Results for "Alexandre Alahi"

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MonoLoco: Monocular 3D Pedestrian Localization and Uncertainty EstimationJun 14 2019We tackle the fundamentally ill-posed problem of 3D human localization from monocular RGB images. Driven by the limitation of neural networks outputting point estimates, we address the ambiguity in the task with a new neural network predicting confidence ... More
Collaborative GAN SamplingFeb 02 2019Generative adversarial networks (GANs) have shown great promise in generating complex data such as images. A standard practice in GANs is to discard the discriminator after training and use only the generator for sampling. However, this loses valuable ... More
Collaborative Sampling in Generative Adversarial NetworksFeb 02 2019Apr 19 2019A standard practice in Generative Adversarial Networks (GANs) is to completely discard the discriminator when generating samples. However, this sampling method loses valuable information learned by the discriminator regarding the data distribution. In ... More
Let Me Not Lie: Learning MultiNomial LogitDec 23 2018Discrete choice models generally assume that model specification is known a priori. In practice, determining the utility specification for a particular application remains a difficult task and model misspecification may lead to biased parameter estimates. ... More
Perceptual Losses for Real-Time Style Transfer and Super-ResolutionMar 27 2016We consider image transformation problems, where an input image is transformed into an output image. Recent methods for such problems typically train feed-forward convolutional neural networks using a \emph{per-pixel} loss between the output and ground-truth ... More
PifPaf: Composite Fields for Human Pose EstimationMar 15 2019We propose a new bottom-up method for multi-person 2D human pose estimation that is particularly well suited for urban mobility such as self-driving cars and delivery robots. The new method, PifPaf, uses a Part Intensity Field (PIF) to localize body parts ... More
Tracking The Untrackable: Learning To Track Multiple Cues with Long-Term DependenciesJan 08 2017Apr 03 2017The majority of existing solutions to the Multi-Target Tracking (MTT) problem do not combine cues in a coherent end-to-end fashion over a long period of time. However, we present an online method that encodes long-term temporal dependencies across multiple ... More
Rethinking Person Re-Identification with ConfidenceJun 11 2019A common challenge in person re-identification systems is to differentiate people with very similar appearances. The current learning frameworks based on cross-entropy minimization are not suited for this challenge. To tackle this issue, we propose to ... More
Recurrent Attention Models for Depth-Based Person IdentificationNov 22 2016We present an attention-based model that reasons on human body shape and motion dynamics to identify individuals in the absence of RGB information, hence in the dark. Our approach leverages unique 4D spatio-temporal signatures to address the identification ... More
PifPaf: Composite Fields for Human Pose EstimationMar 15 2019Apr 05 2019We propose a new bottom-up method for multi-person 2D human pose estimation that is particularly well suited for urban mobility such as self-driving cars and delivery robots. The new method, PifPaf, uses a Part Intensity Field (PIF) to localize body parts ... More
Knowledge Transfer for Scene-specific Motion PredictionMar 22 2016Jul 26 2016When given a single frame of the video, humans can not only interpret the content of the scene, but also they are able to forecast the near future. This ability is mostly driven by their rich prior knowledge about the visual world, both in terms of (i) ... More
Crowd-Robot Interaction: Crowd-aware Robot Navigation with Attention-based Deep Reinforcement LearningSep 24 2018Mobility in an effective and socially-compliant manner is an essential yet challenging task for robots operating in crowded spaces. Recent works have shown the power of deep reinforcement learning techniques to learn socially cooperative policies. However, ... More
Social Scene Understanding: End-to-End Multi-Person Action Localization and Collective Activity RecognitionNov 28 2016We present a unified framework for understanding human social behaviors in raw image sequences. Our model jointly detects multiple individuals, infers their social actions, and estimates the collective actions with a single feed-forward pass through a ... More
Crowd-Robot Interaction: Crowd-aware Robot Navigation with Attention-based Deep Reinforcement LearningSep 24 2018Feb 19 2019Mobility in an effective and socially-compliant manner is an essential yet challenging task for robots operating in crowded spaces. Recent works have shown the power of deep reinforcement learning techniques to learn socially cooperative policies. However, ... More
Convolutional Relational Machine for Group Activity RecognitionApr 05 2019We present an end-to-end deep Convolutional Neural Network called Convolutional Relational Machine (CRM) for recognizing group activities that utilizes the information in spatial relations between individual persons in image or video. It learns to produce ... More
From Bits to Images: Inversion of Local Binary DescriptorsNov 06 2012Local Binary Descriptors are becoming more and more popular for image matching tasks, especially when going mobile. While they are extensively studied in this context, their ability to carry enough information in order to infer the original image is seldom ... More
Characterizing and Improving Stability in Neural Style TransferMay 05 2017Recent progress in style transfer on images has focused on improving the quality of stylized images and speed of methods. However, real-time methods are highly unstable resulting in visible flickering when applied to videos. In this work we characterize ... More
Forecasting Social Navigation in Crowded Complex ScenesJan 05 2016When humans navigate a crowed space such as a university campus or the sidewalks of a busy street, they follow common sense rules based on social etiquette. In this paper, we argue that in order to enable the design of new algorithms that can take fully ... More
Unsupervised Learning of Long-Term Motion Dynamics for VideosJan 07 2017Apr 11 2017We present an unsupervised representation learning approach that compactly encodes the motion dependencies in videos. Given a pair of images from a video clip, our framework learns to predict the long-term 3D motions. To reduce the complexity of the learning ... More
Social GAN: Socially Acceptable Trajectories with Generative Adversarial NetworksMar 29 2018Understanding human motion behavior is critical for autonomous moving platforms (like self-driving cars and social robots) if they are to navigate human-centric environments. This is challenging because human motion is inherently multimodal: given a history ... More
Towards Viewpoint Invariant 3D Human Pose EstimationMar 23 2016Jul 26 2016We propose a viewpoint invariant model for 3D human pose estimation from a single depth image. To achieve this, our discriminative model embeds local regions into a learned viewpoint invariant feature space. Formulated as a multi-task learning problem, ... More
CAR-Net: Clairvoyant Attentive Recurrent NetworkNov 28 2017Jul 31 2018We present an interpretable framework for path prediction that leverages dependencies between agents' behaviors and their spatial navigation environment. We exploit two sources of information: the past motion trajectory of the agent of interest and a ... More
Video Analysis for Body-worn Cameras in Law EnforcementApr 11 2016The social conventions and expectations around the appropriate use of imaging and video has been transformed by the availability of video cameras in our pockets. The impact on law enforcement can easily be seen by watching the nightly news; more and more ... More
Towards Vision-Based Smart Hospitals: A System for Tracking and Monitoring Hand Hygiene ComplianceAug 01 2017Apr 24 2018One in twenty-five patients admitted to a hospital will suffer from a hospital acquired infection. If we can intelligently track healthcare staff, patients, and visitors, we can better understand the sources of such infections. We envision a smart hospital ... More
Superconducting qubitsMay 01 2008From a physicist's standpoint, the most interesting part of quantum computing research may well be the possibility to probe the boundary between the quantum and the classical worlds. The more macroscopic are the structures involved, the better. So far, ... More
Reduction of Algebraic Parametric Systems by Rectification of their Affine Expanded Lie SymmetriesDec 19 2006Lie group theory states that knowledge of a $m$-parameters solvable group of symmetries of a system of ordinary differential equations allows to reduce by $m$ the number of equations. We apply this principle by finding some \emph{affine derivations} that ... More
Non-unitary set-theoretical solutions to the Quantum Yang-Baxter EquationMar 28 2000Aug 24 2000We develop a theory of non-unitary set-theoretical solutions to the Quantum Yang-Baxter equation. Our results generalize those obtained by Etingof, Schedler and the author. We remark that some of our constructions are similar to constructions obtained ... More
Inflaton in R-dependent potentialApr 06 2009Mar 25 2010We consider a non-minimally coupled inflaton, in a higher order curvature background, leading to a potential which evolves with the curvature scalar of the Universe, and which describes two regimes. The first one is a de Sitter phase, where the potential ... More
Non-renormalization for planar Wess-Zumino modelNov 27 2003Using a non-perturbative functional method, where the quantum fluctuations are gradually set up,it is shown that the interaction of a N=1 Wess-Zumino model in 2+1 dimensions does not get renormalized. This result is valid in the framework of the gradient ... More
A control on quantum fluctuations in 2+1 dimensionsJun 04 2003Aug 29 2003A functional method is discussed, where the quantum fluctuations of a theory are controlled by a mass parameter and the evolution of the theory with this parameter is connected to its renormalization. It is found, in the framework of the gradient expansion, ... More
A misleading Wilsonian fixed pointNov 13 2007We exhibit here, for a scalar theory, an apparently non-trivial Wilsonian fixed point, which surprisingly describes a free theory. This modest note is an observation which can be of interest in the framework of functional methods in Quantum Field Theory. ... More
A note on Liouville theoryMar 29 2005May 12 2005An exact differential equation is derived for the evolution of the Liouville effective action with the mass parameter. This derivation is based on properties of the exponential potential and some consequences of the equation are discussed.
An alternative approach to dynamical mass generation in QED3Oct 09 2003Some quantum properties of QED3 are studied with the help of an exact evolution equation of the effective action with the bare fermion mass. The resulting effective theory and the occurrence of a dynamical mass are discussed in the framework of the gradient ... More
Shapelets: I. A Method for Image AnalysisMay 10 2001We present a new method for the analysis of images, a fundamental task in observational astronomy. It is based on the linear decomposition of each object in the image into a series of localised basis functions of different shapes, which we call `Shapelets'. ... More
Constraining ALPs with linear and circular polarisation measurements of quasar lightSep 24 2013We discuss the constraints derived on the mixing of photons with light pseudoscalars using the distributions of good-quality linear and circular polarisation measurements of light from the least polarised classes of quasars. We also provide the dependence ... More
A relation between the dark mass of elliptical galaxies and their shapeApr 25 2013Jan 08 2014We have studied a large number of elliptical galaxies and found a correlation between their dark matter content and the ellipticity of their visible shape. The galaxies were strictly selected so that only typical medium-size elliptical galaxies were considered. ... More
Ring extension of entire ring with conjugation; arithmetic in entire ringsFeb 11 2013Some basic properties of the ring of integers $\mathbb{Z}$ are extended to entire rings. In particular, arithmetic in entire principal rings is very similar than arithmetic in the ring of integers $\mathbb{Z}$. These arithmetic properties are derived ... More
Decaying turbulence for the fractional subcritical Burgers equationAug 04 2016We consider the fractional unforced Burgers equation in the one-dimensional space-periodic setting: $$\partial u/\partial t+(f(u))_x +\nu \Lambda^{\alpha} u= 0, t \geq 0,\ \mathbb{x} \in \mathbb{T}^d=(\mathbb{R}/\mathbb{Z})^d.$$ Here $f$ is strongly convex ... More
BUSSTEPP 2016 lecture notes: Exact Wilsonian RenormalizationAug 31 2015Nov 12 2016These lecture notes introduce exact Wilsonian renormalisation, and describe its technical approach, from an intuitive implementation to more advanced realisations. The methods and concepts are explained with a scalar theory, and their extension to quantum ... More
On the homology of the double cobar construction of a double suspensionJun 20 2014The double cobar construction of a double suspension comes with a Connes-Moscovici structure, that is a homotopy G-algebra (or Gerstenhaber-Voronov algebra) structure together with a particular BV-operator up to a homotopy. We show that the homology of ... More
Expansion of a singularly perturbed equation with a two-scale converging convection termApr 16 2014Feb 04 2015In many physical contexts, evolution convection equations may present some very large amplitude convective terms. As an example, in the context of magnetic confinement fusion, the distribution function that describes the plasma satisfies the Vlasov equation ... More
Multidimensional potential Burgers turbulenceDec 25 2013Oct 06 2015We consider the multidimensional generalised stochastic Burgers equation in the space-periodic setting: $ \partial \mathbf{u}/\partial t+$ $(\nabla f(\mathbf{u}) \cdot \nabla)$ $\mathbf{u} -\nu \Delta \mathbf{u}=$ $\nabla \eta,\quad t \geq 0,\ \mathbf{x} ... More
Exact Large Deviations of the Current in the Asymmetric Simple Exclusion Process with Open BoundariesNov 28 2013In this thesis, we consider one of the most popular models of non-equilibrium statistical physics: the Asymmetric Simple Exclusion Process, in which particles jump stochastically on a one-dimensional lattice, between two reservoirs at fixed densities, ... More
A fresh look on the limit on ultralight axion-like particles from SN1987AOct 16 2014We revisit the limit on very light axion-like particles (ALPs) from the absence of gamma rays coincidental with the neutrino burst from SN1987A. We use updated supernova simulations, modern models for the magnetic field inside the Galaxy, and a Primakoff ... More
Binary Classification in Unstructured Space With Hypergraph Case-Based ReasoningJun 16 2018Nov 30 2018Binary classification is one of the most common problem in machine learning. It consists in predicting whether a given element belongs to a particular class. In this paper, a new algorithm for binary classification is proposed using a hypergraph representation. ... More
The Second Cohomology with Symplectic Coefficients of the Moduli Space of Smooth Projective CurvesNov 04 1996Each finite dimensional irreducible rational representation V of the symplectic group Sp_{2g} determines a generically defined local system \V over the moduli space M_g of genus g smooth projective curves. We study H^2(M_g;\V) and the mixed Hodge structure ... More
Fundamental tone, concentration of density to points and conformal degeneration on surfacesOct 13 2005Mar 21 2011We study the effect of two types of degeneration of the Riemannian metric on the first eigenvalue of the Laplace operator on surfaces. In both cases we prove that the first eigenvalue of the round sphere is an optimal asymptotic upper bound. The first ... More
Notes on Hilbert's 16th: experiencing Viro's theoryOct 07 2013This text is intended to become in the long run Chapter 3 of our long saga dedicated to Riemann, Ahlfors and Rohlin. Yet, as its contents evolved as mostly independent (due to our inaptitude to interconnect both trends as strongly as we wished), it seemed ... More
Normal holomorphic maps from C* to a projective spaceAug 03 2012A theorem of A. Ostrowski describing meromorphic functions f such that the family {f(kz):k in C*} is normal, is generalized to holomorphic maps from $C*$ to a projective space.
Zero Sets of H^p Functions in Convex Domains of Finite TypeFeb 11 2016We give a condition under which a divisor X in a bounded convex domain of finite type D in C^n is the zero set of a function in a Hardy space H^p(D) for some p \textgreater{} 0. This generalizes Varopoulos' result [Zero sets of H^p functions in several ... More
On the limiting absorption principle for a new class of schroedinger hamiltoniansOct 13 2015Nov 23 2017We prove the limiting absorption principle and discuss the continuity properties of the boundary values of the resolvent for a class of form bounded perturbations of the Euclidean Laplacian $\Delta$ that covers both short and long range potentials with ... More
Combination of classifying spaces for proper actionsOct 02 2013Given a group action on a simplicial complex such that each simplex stabiliser admits a cocompact model of classifying space for proper actions, we give conditions implying the existence of a cocompact model of classifying space for proper actions for ... More
On inverse scattering in electromagnetic field in classical relativistic mechanics at high energiesJun 02 2005Jul 12 2006We consider the multidimensional Newton-Einstein equation in static electromagnetic field $$\eqalign{\dot p = F(x,\dot x), F(x,\dot x)=-\nabla V(x)+{1\over c}B(x)\dot x,\cr p={\dot x \over \sqrt{1-{|\dot x|^2 \over c^2}}}, \dot p={dp\over dt}, \dot x={dx\over ... More
Non injectivity of the q-deformed von Neumann algebraMay 31 2006We prove that the von Neumann algebra generated by q-gaussians is not injective as soon as the dimension of the underlying Hilbert space is greater than 1. Our approach is based on a vector valued Khintchine type inequality for Wick products. The same ... More
Type ${\rm III_1}$ factors generated by regular representations of infinite dimensional nilpotent group $B_0^{\mathbb N}$Mar 23 2008Mar 25 2008We study the von Neumann algebra, generated by the unitary representations of infinite-dimensional groups nilpotent group $B_0^{\mathbb N}$. The conditions of the irreducibility of the regular and quasiregular representations of infinite-dimensional groups ... More
Monte Carlo without ChainsFeb 07 2008A sampling method for spin systems is presented. The spin lattice is written as the union of a nested sequence of sublattices, all but the last with conditionally independent spins, which are sampled in succession using their marginals. The marginals ... More
Calculation of norms of some secial elements of cyclotomic fieldsSep 13 2011In this article we prove that (1-zeta+zeta^2) is a unit in the ring of integers of the cyclotomic field where zeta is a primitive n-th root of unity and n is coprime to 2 and 3. We also prove that for prime n, N_{Q(zeta)/Q}(1-zeta-zeta^2)=L(p) the p-th ... More
Segre varieties and Lie symmetriesFeb 24 2000Using the classical S.Lie method we obtain a complete description of infinitesimal symmetries of a holomorphic PDE system defining the Segre family of a real analytic hypersurface. This gives a new proof of some well known results of CR geometry.
Invariant curves and semiconjugacies of rational functionsOct 29 2011Feb 27 2013Jordan analytic curves which are invariant under rational functions are studied
Irreducibility criterion for the set of two matricesJul 29 2008Nov 02 2008We give the criterion for the irreducibility, the Schur irreducibility and the indecomposability of the set of two $n\times n$ matrices $\Lambda_n$ and $A_n$ in terms of the subalgebra associated with the "support" of the matrix $A_n$, where $\Lambda_n$ ... More
On the second main theorem of CartanSep 17 2014Sep 27 2014The possibility of reversion of the inequality in the Second Main Theorem of Cartan in the theory of holomorphic curves in projective space is discussed. A new version of this theorem is proved that becomes an asymptotic equality for a class of holomorphic ... More
The index of G-transversally elliptic families IISep 13 2018Apr 23 2019We define the Chern character of the index class of a $G$-invariant family of $G$-transversally elliptic operators, see [6]. Next we study the Berline-Vergne formula for families in the elliptic and transversally elliptic case.
Image of the Artin groups of classical types inside the finite Iwahori-Hecke algebrasJul 08 2017We determine the image of the Artin groups of types B and D inside the Iwahori-Hecke algebras, when defined over finite fields, in the semisimple case. This generalizes earlier work on type A by Brunat, Magaard and Marin. In this multi-parameter case, ... More
Increment stationarity of $L^2$-indexed stochastic processes: spectral representation and characterizationNov 19 2015We are interested in the increment stationarity property for $L^2$-indexed stochastic processes, which is a fairly general concern since many random fields can be interpreted as the restriction of a more generally defined $L^2$-indexed process. We first ... More
Counting solutions without zeros or repetitions of a linear congruence and rarefaction in b-multiplicative sequencesMar 03 2014Feb 09 2016Consider a strongly $b$-multiplicative sequence and a prime $p$. Studying its $p$-rarefaction consists in characterizing the asymptotic behaviour of the sums of the first terms indexed by the multiples of $p$. The integer values of the "norm" $3$-variate ... More
A multi-scale study of a class of hybrid predator-prey modelsSep 01 2014We address the question of an averaging principle for a general class of multi-scale hybrid predator-prey models. We consider prey-predator models where the kinetic of the prey population, described by a differential equation, is faster than the kinetic ... More
John Cage's Number Pieces as Stochastic Processes: a Large-Scale AnalysisNov 17 2013The Number Pieces are a corpus of works by composer John Cage, which rely on a particular time-structure used for determining the temporal location of sounds, named the "time-bracket". The time-bracket system is an inherently stochastic process, which ... More
An Introduction to Non-diffusive Transport ModelsAug 08 2015The process of diffusion is the most elementary stochastic transport process. Brownian motion, the representative model of diffusion, played a important role in the advancement of scientific fields such as physics, chemistry, biology and finance. However, ... More
Exponential convergence to the stationary measure for a class of 1D Lagrangian systems with random forcingJan 08 2016Aug 04 2016We prove exponential convergence to the stationary measure for a class of 1d Lagrangian systems with random forcing in the space-periodic setting: $$ \phi_t+\phi_x^2/2=F^{\omega}, x \in S^1 = \mathbb{R}/\mathbb{Z}. $$ This confirms a part of a conjecture ... More
Un effet de moiré sur les espaces symétriques de type non-compactFeb 11 2016We prove that if $X$ is a symmetric space of the noncompact type, just as adding Helgason waves which propagate in all direction yields an elementary spherical function for $X$, a Helgason wave can be produced by adding elementary spherical functions ... More
Clean measurements of the nucleon axial-vector and free-neutron magnetic form factorsJul 10 2013Jul 21 2014We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q^2 dependence of the axial-vector form factor g_a(Q^2). It can be measured model-independently and as robustly as for electromagnetic ... More
Single-nucleon experimentsOct 09 2009We discuss the Jefferson Lab low momentum transfer data on moments of the nucleon spin structure functions $g_1$ and $g_2$ and on single charged pion electroproduction off polarized proton and polarized neutron. A wealth of data is now available, while ... More
Simple counterterms for asymptotically AdS spacetimes in Lovelock gravityJul 06 2011Nov 29 2011Although gravitational actions diverge in asymptotically AdS spacetimes, boundary counterterms can be added in order to cancel out those divergences; such counterterms are known in general to third order in the Riemann tensor for the Einstein-Hilbert ... More
Towards A Categorical Approach of Transformational Music TheoryApr 14 2012Jan 23 2014Transformational music theory mainly deals with group and group actions on sets, which are usually constituted by chords. For example, neo-Riemannian theory uses the dihedral group D24 to study transformations between major and minor triads, the building ... More
BUSSTEPP 2016 lecture notes: Exact Wilsonian RenormalizationAug 31 2015Aug 29 2016These lecture notes introduce exact Wilsonian renormalisation, and describe its technical approach, from an intuitive implementation to more advanced realisations. The methods and concepts are explained with a scalar theory, and their extension to quantum ... More
Lifshitz-type Quantum Field Theories in Particle PhysicsSep 26 2011Nov 03 2011This introduction to Lifshitz-type field theories reviews some of its aspects in Particle Physics. Attractive features of these models are described with different examples, as the improvement of graphs convergence, the introduction of new renormalizable ... More
An alternative to exact renormalization equationsMay 03 2005May 09 2005An alternative point of view to exact renormalization equations is discussed, where quantum fluctuations of a theory are controlled by the bare mass of a particle. The procedure is based on an exact evolution equation for the effective action, and recovers ... More
Meromorphic traveling wave solutions of the Kuramoto-Sivashinsky equationApr 25 2005We determine all cases when there exists a meromorphic solution of the third order ODE describing traveling waves solutions of the Kuramoto-Sivashinsky equation. It turns out that there are no other meromorphic solutions besides those explicit solutions ... More
Manifold approximation of set-valued functionsJan 11 2009A new continuity for set-valued functions is introduced, and an existence theorem is proved for such continuous set-valued functions.
Sensitivity Analysis Using a Fixed Point Interval IterationNov 18 2008Proving the existence of a solution to a system of real equations is a central issue in numerical analysis. In many situations, the system of equations depend on parameters which are not exactly known. It is then natural to aim proving the existence of ... More
Generic Dynamical Phase Transition in One-Dimensional Bulk-Driven Lattice Gases with ExclusionFeb 01 2017May 31 2017Dynamical phase transitions are crucial features of the fluctuations of statistical systems, corresponding to boundaries between qualitatively different mechanisms of maintaining unlikely values of dynamical observables over long periods of time. They ... More
Long-Baseline Neutrino Oscillation ExperimentsFeb 06 2011Mar 05 2011During the past decade, long-baseline neutrino experiments played a fundamental role in confirming neutrino flavor change and in measuring the neutrino mixing matrix with high precision. This role will be amplified with the next generation of experiments, ... More
A little scholium on Hilbert-Rohn via the total reality of $M$-curves: Riemann's flirt with Miss RagsdaleApr 22 2013This note presents an elementary proof of Hilbert's 1891 Ansatz of nesting for $M$-sextics, along the line of Riemann's Nachlass 1857 and a simple Harnack-style argument (1876). Our proof seems to have escaped the attention of Hilbert (and all subsequent ... More
Dark Matter freezeout in modified cosmological scenariosMay 08 2019We study the effects of modifying the expansions history of the Universe on Dark Matter freezeout. We derived a modified Boltzmann equation for freeze-out for an arbitrary energy density in the early Universe and provide an analytic approach using some ... More
The Newman phenomenon and Lucas sequenceAug 26 2011Feb 16 2012This article gives an alternative proof of the fact that N_{Q(zeta)/Q}(1-zeta)=p where p is an odd prime number and zeta is a primitive p-th root of unity, and uses it to prove that N_{Q(zeta)/Q}(1+zeta-zeta^2)=L(p) the p-th Lucas number. It shows a relation ... More
A fractional Brownian field indexed by $L^2$ and a varying Hurst parameterDec 20 2013Apr 23 2014Using structures of Abstract Wiener Spaces, we define a fractional Brownian field indexed by a product space $(0,1/2] \times L^2(T,m)$, $(T,m)$ a separable measure space, where the first coordinate corresponds to the Hurst parameter of fractional Brownian ... More
The QCD running coupling at all scales and the connection between hadron masses and Λ_sMar 20 2018We report on recent experimental and theoretical developments in our understanding of the QCD running coupling \alpha_s in QCD's nonperturbative regime. They allow us to analytically compute the hadron mass spectrum, with \Lambda_s the only input necessary ... More
Permutation Orbifolds and ChaosMay 23 2017Nov 28 2017We study out-of-time-ordered correlation functions in permutation orbifolds at large central charge. We show that they do not decay at late times for arbitrary choices of low-dimension operators, indicating that permutation orbifolds are non-chaotic theories. ... More
New self-dual codes of length 72May 16 2017In this paper we obtain at least 61 new singly even (Type I) binary [72,36,12] self-dual codes as a quasi-cyclic codes with m=2 (tailbitting convolutional codes) and at least 13 new doubly even (Type II) binary [72,36,12] self-dual codes by replacing ... More
On the Limiting Absorption Principle for Schr{ö}dinger operators on waveguidesFeb 06 2019We prove a Limiting Absorption Principle for Schr{\"o}dinger operators in tubes about infinite curves embedded in the Euclidian space with different types of boundary conditions. The argument is based on the Mourre theory with conjugate operators different ... More
A New Class of Schrödinger Operators without Positive EigenvaluesNov 20 2017Oct 08 2018Following the proof given by Froese and Herbst in [FH82] with another conjugate operator, we show for a class of real potential that possible eigenfunction of the Schr\"odinger operator has to decay sub-exponentially. We also show that, for a certain ... More
Complexes of groups and geometric small cancellation over graphs of groupsJun 28 2013Feb 06 2014We explain and generalise a construction due to Gromov to realise geometric small cancellation groups over graphs of groups as fundamental groups of non-positively curved 2-dimensional complexes of groups. We then give conditions so that the hyperbolicity ... More
Large values of Hecke-Maass L-functions with prescribed argumentNov 29 2016We investigate the existence of large values of L-functions attached to Maass forms on the critical line with prescribed argument. The results obtained rely on the resonance method developed by Soundararajan and furthered by Hough.
A semilinear parabolic-elliptic chemotaxis system with critical mass in any space dimensionOct 16 2012Jul 15 2013We study radial solutions in a ball of $\mathbb{R}^N$ of a semilinear, parabolic-elliptic Patlak-Keller-Segel system with a nonlinear sensitivity involving a critical power. For $N = 2$, the latter reduces to the classical linear model, well-known for ... More
The Chirka - Lindelof and Fatou theorems for d-bar subsolutionsAug 10 2018We prove analogs of the Chirka - Lindelof and Fatou theorems for bounded functions with bounded d-bar on a strictly pseudoconvex domain in an almost complex manifold
Criteria of irreducibility of the Koopman representations for the group ${\rm GL}_0(2\infty,{\mathbb R})$Oct 15 2016Jan 31 2017Our aim is to find the irreducibility criteria for the Koopman representation, when the group acts on some space with a measure (Conjecture 1.5). Some general necessary conditions of the irreducibility of this representation are established. In the particular ... More
Some remarks on contact manifolds, Monge-Ampere equations and solution singularitiesMar 07 2014We describe some natural relations connecting contact geometry, classical Monge-Ampere equations and theory of singularities of solutions to nonlinear PDEs. They reveal the hidden meaning of Monge-Ampere equations and sheds new light on some aspects of ... More
Unfolding of Finite Concurrent AutomataOct 05 2018We consider recognizable trace rewriting systems with level-regular contexts (RTL). A trace language is level-regular if the set of Foata normal forms of its elements is regular. We prove that the rewriting graph of a RTL is word-automatic. Thus its first-order ... More
On the analogy between real reductive groups and Cartan motion groups. II: Contraction of irreducible tempered representationsAug 28 2018Sep 25 2018Attached to any reductive Lie group $G$ is a "Cartan motion group" $G_0$ $-$ a Lie group with the same dimension as $G$, but a simpler group structure. A natural one-to-one correspondence between the irreducible tempered representations of $G$ and the ... More
On the analogy between real reductive groups and Cartan motion groups. III: A proof of the Connes-Kasparov isomorphismFeb 29 2016Mar 05 2019Alain Connes and Nigel Higson pointed out in the 1990s that the Connes-Kasparov "conjecture"' for the K-theory of reduced groupe $C^\ast$-algebras seemed, in the case of reductive Lie groups, to be a cohomological echo of a conjecture of George Mackey ... More