Results for "Adrian Dobra"

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Identifying mediating variables with graphical models: an application to the study of causal pathways in people living with HIVJul 10 2019We empirically demonstrate that graphical models can be a valuable tool in the identification of mediating variables in causal pathways. We make use of graphical models to elucidate the causal pathway through which the treatment influences the levels ... More
Graphical Modeling of Spatial Health DataNov 24 2014The literature on Gaussian graphical models (GGMs) contains two equally rich and equally significant domains of research efforts and interests. The first research domain relates to the problem of graph determination. That is, the underlying graph is unknown ... More
Dynamic Markov BasesMar 25 2011We present a computational approach for generating Markov bases for multi-way contingency tables whose cells counts might be constrained by fixed marginals and by lower and upper bounds. Our framework includes tables with structural zeros as a particular ... More
Copula Gaussian graphical models and their application to modeling functional disability dataAug 08 2011We propose a comprehensive Bayesian approach for graphical model determination in observational studies that can accommodate binary, ordinal or continuous variables simultaneously. Our new models are called copula Gaussian graphical models (CGGMs) and ... More
Loglinear model selection and human mobilityNov 07 2017Methods for selecting loglinear models were among Steve Fienberg's research interests since the start of his long and fruitful career. After we dwell upon the string of papers focusing on loglinear models that can be partly attributed to Steve's contributions ... More
Measuring Human Activity Spaces from GPS Data with Density Ranking and Summary CurvesAug 16 2017Sep 17 2018Activity spaces are fundamental to the assessment of individuals' dynamic exposure to social and environmental risk factors associated with multiple spatial contexts that are visited during activities of daily living. In this paper we survey existing ... More
Sparse covariance estimation in heterogeneous samplesJan 23 2010Standard Gaussian graphical models (GGMs) implicitly assume that the conditional independence among variables is common to all observations in the sample. However, in practice, observations are usually collected form heterogeneous populations where such ... More
Relational models for contingency tablesFeb 26 2011Mar 03 2011The paper considers general multiplicative models for complete and incomplete contingency tables that generalize log-linear and several other models and are entirely coordinate free. Sufficient conditions of the existence of maximum likelihood estimates ... More
Spatiotemporal Detection of Unusual Human Population Behavior Using Mobile Phone DataNov 22 2014With the aim to contribute to humanitarian response to disasters and violent events, scientists have proposed the development of analytical tools that could identify emergency events in real-time, using mobile phone data. The assumption is that dramatic ... More
Bayesian inference for general Gaussian graphical models with application to multivariate lattice dataMay 21 2010We introduce efficient Markov chain Monte Carlo methods for inference and model determination in multivariate and matrix-variate Gaussian graphical models. Our framework is based on the G-Wishart prior for the precision matrix associated with graphs that ... More
Restricted Covariance Priors with Applications in Spatial StatisticsFeb 23 2014Dec 03 2015We present a Bayesian model for area-level count data that uses Gaussian random effects with a novel type of G-Wishart prior on the inverse variance--covariance matrix. Specifically, we introduce a new distribution called the truncated G-Wishart distribution ... More
A conjugate prior for discrete hierarchical log-linear modelsNov 10 2007Sep 02 2009In Bayesian analysis of multi-way contingency tables, the selection of a prior distribution for either the log-linear parameters or the cell probabilities parameters is a major challenge. In this paper, we define a flexible family of conjugate priors ... More
Modeling association in microbial communities with clique loglinear modelsJan 23 2018There is a growing awareness of the important roles that microbial communities play in complex biological processes. Modern investigation of these often uses next generation sequencing of metagenomic samples to determine community composition. We propose ... More
Analyzing Genome-wide Association Study Data with the R Package genMOSSNov 22 2016The R package (R Core Team (2016)) genMOSS is specifically designed for the Bayesian analysis of genome-wide association study data. The package implements the mode oriented stochastic search (MOSS) procedure as well as a simple moving window approach ... More
Measures of Human Mobility Using Mobile Phone Records Enhanced with GIS DataAug 20 2014In the past decade, large scale mobile phone data have become available for the study of human movement patterns. These data hold an immense promise for understanding human behavior on a vast scale, and with a precision and accuracy never before possible ... More
A note on simplicial dimension shiftingFeb 08 1993We discuss a simplicial dimension shift which associates to each n-manifold an n-1-manifold. As a corollary we show that an invariant which was recently proposed by Ooguri and by Crane and Yetter for the construction of 4-dimensional quantum field theories ... More
Canonical Seesaw Mechanism in Electro-Weak SU(4)L x U(1)Y ModelsAug 12 2009In this paper we prove that the canonical seesaw mechanism can naturally be implemented in a particular class of electro-weak SU(4)L x U(1)Y gauge models. The resulting neutrino mass spectrum is determined by just tuning a unique free parameter 'a' within ... More
Boson mass spectrum in $SU(4)_L\otimes U(1)_Y$ model with exotic electric chargesFeb 11 2009Apr 12 2009The boson mass spectrum of the electro-weak \textbf{$SU(4)_{L}\otimes U(1)_{Y}$} model with exotic electric charges is investigated by using the algebraical approach supplied by the method of exactly solving gauge models with high symmetries. Our approach ... More
Neutrino Masses with a Suitable Parametrization in the PPF 3-3-1 Gauge ModelJul 20 2008Plausible phenomenological consequences of the well-known Pisano-Pleitez- Frampton 3-3-1 model - such as the neutrino masses - are analyzed within the solution provided by the exact algebraical approach - proposed several years ago by Cotaescu - for gauge ... More
Phenomenology of high gluon density QCD and heavy-ion physics at ISMD 2011: x smaller than ever !Dec 14 2011Jan 11 2012I provide a brief summary of the theory presentations at ISMD 2011 related to the phenomenology of small-x QCD evolution and its application to particle production and fluctuations in high-energy hadron and heavy-ion collisions. I also mention some challenges ... More
Compact actions and uniqueness of the group measure space decomposition of II$_1$ factorsDec 05 2011We prove that any II$_1$ factor $L^{\infty}(X)\rtimes\Gamma$ arising from a compact, free, ergodic, probability measure preserving action of a countable group $\Gamma$ with positive first $\ell^2$-Betti number, has a unique group measure space Cartan ... More
W*-superrigidity for Bernoulli actions of property (T) groupsFeb 24 2010Apr 19 2011We consider group measure space II$_1$ factors $M=L^{\infty}(X)\rtimes\Gamma$ arising from Bernoulli actions of ICC property (T) groups $\Gamma$ (more generally, of groups $\Gamma$ containing an infinite normal subgroup with relative property (T)) and ... More
The charm quark mass from non-relativistic sum rulesOct 07 2008We present an analysis to determine the charm quark mass from non-relativistic sum rules, using a combined approach taking into account fixed-order and effective-theory calculations. Non-perturbative corrections as well as higher-order perturbative corrections ... More
Decay of metastable patterns for the Rosensweig instability: revisiting the dispersion relationApr 28 2003The decay of metastable patterns in the form of magnetic liquid ridges is studied in the frame of a linear stability analysis where the ridges are the most unstable linear pattern of the Rosensweig instability. The analysis of the corresponding dispersion ... More
Magnetic Soret effect: Application of the ferrofluid dynamics theoryNov 11 2004The ferrofluid dynamics theory is applied to thermodiffusive problems in magnetic fluids in the presence of magnetic fields. The analytical form for the magnetic part of the chemical potential and the most general expression of the mass flux are given. ... More
Thermomagnetic convection of magnetic fluids in a cylindrical geometryApr 09 2002The thermomagnetic convection of magnetic fluids in a cylindrical geometry subjected to a homogeneous magnetic field is studied. The study is motivated by a novel thermal instability [W. Luo et al., Phys. Rev. Lett. 82, 4134 (1999)]. As model system a ... More
On the Number of Divisors of $n^2 -1$Jul 30 2015We prove an asymptotic formula for the sum $\sum_{n \leq N} d(n^2 - 1)$, where $d(n)$ denotes the number of divisors of $n$. During the course of our proof, we also furnish an asymptotic formula for the sum $\sum_{d \leq N} g(d)$, where $g(d)$ denotes ... More
Quantum Reality via Late Time PhotodetectionAug 16 2016Nov 14 2016We further investigate postulates for realist versions of relativistic quantum theory and quantum field theory in Minkowski space and other background space-times. According to these postulates, quantum theory is supplemented by local variables that depend ... More
Inference-based semantics in Data ExchangeMay 07 2016Data Exchange is an old problem that was firstly studied from a theoretical point of view only in 2003. Since then many approaches were considered when it came to the language describing the relationship between the source and the target schema. These ... More
Implementing inverse seesaw mechanism in SU(3)xSU(4)xU(1) gauge modelsOct 21 2015Generating appropriate tiny neutrino masses via inverse seesaw mechanism within the framework of a particular SU(3)xSU(4)xU(1) gauge model is the main outcome of this letter. It is achieved by simply adding three singlet exotic Majorana neutrinos to the ... More
Some Notes on Digit Strings in the PrimesJul 28 2014Jul 30 2014Let $S$ be a string of $l$ decimal digits. We give an explicit upper bound on some prime $p$ whose decimal representation contains the string $S$. We also show, as a corollary of the Green-Tao theorem, that there are arbitrarily long arithmetic progressions ... More
Privacy and AnonymityJul 01 2014Since the beginning of the digital area, privacy and anonymity have been impacted drastically (both, positively and negatively), by the different technologies developed for communications purposes. The broad possibilities that the Internet offers since ... More
Deformation of Quintic Threefolds to the Chordal VarietyNov 12 2015We consider a family of quintic threefolds specializing to a certain reducible threefold. We describe the space of genus zero stable morphisms to the central fiber (as defined by J. Li). As an elementary application of an extension of the analysis, we ... More
T symmetry invariance tests in neutral meson decaysNov 04 2013We outline how the time-reversal symmetry T can be systematically used to test the Kobayashi-Maskawa mechanism embedded in the CKM matrix using pairs of B mesons created at the Upsilon(4S) and pairs of D mesons from psi(3770).
On Extracting Unit Tests from Interactive Programming SessionsDec 08 2012Software engineering methodologies propose that developers should capture their efforts in ensuring that programs run correctly in repeatable and automated artifacts, such as unit tests. However, when looking at developer activities on a spectrum from ... More
Two--loop heavy Higgs correction to Higgs decay into vector bosonsJul 05 1995Oct 02 1995The leading $m_H$ radiative correction to the Higgs decay width into a pair of weak vector bosons is calculated at the two--loop level, using the equivalence theorem in Landau gauge. The result indicates the breakdown of perturbation theory if the Higgs ... More
Verification, Validation and Integrity of Distributed and Interchanged Rule Based Policies and Contracts in the Semantic WebSep 21 2006Sep 29 2006Rule-based policy and contract systems have rarely been studied in terms of their software engineering properties. This is a serious omission, because in rule-based policy or contract representation languages rules are being used as a declarative programming ... More
The Reaction RuleML Classification of the Event / Action / State Processing and Reasoning SpaceNov 10 2006Reaction RuleML is a general, practical, compact and user-friendly XML-serialized language for the family of reaction rules. In this white paper we give a review of the history of event / action /state processing and reaction rule approaches and systems ... More
A Class of Multirate Infinitesimal GARK MethodsAug 07 2018Differential equations arising in many practical applications are characterized by multiple time scales. Multirate time integration seeks to solve them efficiently by discretizing each scale with a different, appropriate time step, while ensuring the ... More
GGP with Advanced Reasoning and Board Knowledge DiscoveryJan 22 2014Quality of General Game Playing (GGP) matches suffers from slow state-switching and weak knowledge modules. Instantiation and Propositional Networks offer great performance gains over Prolog-based reasoning, but do not scale well. In this publication ... More
A new way of setting the phases for cosmological multi-scale Gaussian initial conditionsJun 25 2013We describe how to define an extremely large discrete realisation of a Gaussian white noise field that has a hierarchical structure and the property that the value of any part of the field can be computed quickly. Tiny subregions of such a field can be ... More
Second-order Lagrangian perturbation theory initial conditions for resimulationsOct 01 2009Jan 11 2010We describe and test a new method for creating initial conditions for cosmological N-body dark matter simulations based on second-order Lagrangian perturbation theory (2lpt). The method can be applied to multi-mass particle distributions making it suitable ... More
Comments on an argument of Tegmark and BostromDec 16 2005Dec 18 2005Withdrawn -- a revised version will appear in due course.
Large N Quantum CryptographyDec 08 2002In quantum cryptography, the level of security attainable by a protocol which implements a particular task $N$ times bears no simple relation to the level of security attainable by a protocol implementing the task once. Useful partial security, and even ... More
Night Thoughts of a Quantum PhysicistJun 22 1999Feb 08 2000The most dramatic developments in theoretical physics in the next millennium are likely to come when we make progress on so far unresolved foundational questions. In this essay I consider two of the deepest problems confronting us, the measurement problem ... More
Quantum HistoriesSep 04 1998There are good motivations for considering some type of quantum histories formalism. Several possible formalisms are known, defined by different definitions of event and by different selection criteria for sets of histories. These formalisms have a natural ... More
Secure Multi-Party Addition via Quantum StatesNov 17 1997Feb 28 2005This paper was withdrawn on 20.11.97.
Quanta and QualiaAug 16 2016Jul 04 2018I sketch a line of thought about consciousness and physics that gives some motivation for the hypothesis that conscious observers deviate - perhaps only very subtly and slightly - from quantum dynamics. Although it is hard to know just how much credence ... More
Location-Oblivious Data Transfer with Flying Entangled QuditsFeb 14 2011Jul 14 2011We present a simple and practical quantum protocol involving two mistrustful agencies in Minkowski space, which allows Alice to transfer data to Bob at a spacetime location that neither can predict in advance. The location depends on both Alice's and ... More
One world versus many: the inadequacy of Everettian accounts of evolution, probability, and scientific confirmationMay 05 2009Jul 04 2013There is a compelling intellectual case for exploring whether purely unitary quantum theory defines a sensible and scientifically adequate theory, as Everett originally proposed. Many different and incompatible attempts to define a coherent Everettian ... More
Problems with empirical bounds for strangelet production at RHICSep 11 2000Sep 11 2000Recent papers by Busza et al. and Dar et al. have considered empirical bounds on the risk of producing a hypothetical stable negatively charged strangelet at the Brookhaven relativistic heavy ion collider (RHIC) experiments, and thereby destroying the ... More
Unconditionally Secure All-Or-Nothing Disclosure of SecretsNov 16 1997Feb 28 2005This paper was withdrawn on 20.11.97.
Causality in Time-Neutral CosmologiesMar 17 1997Nov 26 1998Gell-Mann and Hartle (GMH) have recently considered time-neutral cosmological models in which the initial and final conditions are independently specified, and several authors have investigated experimental tests of such models. We point out here that ... More
Complex product structures on 6-dimensional nilpotent Lie algebrasOct 26 2006We study complex product structures on nilpotent Lie algebras, establishing some of their main properties, and then we restrict ourselves to 6 dimensions, obtaining the classification of 6-dimensional nilpotent Lie algebras admitting such structures. ... More
Regularizing a singular special Lagrangian varietyOct 04 2001Jan 04 2002Suppose $M_{1}$ and $M_{2}$ are two special Lagrangian submanifolds of $\Rtn$ with boundary that intersect transversally at one point $p$. The set $M_{1} \cup M_{2}$ is a singular special Lagrangian variety with an isolated singularity at the point of ... More
Comment on 'Pi in the Sky' by Frolop and Scott: They LieMar 31 2017Frolop and Scott (2016) claim significant 1-1 correspondence between anomalies in the cosmic microwave background (CMB) and the digits of pi, which they call 'Pi in the Sky'. They have without attribution republished the famous work of Joe Hill (Hill ... More
Nearby cycles and semipositivity in positive characteristicFeb 15 2019Mar 12 2019We study restriction of logarithmic Higgs bundles to the boundary divisor and we construct the corresponding nearby-cycles functor in positive characteristic. As applications we prove some strong semipositivity theorems for analogs of complex polarized ... More
On Hecke algebras and simple supercuspidal representations for Sp(4,F)Oct 12 2012A well known result of Borel says that the category of modules over the Iwahori-Hecke algebra of a semisimple p-adic group G describes the Bernstein component associated to the unramified principal series of G. We consider Bernstein components for Sp(4,F) ... More
Relaxation of Functionals in the Space of Vector-Valued Functions of Bounded HessianFeb 08 2018In this paper it is shown that if $\Omega \subset \mathbb{R}^N$ is an open, bounded Lipschitz set, and if $f: \Omega \times \mathbb{R}^{d \times N \times N} \rightarrow [0, \infty)$ is a continuous function with $f(x, \cdot)$ of linear growth for all ... More
Good Reductions of Shimura Varieties of Hodge Type in Arbitrary Unramified Mixed Characteristic, Part IJul 11 2007Sep 08 2016We prove the existence of good smooth integral models of Shimura varieties of Hodge type in arbitrary unramified mixed characteristic $(0,p)$. As a first application we solve a conjecture of Langlands for Shimura varieties of Hodge type. As a second application ... More
Integral canonical models of unitary Shimura varietiesMay 24 2005Oct 11 2007We prove the existence of integral canonical models of unitary Shimura varieties in arbitrary unramified mixed characteristic. Errata to [Va1] are also included.
A motivic conjecture of MilneAug 20 2003Jan 24 2012Let k be an algebraically closed field of characteristic p>0. Let W(k) be the ring of Witt vectors with coefficients in k. We prove a motivic conjecture of Milne that relates, in the case of abelian schemes, the \'etale cohomology with $\dbZ_p$ coefficients ... More
Surjectivity Criteria for p-adic Representations, Part ISep 18 2002Apr 08 2004We prove several surjectivity criteria for $p$-adic representations. In particular, we classify all adjoint and simply connected group schemes $G$ over the Witt ring $W(k)$ of a finite field $k$ such that the epimorphism $G(W_2(k))\twoheadrightarrow G(k)$ ... More
Lübeck's classification of Chevalley groups representations and the inverse Galois problem for some orthogonal groupsDec 15 2017Dec 04 2018In this paper we prove that for each integer of the form $n=4\varpi$ (where $\varpi$ is a prime between $17$ and $73$) at least one of the following groups: $P\Omega^+_n(\mathbb{F}_{\ell^s})$, $PSO^+_n(\mathbb{F}_{\ell^s})$, $PO_n^+(\mathbb{F}_{\ell^s})$ ... More
V-monotone independenceJan 18 2019We introduce and study a new notion of non-commutative independence, called V-monotone independence, which can be viewed as an extension of the monotone independence of Muraki. We investigate the combinatorics of mixed moments of V-monotone random variables ... More
Geometry of Shimura varieties of Hodge type over finite fieldsDec 11 2007We present a general and comprehensive overview of recent developments in the theory of integral models of Shimura varieties of Hodge type. The paper covers the following topics: construction of integral models, their possible moduli interpretations, ... More
The Severi problem for abelian surfaces in the primitive caseNov 03 2018We prove that the irreducible components of primitive class Severi varieties of general abelian surfaces are completely determined by the maximal factorization through an isogeny of the maps from the normalized curves.
Extension theorems for reductive group schemesJun 24 2004Dec 22 2015We prove several basic extension theorems for reductive group schemes. We also prove that each Lie algebra with a perfect Killing form over a commutative $\dbZ$-algebra, is the Lie algebra of an adjoint group scheme.
Generalized Serre--Tate Ordinary TheoryAug 28 2002May 01 2012We study a generalization of Serre--Tate theory of ordinary abelian varieties and their deformation spaces. This generalization deals with abelian varieties equipped with additional structures. The additional structures can be not only an action of a ... More
The Multi-Orientable Random Tensor Model, a ReviewDec 07 2015Jun 15 2016After its introduction (initially within a group field theory framework) in [Tanasa A., J. Phys. A: Math. Theor. 45 (2012), 165401, 19 pages, arXiv:1109.0694], the multi-orientable (MO) tensor model grew over the last years into a solid alternative of ... More
Translation-Invariant Noncommutative RenormalizationMar 25 2010Jun 08 2010We review here the construction of a translation-invariant scalar model which was proved to be perturbatively renormalizable on Moyal space. Some general considerations on nonlocal renormalizability are given. Finally, we present perspectives for generalizing ... More
Tensor models, a quantum field theoretical particularizationNov 19 2012Nov 20 2012Random matrix models have been extensively studied in mathematical physics and have proven useful in combinatorics. In this review paper we introduce a generalization of these models to a class of tensor models. As the topology and combinatorics of these ... More
Scalar and gauge translation-invariant noncommutative modelsAug 27 2008We make here a short overview of the recent developments regarding translation-invariant models on the noncommutative Moyal space. A scalar model was first proposed and proved renormalizable. Its one-loop renormalization group flow and parametric representation ... More
Two-loop effects of enhanced electroweak strength in the Higgs sectorJul 28 1996Aug 11 1996The selfcoupling of the Higgs field grows with the mass of the Higgs particle and induces potentially large radiative corrections in the electroweak model. The technical aspects of performing multiloop calculations in the massive case are discussed briefly. ... More
Electro-weak $SU(4)_L\otimes U(1)_Y$ models without exotic electric chargesFeb 21 2009For the particular class of \textbf{$SU(4)_{L}\otimes U(1)_{Y}$} electro-weak models without exotic electric charges, some plausible phenomenological predictions - such as the boson mass spectrum and charges of all the fermions involved therein - are ... More
Implementing Canonical Seesaw Mechanism in a 3-3-1 Gauge Model without Exotic Electric ChargesMay 13 2006We prove that - even at a low TeV scale - the canonical seesaw mechanism can be naturally implemented in the exact solution of a particular 3-3-1 gauge model, since a very small alteration $\epsilon$ in the parameter matrix of the Higgs sector is taken ... More
The traveling salesman problem for lines and rays in the planeApr 26 2012In the Euclidean TSP with neighborhoods (TSPN), we are given a collection of $n$ regions (neighborhoods) and we seek a shortest tour that visits each region. In the path variant, we seek a shortest path that visits each region. We present several linear-time ... More
Quantum Reality via Late Time PhotodetectionAug 16 2016We further investigate postulates for realist versions of relativistic quantum theory and quantum field theory in Minkowski space and other background space-times. According to these postulates, quantum theory is supplemented by local variables that depend ... More
Color Glass Condensate at RHIC ?Mar 14 2002Heavy-ion collisions at the BNL-RHIC collider can probe whether gluon saturation effects in nuclei at small x have set in, or whether leading-twist perturbative estimates of particle production are still applicable. I discuss that soon to come data from ... More
Abc of SUSYMay 28 2009This article is a very basic introduction to supersymmetry. It introduces the two kinds of superfields needed for supersymmetric extensions of the Standard Model, the chiral superfield and the vector superfield, and discusses in detail how to construct ... More
A theoretical update on t \bar{t} production near thresholdApr 04 2006We present an evaluation of the t\bar{t} cross section near threshold at next-to-next-to-leading logarithmic accuracy, using a two-step matching procedure. QED corrections are taken into account as well and are shown to be numerically important. Finally ... More
The Physics Programme at SuperBDec 06 2011SuperB is a next generation high luminosity $e^+e^-$ collider that will be built at the Cabibbo Laboratory, Tor Vergata, in Italy. The physics goals of this experiment are to search for signs of physics beyond the Standard Model through precision studies ... More
Kelvin force in a layer of magnetic fluidApr 09 2002The Kelvin force in a layer of magnetic fluid subjected to a homogeneous magnetic field and local heating is studied. The study is motivated by the question about the corresponding Kelvin force density [M. Liu, Phys. Rev. Lett., 2762 (2000)]. It is shown ... More
The adjoint problem in the presence of a deformed surface: the example of the Rosensweig instability on magnetic fluidsApr 09 2002The Rosensweig instability is the phenomenon that above a certain threshold of a vertical magnetic field peaks appear on the free surface of a horizontal layer of magnetic fluid. In contrast to almost all classical hydrodynamical systems, the nonlinearities ... More
Use of the gravitational-wave interferometers to test Lorentz invariance violationAug 10 2016Currently operating gravitational-wave interferometers are Michelson interferometers with effective arm length L ~ 4x10e5 m. While the interferometer remains in lock, data at the fsr sideband frequency encode information on slow phase changes in the f ... More
Nearby cycles and semipositivity in positive characteristicFeb 15 2019We study restriction of logarithmic Higgs bundles to the boundary divisor and we construct the corresponding nearby-cycles functor in positive characteristic. As applications we prove some strong semipositivity theorems for analogs of complex polarized ... More
Approximation of smooth functions using Bernstein polynomials in multiple variablesSep 07 2016In this survey, we use (more or less) elementary means to establish the well-known result that for any given smooth multivariate function, the respective multivariate Bernstein polynomials converge to that function in all derivatives on each compact set. ... More
Rule-based Knowledge Representation for Service Level AgreementSep 21 2006Automated management and monitoring of service contracts like Service Level Agreements (SLAs) or higher-level policies is vital for efficient and reliable distributed service-oriented architectures (SOA) with high quality of ser-vice (QoS) levels. IT ... More
Feynman amplitudes in renormalizable non-commutative quantum field theoryNov 21 2007We consider here the Feynman amplitudes of renormalizable non-commutative quantum field theory models. Different representations (the parametric and the Mellin one) are presented. The latter further allows the proof of meromorphy of a amplitude in the ... More
Comment on "Spacetime Information"Oct 31 1996Mar 21 1997A recent paper by Hartle [Phys. Rev. D 51, 1800 (1995)] proposes a definition of "spacetime information" - the information available about a quantum system's boundary conditions in the various sets of decohering histories it may display - and investigates ... More
Beable-Guided Quantum Theories: Generalising Quantum Probability LawsApr 26 2012Jul 27 2018We introduce the idea of a {\it beable-guided quantum theory}. Beable-guided quantum theories (BGQT) are generalisations of quantum theory, inspired by Bell's concept of beables. They modify the quantum probabilities for some specified set of fundamental ... More
Beyond Boundary Conditions: General Cosmological TheoriesMay 05 2009Time-symmetric cosmological theories, in which the initial and final states are arranged to have similar features or are independently fixed, have been quite extensively discussed in the literature. However, a more general and perhaps more useful possibility ... More
Unconditionally Secure Bit CommitmentOct 22 1998Aug 04 1999We describe a new classical bit commitment protocol based on cryptographic constraints imposed by special relativity. The protocol is unconditionally secure against classical or quantum attacks. It evades the no-go results of Mayers, Lo and Chau by requiring ... More
Permanently Secure Quantum Bit Commitment from a Temporary Computation BoundDec 01 1997Aug 20 1999This paper has been withdrawn. See quant-ph/9806031 for a discussion.
Unconditionally Secure Multi-Party ComputationNov 16 1997Feb 28 2005This paper was withdrawn on 20.11.97.
Quantum Histories and Their ImplicationsJul 30 1996May 23 2000Classical mechanics and standard Copenhagen quantum mechanics respect subspace implications. For example, if a particle is confined in a particular region $R$ of space, then in these theories we can deduce that it is confined in regions containing $R$. ... More
Quantum Tagging for Tags Containing Secret Classical DataAug 31 2010Aug 27 2011Various authors have considered schemes for {\it quantum tagging}, that is, authenticating the classical location of a classical tagging device by sending and receiving quantum signals from suitably located distant sites, in an environment controlled ... More
Unconditionally Secure Commitment of a Certified Classical Bit is ImpossibleOct 20 1999Nov 03 1999In a secure bit commitment protocol involving only classical physics, A commits either a 0 or a 1 to B. If quantum information is used in the protocol, A may be able to commit a state of the form $\alpha \ket{0} + \beta \ket{1}$. If so, she can also commit ... More
Coin Tossing is Strictly Weaker Than Bit CommitmentOct 22 1998Oct 29 1999We define cryptographic assumptions applicable to two mistrustful parties who each control two or more separate secure sites between which special relativity guarantees a time lapse in communication. We show that, under these assumptions, unconditionally ... More
Quantum Bit Commitment from a Computation BoundNov 26 1997Aug 20 1999This paper is withdrawn. See quant-ph/9806031 for a discussion.