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Results for "Leila Lobato Graef"

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Swampland conjecture in $f(R)$ gravity by the Noether Symmetry ApproachMay 14 2019Swampland conjecture has been recently proposed to connect early time cosmological models with the string landscape, and then to understand if related scalar fields and potentials can come from some fundamental theory in the high energy regime. In this ... More
Large Deviations for a Class of Semilinear Stochastic Partial Differential Equations in Arbitrary Space DimensionNov 10 2017We prove the large deviation principle (LDP) for the law of the solutions to a class of parabolic semilinear stochastic partial differential equations (SPDEs) driven by multiplicative noise using the weak convergence method. The space dimension is arbitrary ... More
Breaking of Spatial Diffeomorphism Invariance, Inflation and the Spectrum of Cosmological PerturbationsJun 02 2015Standard inflationary models yield a characteristic signature of a primordial power spectrum with a red tensor and scalar tilt. Nevertheless, Cannone et al recently suggested that, by breaking the assumption of spatial diffeomorphism invariance in the ... More
Phase transition of generalized two dimensional Yang-Mills U(N) on the sphere for $G(z)=z^4+λ\,z^3$ and Maxwell constructionAug 05 2016The large-N behavior of the quartic-cubic generalized two dimensional Yang-Mills U(N) on the sphere is investigated for finite cubic couplings. First, it is shown that there are two phase transitions one of which is third order and the other one is second ... More
Scalable Gaussian Process Classification via Expectation PropagationJul 16 2015Variational methods have been recently considered for scaling the training process of Gaussian process classifiers to large datasets. As an alternative, we describe here how to train these classifiers efficiently using expectation propagation. The proposed ... More
ARI, GARI, Zig and Zag: An introduction to Ecalle's theory of multiple zeta valuesJul 06 2015This text has two goals. The first is to give an introduction to Ecalle's work on mould theory, multiple zeta values and double shuffle theory and relate this work explicitly to the classical theory of multiple zeta values and double shuffle expressed ... More
A Note On Gorenstein Injective DimensionMay 22 2006The Chouinard's formula for injective dimension is extended to the Gorenstein injective dimension.
The smallest part of the generic partition of the nilpotent commutator of a nilpotent matrixFeb 22 2013Let $k$ be an infinite field. Fix a Jordan nilpotent $n$ by $n$ matrix $B = J_P$ with entries in $k$ and associated Jordan type $P$. Let $Q(P)$ be the Jordan type of a generic nilpotent matrix commuting with $B$. In this paper, we use the combinatorics ... More
The poset of the nilpotent commutator of a nilpotent matrixFeb 27 2012Dec 21 2012Let $B$ be an $n \times n$ nilpotent matrix with entries in an infinite field $\k$. Assume that $B$ is in Jordan canonical form with the associated Jordan block partition $P$. In this paper, we study a poset $\mathcal{D}_P$ associated to the nilpotent ... More
Double Shuffle and Kashiwara-Vergne Lie algebrasJan 25 2012We prove that the double shuffle Lie algebra ds, dual to the space of new formal multiple zeta values, injects into the Kashiwara-Vergne Lie algebra krv defined and studied by Alekseev-Torossian. The proof is based on a reformulation of the definition ... More
Non-linear diffusion in RD and in Hilbert Spaces, a Cylindrical/Functional Integral StudyFeb 27 2010Jul 02 2012We present a proof for the existence and uniqueness of weak solutions for a cut-off and non cut-off model of non-linear diffusion equation in finite-dimensional space RD useful for modelling flows on porous medium with saturation, turbulent advection, ... More
Gaussian Process Conditional Copulas with Applications to Financial Time SeriesJul 01 2013The estimation of dependencies between multiple variables is a central problem in the analysis of financial time series. A common approach is to express these dependencies in terms of a copula function. Typically the copula function is assumed to be constant ... More
Superstrings, Phenomenology and F-theoryDec 29 2009Jan 05 2010We give brief ideas on building gauge models in superstring theory, especially the four-dimensional models obtained from the compactification of F-theory. According to Vafa, we discuss the construction of F-theory to approach non-perturbative aspects ... More
Using arguments for making decisions: A possibilistic logic approachJul 11 2012Humans currently use arguments for explaining choices which are already made, or for evaluating potential choices. Each potential choice has usually pros and cons of various strengths. In spite of the usefulness of arguments in a decision making process, ... More
Multifractal Formalism and Inequality involving Packing DimensionJun 07 2008This article fits in many studies of multifractal analysis of measure. We took as a starting point the work of F. Ben Nasr in " Calculs de dimension de packing " to give a new inequality involving $Dim(\bar{X}^{\alpha})$ which would be, in certain cases, ... More
Period polynomial relations between double zeta valuesSep 17 2011The even weight period polynomial relations in the double shuffle Lie algebra $\mathfrak{ds}$ were discovered by Ihara, and completely classified by the second author by relating them to restricted even period polynomials associated to cusp forms on $\mathrm{SL}_2(\mathbb{Z})$. ... More
Around a conjecture of ErdH{o}s on graph Ramsey numbersNov 27 2012For given graphs G1 and G2 the Ramsey number R(G1,G2), is the smallest positive integer n such that each blue-red edge coloring of the complete graph Kn contains a blue copy of G1 or a red copy of G2. In 1983, Erdos conjectured that there is an absolute ... More
CLaC at SemEval-2016 Task 11: Exploring linguistic and psycho-linguistic Features for Complex Word IdentificationSep 08 2017This paper describes the system deployed by the CLaC-EDLK team to the "SemEval 2016, Complex Word Identification task". The goal of the task is to identify if a given word in a given context is "simple" or "complex". Our system relies on linguistic features ... More
Simple Mathematical Model Of Pathologic Microsatellite Expansions: When Self-Reparation Does Not WorkJul 29 2007We propose a simple model of pathologic microsatellite expansion, and describe an inherent self-repairing mechanism working against expansion. We prove that if the probabilities of elementary expansions and contractions are equal, microsatellite expansions ... More
ATLAS Sensitivity to the Flavour-Changing Neutral Current Decay $t \to Zq$May 08 2002The sensitivity of the ATLAS experiment to the top-quark rare decay via flavor-changing neutral currents $t \rightarrow Zq$ ($q$ represents $c$ and $u$ quarks) has been studied at $\sqrt{s}$=14 TeV in two decay modes: 1.The pure leptonic decay of gauge ... More
On the derivation representation of the fundamental Lie algebra of mixed elliptic motivesOct 19 2015Richard Hain and Makoto Matsumoto constructed a category of universal mixed elliptic motives, and described the fundamental Lie algebra of this category: it is a semi-direct product of the fundamental Lie algebra Lie$\,\pi_1(MTM)$ of the category of mixed ... More
Mono-Higgs signature in fermionic dark matter modelAug 16 2016In light of Higgs boson discovery, we explore mono-Higgs signature in association with dark matter pair production at the LHC. For two channels with $\gamma\gamma+\text{MET}$ and $b \bar b+\text{MET}$ in the final state we simulate the SM backgrounds ... More
Approximate MMSE Estimator for Linear Dynamic Systems with Gaussian Mixture NoiseApr 14 2014Jun 25 2015In this work we propose an approximate Minimum Mean-Square Error (MMSE) filter for linear dynamic systems with Gaussian Mixture noise. The proposed estimator tracks each component of the Gaussian Mixture (GM) posterior with an individual filter and minimizes ... More
On $m$-Closed GraphsAug 29 2017A graph is closed when its vertices have a labeling by $[n]$ such that the binomial edge ideal $J_G$ has a quadratic Gr\"{o}bner basis with respect to the lexicographic order induced by $x_1 > \cdots > x_n > y_1> \cdots > y_n$. In this paper, we generalize ... More
Monte Carlo Simulation to relate primary and final fragments mass and kinetic energy distribution from low energy fission of $^{234}U$Jan 25 2008The kinetic energy distribution as a function of mass of final fragments (m) from low energy fission of $^{234}U$, measured with the Lohengrin spectrometer by Belhafaf et al. presents a peak around m=108 and another around m = 122. The authors attribute ... More
Relations dans l'algèbre de Lie fondamentale des motifs elliptiques mixtesOct 22 2013Nov 18 2015Hain and Matsumoto constructed a category of universal mixed elliptic motives and described the fundamental Lie algebra of this category, relating it to a certain graded and filtered Lie algebra E. In an unpublished paper, Aaron Pollack proved a result ... More
Mould theory and the double shuffle Lie algebra structureOct 19 2015The real multiple zeta values $\zeta(k_1,\ldots,k_r)$ are known to form a ${\bf Q}$-algebra; they satisfy a pair of well-known families of algebraic relations called the double shuffle relations. In order to study the algebraic properties of multiple ... More
Upper bounding for packing dimension in vectorial multifractal formalismJan 12 2011We establish an other upper bounding for packing dimension in the framework of the vectorial multifractal formalism that is in some cases finer than that established by J. Peyriere.
Argument Labeling of Explicit Discourse Relations using LSTM Neural NetworksAug 11 2017Sep 07 2017Argument labeling of explicit discourse relations is a challenging task. The state of the art systems achieve slightly above 55% F-measure but require hand-crafted features. In this paper, we propose a Long Short Term Memory (LSTM) based model for argument ... More
Analytic MMSE Bounds in Linear Dynamic Systems with Gaussian Mixture Noise StatisticsJun 25 2015Using state-space representation, mobile object positioning problems can be described as dynamic systems, with the state representing the unknown location and the observations being the information gathered from the location sensors. For linear dynamic ... More
A New Reduction Scheme for Gaussian Sum FiltersMay 13 2014In many signal processing applications it is required to estimate the unobservable state of a dynamic system from its noisy measurements. For linear dynamic systems with Gaussian Mixture (GM) noise distributions, Gaussian Sum Filters (GSF) provide the ... More
Gorenstein Dimensions under Base ChangeOct 07 2002Nov 18 2002The so-called 'change-of-ring' results are well-known expressions which present several connections between projective, injective and flat dimensions over the various base rings. In this note we extend these results to the Gorenstein dimensions over Cohen-Macaulay ... More
Improving Discourse Relation Projection to Build Discourse Annotated CorporaJul 20 2017The naive approach to annotation projection is not effective to project discourse annotations from one language to another because implicit discourse relations are often changed to explicit ones and vice-versa in the translation. In this paper, we propose ... More
Automatic Disambiguation of French Discourse ConnectivesApr 18 2017Discourse connectives (e.g. however, because) are terms that can explicitly convey a discourse relation within a text. While discourse connectives have been shown to be an effective clue to automatically identify discourse relations, they are not always ... More
Large Deviations for a Class of Semilinear Stochastic Partial Differential EquationsJul 02 2016We prove the large deviations principle (LDP) for the law of the solutions to a class of semilinear stochastic partial differential equations driven by multiplicative noise. Our proof is based on the weak convergence approach and significantly improves ... More
Nonparametric Independence Testing for Small Sample SizesJun 07 2014Sep 03 2015This paper deals with the problem of nonparametric independence testing, a fundamental decision-theoretic problem that asks if two arbitrary (possibly multivariate) random variables $X,Y$ are independent or not, a question that comes up in many fields ... More
Optimal third root asymptotic bounds in the statistical estimation of thresholdsDec 06 2007This paper is concerned with estimating the intersection point of two densities, given a sample of both of the densities. This problem arises in classification theory. The main results provide lower bounds for the probability of the estimation errors ... More
Mono-Higgs signature in fermionic dark matter modelAug 16 2016Aug 12 2017In light of the Higgs boson discovery, we explore mono-Higgs signature in association with dark matter pair production at the LHC in a renormalizable model with a fermionic dark matter candidate. For two channels with $\gamma\gamma+\text{MET}$ and $b ... More
Bound on the Jordan type of a generic nilpotent matrix commuting with a given matrixApr 20 2012Nov 20 2012It is well-known that a nilpotent n by n matrix B is determined up to conjugacy by a partition of n formed by the sizes of the Jordan blocks of B. We call this partition the Jordan type of B. We obtain partial results on the following problem: for any ... More
Cohen--Macaulayness of tensor productsSep 24 2002Let $(R,\fm)$ be a commutative Noetherian local ring. Suppose that $M$ and $N$ are finitely generated modules over $R$ such that $M$ has finite projective dimension and such that $\Tor^R_i(M,N)=0$ for all $i>0$. The main result of this note gives a condition ... More
Distributed State Machine Supervision for Long-baseline Gravitational-wave DetectorsApr 06 2016Aug 11 2016The Laser Interferometer Gravitational-wave Observatory (LIGO) consists of two identical yet independent, widely-separated, long-baseline gravitational-wave detectors. Each Advanced LIGO detector consists of complex optical-mechanical systems isolated ... More
A Model for Dark Energy decayFeb 02 2012Aug 06 2013We discuss a model of non perturbative decay of dark energy into hot and cold dark matter. This model provides a mechanism from the field theory to realize the energy transfer from dark energy into dark matter, which is the requirement to alleviate the ... More
A control theorem for $p$-adic automorphic forms and Teitelbaum's $\mathcal{L}$-invariantMay 05 2017In this article, we describe an efficient method for computing Teitelbaum's $p$-adic $\mathcal{L}$-invariant. These invariants are realized as the eigenvalues of the $\mathcal{L}$-operator acting on a space of harmonic cocycles on the Bruhat-Tits tree ... More
Quantum Transport of Dirac fermions in graphene with a spatially varying Rashba spin-orbit couplingJan 20 2016We theoretically study electronic transport through a region with inhomogeneous Rashba spin-orbit (RSO) coupling placed between two normal regions in a monolayer graphene. The inhomogeneous RSO region is characterized by linearly varying RSO strength ... More
On a partially ordered set associated to ring morphismsOct 14 2018We associate to any ring $R$ with identity a partially ordered set Hom$(R)$, whose elements are all pairs $(\mathfrak a,M)$, where $\mathfrak a=\ker\varphi$ and $M=\varphi^{-1}(U(S))$ for some ring morphism $\varphi$ of $R$ into an arbitrary ring $S$. ... More
An extension of properties of symmetric group to monoids and a pretorsion theory in the category of mappingsFeb 14 2019Several elementary properties of the symmetric group $S_n$ extend in a nice way to the full transformation monoid $M_n$ of all maps of the set $X:=\{1,2,3,\dots,n\}$ into itself. The group $S_n$ turns out to be in some sense the torsion part of the monoid ... More
Probabilistic Backpropagation for Scalable Learning of Bayesian Neural NetworksFeb 18 2015Jul 15 2015Large multilayer neural networks trained with backpropagation have recently achieved state-of-the-art results in a wide range of problems. However, using backprop for neural net learning still has some disadvantages, e.g., having to tune a large number ... More
Dealing with Integer-valued Variables in Bayesian Optimization with Gaussian ProcessesJun 12 2017Jun 13 2017Bayesian optimization (BO) methods are useful for optimizing functions that are expensive to evaluate, lack an analytical expression and whose evaluations can be contaminated by noise. These methods rely on a probabilistic model of the objective function, ... More
Constrained Bayesian Optimization for Automatic Chemical DesignSep 16 2017Jun 27 2018Automatic Chemical Design provides a framework for generating novel molecules with optimized molecular properties. The current model suffers from the pathology that it tends to produce invalid molecular structures. By reformulating the search procedure ... More
Exact Solutions of a Fermion-Soliton System in Two DimensionsSep 12 2013We investigate a coupled system of a Dirac particle and a pseudoscalar field in the form of a soliton in (1+1) dimensions and find some of its exact solutions numerically. We solve the coupled set of equations self-consistently and non-perturbatively ... More
Irreducible representations of knot groups into SL(n,C)Feb 13 2015The aim of this article is to study the existence of certain reducible, metabelian representations of knot groups into $\mathrm{SL}(n,\mathbf{C})$ which generalise the representations studied previously by G.~Burde and G.~de Rham. Under specific hypotheses ... More
Roughness exponent in two-dimensional percolation, Potts and clock modelsMar 16 2001We present a numerical study of the self-affine profiles obtained from configurations of the q-state Potts (with q=2,3 and 7) and p=10 clock models as well as from the occupation states for site-percolation on the square lattice. The first and second ... More
Predictive Entropy Search for Multi-objective Bayesian OptimizationNov 17 2015Feb 21 2016We present PESMO, a Bayesian method for identifying the Pareto set of multi-objective optimization problems, when the functions are expensive to evaluate. The central idea of PESMO is to choose evaluation points so as to maximally reduce the entropy of ... More
Training Deep Gaussian Processes using Stochastic Expectation Propagation and Probabilistic BackpropagationNov 11 2015Deep Gaussian processes (DGPs) are multi-layer hierarchical generalisations of Gaussian processes (GPs) and are formally equivalent to neural networks with multiple, infinitely wide hidden layers. DGPs are probabilistic and non-parametric and as such ... More
$W'$ Pair Production in the Light of CMS SearchesOct 14 2017Oct 07 2018For the first time, the pair production of the heavy charged gauge bosons, known as $W'$ bosons is considered, when both decay to $\tau$ leptons. The reported detailed efficiency of object/event selection by the CMS experiment is used to find the lower ... More
Consecutive cancellations in Betti numbers of local ringsApr 07 2009Let I be a homogeneous ideal in a polynomial ring P over a field. By Macaulay's Theorem, there exists a lexicographic ideal L=Lex(I) with the same Hilbert function as I. Peeva has proved that the Betti numbers of P/I can be obtained from the graded Betti ... More
On the structure of sequentially Cohen--Macaulay bigraded modulesJan 29 2013Oct 14 2015Let $K$ be a field and $S=K[x_1,\ldots,x_m, y_1,\ldots,y_n]$ be the standard bigraded polynomial ring over $K$. In this paper, we explicitly describe the structure of finitely generated bigraded "sequentially Cohen--Macaulay" $S$-modules with respect ... More
Do joint CMB and HST data support a scale invariant spectrum?Feb 21 2017We combine current measurements of the local expansion rate, $H_0$, and Big Bang Nucleosynthesis (BBN) estimates of helium abundance with the latest cosmic microwave background (CMB) data from the Planck Collaboration to discuss the observational viability ... More
Primordial gravitational waves and the H0-tension problemSep 12 2018Feb 16 2019We analyse the H0-tension problem in the context of models of the early universe that predict a blue tilted spectrum of primordial gravitational waves (GW's). By considering the GW's contribution, Neff^GW, to the effective number of relativistic degrees ... More
The $H_0$ and $σ_8$ tensions and the scale invariant spectrumDec 02 2017Jun 21 2018In a previous communication we showed that a joint analysis of Cosmic Microwave Background (CMB) data and the current measurement of the local expansion rate favours a model with a scale invariant spectrum (HZ) over the minimal $\Lambda$CDM scenario provided ... More
Back-Reaction of Super-Hubble Cosmological Perturbations Beyond Perturbation TheoryJul 19 2018We discuss the effect of super-Hubble cosmological fluctuations on the locally measured Hubble expansion rate. We consider a large bare cosmological constant in the early universe in the presence of scalar field matter (the dominant matter component), ... More
Face Recognition: A Novel Multi-Level Taxonomy based SurveyJan 03 2019In a world where security issues have been gaining growing importance, face recognition systems have attracted increasing attention in multiple application areas, ranging from forensics and surveillance to commerce and entertainment. To help understanding ... More
A Note on Trans-Planckian Tail EffectsMay 10 2015We study the proposal by Mersini et al. that the observed dark energy might be explained by the back-reaction of the set of tail modes in a theory with a dispersion relation in which the mode frequency decays exponentially in the trans-Planckian regime. ... More
Casimir Energy for a Coupled Fermion-Soliton SystemSep 24 2012In this paper we compute the Casimir energy for a coupled fermion-pseudoscalar field system. In the model considered in this paper the pseudoscalar field is \textit{static} and \textit{prescribed} with two adjustable parameters. These parameters determine ... More
Computing discrete Morse complexes from simplicial complexesNov 11 2018We consider the problem of efficiently computing a discrete Morse complex on simplicial complexes of arbitrary dimension and very large size. Based on a common graph-based formalism, we analyze existing data structures for simplicial complexes, and we ... More
The possible extremal Betti numbers of a homogeneous idealNov 02 2011Aug 28 2013We give a numerical characterization of the possible extremal Betti numbers (values as well as positions) of any homogeneous ideal in a polynomial ring over a field.
The Robertson-Walker Metric in a Pseudo-Complex General RelativityJan 28 2010We investigate the consequences of the pseudo-complex General Relativity within a pseudo-complexified Roberston-Walker metric. A contribution to the energy-momentum tensor arises, which corresponds to a dark energy and may change with the radius of the ... More
A molecular dynamics approach to dissipative relativistic hydrodynamics: propagation of fluctuationsNov 12 2016Relativistic generalization of hydrodynamic theory has attracted much attention from a theoretical point of view. However, it has many important practical applications in high energy as well as astrophysical contexts. Despite various attempts to formulate ... More
Large Eddy Simulation of Turbulent Barotropic Flows in Spectral Space on the SphereApr 08 2014Numerical simulations of atmospheric circulation models are limited by their finite spatial resolution, and so large eddy simulation (LES) is the preferred approach to study these models. In LES a low-pass filter is applied to the flow field to separate ... More
Tunnel Effect or 'Saute-Mouton'?Nov 23 2011An infinite well potential containing a rectangular barrier in its center is used to verify if the passage of a quantum particle through the barrier is described by tunnel effect or 'saute-mouton'.
Deformations of metabelian representations of knot groups into $SL(3,\mathbb{C})$Oct 18 2007Oct 16 2008Let K be a knot in $S^3$ and $X$ its complement. We study deformations of reducible metabelian representations of the knot group $\pi_1(X)$ into $SL(3,\mathbb{C})$ which are associated to a double root of the Alexander polynomial. We prove that these ... More
A Novel Device-to-Device Discovery Scheme for Underlay Cellular NetworksFeb 26 2017Tremendous growing demand for high data rate services such as video, gaming and social networking in wireless cellular systems, attracted researchers' attention to focus on developing proximity services. In this regard, device-to-device (D2D) communications ... More
Actively Learning what makes a Discrete Sequence ValidAug 15 2017Deep learning techniques have been hugely successful for traditional supervised and unsupervised machine learning problems. In large part, these techniques solve continuous optimization problems. Recently however, discrete generative deep learning models ... More
Inference in Deep Gaussian Processes using Stochastic Gradient Hamiltonian Monte CarloJun 14 2018Nov 12 2018Deep Gaussian Processes (DGPs) are hierarchical generalizations of Gaussian Processes that combine well calibrated uncertainty estimates with the high flexibility of multilayer models. One of the biggest challenges with these models is that exact inference ... More
The impact of supernovae driven winds on stream-fed protogalaxiesDec 13 2010Mar 09 2011SNe driven winds are widely thought to be very influential in the high-redshift Universe, shaping the properties of the circum-galactic medium, enriching the IGM with metals and driving the evolution of low-mass galaxies. However, it is not yet fully ... More
Waiting time distributions for the transport through a quantum dot tunnel coupled to one normal and one superconducting leadApr 16 2013Aug 22 2013We have studied the Waiting Time Distributions (WTDs) for sub-gap transport through a single-level quantum dot tunnel coupled to one normal and one superconducting lead. The WTDs reveal the internal dynamics of the system in particular the coherent transfer ... More
Explicit Filtering in Large Eddy Simulation of Barotropic Turbulence in Spectral SpaceApr 05 2014Explicit filtering in large eddy simulation (LES) of a turbulent barotropic flow on the sphere in spectral space is studied and compared to implicit filtering. Here, a smooth filter is applied to the nondivergent barotropic vorticity equation (BVE) on ... More
The optimal multilevel Monte-Carlo approximation of the stochastic drift-diffusion-Poisson systemOct 14 2016Existence and local-uniqueness theorems for weak solutions of a system consisting of the drift-diffusion-Poisson equations and the Poisson-Boltzmann equation, all with stochastic coefficients, are presented. For the numerical approximation of the expected ... More
Thanks for Stopping By: A Study of "Thanks" Usage on WikimediaMar 08 2019The Thanks feature on Wikipedia, also known as "Thanks", is a tool with which editors can quickly and easily send one other positive feedback. The aim of this project is to better understand this feature: its scope, the characteristics of a typical "Thanks" ... More
Replica symmetry breaking in multi-species Sherrington--Kirkpatrick modelOct 07 2018Jan 01 2019In the Sherrington--Kirkpatrick (SK) and related mixed $p$-spin models, there is interest in understanding replica symmetry breaking at low temperatures. For this reason, the so-called AT line proposed by de Almeida and Thouless as a sufficient (and conjecturally ... More
Dynamic Covariance Models for Multivariate Financial Time SeriesMay 18 2013Jun 02 2013The accurate prediction of time-changing covariances is an important problem in the modeling of multivariate financial data. However, some of the most popular models suffer from a) overfitting problems and multiple local optima, b) failure to capture ... More
Gaussian Process Vine Copulas for Multivariate DependenceFeb 16 2013Copulas allow to learn marginal distributions separately from the multivariate dependence structure (copula) that links them together into a density function. Vine factorizations ease the learning of high-dimensional copulas by constructing a hierarchy ... More
Predictive Entropy Search for Efficient Global Optimization of Black-box FunctionsJun 10 2014We propose a novel information-theoretic approach for Bayesian optimization called Predictive Entropy Search (PES). At each iteration, PES selects the next evaluation point that maximizes the expected information gained with respect to the global maximum. ... More
Atomic and electronic structure transformations of silver nanoparticles under rapid cooling conditionsSep 08 2008Jan 22 2009The structural evolution and dynamics of silver nanodrops Ag${}_{2896}$ (4.4 nm in diameter) during rapid cooling conditions has been studied by means of molecular dynamics simulations and electronic density of state calculations. The interaction of silver ... More
Deconfounding Reinforcement Learning in Observational SettingsDec 26 2018We propose a general formulation for addressing reinforcement learning (RL) problems in settings with observational data. That is, we consider the problem of learning good policies solely from historical data in which unobserved factors (confounders) ... More
Non-adiabatic Non-cyclic Generalization of the Berry Phase for a Spin-1/2 Particle in a Rotating Magnetic FieldDec 10 2012In this paper we define a non-dynamical phase for a spin-1/2 particle in a rotating magnetic field in the non-adiabatic non-cyclic case, and this phase can be considered as a generalized Berry phase. We show that this phase reduces to the geometric Berry ... More
Elliptic multiple zeta values and the elliptic double shuffle relationsMar 28 2017We study the algebra $\mathcal{E}$ of elliptic multiple zeta values, which is an elliptic analog of the algebra of multiple zeta values. We identify a set of generators of $\mathcal{E}$, which satisfy a double shuffle type family of algebraic relations, ... More
The CLaC Discourse Parser at CoNLL-2015Aug 19 2017This paper describes our submission (kosseim15) to the CoNLL-2015 shared task on shallow discourse parsing. We used the UIMA framework to develop our parser and used ClearTK to add machine learning functionality to the UIMA framework. Overall, our parser ... More
Complete intersection Jordan types in height twoOct 01 2018Nov 04 2018We determine every Jordan type partition that occurs as the Jordan block decomposition for the multiplication map by a linear form in a height two homogeneous complete intersection (CI) Artinian algebra $A$ over an algebraically closed field $\sf k$ of ... More
Electroweak fragmentation functions for dark matter annihilationSep 29 2014Jul 05 2016Electroweak corrections can play a crucial role in dark matter annihilation. The emission of gauge bosons, in particular, leads to a secondary flux consisting of all Standard Model particles, and may be described by electroweak fragmentation functions. ... More
Analyses and performance of techniques PAPR reduction for STBC MIMO-OFDM system in (4G) wireless communicationNov 14 2013An OFDM system is combined with multiple-input multiple-output (MIMO) in order to increase the diversity gain and system capacity over the time variant frequency-selective channels. However, a major drawback of MIMO-OFDM system is that the transmitted ... More
Casimir Energy for a Coupled Fermion-Kink System and its stabilitySep 20 2012Sep 22 2012We compute the Casimir energy for a system consisting of a fermion and a pseudoscalar field in the form of a prescribed kink. This model is not exactly solvable and we use the phase shift method to compute the Casimir energy. We use the relaxation method ... More
The algebra of cell-zeta valuesOct 01 2009In this paper, we introduce cell-forms on $\mathcal{M}_{0,n}$, which are top-dimensional differential forms diverging along the boundary of exactly one cell (connected component) of the real moduli space $\mathcal{M}_{0,n}(\mathbb{R})$. We show that the ... More
Variational Implicit ProcessesJun 06 2018This paper introduces the variational implicit processes (VIPs), a Bayesian nonparametric method based on a class of highly flexible priors over functions. Similar to Gaussian processes (GPs), in implicit processes (IPs), an implicit multivariate prior ... More
Gaussian Process Volatility ModelFeb 13 2014The accurate prediction of time-changing variances is an important task in the modeling of financial data. Standard econometric models are often limited as they assume rigid functional relationships for the variances. Moreover, function parameters are ... More
Minimal Random Code Learning: Getting Bits Back from Compressed Model ParametersSep 30 2018While deep neural networks are a highly successful model class, their large memory footprint puts considerable strain on energy consumption, communication bandwidth, and storage requirements. Consequently, model size reduction has become an utmost goal ... More
Quasi Monte Carlo integration and kernel-based function approximation on GrassmanniansMay 30 2016Numerical integration and function approximation on compact Riemannian manifolds based on eigenfunctions of the Laplace-Beltrami operator have been widely studied in the recent literature. The standard example in numerical experiments is the Euclidean ... More
From low to high-dimensional moments without magicJan 27 2016We aim to compute the first few moments of a high-dimensional random vector from the first few moments of a number of its low-dimensional projections. To this end, we identify algebraic conditions on the set of low-dimensional projectors that yield explicit ... More
Phase retrieval using random cubatures and fusion frames of positive semidefinite matricesMay 19 2015As a generalization of the standard phase retrieval problem, we seek to reconstruct symmetric rank-1 matrices from inner products with subclasses of positive semidefinite matrices. For such subclasses, we introduce random cubatures for spaces of multivariate ... More
Points on manifolds with asymptotically optimal covering radiusJul 23 2016Given a finite set of points on the Euclidean sphere, the worst case quadrature error in Sobolev spaces has recently been shown to provide upper bounds on the covering radius of the point set. Moreover, quasi-Monte Carlo integration points on the sphere ... More