Results for "George Adaimi"

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Rethinking Person Re-Identification with ConfidenceJun 11 2019A common challenge in person re-identification systems is to differentiate people with very similar appearances. The current learning frameworks based on cross-entropy minimization are not suited for this challenge. To tackle this issue, we propose to ... More
Valley currents and non-local resistances of graphene nanostructures with broken inversion symmetry from the perspective of scattering theorySep 23 2015Valley currents and non-local resistances of graphene nanostructures with broken inversion symmetry are considered theoretically in the linear response regime. Scattering state wave functions of electrons entering the nanostructure from the contacts represented ... More
Ideal Spin Filters: Theoretical Study of Electron Transmission Through Ordered and Disordered Interfaces Between Ferromagnetic Metals and SemiconductorsOct 11 2000It is predicted that certain atomically ordered interfaces between some ferromagnetic metals (F) and semiconductors (S) should act as ideal spin filters that transmit electrons only from the majority spin bands or only from the minority spin bands of ... More
Why Are Large Persistent Currents Observed in Small Gold Rings?Jan 13 1995It is demonstrated using three-dimensional computer simulations that some simple non-interacting electron models that include electron scattering by grain boundaries, exhibit coexistence of large persistent currents and small conductances, similar to ... More
Sentient NetworksDec 13 1997In this paper we consider the question whether a distributed network of sensors and data processors can form "perceptions" based on the sensory data. Because sensory data can have exponentially many explanations, the use of a central data processor to ... More
Quantum Mechanics as Information FusionDec 04 1999We provide evidence that quantum mechanics can be interpreted as a rational algorithm for finding the least complex description for the correlations in the outputs of sensors in a large array. In particular, by comparing the self-organization approach ... More
A Natural Cosmological Model with Omega_matter <1Feb 12 1999Flat cosmological models with a cosmological constant on the order of the Einstein-de Sitter critical density are enigmatic in the sense that there does not appear to be any natural explanation for why there should be a cosmological constant with such ... More
The Black Hole Information Puzzle and Evidence for a Cosmological ConstantJul 22 1998Recent hints from observations of distant supernovae of a positive cosmological constant with magnitude comparable to the average density of matter seem to point in the direction of a two fluid model for spacetime; where the "normal" component consists ... More
The Monster Sporadic Group and a Theory Underlying Superstring ModelsSep 18 1996The pattern of duality symmetries acting on the states of compactified superstring models reinforces an earlier suggestion that the Monster sporadic group is a hidden symmetry for superstring models. This in turn points to a supersymmetric theory of self-dual ... More
Change Detection with Compressive MeasurementsApr 11 2014Quickest change point detection is concerned with the detection of statistical change(s) in sequences while minimizing the detection delay subject to false alarm constraints. In this paper, the problem of change point detection is studied when the decision ... More
Discussion of "Estimating the historical and future probabilities of large terrorist events" by Aaron Clauset and Ryan WoodardJan 10 2014Discussion of "Estimating the historical and future probabilities of large terrorist events" by Aaron Clauset and Ryan Woodard [arXiv:1209.0089].
Modeling and estimation of multi-source clustering in crime and security dataNov 28 2013While the presence of clustering in crime and security event data is well established, the mechanism(s) by which clustering arises is not fully understood. Both contagion models and history independent correlation models are applied, but not simultaneously. ... More
Three-Dimensional Reddening Map for Stars from 2MASS Photometry: The Method and the First ResultsJul 02 2016The first results of the construction of a 3D reddening map for stars within 1600 pc of the Sun are presented. Analysis of the distribution of 70 million stars from the 2MASS catalog with the most accurate photometry on the (J-Ks) - Ks diagram supplemented ... More
Four Weak Gauge Boson Production at Photon Linear Collider and Heavy Higgs SignalJul 28 1994We study the signals and backgrounds for a heavy Higgs boson in the processes $\gamma\gamma\to WWWW$, $\gamma\gamma\to WWZZ$ at the photon linear collider. The results are based on the complete tree level SM calculation for these reactions. We show that ... More
Spatial Variations of the Extinction Law in the Galactic Disk from Infrared ObservationsJun 28 2016Infrared photometry in the J (1.2 microns), H (1.7 microns), Ks (2.2 microns) bands from the 2MASS catalogue and in the W1 (3.4 microns), W2 (4.6 microns), W3 (12 microns), W4 (22 microns) bands from the WISE catalogue is used to reveal the spatial variations ... More
A Person Re-Identification System For Mobile DevicesDec 13 2015Person re-identification is a critical security task for recognizing a person across spatially disjoint sensors. Previous work can be computationally intensive and is mainly based on low-level cues extracted from RGB data and implemented on a PC for a ... More
Verso folio: Diversified Ranking for Large Graphs with Context-Aware ConsiderationsJul 25 2016This work is pertaining to the diversified ranking of web-resources and interconnected documents that rely on a network-like structure, e.g. web-pages. A practical example of this would be a query for the k most relevant web-pages that are also in the ... More
Connections Between Symmetries and Conservation LawsNov 09 2005This paper presents recent work on connections between symmetries and conservation laws. After reviewing Noether's theorem and its limitations, we present the Direct Construction Method to show how to find directly the conservation laws for any given ... More
Mirror mesons at the Large Hadron Collider (LHC)Jun 23 2016The existence of mirror partners of Standard-Model fermions offers a viable alternative to a fundamental BEH mechanism, with the coupling corresponding to the gauged mirror generation symmetry becoming naturally strong at energies around 1 TeV. The resulting ... More
A Bayesian Nonparametric IRT ModelFeb 11 2015This paper introduces a flexible Bayesian nonparametric Item Response Theory (IRT) model, which applies to dichotomous or polytomous item responses, and which can apply to either unidimensional or multidimensional scaling. This is an infinite-mixture ... More
Variations of the Interstellar Extinction Law within the Nearest KiloparsecJun 30 2016Multicolor photometry from the Tycho-2 and 2MASS catalogues for 11 990 OB and 30 671 K-type red giant branch stars is used to detect systematic large-scale variations of the interstellar extinction law within the nearest kiloparsec. The characteristic ... More
Some Properties of Dust Outside the Galactic DiskJun 28 2016The joint use of accurate near- and mid-infrared photometry from the 2MASS and WISE catalogues has allowed the variations of the extinction law and the dust grain size distribution in high Galactic latitudes (|b|>50) at distances up to 3 kpc from the ... More
Influence of the Gould Belt on Interstellar ExtinctionJun 30 2016A new analytical 3D model of interstellar extinction within 500 pc of the Sun as a function of the Galactic spherical coordinates is suggested. This model is physically more justified than the widely used Arenou model, since it takes into account the ... More
On the maximal operators of Walsh-Kaczmarz-Fejér meansOct 05 2014The main aim of this paper is to prove that the maximal operator $\sigma_{p}^{\kappa ,\ast }f:=\sup_{n\in \mathbf{P}}\left\vert \sigma_{n}^{\kappa }f\right\vert /\left( n+1\right) ^{1/p-2}$ is bounded from the Hardy space $% H_{p}$ to the space $L_{p},$ ... More
Travelling waves in the expanding spatially homogeneous space-timesNov 11 2014Some classes of the so called "travelling wave" solutions of Einstein and Einstein - Maxwell equations in General Relativity and of dynamical equations for massless bosonic fields in string gravity in four and higher dimensions are presented. Similarly ... More
Projective Connections and the Algebra of DensitiesAug 20 2008Projective connections first appeared in Cartan's papers in the 1920's. Since then they have resurfaced periodically in, for example, integrable systems and perhaps most recently in the context of so called projectively equivariant quantisation. We recall ... More
Black Holes and Sphalerons in Low Energy Effective String TheoryOct 25 1994Talk given at the 7th Marcel Grossmann Meeting on General Relativity, Stanford University, July 24-30, 1994.
New half supersymmetric solutions of the heterotic stringSep 07 2008May 26 2009We describe all supersymmetric solutions of the heterotic string which preserve 8 supersymmetries and show that are distinguished by the holonomy, ${\rm hol}(\hat\nabla)$, of the connection, $\hat\nabla$, with skew-symmetric torsion. The ${\rm hol}(\hat\nabla) ... More
Resonant capture of multiple planet systems under dissipation and stable orbital configurationsApr 12 2016Migration of planetary systems caused by the action of dissipative forces may lead the planets to be trapped in a resonance. In this work we study the conditions and the dynamics of such resonant trapping. Particularly, we are interested in finding out ... More
Quenched Chiral Perturbation Theory for Heavy BaryonsApr 28 1997Heavy baryon chiral perturbation theory is extended to include the effects of quenching. In this framework the leading nonanalytic dependence of the heavy baryon masses on the light quark masses is studied. The size of quenching effects is estimated by ... More
Spatial Variations of the Interstellar Polarization and Interstellar ExtinctionJul 24 2017For more than 5000 stars with accurate parallaxes from the Hipparcos and Gaia DR1 Tycho-Gaia astrometric solution (TGAS), Tycho-2 photometry, interstellar polarization from eight catalogues and interstellar extinction from eight 3D maps the largest up ... More
Quantization of maximally-charged slowly-moving black holesSep 15 2000Jan 11 2001We discuss the quantization of a system of slowly-moving extreme Reissner-Nordstrom black holes. In the near-horizon limit, this system has been shown to possess an SL(2,R) conformal symmetry. However, the Hamiltonian appears to have no well-defined ground ... More
Canonical quantization of a particle near a black holeJun 12 2000We discuss the quantization of a particle near an extreme Reissner-Nordstrom black hole in the canonical formalism. This model appears to be described by a Hamiltonian with no well-defined ground state. This problem can be circumvented by a redefinition ... More
Thermodynamic calculation of spin scaling functionsAug 23 2018Critical phenomena theory centers on the scaled thermodynamic potential per spin $\phi(\beta, h)=|t|^{p}Y(h|t|^{-q})$, with inverse temperature $\beta=1/T$, $h=-\beta H$, ordering field $H$, reduced temperature $t=t(\beta)$, critical exponents $p$ and ... More
Cryptocurrencies, Mainstream Asset Classes and Risk Factors - A Study of ConnectednessSep 10 2018We investigate connectedness within and across two major groups or assets: i) five popular cryptocurrencies, and ii) six major asset classes plus two commonly employed risk factors. Granger-causality tests uncover six direct channels of causality from ... More
Genus theory and $ε$-conjectures on p-class groupsMar 07 2019Mar 21 2019We suspect that the "genus part" of the class number of a number field K may be an obstruction for an "easy proof" of the classical $\epsilon$-conjecture for p-class groups and, a fortiori, for a proof of the "strong $\epsilon$-conjecture": \#Cl\_K <<\_(d,p,$\epsilon$) ... More
Congruences in slim, planar, semimodular lattices: The Swing LemmaDec 30 2014Apr 24 2015In an earlier paper, to describe how a congruence spreads from a prime interval to another in a finite lattice, I introduced the concept of prime-perspectivity and its transitive extension, prime-projectivity and proved the Prime-projectivity Lemma. In ... More
Congruences of the fork extensions. I. The Congruence Extension PropertyJul 02 2013Sep 08 2013For a slim, planar, semimodular lattice, G. Cz\'edli and E.\,T. Schmidt introduced the fork extension in 2012. In this note we prove that the fork extension has the Congruence Extension Property. This paper has been merged with Part II, under the title ... More
Single or combined location measurements of the same parameter without prior probability. (Altern. title, Parametric inference as useful illusion; Part 1)Mar 28 2002May 13 2003Motivation. This version is based solely on the calculus of probability, excluding any statistical principle. "Location measurement" means the pdf of the error is known. When the datum is obtained, intuition suggests something like a pdf for the parameter; ... More
Multiple membership multilevel modelsJul 04 2019Multiple membership multilevel models are an extension of standard multilevel models for non-hierarchical data that have multiple membership structures. Traditional multilevel models involve hierarchical data structures whereby lower-level units such ... More
Multilevel models for continuous outcomesJul 12 2019Multilevel models (mixed-effect models or hierarchical linear models) are now a standard approach to analysing clustered and longitudinal data in the social, behavioural and medical sciences. This review article focuses on multilevel linear regression ... More
Performance evaluation of a production line operated under an echelon buffer policyMar 09 2019We consider a production line consisting of several machines in series separated by intermediate finite-capacity buffers. The line operates under an "echelon buffer" (EB) policy according to which each machine can store the parts that it produces in any ... More
On The maximal operators of Vilenkin-Fejér means on Hardy spacesOct 05 2014The main aim of this paper is to prove that when $0<p<1/2$ the maximal operator $\overset{\sim }{\sigma }_{p}^{\ast }f:=\underset{n\in \mathbb{N}}{% \sup }\frac{\left\vert \sigma_{n}f\right\vert }{\left( n+1\right) ^{1/p-2}}$ is bounded from the martingale ... More
On the convergence of Fejér means of Walsh-Fourier series in the space $H_{p}$Sep 17 2014The main aim of this paper is to find the necessary and sufficient conditions for a modulus of continuity of a martingale $F\in H_{p},$ for which Fej\'er means convergence in $H_{p}$-norm, when $0<p\leq 1/2.$
A counterexample to a question of Haydon, Odell and RosenthalOct 14 1996We give an example of a compact metric space $K$, an open dense subset $U$ of $K$, and a sequence $(f_n)$ in $C(K)$ which is pointwise convergent to a non-continuous function on $K$, such that for every $u \in U$ there exists $n \in \N$ with $f_n(u)=f_m(u)$ ... More
Conformal Scalar Propagation inside the Schwarzschild Black HoleOct 04 2011The analytic expression obtained in the preceding project for the massless conformal scalar propagator in the Hartle-Hawking vacuum state for small values of the Schwarzschild radial coordinate above $ r = 2M$ is analytically extended into the interior ... More
Perturbative Evaluation of the Zero-Point function for Self-Interacting Scalar Field on a Manifold with BoundaryJul 03 2001Jan 08 2002The character of quantum corrections to the gravitational action of a conformally invariant field theory for a self-interacting scalar field on a manifold with boundary is considered at third loop-order in the perturbative expansion of the zero-point ... More
Scaling Behaviour of Conformal Fields in Curved Three-dimensional SpaceJan 12 1998Jan 15 1998The limitations of three-dimensional semi-classical gravity are explored in the context of a conformally invariant theory for a self-interacting scalar field. The analysis of the theory's scaling behaviour reveals that scalar-loop effects contribute to ... More
Conformal Anomaly for Free Scalar Propagation on Curved Bounded ManifoldsSep 15 2004The trace anomaly for free propagation in the context of a conformally invariant scalar field theory defined on a curved manifold of positive constant curvature with boundary is evaluated through use of an asymptotic heat kernel expansion. In addition ... More
Spherical Formulation for Diagramatic Evaluations on a Manifold with BoundaryJul 03 2001Jan 08 2002The mathematical formalism necessary for the diagramatic evaluation of quantum corrections to a conformally invariant field theory for a self-interacting scalar field on a curved manifold with boundary is considered. The evaluation of quantum corrections ... More
Interior error estimate for periodic homogenizationSep 09 2011In a previous article about the homogenization of the classical problem of diff usion in a bounded domain with su ciently smooth boundary we proved that the error is of order $\epsilon^{1/2}$. Now, for an open set with su ciently smooth boundary $C^{1,1}$ ... More
Heuristics in direction of a p-adic Brauer--Siegel theoremJan 12 2018Mar 13 2018Let p be a fixed prime number. Let K be a totally real number field of discriminant D\_K and let T\_K be the torsion group of the Galois group of the maximal abelian p-ramified pro-p-extension of K (under Leopoldt's conjecture). We conjecture the existence ... More
Interval Garside Structures for the Complex Braid Groups B(e,e,n)Jul 21 2017Oct 23 2018We define geodesic normal forms for the general series of complex reflection groups G(e,e,n). This requires the elaboration of a combinatorial technique in order to explicitly determine minimal word representatives of the elements of G(e,e,n) over the ... More
The p-adic Kummer-Leopoldt constant - Normalized p-adic regulatorJan 24 2017Apr 03 2017The p-adic Kummer--Leopoldt constant kappa\_K of a number field K is (assuming the Leopoldt conjecture) the least integer c such that for all n \textgreater{}\textgreater{} 0, any global unit of K, which is locally a p^(n+c)th power at the p-places, is ... More
Large-x structure of physical evolution kernels in Deep Inelastic ScatteringNov 23 2009Mar 11 2010The modified evolution equation for parton distributions of Dokshitzer, Marchesini and Salam is extended to non-singlet Deep Inelastic Scattering coefficient functions and the physical evolution kernels which govern their scaling violation. Considering ... More
On threshold resummation of the longitudinal structure functionOct 20 2009The validity of a previously proposed momentum space ansatz for threshold resummation of the non-singlet longitudinal structure function F_L is checked against existing finite order three-loop results. It is found that the ansatz, which is an assumption ... More
The classical pion field in a nucleusNov 08 2007Sep 04 2008A self-consistent symmetry arises when the nucleon angular momentum j and the isospin t are coupled to a grand spin G. Closed G shells become sources of a classical pion field with a hedgehog shape. Although the amplitude of the pion field, as measured ... More
Mass Determinations of Star ClustersJul 03 2001Mass determinations are difficult to obtain and still frequently characterised by deceptively large uncertainties. We review below the various mass estimators used for star clusters of all ages and luminosities. We highlight a few recent results related ... More
FreeFem++, a tool to solve PDEs numericallyMay 07 2012FreeFem++ is an open source platform to solve partial differential equations numerically, based on finite element methods. It was developed at the Laboratoire Jacques-Louis Lions, Universit\'e Pierre et Marie Curie, Paris by Fr\'ed\'eric Hecht in collaboration ... More
The Equation of a Light Leptonic Magnetic Monopole and its Experimental AspectsJan 17 2008The present theory is closely related to Dirac's equation of the electron, but not to his magnetic monopole theory, except for his relation between electric and magnetic charge. The theory is based on the fact, that the massless Dirac equation admits ... More
Doubles melanges des polylogarithmes multiples aux racines de l'unit'eFeb 15 2002The values at positive integers of the polyzeta functions are solutions of the polynomial equations arising from Drinfeld's associators, which have numerous applications in quantum algebra. Considered as iterated integrals they become periods of the motivic ... More
Annihilation of tor\_p(G\_S^ab) for real abelian extensionsJun 08 2018Oct 05 2018Preprint of a paper to appear in "Communications in Advanced Mathematical Sciences". Let K be a real abelian extension of Q. Let p be a prime number, S the set of p-places of K and G\_K,S the Galois group of the maximal S-ramified pro-p-extension of K ... More
Local theta-regulators of an algebraic number -- p-adic ConjecturesJan 10 2017Let K/Q be Galois and let eta in K* be such that the multiplicative Z[G]-module generated by eta is of Z-rank n.We define the local theta-regulators Delta\_p^theta(eta) in F\_p for the Q\_p-irreducible characters theta of G=Gal(K/Q). Let V\_theta be the ... More
Reduced 2-coloured Khovanov Homology detects the TrefoilAug 31 2018We prove that the reduced 2-coloured Khovanov homology detects the trefoil, using a spectral sequence to knot Floer homology.
Automorphisms of an orthomodular poset of projectionsNov 29 2002Oct 07 2003By using a lattice characterization of continuous projections defined on a topological vector space E arising from a dual pair, we determine the automorphism group of their orthomodular poset Proj(E) by means of automorphisms and anti-automorphisms of ... More
On higher energy decompositions and the sum-product phenomenonMar 13 2018Jun 04 2018Let $A \subset \mathbb{R}$ be finite. We quantitatively improve the Balog-Wooley decomposition, that is $A$ can be partitioned into sets $B$ and $C$ such that $$\max\{E^+(B) , E^{\times}(C)\} \lesssim |A|^{3 - 7/26}, \ \ \max \{E^+(B,A) , E^{\times}(C, ... More
Nondifferentiable functions of one-dimensional semimartingalesFeb 04 2008Jan 26 2010We consider decompositions of processes of the form $Y=f(t,X_t)$ where $X$ is a semimartingale. The function $f$ is not required to be differentiable, so It\^{o}'s lemma does not apply. In the case where $f(t,x)$ is independent of $t$, it is shown that ... More
Quillen's adjunction theorem for derived functors, revisitedNov 30 2006The aim of this paper is to present a very simple original, purely formal, proof of Quillen's adjunction theorem for derived functors, and of some more recent variations and generalizations of this theorem. This is obtained by proving an abstract adjunction ... More
Remark on non-Noether symmetries and bidifferential calculiMay 25 2001Jun 20 2001In the past few years both non-Noether symmetries and bidifferential calculi has been successfully used in generating conservation laws and both lead to the similar families of conserved quantities.Here relationship between Lutzky's integrals of motion ... More
Non-Noether symmetries in integrable modelsJul 09 2003Aug 13 2003In the present paper the non-Noether symmetries of the Toda model, nonlinear Schodinger equation and Korteweg-de Vries equations (KdV and mKdV) are discussed. It appears that these symmetries yield the complete sets of conservation laws in involution ... More
Enumerating quasi-Yamanouchi tableaux of Durfee size twoOct 13 2016Feb 20 2018Quasi-Yamanouchi tableaux connect the two most studied types of tableaux. They are a subset of semistandard Young tableaux that are also a refinement on standard Young tableaux, and they can be used to improve the fundamental quasisymmetric expansion ... More
Invariance principles for random walks in random environment on treesDec 26 2018We prove that, after rescaling the bias parameter properly, the biased random walk on the range of a large critical non-lattice branching random walk converges to a Brownian motion in a random Gaussian potential on Aldous' continuum random tree (CRT). ... More
Convergence of blanket times for sequences of random walks on critical random graphsOct 17 2018Under the assumption that sequences of graphs equipped with resistances, associated measures, walks and local times converge in a suitable Gromov-Hausdorff topology, we establish asymptotic bounds on the distribution of the $\varepsilon$-blanket times ... More
Matching of analytical and numerical solutions for neutron stars of arbitrary rotationJan 29 2012We demonstrate the results of an attempt to match the two-soliton analytical solution with the numerically produced solutions of the Einstein field equations, that describe the spacetime exterior of rotating neutron stars, for arbitrary rotation. The ... More
The April First PhenomenonMar 28 2014A true quantum reason for why people fib on April first.
A toy quantum analog of enzymesOct 19 2015We present a quantum system incorporating qualitative aspects of enzyme action in which the possibility of quantum superposition of several conformations of the enzyme-substrate complex is investigated. We present numerical results showing quantum effects ... More
Comparison of the Pulkovo Compilation of Radial Velocities with the RAVE DR1 CatalogueJun 25 2016The Data Release 1 of the Radial-Velocity Experiment (RAVE DR1, 24 748 stars) is compared with the May 15, 2006 version of the Pulkovo Compilation of Radial Velocities (PCRV, 35 495 stars). RAVE DR1 includes mostly $9^m-13^m$ stars, while the PCRV contains ... More
Localizing subcategories in the bootstrap category of filtered C*-algebrasFeb 01 2016We use the abelian approximation for the bootstrap category of filtered C*-algebras to define a sensible notion of support for its objects. As a consequence, we provide a full classification of localizing subcategories in terms of a product of lattices ... More
H0 RevisitedNov 14 2013Feb 08 2014I reanalyse the Riess et al. (2011, hereafter R11) Cepheid data using the revised geometric maser distance to NGC 4258 of Humphreys et al. (2013). I explore different outlier rejection criteria designed to give a reduced chi-squared of unity and compare ... More
Normal Galaxies in the InfraredMay 09 2000This review addresses what can be learned from infrared observations about galaxies powered predominantly by star formation. Infrared techniques mostly probe the interstellar medium of galaxies, yielding physical and chemical information on the medium ... More
A note on the norm convergence by Vilenkin-Fejér meansFeb 14 2015The main aim of this paper is to find necessary and sufficient conditions for the convergence of Fej\'er means in terms of the modulus of continuity on the Hardy spaces $H_{p},$ when $0<p\leq 1/2.$
Survival exponents for some Gaussian processesMar 12 2012The problem is a power-law asymptotics of the probability that a self-similar process does not exceed a fixed level during long time. The exponent in such asymptotics is estimated for some Gaussian processes, including the fractional Brownian motion (FBM) ... More
On the homotopy type of certain cobordism categories of surfacesAug 30 2010Mar 14 2011Let $\mathcal{A}_{g,d}$ be the (topological) cobordism category of orientable surfaces whose connected components are homeomorphic to either $S^1 \times I$ with one incoming and one outgoing boundary component or the surface $\Sigma_{g,d}$ of genus $g$ ... More
Projective Connections and Schwarzian Derivatives for Supermanifolds, and Batalin-Vilkovisky OperatorsSep 29 2009We extend the notion of a Thomas projective connection (a projective equivalence class of linear connections) for supermanifolds. As a by-product, we arrive at a generalisation of the multidimensional Schwarzian derivative for the super case which was ... More
A Canonical Laplacian on the Algebra of Densities on a Projectively Connected ManifoldSep 29 2009On a manifold with a projective connection we canonically assign a second order differential operator acting on the algebra of all densities to any tensor density $S^{ij}$ of fixed weight $\lambda$. In particular, this implies that on any projectively ... More
Some Early Ideas on the Metric Geometry of ThermodynamicsApr 09 2016It is a pleasure to write for this 90'th anniversary volume of Journal of Low Temperature Physics dedicated to Horst Meyer at Duke University. I was a PhD student with Horst in the period 1975-1980, working in experimental low temperature physics. While ... More
Notes on the vector adelic GrassmannianJun 23 2015These are notes about the connection between the Gibbons-Hermsen system and the multi-component KP hierarchy: they were intended as a first sketch of a paper on that subject, but since it seems unlikely that I will ever write such a paper I have decided ... More
On the quadratic action of the Hawking-Turok instantonApr 22 1998May 01 1998Positive definiteness of the quadratic part of the action of the Hawking-Turok instanton is investigated. The Euclidean quadratic action for scalar perturbations is expressed in terms of a single gauge invariant quantity $q$. The mode functions satisfy ... More
On instability of Rubakov-Shaposhnikov modelFeb 24 2010Instability of 6 dimensional Rubakov-Shaposhnikov model is reinvestigated. It is shown that the model is unstable in scalar perturbations sector with very particular instability pattern: there are no unstable modes for the first two lowest angular harmonics, ... More
Gravitating, Gravitational and Dilatonic SphaleronsAug 05 1995This is a brief review of the main properties of sphalerons in various theories with a Yang--Mills field. Talk given at the Heat Kernel Techniques and Quantum Gravity, Winnipeg, Canada, August 2-6, 1994.
Solution of the Gross-Pitaevskii equation in terms of the associated non-linear Hartree potentialJul 15 2013The Gross-Pitaevskii equation (GP), that describes the wave function of a number of coherent Bose particles contained in a trap, contains the cube of the normalized wave function, times a factor proportional to the number of coherent atoms. The square ... More
Iterative solution of integral equations on a basis of positive energy Sturmian eigenfunctionsFeb 10 2011Years ago S. Weinberg suggested the "Quasi-Particle" method (Q-P) for iteratively solving an integral equation, based on an expansion in terms of sturmian functions that are eigenfunctions of the integral kernel. An improvement of this method is presented ... More
Rashba-Dirac cones at the tungsten surface: Insights from a tight-binding model and thin film subband structureNov 11 2016A tight-binding model of bcc tungsten that includes spin-orbit coupling is developed and applied to the surface states of (110) tungsten thin films. The model describes accurately the anisotropic Dirac cone-like dispersion and Rashba-like spin polarization ... More
On the appearance of compact objects at radio and optical frequenciesJun 25 2009In the dark energy star picture a compact object is transparent at radio and optical frequencies, and acts as a defocusing lens. Thus the object itself appears as a luminous disk whose surface brightness reflects the surface brightness of the background. ... More
Blueprint for a rotating UniversAug 17 2006Aug 24 2006A solution of the vacuum Einstein equations with a cosmological constant is exhibited which can perhaps be used to describe the interior of compact rotating objects, and may also provide a description of our universe on length scales approaching the size ... More
Quantum Criticality and the Alpha/Delta PuzzleOct 11 2008In this paper we suggest a novel explanation for the alpha-delta transition in plutonium based on an analogy between the evolution of the actinide ground state as a function of spin orbit coupling and the behaviour of thin film superconductors in a magnetic ... More
Quantized Detector Networks: A review of recent developmentsSep 26 2007QDN (quantized detector networks) is a description of quantum processes in which the principal focus is on observers and their apparatus, rather than on states of SUOs (systems under observation). It is a realization of Heisenberg's original instrumentalist ... More
The running of the Universe and the quantum structure of timeMay 04 2001May 14 2001Some principles underpinning the running of the Universe are discussed. The most important, the machine principle, states that the Universe is a fully autonomous, self-organizing and self-testing quantum automaton. Continuous space and time, consciousness ... More
Discrete spacetime: classical causality,prediction, retrodiction and the mathematical arrow of timeApr 08 2000A mathematical definition of classical causality over discrete spacetime dynamics is formulated. The approach is background free and permits a definition of causality in a precise way whenever the spacetime dynamics permits. It gives a natural meaning ... More
The Emergence of Norms via Contextual Agreements in Open SocietiesMar 24 2015This paper explores the emergence of norms in agents' societies when agents play multiple -even incompatible- roles in their social contexts simultaneously, and have limited interaction ranges. Specifically, this article proposes two reinforcement learning ... More