jul 22 2014What is the minimum number of extra qubits needed to perform a large fault-tolerant quantum circuit? Working in a common model of fault-tolerance, I show that in the asymptotic limit of large circuits, the ratio of physical qubits to logical qubits can ... More
On the Theory of Quantum Secret SharingOct 14 1999I present a variety of results on the theory of quantum secret sharing. I show that any mixed state quantum secret sharing scheme can be derived by discarding a share from a pure state scheme, and that the size of each share in a quantum secret sharing ... More
Quantum transport in quantum networks and photosynthetic complexes at the steady stateJun 09 2012Feb 25 2013Recently, several works have analysed the efficiency of photosynthetic complexes in a transient scenario and how that efficiency is affected by environmental noise. Here, following a quantum master equation approach, we study the energy and excitation ... More
Information and Entanglement Measures in Quantum Systems With Applications to Atomic PhysicsMar 16 2011This thesis is a multidisciplinary contribution to the information theory of single-particle Coulomb systems in their relativistic and not relativistic description, to the theory of special functions of mathematical physics with the proposal and analysis ... More
The de Broglie Wave as Evidence of a Deeper Wave StructureMar 06 2015Aug 08 2015It is argued that the de Broglie wave is not the wave usually supposed, but the relativistically induced modulation of an underlying carrier wave that moves with the velocity of the particle. In the rest frame of the particle this underlying structure ... More
Rule-Based Semantic Tagging. An Application Undergoing Dictionary GlossesMay 16 2013May 17 2013The project presented in this article aims to formalize criteria and procedures in order to extract semantic information from parsed dictionary glosses. The actual purpose of the project is the generation of a semantic network (nearly an ontology) issued ... More
The unfolded universe of elementary particles. A geometric explanation of the standard model structureJan 16 2016We propose a geometric explanation of the standard model of Glashow, Weinberg and Salam for the known elementary particles. Our model is a generic Quantum Field Theory in dimension four, obtained by developing along a Lorentz sub-manifold the lagrangian ... More
Generalization of Gabidulin Codes over Fields of Rational FunctionsDec 15 2014We transpose the theory of rank metric and Gabidulin codes to the case of fields which are not finite fields. The Frobenius automorphism is replaced by any element of the Galois group of a cyclic algebraic extension of a base field. We use our framework ... More
Two semi-coninuity results for the algebraic dimension of compact complex manifoldsApr 07 2014Using some relative codimension 1 cycle-space method, we give, following the ideas of D. Popovici [P.13], semicontinuity results for the algebraic dimension in a family a compact complex manifolds parametrized by a disc.
Towards More Data-Aware Application Integration (extended version)Apr 22 2015Although most business application data is stored in relational databases, programming languages and wire formats in integration middleware systems are not table-centric. Due to costly format conversions, data-shipments and faster computation, the trend ... More
Liquidity, risk measures, and concentration of measureOct 23 2015Oct 27 2015Expanding on techniques of concentration of measure, we develop a quantitative framework for modeling liquidity risk using convex risk measures. The fundamental objects of study are curves of the form $(\rho(\lambda X))_{\lambda \ge 0}$, where $\rho$ ... More
Law invariant risk measures and information divergencesOct 23 2015Jun 04 2016A one-to-one correspondence is drawn between law invariant risk measures and divergences, which we define as functionals of pairs of probability measures on arbitrary standard Borel spaces satisfying a few natural properties. Divergences include many ... More
Connecting the generalized robustness and the geometric measure of entanglementFeb 02 2006Jan 07 2008The main goal of this paper is to provide a connection between the generalized robustness of entanglement ($R_g$) and the geometric measure of entanglement ($E_{GME}$). First, we show that the generalized robustness is always higher than or equal to the ... More
Asteroseismology of Eclipsing Binary Stars in the Kepler EraApr 29 2014Eclipsing binary stars have long served as benchmark systems to measure fundamental stellar properties. In the past few decades, asteroseismology - the study of stellar pulsations - has emerged as a new powerful tool to study the structure and evolution ... More
Ferromagnetism, antiferromagnetism, and the curious nematic phase of S=1 quantum spin systemsJun 09 2014Apr 23 2015We investigate the phase diagram of S=1 quantum spin systems with SU(2)-invariant interactions, at low temperatures and in three spatial dimensions. Symmetry breaking and the nature of pure states can be studied using random loop representations. The ... More
Quantum Heisenberg models and random loop representationsNov 17 2012We review random loop representations for the spin-1/2 quantum Heisenberg models, that are due to Toth (ferromagnet) and Aizenman-Nachtergaele (antiferromagnet). These representations can be extended to models that interpolate between the two Heisenberg ... More
Symplectic automorphisms of K3 surfaces of arbitrary orderMay 15 2012It is observed that the recent result of Voisin and earlier ones of the author suffice to prove in complete generality that symplectic automorphisms of finite order of a K3 surface X act as identity on the Chow group CH^2(X) of zero-cycles.
Projectivity of Kaehler manifolds - Kodaira's problem (after C. Voisin)Dec 01 2005In this expository paper (Bourbaki talk) we survey results of Claire Voisin showing that there exist compact Kaehler manifolds which are not homeomorphic to any projective manifold.
A short proof of a Theorem by HopfJul 24 2015A proof based on the Chern-Gauss-Bonnet Theorem is given to Hopf Theorem concerning the degree of the Gauss map of a hypersurface in $\mathbb{R}^n$.
Asymmetric parton distributions of the nucleonSep 01 2012This contribution to CIPANP 2012 highlights what we have learned about the asymmetric parton distributions of the nucleon over the past 20 years. These distributions include the transverse momentum dependent parton distributions describing spin-orbit ... More
Theoretical aspects of transversity observablesSep 24 2001Theoretical aspects of transversity observables are reviewed. The main focus is on two leading twist transversity single spin asymmetries, one arising from the Collins effect and one from the interference fragmentation functions. Electron-positron annihilation ... More
Theoretical aspects of spin physicsDec 11 2003A summary is given of how spin enters in collinearly factorizing processes. Next, theoretical aspects of polarization in processes beyond collinear factorization are discussed in more detail, with special focus on recent developments concerning the color ... More
The influence of the first term of an arithmetic progressionApr 13 2011The goal of this article is to study the discrepancy of the distribution of arithmetic sequences in arithmetic progressions. We will fix a sequence $\A=\{\a(n)\}_{n\geq 1}$ of non-negative real numbers in a certain class of arithmetic sequences. For a ... More
On Automorphisms and Universal R-Matrices at Roots of UnityMar 18 1994Invertible universal R-matrices of quantum Lie algebras do not exist at roots of unity. There exist however quotients for which intertwiners of tensor products of representations always exist, i.e. R-matrices exist in the representations. One of these ... More
Fusion Rules and R-Matrices For Representations of $SL(2)_q$ at Roots of UnityMar 04 1992We recall the classification of the irreducible representations of $SL(2)_q$, and then give fusion rules for these representations. We also consider the problem of $\cR$-matrices, intertwiners of the differently ordered tensor products of these representations, ... More
Non integrable representations of the restricted quantum analogue of sl(3) at roots of 1Oct 22 1996Feb 27 1997The structure of irreducible representations of (restricted) U_q(sl(3)) at roots of unity is understood within the Gelfand--Zetlin basis. The latter needs a weakened definition for non integrable representations, where the quadratic Casimir operator of ... More
Thin tubes in mathematical physics, global analysis and spectral geometryFeb 19 2008A thin tube is an $n$-dimensional space which is very thin in $n-1$ directions, compared to the remaining direction, for example the $\epsilon$-neighborhood of a curve or an embedded graph in $\R^n$ for small $\epsilon$. The Laplacian on thin tubes and ... More
Basics of the b-calculusOct 31 2000R. B. Melrose's b-calculus provides a framework for dealing with problems of partial differential equations that arise in singular or degenerate geometric situations. This article is a somewhat informal short course introducing many of the basic ideas ... More
Finding the Most Distant Quasars Using Bayesian Selection MethodsMay 19 2014Quasars, the brightly glowing disks of material that can form around the super-massive black holes at the centres of large galaxies, are amongst the most luminous astronomical objects known and so can be seen at great distances. The most distant known ... More
On extensions of the Alon-Tarsi Latin Square conjectureApr 24 2012Sep 03 2012Expressions involving the product of the permanent with the (n-1)th power of the determinant of a matrix of indeterminates, and of (0,1)-matrices, are shown to be related to two conjectures that extend the Alon-Tarsi Latin square conjecture to odd dimensions. ... More
A Characterization of Binary Matroids by Basis-ExchangeDec 12 2011Mar 01 2012The effect of replacing a basis element on the way the basis spans other elements is studied. This leads to a new characterization of binary matroids.
Adding flavor on the Higgs branchMay 22 2008We study the holographic dual of the Higgs branch of N=4 SYM in four dimensions coupled to quenched fundamental matter. The fundamentals are added via flavor D7-branes and the Higgs phase is obtained when the color D3-branes and the flavor D7-branes recombine ... More
Condensates and quasiparticles in inflationary cosmology: mass generation and decay widthsMar 17 2012Jun 18 2012During de Sitter inflation massless particles of minimally coupled scalar fields acquire a mass and a decay width thereby becoming \emph{quasiparticles}. For bare massless particles non-perturbative infrared radiative corrections lead to a self-consistent ... More
Short baseline neutrino oscillations: when entanglement suppresses coherenceJun 30 2011Sep 01 2011For neutrino oscillations to take place the entangled quantum state of a neutrino and a charged lepton produced via charged current interactions must be disentangled. Implementing a non-perturbative Wigner-Weisskopf method we obtain the correct \emph{entangled} ... More
Fermionic influence (action) on inflationary fluctuationsFeb 17 2016Apr 13 2016Motivated by apparent persistent large scale anomalies in the CMB we study the influence of fermionic degrees of freedom on the dynamics of inflaton fluctuations as a possible source of violations of (nearly) scale invariance on cosmological scales. We ... More
Free streaming in mixed dark matterNov 03 2007Dec 14 2007Free streaming in a \emph{mixture} of collisionless non-relativistic dark matter (DM) particles is studied by implementing methods from the theory of multicomponent plasmas. The mixture includes Fermionic, condensed and non condensed Bosonic particles ... More
On Weak Hamiltonicity of a Random HypergraphOct 27 2014A {\it weak (Berge) cycle} is an alternating sequence of vertices and (hyper)edges $C=(v_0, e_1, v_1, ..., v_{\ell-1}, e_\ell, v_{\ell}=v_0)$ such that the vertices $v_0, ..., v_{\ell-1}$ are distinct with $v_k, v_{k+1} \in e_{k}$ for each $k$, but the ... More
A multivariate Gnedenko law of large numbersJan 25 2011Oct 21 2013We show that the convex hull of a large i.i.d. sample from an absolutely continuous log-concave distribution approximates a predetermined convex body in the logarithmic Hausdorff distance and in the Banach-Mazur distance. For log-concave distributions ... More
A parton recombination approach to heavy ion collisions at RHIC and LHCJan 23 2009This thesis discusses the phenomenological parton recombination approach to describe hadronization in heavy ion collisions. The very good agreement to RHIC data for the flow coefficients v_2 and v_4 is shown and extrapolations are used to make predictions ... More
Decomposition width - a new width parameter for matroidsApr 17 2009We introduce a new width parameter for matroids called decomposition width and prove that every matroid property expressible in the monadic second order logic can be computed in linear time for matroids with bounded decomposition width if their decomposition ... More
Properties of the Top QuarkMay 14 2010Sep 16 2011The top quark was discoverd at the CDF and D0 experiments in 1995. As the partner of the bottom quark its properties within the Standard Model are fully defined. Only the mass is a free parameter. The measurement of the top quark mass and the verification ... More
Chiral Perturbation Theory on the Lattice and its ApplicationsJun 09 2004Chiral perturbation theory (CPT), the low-energy effective theory of QCD, can be used to describe QCD observables in the low-energy region in a model-independent way. At any given order in the chiral expansion, CPT introduces a finite number of parameters ... More
Quasiparticle excitations in relativistic quantum field theoryJan 28 2008Dec 05 2008We analyze the particle-like excitations arising in relativistic field theories in states different than the vacuum. The basic properties characterizing the quasiparticle propagation are studied using two different complementary methods. First we introduce ... More
Particle propagation in non-trivial backgrounds: a quantum field theory approachJul 26 2007Sep 13 2007The basic aim of the thesis is the study of the propagation of particles and quasiparticles in non-trivial backgrounds from the quantum field theory point of view. By "non-trivial background" we mean either a non-vacuum state in Minkowski spacetime or ... More
General-Purpose Join Algorithms for Listing Triangles in Large GraphsJan 27 2015We investigate applying general-purpose join algorithms to the triangle listing problem in an out-of-core context. In particular, we focus on Leapfrog Triejoin (LFTJ) by Veldhuizen 2014, a recently proposed, worst-case optimal algorithm. We present "boxing": ... More
Power Corrections at LEPMay 20 1998The size of non-perturbative corrections to event shape observables is predicted to fall like powers of the inverse centre of mass energy. These power corrections are investigated for different observables from $e^+e^-$-annihilation measured at LEP as ... More
Determination of α_s from Event Shapes and Power CorrectionsAug 26 1997The size of non-perturbative corrections to event shape observables is predicted to fall like a power of the inverse centre of mass energy. These power corrections are investigated for different observables from e+e-annihilation and compared to the theoretical ... More
A note on polynomial solvability of the CDT problemJun 25 2014Feb 23 2015We describe a simple polynomial-time algorithm for the CDT problem that relies on a construction of Barvinok.
W Mass as a Calibration of the Jet Energy Scale at ATLASSep 17 2008Nov 14 2008Top-antitop pairs will be copiously produced at the LHC, at a rate of roughly one per second at a luminosity of10^{33} cm^{-2} s^{-1}. These events have low background and produce large numbers of jets via the hadronic decay of the W's which may be used ... More
Substitutions over infinite alphabet generating (-β)-integersAug 18 2011This contribution is devoted to the study of positional numeration systems with negative base introduced by Ito and Sadahiro in 2009, called (-\beta)-expansions. We give an admissibility criterion for more general case of (-\beta)-expansions and discuss ... More
Hierarchical Parallelisation of Functional Renormalisation Group Calculations -- hp-fRGOct 27 2015May 25 2016The functional renormalisation group (fRG) has evolved into a versatile tool in condensed matter theory for studying important aspects of correlated electron systems. Practical applications of the method often involve a high numerical effort, motivating ... More
Incorporating non-adiabatic effects in Embedded Atom potentials for radiation damage cascade simulationsSep 04 2014Mar 03 2015In radiation damage cascade displacement spikes ions and electrons can reach very high temperatures and be out of thermal equilibrium. Correct modelling of cascades with molecular dynamics should allow for the non-adiabatic exchange of energy between ... More
Structured Sparse AggregationNov 18 2011We introduce a method for aggregating many least squares estimator so that the resulting estimate has two properties: sparsity and structure. That is, only a few candidate covariates are used in the resulting model, and the selected covariates follow ... More
Conserved quantities in isotropic loop quantum cosmologyApr 16 2012We develop an action principle for those models arising from isotropic loop quantum cosmology, and show that there is a natural conserved quantity $Q$ for the discrete difference equation arising from the Hamiltonian constraint. This quantity $Q$ relates ... More
Quantifying the Fermi paradox in the local Solar neighborhoodApr 01 2014The Fermi paradox highlights the dichotomy between the lack of physical contact with other civilizations and the expectation that technological civilizations are assumed likely to evolve in many locations in the Milky Way galaxy, given the large number ... More
Vector-Valued Rademacher Sums and Automorphic IntegralsJun 03 2014Apr 01 2016We present bases for certain spaces of meromorphic vector-valued rational-weight mock modular forms constructed using Rademacher sums.
Centering in Dynamic SemanticsJul 14 1998Centering theory posits a discourse center, a distinguished discourse entity that is the topic of a discourse. A simplified version of this theory is developed in a Dynamic Semantics framework. In the resulting system, the mechanism of center shift allows ... More
Machine Learning and Cloud Computing: Survey of Distributed and SaaS SolutionsMar 29 2016Applying popular machine learning algorithms to large amounts of data raised new challenges for the ML practitioners. Traditional ML libraries does not support well processing of huge datasets, so that new approaches were needed. Parallelization using ... More
Bifurcation in epigenetics: implications in development, proliferation and diseasesJan 13 2014Cells often exhibit different and stable phenotypes from the same DNA sequence. Robustness and plasticity of such cellular states are controlled by diverse transcriptional and epigenetic mechanisms, among them the modification of biochemical marks on ... More
Equations for Complex-Valued, Twisting, Type N, Vacuum Solutions, with one or two Killing/homothetic vectorsAug 23 2001HH-spaces, i.e., complex spacetimes, of Petrov type NxN are determined by a trio of pde's for two functions, lambda and a, of three independent variables (and also two gauge functions, chosen to be two of the independent variables if one prefers). As ... More
An Infinite Family of Links with Critical Bridge SpheresFeb 17 2016For any counting numbers $b\geq 3$ and $c\leq b$, there exists an infinite family of $c$-component, $b$-bridge links whose bridge spheres are critical.
A signature of quantum gravity at the source of the seeds of cosmic structure?Jan 13 2007This article reviews a recent work by a couple of colleagues and myself about the shortcomings of the standard explanations of the quantum origin of cosmic structure in the inflationary scenario, and a proposal to address them. The point it that in the ... More
A Simple Bound on the Error of Perturbation Theory in Quantum MechanicsMay 15 2009Jun 22 2009I provide a straightforward proof that a simple harmonic oscillator perturbed by an (almost) arbitrary positive interaction has a perturbative expansion for any finite-time Euclidian transition amplitude which obeys the following result: the difference ... More
Decoherence in a system of many two--level atomsNov 29 2005Sep 19 2006I show that the decoherence in a system of $N$ degenerate two--level atoms interacting with a bosonic heat bath is for any number of atoms $N$ governed by a generalized Hamming distance (called ``decoherence metric'') between the superposed quantum states, ... More
Spectral properties of Dissipative Chaotic Quantum MapsMar 29 1999I examine spectral properties of a dissipative chaotic quantum map with the help of a recently discovered semiclassical trace formula. I show that in the presence of a small amount of dissipation the traces of any finite power of the propagator of the ... More
Generating Cycloidal Gears for 3D PrintingJul 12 2016(Shortened version of abstract in article itself) This article describes an algorithm for producing, for any desired resolution and any desired numbers of wheel and pinion teeth, polygonal approximations to the shapes of a pair of cycloidal gears that ... More
Hyperbolic outer billiards : a first exampleJan 13 2006Apr 13 2006We present the first example of a hyperbolic outer billiard. More precisely we construct a one parameter family of examples which in some sense correspond to the Bunimovich billiards.
On the non additivity of the trace in derived categoriesJun 29 2005In this note we provide an example of an endomorphism of a short exact sequence of perfect complexes, with the trace of the middle map not equal to the sum of the traces of the two other ones. The point is that the squares involved are commutative only ... More