Results for "Marc Raventós"

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The hammock localization preserves homotopiesApr 29 2014May 13 2015The hammock localization provides a model for a homotopy function complex in any Quillen model category. We prove that a homotopy between a pair of morphisms induces a homotopy between the maps induced by taking the hammock localization. We describe applications ... More
Leishmaniasis Parasite Segmentation and Classification using Deep LearningDec 30 2018Leishmaniasis is considered a neglected disease that causes thousands of deaths annually in some tropical and subtropical countries. There are various techniques to diagnose leishmaniasis of which manual microscopy is considered to be the gold standard. ... More
Laue three dimensional neutron diffractionFeb 08 2019This article presents a measurement technique and data analysis tool to perform 3D grain distribution mapping and indexing of oligocrystalline samples using neutrons: Laue three-dimensional neutron diffraction (Laue3DND). The approach builds on forward ... More
Transfinite Adams representabilityApr 12 2013Feb 02 2016In a well generated triangulated category T, given a regular cardinal a, we consider the following problems: given a functor from the category of a-compact objects to abelian groups that preserves products of <a objects and takes exact triangles to exact ... More
On the Cartesian Skeleton and the Factorization of the Strong Product of DigraphsJan 20 2014The three standard products (the Cartesian, the direct and the strong product) of undirected graphs have been wellinvestigated, unique prime factor decomposition (PFD) are known and polynomial time algorithms have been established for determining the ... More
Comparing localizations across adjunctionsApr 29 2014Jun 22 2018We show that several apparently unrelated formulas involving left or right Bousfield localizations in homotopy theory are induced in a similar way by comparison maps associated with pairs of adjoint functors. Such comparison maps are used in the article ... More
Cold bosons in optical lattices: correlations, localization, and fragmentationOct 27 2014Bosons in optical lattices may exhibit interesting quantum phenomena like fragmentation and coherence. Applying direct diagonalization to a small system, we explore different aspects of such setup: We show that, for a microscopic sample, the superfluid ... More
Comparing localizations across adjunctionsApr 29 2014We show that several apparently unrelated formulas involving localizations in homotopy theory are special cases of comparison maps associated with a pair of adjoint functors. In doing so, we find that some of these formulas can be generalized and obtain ... More
Newton methods for k-order Markov Constrained Motion ProblemsJul 01 2014This is a documentation of a framework for robot motion optimization that aims to draw on classical constrained optimization methods. With one exception the underlying algorithms are classical ones: Gauss-Newton (with adaptive step size and damping), ... More
A new approach to the orientation of random hypergraphsJan 25 2012A h-uniform hypergraph H=(V,E) is called (l,k)-orientable if there exists an assignment of each hyperedge e to exactly l of its vertices such that no vertex is assigned more than k hyperedges. Let H_{n,m,h} be a hypergraph, drawn uniformly at random from ... More
X-rays of Stellar Coronae with Chandra and XMM-Newton: Flares and Elemental Composition in Stellar Atmospheres (Invited review)Sep 21 2004Observations of magnetically active stars with Chandra and XMM-Newton have deepened our knowledge of the physics of the atmospheres in late-type stars. In this review paper, I discuss two topics that have profited significantly from Chandra and XMM-Newton. ... More
Working group summary: pi-N sigma termDec 21 1999Several new theoretical and experimental developments concerning the determination of the nucleon sigma term are presented and discussed. Contribution to the Eighth International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon, Zuoz, ... More
Optimization and Physics: On the satisfiability of random Boolean formulaeDec 18 2002Dec 20 2002LECTURE GIVEN AT TH2002. Given a set of Boolean variables, and some constraints between them, is it possible to find a configuration of the variables which satisfies all constraints? This problem, which is at the heart of combinatorial optimization and ... More
Shock-in-jet model for quasars and microquasarsOct 05 2010We present the theoretical background and detailed equations for the synchrotron emission of a shock wave propagating in a relativistic jet. We then show how the evolution of an outburst in this shock-in-jet scenario can be analytically described and ... More
Review of prospects for H^+ in non-SUSY multi-Higgs models in view of LHC resultsDec 04 2012In this talk, prospects for the charged Higgs in non-SUSY models are reviewed, in view of LHC results (as of October, 2012). The four models (Type I, Type II, lepton-specific and flipped) without tree level flavor-changing neutral currents are discussed. ... More
Large Electric Dipole Moments of Heavy LeptonsMay 31 2001Jul 25 2001In many models of CP violation, the electric dipole moments (EDMs) of leptons scale as the cube of the lepton mass. In these models, the EDM of a 100 GeV heavy lepton would be a billion times greater than that of the muon, and could be as large as a 0.01 ... More
Precise Vacuum Stability Bound in the Standard Model (addendum)Apr 27 1994This is an addendum to the paper of the above title published in Physics Letters B317, 159 (1993). In that paper, I found the lower bound to the Higgs mass as a function of the top quark mass one obtains by requiring that the standard model vacuum be ... More
Long-Lived Charged Heavy LeptonsOct 18 1993Very little is known about the mass spectrum of fermions in the standard model. In this talk, I point out that in the simplest extension of the standard model, in which all right-handed fields are singlets, it is quite possible that a fourth-generation ... More
Attaching handlebodies to 3-manifoldsSep 09 2001Jan 09 2003The main theorem of this paper is a generalisation of well known results about Dehn surgery to the case of attaching handlebodies to a simple 3-manifold. The existence of a finite set of `exceptional' curves on the boundary of the 3-manifold is established. ... More
eta and eta' Physics at MAMIOct 07 2009The Crystal Ball at MAMI setup offers an excellent possibility to study decays of the eta and eta' meson. Here, recent results of the Crystal Ball at MAMI experiment from eta meson decays are presented. Furthermore, future perspectives of this experiment ... More
Properties of confining gauge field configurations in the pseudoparticle approachOct 23 2006The pseudoparticle approach is a numerical method to approximate path integrals in SU(2) Yang-Mills theory. Path integrals are computed by summing over all gauge field configurations, which can be represented by a linear superposition of a small number ... More
Perturbative theory for the Boltzmann equation in bounded domains with different boundary conditionsJul 11 2015Jul 21 2016We study the Boltzmann equation near a global Maxwellian in the case of bounded domains. We consider the boundary conditions to be either specular reflections or Maxwellian diffusion. Starting from the reference work of Guo in $L^\infty_{x,v}\left(\left(1+|v|\right)^\beta ... More
A Novel Augmented Lagrangian Approach for Inequalities and Convergent Any-Time Non-Central UpdatesDec 14 2014Motivated by robotic trajectory optimization problems we consider the Augmented Lagrangian approach to constrained optimization. We first propose an alternative augmentation of the Lagrangian to handle the inequality case (not based on slack variables) ... More
Homomorphisms and rigid isomorphisms of twisted group doublesMay 01 2016Jun 11 2016We prove several results concerning quasi-bialgebra morphisms $\mathcal{D}^\omega(G)\to\mathcal{D}^\eta(H)$ of twisted group doubles. We take a particular focus on the isomorphisms which are simultaneously isomorphisms $\mathcal{D}(G)\to\mathcal{D}(H)$. ... More
A global take on congestion in urban areasApr 13 2016May 04 2016We analyze the congestion data collected by a GPS device company (TomTom) for almost 300 urban areas in the world. Using simple scaling arguments and data fitting we show that congestion during peak hours in large cities grows essentially as the square ... More
About Gordan's algorithm for binary formsMar 04 2014Jun 19 2015In this paper, we present a modern version of Gordan's algorithm on binary forms. Symbolic method is reinterpreted in terms of $\mathsf{SL}_2(\mathbb{C})$--equivariant homomorphisms defined upon Cayley operator and polarization operator. A graphical approach ... More
Quantum attacks against iterated block ciphersOct 06 2014Apr 26 2015We study the amplification of security against quantum attacks provided by iteration of block ciphers. In the classical case, the Meet-in-the-middle attack is a generic attack against those constructions. This attack reduces the time required to break ... More
Statistical mechanics of two-dimensional foams: Physical foundations of the modelJul 16 2015Jan 11 2016In a recent series of papers [1--3], a statistical model that accounts for correlations between topological and geometrical properties of a two-dimensional shuffled foam has been proposed and compared with experimental and numerical data. Here, the various ... More
Optimizing the bulk modulus of cellular networksApr 05 2005We present an alternative derivation of upper-bounds for the bulk modulus of both two-dimensional and three-dimensional cellular materials. For two-dimensional materials, we recover exactly the expression of the Hashin-Shtrikman (HS) upper-bound in the ... More
Some conditionally hard problems on links and 3-manifoldsFeb 26 2016Apr 04 2016We show that three natural decision problems about links and 3-manifolds are computationally hard, assuming some standard conjectures in complexity theory. These problems are: the problem of determining whether a link in the 3-sphere bounds a Seifert ... More
Localizing VolatilitiesApr 13 2006We propose two main applications of Gy\"{o}ngy (1986)'s construction of inhomogeneous Markovian stochastic differential equations that mimick the one-dimensional marginals of continuous It\^{o} processes. Firstly, we prove Dupire (1994) and Derman and ... More
Colourability and word-representability of near-triangulationsMay 05 2016Oct 20 2016A graph $G = (V,E)$ is word-representable if there is a word $w$ over the alphabet $V$ such that $x$ and $y$ alternate in $w$ if and only if the edge $(x, y)$ is in $G$. It is known \cite{HKP2015} that all $3$-colourable graphs are word-representable, ... More
Finite-temperature perturbation theory for quasi-one-dimensional spin-1/2 Heisenberg antiferromagnetsOct 20 2001We develop a finite-temperature perturbation theory for quasi-one-dimensional quantum spin systems, in the manner suggested by H.J. Schulz (1996) and use this formalism to study their dynamical response. The corrections to the random-phase approximation ... More
Stability and angular-momentum transport of fluid flows between corotating cylindersMar 22 2012Turbulent transport of angular momentum is a necessary process to explain accretion in astrophysical disks. Although the hydrodynamic stability of disk-like flows has been tested in experiments, results are contradictory and suggest either laminar or ... More
The crossing number of composite knotsMay 30 2008Aug 25 2009It is a very old conjecture that the crossing number of knots is additive under connected sum. In other words, if K#K' is the connected sum of knots K and K', then does the equality c(K#K') = c(K) + c(K') hold? We prove that c(K#K') is at most c(K) + ... More
Adding high powered relations to large groupsDec 15 2005Mar 29 2007A group is known as `large' if some finite index subgroup admits a surjective homomorphism onto a non-abelian free group. The main theorem of the paper is as follows. Let G be a finitely generated, large group and let g_1,...,g_r be a collection of elements ... More
How Machine (Deep) Learning Helps Us Understand Human Learning: the Value of Big IdeasFeb 16 2019I use simulation of two multilayer neural networks to gain intuition into the determinants of human learning. The first network, the teacher, is trained to achieve a high accuracy in handwritten digit recognition. The second network, the student, learns ... More
Extremality for the Vafa-Witten bound on the sphereJul 30 2004Nov 29 2004We prove that the round metric on the sphere has the largest first eigenvalue of the Dirac operator among all metrics that are larger than it. As a corollary, this gives an alternative proof of an extremality result for scalar curvature due to M. Llarull. ... More
Non-resonant tori in symplectic twist maps without conjugate pointsFeb 08 2018We study the dynamics of a symplectic twist map without conjugate points. We show that in a neighborhood of a totally periodic Lagrangian manifold, there exists a large family of invariant Lagrangian tori on which the twist map is conjugated to a translation ... More
Local methods for blocks of finite simple groupsDec 24 2017This survey is about old and new results about the modular representation theory of finite reductive groups with a strong emphasis on local methods. This includes subpairs, Brauer's Main Theorems, fusion, Rickard equivalences. In the defining characteristic ... More
How Machine (Deep) Learning Helps Us Understand Human Learning: the Value of Big IdeasFeb 16 2019Mar 20 2019I use simulation of two multilayer neural networks to gain intuition into the determinants of human learning. The first network, the teacher, is trained to achieve a high accuracy in handwritten digit recognition. The second network, the student, learns ... More
Transitions in spatial networksOct 20 2018Dec 18 2018Networks embedded in space can display all sorts of transitions when their structure is modified. The nature of these transitions (and in some cases crossovers) can differ from the usual appearance of a giant component as observed for the Erdos-Renyi ... More
The localization theorem for framed motivic spacesJul 11 2018Sep 28 2018We prove the analog of the Morel-Voevodsky localization theorem for framed motivic spaces. We deduce that framed motivic spectra are equivalent to motivic spectra over arbitrary schemes.
Circular polarization in a spherical basisApr 17 2018Circular polarization of the cosmic microwave background (CMB) arises in the standard cosmological model from Faraday conversion of the linear polarization generated at the surface of last scatter by various sources of birefringence along the line of ... More
Role of salt valency in the switch of H-NS proteins between DNA-bridging and DNA-stiffening modesMar 26 2018This work investigates the interactions of H-NS proteins and bacterial genomic DNA through computer simulations performed with a coarse-grained model. The model was developed specifically to study the switch of H-NS proteins from the DNA-stiffening to ... More
How Problematic is the Near-Euclidean Spatial Geometry of the Large-Scale Universe?Mar 14 2018Oct 15 2018Modern observations based on general relativity indicate that the spatial geometry of the expanding, large-scale Universe is very nearly Euclidean. This basic empirical fact is at the core of the so-called "flatness problem", which is widely perceived ... More
Segregative phase separation scenario of the formation of the bacterial nucleoidSep 19 2018The mechanism responsible for the compaction of the genomic DNA of bacteria inside a structure called the nucleoid is a longstanding but still lively debated question. Most puzzling is the fact that the nucleoid occupies only a small fraction of the cell, ... More
Configuration Space Singularities of The Delta ManipulatorAug 29 2018We investigate the configuration space of the Delta-Manipulator, identify 24 points in the configuration space, where the Jacobian of the Constraint Equations looses rank and show, that these are not manifold points of the Real Algebraic Set, which is ... More
Comparing Gröbner bases and word reversingDec 04 2007Gr\"obner bases, in their noncommutative version, and word reversing are methods for solving the word problem of a presented monoid, and both rely on iteratively completing the initial list of relations. Simple examples may suggest to conjecture that ... More
A remark on renormalized volume and Euler characteristic for ACHE 4-manifoldsMay 09 2003May 16 2004This note computes the "renormalized volume" and a renormalizedGauss-Bonnet-Chern formula for the Euler characteristic ofasymptotically complex hyperbolic Einstein (in short: ACHE)4-manifolds.
From algebraic cobordism to motivic cohomologyOct 26 2012Aug 28 2014Let S be an essentially smooth scheme over a field of characteristic exponent c. Let MGL and HZ denote the algebraic cobordism spectrum and the motivic cohomology spectrum over S, respectively. We show that the canonical map MGL/(a1, a2, ...) -> HZ induced ... More
Intersection theory in algebraic cobordismDec 30 2015We give a more detailed construction of the operation "intersection with a pseudo-divisor" in algebraic cobordism. Using arguments from Levine-Morel, Algebraic Cobordism, sections 6.2, 6.3, this gives a new proof of the contravariant functoriality of ... More
Powers of ideals and the cohomology of stalks and fibers of morphismsSep 07 2010Feb 09 2012We first provide here a very short proof of a refinement of a theorem of Kodiyalam and Cutkosky, Herzog and Trung on the regularity of powers of ideals. This result implies a conjecture of H\`a and generalizes a result of Eisenbud and Harris concerning ... More
Elementary knot theoryApr 13 2016The aim of this survey article is to highlight several notoriously intractable problems about knots and links, as well as to provide a brief discussion of what is known about them.
A remark on the rigidity case of the positive energy theoremApr 30 2010In their proof of the positive energy theorem, Schoen and Yau showed that every asymptotically flat spacelike hypersurface M of a Lorentzian manifold which is flat along M can be isometrically imbedded with its given second fundamental form into Minkowski ... More
Deep Learning in steganography and steganalysis from 2015 to 2018Mar 31 2019For almost 10 years, the detection of a message hidden in an image has been mainly carried out by the computation of a Rich Model (RM), followed by a classification by an Ensemble Classifier (EC). In 2015, the first study using a convolutional neural ... More
A characterisation of large finitely presented groupsMar 08 2004Apr 01 2005A group is known as `large' if some finite index subgroup admits a surjective homomorphism onto a non-abelian free group. In this paper, we give a necessary and sufficient condition for a finitely presented group to be large, in terms of the existence ... More
A metric graph satisfying $w^1_4=1$ that cannot be lifted to a curve satisfying $\dim (W^1_4)=1$Jan 15 2015For all integers $g \geq 6$ we prove the existence of a metric graph $G$ with $w^1_4=1$ such that $G$ has Clifford index 2 and there is no tropical modification $G'$ of $G$ such that there exists a finite harmonic morphism of degree 2 from $G'$ to a metric ... More
Braid gaugings and categorical invariantsAug 22 2017Apr 15 2019We study the categorical notion of braid gauging and obtain its classical Hopf algebraic description. We demonstrate how braid gauging can provide new insights on certain categorical invariants, such as the fusion rules and the higher Frobenius-Schur ... More
Non vanishing of theta functions and sets of small multiplicative energyOct 12 2018Let $\chi$ range over the $(p-1)/2$ even Dirichlet characters modulo a prime $p$ and denote by $\theta (x,\chi)$ the associated theta series. The asymptotic behaviour of the second and fourth moments proved by Louboutin and the author implies that there ... More
Cosmetic contact surgeries along transverse knots and the knot complement problemMar 16 2017Feb 01 2019We study cosmetic contact surgeries along transverse knots in the standard contact 3-sphere, i.e. contact surgeries that yield again the standard contact 3-sphere. The main result is that we can exclude non-trivial cosmetic contact surgeries along all ... More
Oriented cohomology, Borel-Moore homology and algebraic cobordismJul 14 2008We examine various versions of oriented cohomology and Borel-Moore homology theories in algebraic geometry and put these two together in the setting of an "oriented duality theory", a generalization of Bloch-Ogus twisted duality theory. This combines ... More
A quadratic refinement of the Grothendieck-Lefschetz-Verdier trace formulaSep 24 2013Aug 28 2014We prove a trace formula in stable motivic homotopy theory over a general base scheme, equating the trace of an endomorphism of a smooth proper scheme with the "Euler characteristic integral" of a certain cohomotopy class over its scheme of fixed points. ... More
The separating gonality of a separating real curveSep 11 2011A smooth real curve is called separating in case the complement of the real locus inside the complex locus is disconnected. This is the case if there exists a morphism to the projective line whose inverse image of the real locus of the projective line ... More
Modular hyperbolas and Beatty sequencesAug 01 2018Aug 02 2018Bounds for $\max\{m,\tilde{m}\}$ subject to $m,\tilde{m} \in \mathbb{Z}\cap[1,p)$, $p$ prime, $z$ indivisible by $p$, $m\tilde{m}\equiv z\bmod p$ and $m$ belonging to some fixed Beatty sequence $\{ \lfloor n\alpha+\beta \rfloor : n\in\mathbb{N} \}$ are ... More
Links between functions and subdifferentialsFeb 17 2018Oct 15 2018A function in a class $\mathcal{F}(X)$ is said to be subdifferentially determined in $\mathcal{F}(X)$ if it is equal up to an additive constant to any function in $\mathcal{F}(X)$ with the same subdifferential. A function is said to be subdifferentially ... More
Characterization of the monotone polar of subdifferentialsJul 07 2013We show that a point is solution of the Minty variational inequality of subdifferential type for a given function if and only if the function is increasing along rays starting from that point. This provides a characterization of the monotone polar of ... More
Left determined model structures for locally presentable categoriesJan 12 2009Jun 24 2009We extend a result of Cisinski on the construction of cofibrantly generated model structures from (Grothendieck) toposes to locally presentable categories and from monomorphism to more general cofibrations. As in the original case, under additional conditions, ... More
On the Complexity of Recognizing S-composite and S-prime GraphsMay 04 2012Jan 16 2013S-prime graphs are graphs that cannot be represented as nontrivial subgraphs of nontrivial Cartesian products of graphs, i.e., whenever it is a subgraph of a nontrivial Cartesian product graph it is a subgraph of one the factors. A graph is S-composite ... More
Loopy annealing belief propagation for vertex cover and matching: convergence, LP relaxation, correctness and Bethe approximationJan 30 2014Jul 07 2014For the minimum cardinality vertex cover and maximum cardinality matching problems, the max-product form of belief propagation (BP) is known to perform poorly on general graphs. In this paper, we present an iterative loopy annealing BP (LABP) algorithm ... More
The structure of evolutionary exploration: On crossover, buildings blocks and Estimation-Of-Distribution AlgorithmsDec 11 2002The notion of building blocks can be related to the structure of the offspring probability distribution: loci of which variability is strongly correlated constitute a building block. We call this correlated exploration. With this background we analyze ... More
A Simple Transformation for Offline-Parsable Grammars and its Termination PropertiesMay 14 1996We present, in easily reproducible terms, a simple transformation for offline-parsable grammars which results in a provably terminating parsing program directly top-down interpretable in Prolog. The transformation consists in two steps: (1) removal of ... More
Spatial NetworksOct 02 2010Nov 04 2010Complex systems are very often organized under the form of networks where nodes and edges are embedded in space. Transportation and mobility networks, Internet, mobile phone networks, power grids, social and contact networks, neural networks, are all ... More
Spheroid and disk signatures in galaxy bulgesJan 31 2003Recent progress on the structure and dynamics of bulges is reviewed. Those aspects that link galaxy bulges either to oblate spheroids akin to elliptical galaxies or to rapidly-rotating, flattened systems more nearly resembling the products of disk internal ... More
Two tails in NGC 3656, and the major merger origin of shell and minor axis dust lane ellipticalsJul 01 1997I report on the discovery of two faint (~ 26.8 Rmag/arcsec^2) tidal tails around the shell elliptical NGC 3656 (Arp 155). This galaxy had previously been interpreted as a case of accretion, or minor merger. The two tidal tails are inconsistent with a ... More
The anomalous magnetic moment of the muon: a theoretical introductionJul 18 2003These notes, based on the lectures delivered at the 2003 Schladming School of Theoretical Physics, provide an introduction to the theory of the anomalous magnetic moments of the muon and of the electron.
Experimental determination of Chiral Symmetry Breaking ParametersMay 27 1993In the low energy domain, Chiral Perturbation Theory parametrizes the small chiral symmetry breaking effects, produced by the quark masses $m_u$, $m_d$ and $m_s$, in terms of order parameters of massless QCD. The latter can then, in principle, be measured ... More
Message passing in random satisfiability problemsJan 14 2004This talk surveys the recent development of message passing procedures for solving constraint satisfaction problems. The cavity method from statistical physics provides a generalization of the belief propagation strategy that is able to deal with the ... More
Statistical Physics of the Glass PhaseOct 18 2001This paper gives an introduction to some of the statistical physics problems which appear in the study of structural glasses. It is a shortened and updated version of a more detailed review paper which has appeared in cond-mat/0005173.
First Steps in Glass TheoryMay 10 2000This paper is an introduction to some of the main present issues in the theory of structural glasses. After recalling a few experimental facts, it gives a short account of the analogy between fragile glasses and the mean field discontinuous spin glasses. ... More
Tau Decays to Mu + Eta in Supersymmetric ModelsJul 10 2002Jul 31 2002The existence of large \nu_\mu-\nu_\tau mixing suggests the likelihood of large smuon-stau mixing in supersymmetric models, leading to \mu and \tau number violation. In addition to interesting signatures in slepton and neutralino production and decay, ... More
Precise Vacuum Stability Bound in the Standard ModelJul 27 1993In the standard model, a lower bound to the Higgs mass (for a given top quark mass) exists if one requires that the standard model vacuum be stable. This bound is calculated as precisely as possible, including the most recent values of the gauge couplings, ... More
Scalar-Mediated Flavor-Changing Neutral CurrentsSep 30 1998The simplest extension of the standard model involves adding a scalar doublet--the so-called two-Higgs model. In general, the additional scalar will mediate tree-level flavor-changing neutral currents. Although one can arbitrarily impose a discrete symmetry ... More
SUSY GUTs without light Higgs bosonsJun 08 1994Jun 14 1994There are two different types of perturbative unification in SUSY GUTs. Perturbative gauge unification is necessary for the extremely successful prediction of $\sin^2\theta_w$. ``Perturbative validity'' requires that {\it all} couplings (not just the ... More
Classification of alternating knots with tunnel number oneMar 30 2001Aug 05 2002This paper gives a complete classification of all alternating knots with tunnel number one, and all their unknotting tunnels. We prove that the only such knots are two-bridge knots and certain Montesinos knots.
The volume of hyperbolic alternating link complementsDec 19 2000Jun 16 2003If a hyperbolic link has a prime alternating diagram D, then we show that the link complement's volume can be estimated directly from D. We define a very elementary invariant of the diagram D, its twist number t(D), and show that the volume lies between ... More
Classification of vertex-transitive cubic partial cubesSep 15 2015Jul 21 2016Partial cubes are graphs isometrically embeddable into hypercubes. In this paper it is proved that every cubic, vertex-transitive partial cube is isomorphic to one of the following graphs: $K_2 \, \square \, C_{2n}$, for some $n\geq 2$, the generalized ... More
Stability of global equilibrium for the multi-species Boltzmann equation in $L^\infty$ settingsMar 04 2016Jul 19 2016We prove the stability of global equilibrium in a multi-species mixture, where the different species can have different masses, on the $3$-dimensional torus. We establish stability estimates in $L^\infty_{x,v}(w)$ where $w=w(v)$ is either polynomial or ... More
OBDDs and (Almost) $k$-wise Independent Random VariablesApr 15 2015OBDD-based graph algorithms deal with the characteristic function of the edge set E of a graph $G = (V,E)$ which is represented by an OBDD and solve optimization problems by mainly using functional operations. We present an OBDD-based algorithm which ... More
Computing asymptotic invariants with the Ricci tensor on asymptotically flat and hyperbolic manifoldsMar 02 2015Apr 22 2016We prove in a simple and coordinate-free way the equivalence bteween the classical definitions of the mass or the center of mass of an asymptotically flat manifold and their alternative definitions depending on the Ricci tensor and conformal Killing fields. ... More
The Muon Anomalous Magnetic MomentDec 03 2014The calculations entering the prediction of the standard model value for the anomalous magnetic moment of the muon $a_\mu$ are reviewed, and compared to the very accurate experimental measurement. The situation for the electron is discussed in parallel. ... More
Instantaneous exponential lower bound for solutions to the Boltzmann equation with Maxwellian diffusion boundary conditionsOct 22 2014Nov 05 2014We prove the immediate appearance of an exponential lower bound, uniform in time and space, for continuous mild solutions to the full Boltzmann equation in a $C^2$ convex bounded domain with the physical Maxwellian diffusion boundary conditions, under ... More
Alternative determinism principle for topological analysis of chaosMar 04 2005Aug 31 2006The topological analysis of chaos based on a knot-theoretic characterization of unstable periodic orbits has proved a powerful method, however knot theory can only be applied to three-dimensional systems. Still, the core principles upon which this approach ... More
Fermions in the pseudoparticle approachApr 23 2007The pseudoparticle approach is a numerical technique to compute path integrals without discretizing spacetime. The basic idea is to integrate over those field configurations, which can be represented by a sum of a fixed number of localized building blocks ... More
Classes of confining gauge field configurationsAug 08 2006Dec 18 2006We present a numerical method to compute path integrals in effective SU(2) Yang-Mills theories. The basic idea is to approximate the Yang-Mills path integral by summing over all gauge field configurations, which can be represented as a linear superposition ... More
Structure of Optimal Transport Networks Subject to a Global ConstraintAug 09 2006Sep 07 2010The structure of pipe networks minimizing the total energy dissipation rate is studied analytically. Among all the possible pipe networks that can be built with a given total pipe volume (or pipe lateral surface area), the network which minimizes the ... More
Architecture of optimal transport networksApr 06 2005We analyze the structure of networks minimizing the global resistance to flow (or dissipated energy) with respect to two different constraints: fixed total channel volume and fixed total channel surface area. First, we determine the shape of channels ... More
Statistical Mechanics of Two-dimensional FoamsSep 07 2010The methods of statistical mechanics are applied to two-dimensional foams under macroscopic agitation. A new variable -- the total cell curvature -- is introduced, which plays the role of energy in conventional statistical thermodynamics. The probability ... More
In vivo compaction dynamics of bacterial DNA: A fingerprint of DNA/RNA demixing ?Sep 26 2016The volume occupied by unconstrained bacterial DNA in physiological solutions exceeds 1000 times the volume of the cell. Still, it is confined to a well defined region of the cell called the nucleoid, which occupies only a fraction of the cell volume. ... More
On the confinement of semiflexible chains under torsionDec 27 2012The effect of a finite torque on semiflexible polymers in a confined environment is investigated. It is shown how a new lengthscale appears in the strongly confined limit. The influence of a torque on the extension of biopolymers in nanochannels is also ... More