Results for "Jérémie Leguay"

total 319took 0.11s
Adapting Caching to Audience Retention Rate: Which Video Chunk to Store?Dec 10 2015Rarely do users watch online contents entirely. We study how to take this into account to improve the performance of cache systems for video-on-demand and video-sharing platforms in terms of traffic reduction on the core network. We exploit the notion ... More
Overlay Routing for Fast Video Transfers in CDNJan 31 2017Content Delivery Networks (CDN) are witnessing the outburst of video streaming (e.g., personal live streaming or Video-on-Demand) where the video content, produced or accessed by mobile phones, must be quickly transferred from a point to another of the ... More
DISCO: Distributed Multi-domain SDN ControllersAug 28 2013Aug 29 2013Modern multi-domain networks now span over datacenter networks, enterprise networks, customer sites and mobile entities. Such networks are critical and, thus, must be resilient, scalable and easily extensible. The emergence of Software-Defined Networking ... More
Real-Time Fair Resource Allocation in Distributed Software Defined NetworksNov 27 2017The performance of computer networks relies on how bandwidth is shared among different flows. Fair resource allocation is a challenging problem particularly when the flows evolve over time.To address this issue, bandwidth sharing techniques that quickly ... More
Multi-Path Alpha-Fair Resource Allocation at Scale in Distributed Software Defined NetworksSep 04 2018Sep 12 2018The performance of computer networks relies on how bandwidth is shared among different flows. Fair resource allocation is a challenging problem particularly when the flows evolve over time. To address this issue, bandwidth sharing techniques that quickly ... More
Lower Bounds for the Fair Resource Allocation ProblemFeb 08 2018The $\alpha$-fair resource allocation problem has received remarkable attention and has been studied in numerous application fields. Several algorithms have been proposed in the context of $\alpha$-fair resource sharing to distributively compute its value. ... More
Virtual Function Placement for Service Chaining with Partial Orders and Anti-Affinity RulesMay 30 2017Aug 08 2017Software Defined Networking and Network Function Virtualization are two paradigms that offer flexible software-based network management. Service providers are instantiating Virtualized Network Functions - e.g., firewalls, DPIs, gateways - to highly facilitate ... More
Evaluating Mobility Pattern Space Routing for DTNsNov 29 2005Because a delay tolerant network (DTN) can often be partitioned, the problem of routing is very challenging. However, routing benefits considerably if one can take advantage of knowledge concerning node mobility. This paper addresses this problem with ... More
Relieving the Wireless Infrastructure: When Opportunistic Networks Meet Guaranteed DelaysJul 30 2010May 30 2011Major wireless operators are nowadays facing network capacity issues in striving to meet the growing demands of mobile users. At the same time, 3G-enabled devices increasingly benefit from ad hoc radio connectivity (e.g., Wi-Fi). In this context of hybrid ... More
Hilbert manifold structure for asymptotically hyperbolic relativistic initial dataJul 19 2016We provide a Hilbert manifold structure {\`a} la Bartnik for the space of asymptotically hyperbolic initial data for the vacuum constraint equations. The adaptation led us to prove new weighted Poincar{\'e} and Korn type inequalities for AH manifolds ... More
Convergence of uniform noncrossing partitions toward the Brownian triangulationNov 13 2017Mar 07 2018We give a short proof that a uniform noncrossing partition of the regular $n$-gon weakly converges toward Aldous's Brownian triangulation of the disk, in the sense of the Hausdorff topology. This result was first obtained by Curien & Kortchemski, using ... More
Online and Global Network Optimization: Towards the Next-Generation of Routing PlatformsFeb 04 2016The computation power of SDN controllers fosters the development of a new generation of control plane that uses compute-intensive operations to automate and optimize the network configuration across layers. From now on, cutting-edge optimization and machine ... More
Hazard analysis of human--robot interactions with HAZOP--UMLFeb 09 2016New safety critical systems are about to appear in our everyday life: advanced robots able to interact with humans and perform tasks at home, in hospitals , or at work. A hazardous behavior of those systems, induced by failures or extreme environment ... More
Optimal Discrete Uniform Generation from Coin Flips, and ApplicationsApr 06 2013This article introduces an algorithm to draw random discrete uniform variables within a given range of size n from a source of random bits. The algorithm aims to be simple to implement and optimal both with regards to the amount of random bits consumed, ... More
Fréchet means of curves for signal averaging and application to ECG data analysisNov 08 2011Signal averaging is the process that consists in computing a mean shape from a set of noisy signals. In the presence of geometric variability in time in the data, the usual Euclidean mean of the raw data yields a mean pattern that does not reflect the ... More
Searching for New Physics in Scalar Top-Pair ResonanceDec 02 2016We consider the effects in the production via gluon fusion in LHC collisions of one or two spin-zero new resonant particles $\Phi$ that decay into a top quark pair. We revisit previous analyses of the interferences between the heavy-fermion loop-induced ... More
A bijection for nonorientable general mapsDec 07 2015Feb 17 2016We give a different presentation of a recent bijection due to Chapuy and Do{\l}\k{e}ga for nonorientable bipartite quadrangulations and we extend it to the case of nonorientable general maps. This can be seen as a Bouttier--Di Francesco--Guitter-like ... More
Integral Formula for the Characteristic Cauchy Problem on a curved BackgroundOct 24 2009We give a local integral formula, valid on general curved space-times, for the characteristic Cauchy problem for the Dirac equation with arbitrary spin using the method developed by Friedlander in his book "the wave equation on a curved spacetime" (1975). ... More
DTN Routing in a Mobility Pattern SpaceApr 11 2005Routing in Delay Tolerant Networks (DTNs) benefits considerably if one can take advantage of knowledge concerning node mobility. The main contribution of this paper is the definition of a generic routing scheme for DTNs using a high-dimensional Euclidean ... More
Simplified description of the MSSM Higgs sectorMay 09 2014In the Minimal Supersymmetric extension of the Standard Model or MSSM, the lighter Higgs boson has a rather large mass, $M_h\approx 125$ GeV. Together with the non-observation of superpartners at the LHC, this suggests that the SUSY-breaking scale is ... More
An automata group of intermediate growth and exponential activityOct 27 2017We give a new example of an automata group of intermediate growth. It is generated by an automaton with 4 states on an alphabet with 8 letters. This automata group has exponential activity and its limit space is not simply connected.
Growth behaviors in the range $e^{r^α}$Jul 08 2011Sep 06 2013For every $\alpha \leq \beta$ in a left neighborhood $[\alpha_0,1]$ of 1, a group $G(\alpha,\beta)$ is constructed, the growth function of which satisfies $\limsup \frac{\log \log b_{G(\alpha,\beta)}(r)}{\log r}=\alpha$ and $\liminf \frac{\log \log b_{G(\alpha,\beta)}(r)}{\log ... More
About the speed of random walks on solvable groupsMay 13 2015We show that for each $\lambda \in [\frac{1}{2}, 1]$, there exists a solvable group and a finitely supported measure such that the associated random walk has upper speed exponent $\lambda$.
Moment estimates for solutions of linear stochastic differential equations driven by analytic fractional Brownian motionMay 06 2009As a general rule, differential equations driven by a multi-dimensional irregular path $\Gamma$ are solved by constructing a rough path over $\Gamma$. The domain of definition ? and also estimates ? of the solutions depend on upper bounds for the rough ... More
Gluing for the constraints for higher spin fieldsApr 04 2017This short note is a follow-up on the paper by Beig and Chru\'sciel regarding the use of potentials to perform a gluing and shielding of initial data for Maxwell fields and linearised gravity. Based on a work in collaboration with Andersson and B\"ackdahl, ... More
Conformal scattering for a nonlinear wave equation on a curved backgroundApr 09 2010Oct 29 2010The purpose of this paper is to establish a geometric scattering result for a conformally invariant nonlinear wave equation on an asymptotically simple spacetime. The scattering operator is obtained via trace operators at null infinities. The proof is ... More
Slit-slide-sew bijections for bipartite and quasibipartite plane mapsNov 19 2018Dec 20 2018We unify and extend previous bijections on plane quadrangulations to bipartite and quasibipartite plane maps. Starting from a bipartite plane map with a distinguished edge and two distinguished corners (in the same face or in two different faces), we ... More
Hörmander's method for the characteristic Cauchy problem and conformal scattering for a non linear wave equationMar 29 2019The purpose of this note is to prove the existence of a conformal scattering operator for the cubic defocusing wave equation on a non-stationary background. The proof essentially relies on solving the characteristic initial value problem by the method ... More
The heterogeneity of inter-contact time distributions: its importance for routing in delay tolerant networksSep 12 2006Jan 05 2007Prior work on routing in delay tolerant networks (DTNs) has commonly made the assumption that each pair of nodes shares the same inter-contact time distribution as every other pair. The main argument in this paper is that researchers should also be looking ... More
A simple explicit bijection between (n,2) Gog and Magog trapezoidsDec 10 2015Apr 11 2016A sub-problem of the open problem of finding an explicit bijection between alternating sign matrices and totally symmetric self-complementary plane partitions consists in finding an explicit bijection between so-called $(n,k)$ Gog trapezoids and $(n,k)$ ... More
Stochastic calculus for fractional Brownian motion with Hurst exponent $H>1/4$: A rough path method by analytic extensionMar 23 2007Jun 10 2009The $d$-dimensional fractional Brownian motion (FBM for short) $B_t=((B_t^{(1)},...,B_t^{(d)}),t\in\mathbb{R})$ with Hurst exponent $\alpha$, $\alpha\in(0,1)$, is a $d$-dimensional centered, self-similar Gaussian process with covariance ${\mathbb{E}}[B_s^{(i)}B ... More
Geodesics in Brownian surfaces (Brownian maps)Jan 15 2014Apr 01 2016We define a class a metric spaces we call Brownian surfaces, arising as the scaling limits of random maps on general orientable surfaces with a boundary and we study the geodesics from a uniformly chosen random point. These metric spaces generalize the ... More
Enumerations, Forbidden Subgraph Characterizations, and the Split-DecompositionAug 04 2016Forbidden characterizations may sometimes be the most natural way to describe families of graphs, and yet these characterizations are usually very hard to exploit for enumerative purposes. By building on the work of Gioan and Paul (2012) and Chauve et ... More
Nonparametric adaptive time-dependent multivariate function estimationOct 29 2012Oct 31 2012We consider the nonparametric estimation problem of time-dependent multivariate functions observed in a presence of additive cylindrical Gaussian white noise of a small intensity. We derive minimax lower bounds for the $L^2$-risk in the proposed spatio-temporal ... More
Characterization of barycenters in the Wasserstein space by averaging optimal transport mapsDec 11 2012Nov 29 2017This paper is concerned by the study of barycenters for random probability measures in the Wasserstein space. Using a duality argument, we give a precise characterization of the population barycenter for various parametric classes of random probability ... More
Repetition cat-qubits: fault-tolerant quantum computation with highly reduced overheadApr 20 2019Is it possible to reduce the complexity of quantum error correction close to that of a classical one? We present a repetition code based on the so-called cat-qubits as a viable approach towards a massive reduction in the hardware requirements for universal ... More
Axions are blind to anomaliesMar 29 2019The axion couplings to gauge bosons are derived in various models, and shown to always arise entirely from non-anomalous fermion loops. They are thus independent of the anomaly structure of the model. This fact is without consequence for vector gauge ... More
A One-Sample Test for Normality with Kernel MethodsJul 10 2015We propose a new one-sample test for normality in a Reproducing Kernel Hilbert Space (RKHS). Namely, we test the null-hypothesis of belonging to a given family of Gaussian distributions. Hence our procedure may be applied either to test data for normality ... More
Constellations and multicontinued fractions: application to Eulerian triangulationsDec 29 2011We consider the problem of enumerating planar constellations with two points at a prescribed distance. Our approach relies on a combinatorial correspondence between this family of constellations and the simpler family of rooted constellations, which we ... More
Consistent estimation of a mean planar curve modulo similaritiesOct 25 2011Oct 31 2012We consider the problem of estimating a mean planar curve from a set of $J$ random planar curves observed on a $k$-points deterministic design. We study the consistency of a smoothed Procrustean mean curve when the observations obey a deformable model ... More
Minimax properties of Fréchet means of discretely sampled curvesOct 02 2012Jun 11 2013We study the problem of estimating a mean pattern from a set of similar curves in the setting where the variability in the data is due to random geometric deformations and additive noise. We propose an estimator based on the notion of Frechet mean that ... More
Quasi-geostrophic modes in the Earth's fluid core with an outer stably stratified layerJan 28 2015Jun 26 2015Seismic waves sensitive to the outermost part of the Earth's liquid core seem to be affected by a stably stratified layer at the core-mantle boundary. Such a layer could have an observable signature in both long-term and short-term variations of the magnetic ... More
Repetition cat-qubits: fault-tolerant quantum computation with highly reduced overheadApr 20 2019Apr 29 2019We present a 1D repetition code based on the so-called cat-qubits as a viable approach towards a massive reduction in the hardware requirements for universal and fault-tolerant quantum computation. The cat-qubits that are stabilized by a two-photon driven ... More
A strong direct product theorem for quantum query complexityApr 22 2011Jul 08 2011We show that quantum query complexity satisfies a strong direct product theorem. This means that computing $k$ copies of a function with less than $k$ times the quantum queries needed to compute one copy of the function implies that the overall success ... More
From constructive field theory to fractional stochastic calculus. (II) Constructive proof of convergence for the Lévy area of fractional Brownian motion with Hurst index $α\in(1/8,1/4)$Mar 09 2011{Let $B=(B_1(t),...,B_d(t))$ be a $d$-dimensional fractional Brownian motion with Hurst index $\alpha<1/4$, or more generally a Gaussian process whose paths have the same local regularity. Defining properly iterated integrals of $B$ is a difficult task ... More
A counterexample to Thiagarajan's conjecture on regular event structuresMay 26 2016Oct 27 2016We provide a counterexample to a conjecture by Thiagarajan (1996 and 2002) that regular prime event structures correspond exactly to finite 1-safe Petri nets. The same counterexample is used to disprove a closely related conjecture by Badouel, Darondeau, ... More
Reducing statistical time-series problems to binary classificationOct 22 2012Jun 07 2013We show how binary classification methods developed to work on i.i.d. data can be used for solving statistical problems that are seemingly unrelated to classification and concern highly-dependent time series. Specifically, the problems of time-series ... More
Compact Brownian surfaces I. Brownian disksJul 31 2015Feb 11 2016We show that, under certain natural assumptions, large random plane bipartite maps with a boundary converge after rescaling to a one-parameter family ($\mathrm{BD}_L$, $0 < L < \infty$) of random metric spaces homeomorphic to the closed unit disk of $\mathbb{R}^2$, ... More
On the consistency of Fréchet means in deformable models for curve and image analysisOct 03 2010Aug 22 2011A new class of statistical deformable models is introduced to study high-dimensional curves or images. In addition to the standard measurement error term, these deformable models include an extra error term modeling the individual variations in intensity ... More
Optimal Partial Tiling of Manhattan PolyominoesNov 14 2009Finding an efficient optimal partial tiling algorithm is still an open problem. We have worked on a special case, the tiling of Manhattan polyominoes with dominoes, for which we give an algorithm linear in the number of columns. Some techniques are borrowed ... More
1-Safe Petri nets and special cube complexes: equivalence and applicationsOct 08 2018Nielsen, Plotkin, and Winskel (1981) proved that every 1-safe Petri net $N$ unfolds into an event structure $\mathcal{E}_N$. By a result of Thiagarajan (1996 and 2002), these unfoldings are exactly the trace regular event structures. Thiagarajan (1996 ... More
Noise sensitivity of random walks on groupsJan 11 2019A random walk on a group is noise sensitive if resampling every step independantly with a small probability results in an almost independant output. We precisely define two notions: $\ell^1$-noise sensitivity and entropy noise sensitivity. Groups with ... More
Turbulence of generalised flows in two dimensionsDec 05 2018This paper discusses the generalised least-action principle introduced by Brenier (J. Am. Math. Soc, 1989), from the perspective of turbulence modelling. In essence, Brenier's least-action principle extends to a probabilistic setting Arnold's geometric ... More
Shalom's property $H_{\mathrm{FD}}$ and extensions by $\mathbb{Z}$ of locally finite groupsJun 02 2017Oct 26 2017We show that every finitely generated extension by $\mathbb{Z}$ of a locally normally finite group has Shalom's property $H_{\mathrm{FD}}$. This is no longer true without the normality assumption. This permits to answer some questions of Shalom, Erschler-Ozawa ... More
Discrete random walks on the group SolJun 26 2013Dec 09 2015The harmonic measure $\nu$ on the boundary of the group $Sol$ associated to a discrete random walk of law $\mu$ was described by Kaimanovich. We investigate when it is absolutely continuous or singular with respect to Lebesgue measure. By ratio entropy ... More
The rough path associated to the multidimensional analytic fbm with any Hurst parameterOct 08 2008In this paper, we consider a complex-valued d-dimensional fractional Brownian motion defined on the closure of the complex upper half-plane, called analytic fractional Brownian motion. This process has been introduced by the second author of the article, ... More
Asymptotic lowest two-sided cellMar 21 2011Apr 19 2011To a Coxeter system $(W,S)$ (with $S$ finite) and a weight function $L : W \to \NM$ is associated a partition of $W$ into Kazhdan-Lusztig (left, right or two-sided) $L$-cells. Let $S^\circ = \{s \in S | L(s)=0\}$, $S^+=\{s \in S | L(s) > 0\}$ and let ... More
Distributed Stochastic Approximation for Constrained and Unconstrained OptimizationApr 14 2011Apr 19 2011In this paper, we analyze the convergence of a distributed Robbins-Monro algorithm for both constrained and unconstrained optimization in multi-agent systems. The algorithm searches for local minima of a (nonconvex) objective function which is supposed ... More
Isomorphic induced modules and Dynkin diagram automorphisms of semisimple Lie algebrasDec 02 2013Consider a simple Lie algebra $\mathfrak{g}$ and $\overline{\mathfrak{g}}% \subset \mathfrak{g}$ a Levi subalgebra. Two irreducible $\overline{% \mathfrak{g}}$-modules yield isomorphic inductions to $\mathfrak{g}$ when their highest weights coincide up ... More
A model for particle production in nuclear reactions at intermediate energies: application to C-C collisions at 95 MeV/nucleonFeb 04 2016A model describing nuclear collisions at intermediate energies is presented and the results are compared with recently measured double differential cross sections in C-C reactions at 95 MeV/nucleon. Results show the key role played by geometrical effects ... More
Additive noise quenches delay-induced oscillationsMar 14 2013Noise has significant impact on nonlinear phenomena. Here we demonstrate that, in opposition to previous assumptions, additive noise interfere with the linear stability of scalar nonlinear systems when these are subject to time delay. We show this by ... More
Speed of random walks, isoperimetry and compression of finitely generated groupsOct 27 2015Jul 07 2016We give a solution to the inverse problem (given a function, find a corresponding group) for large classes of speed, entropy, isoperimetric profile, return probability and $L_p$-compression functions of finitely generated groups of exponential volume ... More
Nonlinear Nonoverlapping Schwarz Waveform Relaxation for Semilinear Wave PropagationJan 31 2007We introduce a non-overlapping variant of the Schwarz waveform relaxation algorithm for semilinear wave propagation in one dimension. Using the theory of absorbing boundary conditions, we derive a new nonlinear algorithm. We show that the algorithm is ... More
A universal adiabatic quantum query algorithmSep 11 2014Jun 29 2015Quantum query complexity is known to be characterized by the so-called quantum adversary bound. While this result has been proved in the standard discrete-time model of quantum computation, it also holds for continuous-time (or Hamiltonian-based) quantum ... More
The periodic Schur process and free fermions at finite temperatureJul 24 2018Jan 21 2019We revisit the periodic Schur process introduced by Borodin in 2007. Our contribution is threefold. First, we provide a new simpler derivation of its correlation functions via the free fermion formalism. In particular, we shall see that the process becomes ... More
The scaling limit of the KPZ equation in space dimension 3 and higherFeb 10 2017Jan 23 2018We study in the present article the Kardar-Parisi-Zhang (KPZ) equation $$ \partial_t h(t,x)=\nu\Delta h(t,x)+\lambda |\nabla h(t,x)|^2 +\sqrt{D}\, \eta(t,x), \qquad (t,x)\in\mathbb{R}_+\times\mathbb{R}^d $$ in $d\ge 3$ dimensions in the perturbative regime, ... More
TACTICS: TACTICal Service Oriented ArchitectureApr 28 2015Due to the increasing complexity and heterogeneity of contemporary Command, Control, Communications, Computers, & Intelligence systems at all levels within military organizations, the adoption of the Service Oriented Architectures (SOA) principles and ... More
Describing and Simulating Internet RoutesNov 16 2004This paper introduces relevant statistics for the description of routes in the internet, seen as a graph at the interface level. Based on the observed properties, we propose and evaluate methods for generating artificial routes suitable for simulation ... More
Problems with Time-Varying Extra Dimensions or "Cardassian Expansion" as Alternatives to Dark EnergyNov 18 2002May 29 2003It has recently been proposed that the Universe might be accelerating as a consequence of extra dimensions with time varying size. We show that although these scenarios can lead to acceleration, they run into serious difficulty when taking into account ... More
Order rho^2 Corrections to Randall-Sundrum I CosmologyJan 07 2002Jan 12 2007We derive the corrections to the Friedmann equation of order rho^2 in the Randall-Sundrum (RS) model, where two 3-branes bound a slice of five-dimensional Anti-deSitter space. The effects of radion stabilization by the Goldberger-Wise mechanism are taken ... More
Explicit relation between all lower bound techniques for quantum query complexitySep 12 2012Jun 03 2013The polynomial method and the adversary method are the two main techniques to prove lower bounds on quantum query complexity, and they have so far been considered as unrelated approaches. Here, we show an explicit reduction from the polynomial method ... More
Optimal finite measurements and Gauss quadraturesOct 28 2004Apr 08 2006We exhibit measurements for optimal state estimation which have a finite number of outcomes. This is achieved by a connection between finite optimal measurements and Gauss quadratures. The example we consider to illustrate this connection is that of state ... More
Convergence of a Multi-Agent Projected Stochastic Gradient Algorithm for Non-Convex OptimizationJul 13 2011Dec 02 2013We introduce a new framework for the convergence analysis of a class of distributed constrained non-convex optimization algorithms in multi-agent systems. The aim is to search for local minimizers of a non-convex objective function which is supposed to ... More
Characterization of barycenters in the Wasserstein space by averaging optimal transport mapsDec 11 2012Jul 17 2015This paper is concerned by the study of barycenters for random probability measures in the Wasserstein space. Using a duality argument, we give a precise characterization of the population barycenter for various parametric classes of random probability ... More
A deconvolution approach to estimation of a common shape in a shifted curves modelDec 18 2008Oct 20 2010This paper considers the problem of adaptive estimation of a mean pattern in a randomly shifted curve model. We show that this problem can be transformed into a linear inverse problem, where the density of the random shifts plays the role of a convolution ... More
Concentrations of inertial particles in the turbulent wake of an immobile sphereJan 27 2015Direct numerical simulations are used to study the interaction of a stream of small heavy inertial particles with the laminar and turbulent wakes of an immobile sphere facing an incompressible uniform inflow. Particles that do not collide with the obstacle ... More
From constructive field theory to fractional stochastic calculus. (I) An introduction: rough path theory and perturbative heuristicsDec 17 2010Let $B=(B_1(t),..,B_d(t))$ be a $d$-dimensional fractional Brownian motion with Hurst index $\alpha\le 1/4$, or more generally a Gaussian process whose paths have the same local regularity. Defining properly iterated integrals of $B$ is a difficult task ... More
New normality test in high dimension with kernel methodsApr 11 2014A new goodness-of-fit test for normality in high-dimension (and Reproducing Kernel Hilbert Space) is proposed. It shares common ideas with the Maximum Mean Discrepancy (MMD) it outperforms both in terms of computation time and applicability to a wider ... More
Connectedness of spheres in Cayley graphsJun 08 2016We introduce the notion of connection thickness of spheres in a Cayley graph, related to dead-ends and their retreat depth. It was well-known that connection thickness is bounded for finitely presented one-ended groups. We compute that for natural generating ... More
1-Safe Petri nets and special cube complexes: equivalence and applicationsOct 08 2018Apr 24 2019Nielsen, Plotkin, and Winskel (1981) proved that every 1-safe Petri net $N$ unfolds into an event structure $\mathcal{E}_N$. By a result of Thiagarajan (1996 and 2002), these unfoldings are exactly the trace regular event structures. Thiagarajan (1996 ... More
Approximation by random complex polynomials and rational functionsSep 24 2017We seek random versions of some classical theorems on complex approximation by polynomials and rational functions, as well as investigate properties of random compact sets in connection to complex approximation.
Order rho^2 Corrections to Cosmology with Two BranesJul 19 2002We present the results of work in which we derived the order rho^2 corrections to the Friedmann equations in the Randall-Sundrum I model. The effects of Golberger-Wise stabilization are taken into account. We surprisingly find that in the cases of inflation ... More
Codimension-two branes in six-dimensional supergravity and the cosmological constant problemJan 13 2005Mar 17 2005We investigate in detail recent suggestions that codimension-two braneworlds in six dimensional supergravity might circumvent Weinberg's no-go theorem for self-tuning of the cosmological constant. The branes are given finite thickness in order to regularize ... More
Can codimension-two branes solve the cosmological constant problem?Jun 16 2004Oct 18 2004It has been suggested that codimension-two braneworlds might naturally explain the vanishing of the 4D effective cosmological constant, due to the automatic relation between the deficit angle and the brane tension. To investigate whether this cancellation ... More
Adiabatic quantum search algorithm for structured problemsApr 04 2003The study of quantum computation has been motivated by the hope of finding efficient quantum algorithms for solving classically hard problems. In this context, quantum algorithms by local adiabatic evolution have been shown to solve an unstructured search ... More
Push-and-Track: Saving Infrastructure Bandwidth Through Opportunistic ForwardingJan 20 2012Feb 18 2012Major wireless operators are nowadays facing network capacity issues in striving to meet the growing demands of mobile users. At the same time, 3G-enabled devices increasingly benefit from ad hoc radio connectivity (e.g., Wi-Fi). In this context of hybrid ... More
Inference with penalized likelihoodJan 30 2014This work studies the statistical properties of the maximum penalized likelihood approach in a semi-parametric framework. We recall the penalized likelihood approach for estimating a function and review some asymptotic results. We investigate the properties ... More
Hybrid Recommender System based on AutoencodersJun 24 2016A standard model for Recommender Systems is the Matrix Completion setting: given partially known matrix of ratings given by users (rows) to items (columns), infer the unknown ratings. In the last decades, few attempts where done to handle that objective ... More
The scaling limit of uniform random plane maps, via the Ambjørn-Budd bijectionDec 20 2013We prove that a uniform rooted plane map with n edges converges in distribution after a suitable normalization to the Brownian map for the Gromov-Hausdorff topology. A recent bijection due to Ambj{\o}rn and Budd allows to derive this result by a direct ... More
Bandits Warm-up Cold Recommender SystemsJul 10 2014We address the cold start problem in recommendation systems assuming no contextual information is available neither about users, nor items. We consider the case in which we only have access to a set of ratings of items by users. Most of the existing works ... More
An analysis of block sampling strategies in compressed sensingMay 20 2013Jul 21 2014Compressed sensing is a theory which guarantees the exact recovery of sparse signals from a small number of linear projections. The sampling schemes suggested by current compressed sensing theories are often of little practical relevance since they cannot ... More
Timescales of Turbulent Relative DispersionJun 29 2012Tracers in a turbulent flow separate according to the celebrated $t^{3/2}$ Richardson--Obukhov law, which is usually explained by a scale-dependent effective diffusivity. Here, supported by state-of-the-art numerics, we revisit this argument. The Lagrangian ... More
Penalized Barycenters in the Wasserstein SpaceJun 03 2016Mar 18 2019In this paper, a regularization of Wasserstein barycenters for random measures supported on $\mathbb{R}^{d}$ is introduced via convex penalization. The existence and uniqueness of such barycenters is first proved for a large class of penalization functions. ... More
Quantum Weak Coin FlippingNov 06 2018We investigate weak coin flipping, a fundamental cryptographic primitive where two distrustful parties need to remotely establish a shared random bit. A cheating player can try to bias the output bit towards a preferred value. For weak coin flipping the ... More
Data-driven regularization of Wasserstein barycenters with an application to multivariate density registrationApr 24 2018Jun 29 2018We present a framework to simultaneously align and smooth data in the form of multiple point clouds sampled from unknown densities with support in a $d$-dimensional Euclidean space. This work is motivated by applications in bioinformatics where researchers ... More
Sharp asymptotics for small data solutions of the Vlasov-Nordström system in three dimensionsApr 18 2017This paper proves almost-sharp asymptotics for small data solutions of the Vlasov-Nordstr\"om system in dimension three. This system consists of a wave equation coupled to a transport equation and describes an ensemble of relativistic, self-gravitating ... More
The effective action for gauge bosonsOct 16 2018By treating the vacuum as a medium, H. Euler and W. Heisenberg estimated the non-linear interactions between photons well before the advent of Quantum Electrodynamics. In a modern language, their result is often presented as the archetype of an Effective ... More
Doubling Up on Supersymmetry in the Higgs SectorJul 19 2016We explore the possibility that physics at the TeV scale possesses approximate $N = 2$ supersymmetry, which is reduced to the $N=1$ minimal supersymmetric extension of the Standard Model (MSSM) at the electroweak scale. This doubling of supersymmetry ... More
RT-ByzCast: Byzantine-Resilient Real-Time Reliable BroadcastJul 03 2018Today's cyber-physical systems face various impediments to achieving their intended goals, namely, communication uncertainties and faults, relative to the increased integration of networked and wireless devices, hinder the synchronism needed to meet real-time ... More
Central limit theorems for entropy-regularized optimal transport on finite spaces and statistical applicationsNov 24 2017Feb 07 2019The notion of entropy-regularized optimal transport, also known as Sinkhorn divergence, has recently gained popularity in machine learning and statistics, as it makes feasible the use of smoothed optimal transportation distances for data analysis. The ... More