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Learning Gaussian Graphical Models by symmetric parallel regression techniqueFeb 08 2019In this contribution we deal with the problem of learning an undirected graph which encodes the conditional dependence relationship between variables of a complex system, given a set of observations of this system. This is a very central problem of modern ... More

Simultaneous nonparametric regression in RADWT dictionariesFeb 08 2019A new technique for nonparametric regression of multichannel signals is presented. The technique is based on the use of the Rational-Dilation Wavelet Transform (RADWT), equipped with a tunable Q-factor able to provide sparse representations of functions ... More

Estimation of delta-contaminated density of the random intensity of Poisson dataSep 01 2015In the present paper, we constructed an estimator of a delta contaminated mixing density function $g(\lambda)$ of the intensity $\lambda$ of the Poisson distribution. The estimator is based on an expansion of the continuous portion $g_0(\lambda)$ of the ... More

De-noising procedures for frame operatorsJan 16 2013The present paper provides a comprehensive study of de-noising properties of frames and, in particular, tight frames, which constitute one of the most popular tools in contemporary signal processing. The objective of the paper is to bridge the existing ... More

Minimizers of Convex Functionals Arising in Random SurfacesSep 22 2008We investigate regularity of minimizers in two dimensions for certain classes of non-smooth convex functionals. In particular our results apply to the surface tensions that appear in recent works on random surfaces and random tilings of Kenyon, Okounkov ... More

Dispersive to non-dispersive transition and phase velocity transient for linear waves in plane wake and channel flowsApr 21 2015Feb 12 2016In this study we analyze the phase and group velocity of three-dimensional linear traveling waves in two sheared flows, the plane channel and the wake flows. This was carried out by varying the wave number over a large interval of values at a given Reynolds ... More

The Dirichlet problem for singular elliptic equations with general nonlinearitiesJan 10 2018In this paper, under very general assumptions, we prove existence and regularity of distributional solutions to homogeneous Dirichlet problems of the form $$\begin{cases} \displaystyle - \Delta_{1} u = h(u)f & \text{in}\, \Omega,\newline u\geq 0& \text{in}\ ... More

Hydrodynamics of Hypersonic Jets: Experiments and Numerical SimulationsJan 15 2011Stars form in regions of the galaxy that are denser and cooler than the mean interstellar medium. These regions are called Giant Molecular Clouds. At the beginning of their life, up to $10^5-10^6$ years, stars accrete matter from their rich surrounding ... More

Model surgery: joining and splitting models with Markov meldingJul 22 2016Sep 02 2016Analysing multiple evidence sources is often feasible only via a modular approach, with separate submodels specified for smaller components of the available evidence. Here we introduce a generic framework that enables fully Bayesian analysis in this setting. ... More

Coverings of the Symmetric and Alternating GroupsSep 20 2010We analyse for which $n$ there exist in $G=A_n,S_n$ two proper subgroups $H,K$ such that $G$ is the union of the $G$-conjugacy classes of $H$ and $K$.

A Characterization Theorem for Local Operators in Factorizing Scattering ModelsNov 15 2012In quantum field theory, the rigorous construction of local observables in the presence of nontrivial interaction is a crucial problem. In a class of integrable quantum field theories, a very abstract existence proof has recently been given by Lechner. ... More

Asymptotic behaviour of the simple random walk on the 2-combMay 29 2006We analyze the differences between the horizontal and the vertical component of the simple random walk on the 2-dimensional comb. In particular we evaluate by combinatorial methods the asymptotic behaviour of the expected value of the distance from the ... More

Kantorovich vs. Monge: A Numerical Classification of Extremal Multi-Marginal Mass Transports on Finite State SpacesJan 14 2019Jan 20 2019We analyze the validity of Monge's ansatz regarding the symmetric multi-marginal Kantorovich optimal transport problem on finite state spaces, with uniform-marginal constraint. The class of Monge states reduces the number of unknowns from combinatorial ... More

Modeling of the HIV infection epidemic in the Netherlands: A multi-parameter evidence synthesis approachFeb 27 2012Multi-parameter evidence synthesis (MPES) is receiving growing attention from the epidemiological community as a coherent and flexible analytical framework to accommodate a disparate body of evidence available to inform disease incidence and prevalence ... More

Reconstructing transmission trees for communicable diseases using densely sampled genetic dataJan 08 2014Dec 06 2015Whole genome sequencing of pathogens from multiple hosts in an epidemic offers the potential to investigate who infected whom with unparalleled resolution, potentially yielding important insights into disease dynamics and the impact of control measures. ... More

Variational regularization of the weighted conical Radon transformAug 04 2018Recovering a function from integrals over conical surfaces recently got significant interest. It is relevant for emission tomography with Compton cameras and other imaging applications. In this paper, we consider the weighted conical Radon transform with ... More

On the reversal bias of the Minimax social choice correspondenceAug 18 2015Dec 21 2015We introduce three different qualifications of the reversal bias in the framework of social choice correspondences. For each of them, we prove that the Minimax social choice correspondence is immune to it if and only if the number of voters and the number ... More

A generating function approach to branching random walksNov 24 2015Nov 24 2016It is well known that the behaviour of a branching process is completely described by the generating function of the offspring law and its fixed points. Branching random walks are a natural generalization of branching processes: a branching process can ... More

A dynamical presentation of the better than nice metric on the discMay 12 2016This is a postprint of our paper "Force free Moebius motions of the circle" (J. Geom. Symmetry Phys. 27 (2012) 59-65), which we hadn't uploaded to arXiv previously. We would like to draw attention to the relationship with the article "A geometry where ... More

Wedge-local fields in integrable models with bound states II. Diagonal S-matrixJan 26 2016Aug 18 2016We construct candidates for observables in wedge-shaped regions for a class of 1+1-dimensional integrable quantum field theories with bound states whose S-matrix is diagonal, by extending our previous methods for scalar S-matrices. Examples include the ... More

Recent results on branching random walksApr 27 2011Jun 05 2011This paper is a collection of recent results on discrete-time and continuous-time branching random walks. Some results are new and others are known. Many aspects of this theory are considered: local, global and strong local survival, the existence of ... More

A survey on Hamilton cycles in directed graphsJun 03 2010We survey some recent results on long-standing conjectures regarding Hamilton cycles in directed graphs, oriented graphs and tournaments. We also combine some of these to prove the following approximate result towards Kelly's conjecture on Hamilton decompositions ... More

On Posa's conjecture for random graphsMar 28 2012Jul 30 2012The famous Posa conjecture states that every graph of minimum degree at least 2n/3 contains the square of a Hamilton cycle. This has been proved for large n by Koml\'os, Sark\"ozy and Szemer\'edi. Here we prove that if p > n^{-1/2+\eps}, then asymptotically ... More

Hamilton decompositions of regular expanders: applicationsMar 03 2012Oct 31 2013In a recent paper, we showed that every sufficiently large regular digraph G on n vertices whose degree is linear in n and which is a robust outexpander has a decomposition into edge-disjoint Hamilton cycles. The main consequence of this theorem is that ... More

Tailored long range forces on polarizable particles by collective scattering of broadband radiationJul 13 2016Collective coherent light scattering by polarizable particles creates surprisingly strong, long range inter-particle forces originating from interference of the light scattered by different particles. While for monochromatic laser beams this interaction ... More

Normal coverings of finite symmetric and alternating groupsNov 19 2010In this paper we investigate the minimum number of maximal subgroups H_i for i=1 ...k of the symmetric group S_n (or the alternating group A_n) such that each element in the group S_n (respectively A_n) lies in some conjugate of one of the H_i. We prove ... More

Maximal Blaschke ProductsMar 27 2013Mar 28 2013We consider the classical problem of maximizing the derivative at a fixed point over the set of all bounded analytic functions in the unit disk with prescribed critical points. We show that the extremal function is essentially unique and always an indestructible ... More

Planetary Nebulae distances in GAIA DR2Jul 17 2018Context: Planetary Nebula distance scales often suffer for model dependent solutions. Model independent trigonometric parallaxes have been rare. Space based trigonometric parallaxes are now available for a larger sample using the second data release of ... More

Hamilton decompositions of regular expanders: a proof of Kelly's conjecture for large tournamentsFeb 28 2012May 10 2013A long-standing conjecture of Kelly states that every regular tournament on n vertices can be decomposed into (n-1)/2 edge-disjoint Hamilton cycles. We prove this conjecture for large n. In fact, we prove a far more general result, based on our recent ... More

Linkedness and ordered cycles in digraphsApr 02 2007The minimum semi-degree of a digraph D is the minimum of its minimum outdegree and its minimum indegree. We show that every sufficiently large digraph D with minimum semi-degree at least n/2 +k-1 is k-linked. The bound on the minimum semi-degree is best ... More

Intrinsic Differentiability and Intrinsic Regular Surfaces in Carnot GroupsNov 13 2018A Carnot group G is a connected, simply connected, nilpotent Lie group with stratified Lie algebra. Intrinsic regular surfaces in Carnot groups play the same role as C^1 surfaces in Euclidean spaces. As in Euclidean spaces, intrinsic regular surfaces ... More

Area preserving maps and volume preserving maps between a class of polyhedrons and a sphereApr 07 2015For a class of polyhedrons denoted $\mathbb K_n(r,\varepsilon)$, we construct a bijective continuous area preserving map from $\mathbb K_n(r,\varepsilon)$ to the sphere $\mathbb S^{2}(r)$, together with its inverse. Then we investigate for which polyhedrons ... More

HST/WFPC2 imaging analysis and Cloudy modelling of the multiple shell planetary nebulae NGC 3242, NGC 6826 and NGC 7662Jul 04 2018We performed a detailed photometric analysis and photoionisation modelling on three high excitation multiple shell planetary nebulae: NGC 3242, NGC 6826 and NGC 7662. Archival HST/WFPC2 narrow band filter images were used to investigate shocked regions ... More

Infinite primitive and distance transitive directed graphs of finite out-valencyMay 12 2014We give certain properties which are satisfied by the descendant set of a vertex in an infinite, primitive, distance transitive digraph of finite out-valency and provide a strong structure theory for digraphs satisfying these properties. In particular, ... More

Free boundary regularity for a problem with right hand sideDec 10 2009We consider a one-phase free boundary problem with variable coefficients and non-zero right hand side. We prove that flat free boundaries are $C^{1,\alpha}$ using a different approach than the classical supconvolution method of Caffarelli. We use this ... More

Bernstein-type techniques for 2D free boundary graphsDec 15 2006We prove an a-priori bound for the Lipschitz constant of a smooth one-phase free boundary graph F(u) in two dimensions. The function u satisfies a fully nonlinear elliptic equation in its positive side, and the gradient of u is equal to 1 on F(u).

Existence and regularity of monotone solutions to a free boundary problemJan 15 2007We investigate existence and regularity properties of one-phase free boundary graphs, in connection with the question of whether there exists a complete non-planar free boundary graph in high dimensions.

Gravitational entropy of Kerr black holesJul 25 2014Classical invariants of General Relativity can be used to approximate the entropy of the gravitational field. In this work, we study two proposed estimators based on scalars constructed out from the Weyl tensor, in Kerr spacetime. In order to evaluate ... More

New remarks on the Cosmological ArgumentFeb 16 2012We present a formal analysis of the Cosmological Argument in its two main forms: that due to Aquinas, and the revised version of the Kalam Cosmological Argument more recently advocated by William Lane Craig. We formulate these two arguments in such a ... More

Deterministic global optimization using space-filling curves and multiple estimates of Lipschitz and Holder constantsSep 11 2015In this paper, the global optimization problem $\min_{y\in S} F(y)$ with $S$ being a hyperinterval in $\Re^N$ and $F(y)$ satisfying the Lipschitz condition with an unknown Lipschitz constant is considered. It is supposed that the function $F(y)$ can be ... More

LEGUS Discovery of a Light Echo Around Supernova 2012awApr 30 2015We have discovered a luminous light echo around the normal Type II-Plateau Supernova (SN) 2012aw in Messier 95 (M95; NGC 3351), detected in images obtained approximately two years after explosion with the Wide Field Channel 3 on-board the Hubble Space ... More

Simplicity and exceptionality of syzygy bundles over P^nJun 26 2013In this work we will prove results that ensure the simplicity and the exceptionality of vector bundles which are defined by the splitting of pure resolutions. We will call such objects syzygy bundles.

Optimal Distributed Searching in the Plane with and without UncertaintyOct 04 2014Jun 25 2015We consider the problem of multiple agents or robots searching for a target in the plane. This is motivated by Search and Rescue operations (SAR) in the high seas which in the past were often performed with several vessels, and more recently by swarms ... More

Presentism meets black holesMar 14 2014Presentism is, roughly, the metaphysical doctrine that maintains that whatever exists, exists in the present. The compatibility of presentism with the theories of special and general relativity was much debated in recent years. It has been argued that ... More

Time and irreversibility in an accelerating universeMay 18 2011Sep 22 2011It is a remarkable fact that all processes occurring in the observable Universe are irreversible, whereas the equations through which the fundamental laws of physics are formulated are invariant under time reversal. The emergence of irreversibility from ... More

VHE observations of binary systems performed with the MAGIC telescopesJul 25 2018The improvement on the Imaging Air Cherenkov Technique (IACT) led to the discovery of a new type of sources that can emit at very high energies: the gamma-ray binaries. Only six systems are part of this exclusive class. We summarize the latest results ... More

Model Checking Classes of Metric LTL Properties of Object-Oriented Real-Time Maude SpecificationsSep 22 2010This paper presents a transformational approach for model checking two important classes of metric temporal logic (MTL) properties, namely, bounded response and minimum separation, for nonhierarchical object-oriented Real-Time Maude specifications. We ... More

On the Optimality of Uncoded Cache PlacementNov 06 2015Caching is an efficient way to reduce peak-hour network traffic congestion by storing some contents at user's local cache without knowledge of later demands. Maddah-Ali and Niesen initiated a fundamental study of caching systems; they proposed a scheme ... More

Hamiltonian degree sequences in digraphsJul 11 2008Dec 01 2009We show that for each \eta>0 every digraph G of sufficiently large order n is Hamiltonian if its out- and indegree sequences d^+_1\le ... \le d^+_n and d^- _1 \le ... \le d^-_n satisfy (i) d^+_i \geq i+ \eta n or d^-_{n-i- \eta n} \geq n-i and (ii) d^-_i ... More

Proof of a tournament partition conjecture and an application to 1-factors with prescribed cycle lengthsSep 29 2013Nov 05 2015In 1982 Thomassen asked whether there exists an integer f(k,t) such that every strongly f(k,t)-connected tournament T admits a partition of its vertex set into t vertex classes V_1,...,V_t such that for all i the subtournament T[V_i] induced on T by V_i ... More

Effect of selfish choices in deferred acceptance with short listsJan 03 2017We study the outcome of deferred acceptance when prospective medical residents can only apply to a limited set of hospitals. This limitation requires residents to make a strategic choice about the quality of hospitals they apply to. Through a mix of theoretical ... More

The algebra of bounded type holomorphic functions on the ballNov 09 2018We study the spectrum $M_b(U)$ of the algebra of bounded type holomorphic functions on a complete Reinhardt domain in a symmetrically regular Banach space $E$ as an analytic manifold over the bidual of the space. In the case that $U$ is the unit ball ... More

C^{2,α}$ regularity of flat free boundaries for the thin one-phase problemNov 10 2011We prove $C^{2,\alpha}$ regularity of sufficiently flat free boundaries, for the thin one-phase problem in which the free boundary occurs on a lower dimensional subspace. This problem appears also as a model of a one-phase free boundary problem in the ... More

A gradient bound for free boundary graphsSep 23 2010We prove an analogue for a one-phase free boundary problem of the classical gradient bound for solutions to the minimal surface equation. It follows, in particular, that every energy-minimizing free boundary that is a graph is also smooth. The method ... More

Regularity of Lipschitz free boundaries for the thin one-phase problemMay 08 2012We study regularity properties of the free boundary for the thin one-phase problem which consists of minimizing the energy functional $$\label{E} E(u,\Omega) = \int_\Omega |\nabla u|^2 dX + \mathcal{H}^n(\{u>0\} \cap \{x_{n+1} = 0\}), \quad \Omega \subset ... More

$C^{\infty}$ regularity of certain thin free boundariesFeb 05 2014We continue our study of the free boundary regularity in the thin one-phase problem and show that $C^{2,\alpha}$ free boundaries are smooth.

Boundary Harnack estimates in slit domains and applications to thin free boundary problemsJun 23 2014We provide a higher order boundary Harnack inequality for harmonic functions in slit domains. As a corollary we obtain the $C^\infty$ regularity of the free boundary in the Signorini problem near non-degenerate points.

A note on higher regularity boundary Harnack inequalityMar 11 2014We show that the quotient of two positive harmonic functions vanishing on the boundary of a $C^{k,\alpha}$ domain is of class $C^{k,\alpha}$ up to the boundary.

A fully nonlinear problem with free boundary in the planeNov 10 2008We prove that bounded solutions to an overdetermined fully nonlinear free boundary problem in the plane are one dimensional. Our proof relies on maximum principle techniques and convexity arguments.

Low regularity solutions for a 2D quadratic non-linear Schrödinger equationSep 08 2006We establish that the initial value problem for the quadratic non-linear Schr\"odinger equation $$ iu_t - \Delta u = u^2$$ where $u: \R^2 \times \R \to \C$, is locally well-posed in $H^s(\R^2)$ when $s > -1$. The critical exponent for this problem is ... More

Normal coverings and pairwise generation of finite alternating and symmetric groupsNov 12 2012Jan 29 2013The normal covering number $\gamma(G)$ of a finite, non-cyclic group $G$ is the least number of proper subgroups such that each element of $G$ lies in some conjugate of one of these subgroups. We prove that there is a positive constant $c$ such that, ... More

Dark energy and Dark matter interaction in light of the second law of thermodynamicsDec 09 2018In the context of thermodynamics we discuss the way inevitable emerge an interaction between dark components, and in this way, provide a mechanism to understand the limits of the LCDM model and the class of interaction models between dark components. ... More

SCALPEL: Extracting Neurons from Calcium Imaging DataMar 20 2017In the past few years, new technologies in the field of neuroscience have made it possible to simultaneously image activity in large populations of neurons at cellular resolution in behaving animals. In mid-2016, a huge repository of this so-called "calcium ... More

k-Nearest neighbor density estimation on Riemannian ManifoldsJun 23 2011In this paper, we consider a k-nearest neighbor kernel type estimator when the random variables belong in a Riemannian manifolds. We study asymptotic properties such as the consistency and the asymptotic distribution. A simulation study is also consider ... More

String Moduli Stabilization at the ConifoldMay 20 2016Oct 17 2016We study moduli stabilization for type IIB orientifolds compactified on Calabi-Yau threefolds in the region close to conifold singularities in the complex structure moduli space. The form of the periods implies new phenomena like exponential mass hierarchies ... More

Hofstadter-type energy spectra in lateral superlattices defined by periodic magnetic and electrostatic fieldsJan 16 1996We calculate the energy spectrum of an electron moving in a two-dimensional lattice which is defined by an electric potential and an applied perpendicular magnetic field modulated by a periodic surface magnetization. The spatial direction of this magnetization ... More

Message Error Analysis of Loopy Belief Propagation for the Sum-Product AlgorithmSep 13 2010Feb 12 2013Belief propagation is known to perform extremely well in many practical statistical inference and learning problems using graphical models, even in the presence of multiple loops. The iterative use of belief propagation algorithm on loopy graphs is referred ... More

A new type of dark compact objects in massive tensor-multi-scalar theories of gravityJan 18 2019In the present paper we consider special classes of tensor-multi-scalar theories of gravity whose target-space metric admits Killing field(s) with a periodic flow. For such tensor-multi-scalar theories we show that if the dynamics of the scalar fields ... More

Global survival of branching random walks and tree-like branching random walksMar 13 2017Apr 27 2017The reproduction speed of a continuous-time branching random walk is proportional to a positive parameter $\lambda$. There is a threshold for $\lambda$, which is called $\lambda_w$, that separates almost sure global extinction from global survival. Analogously, ... More

Wavelet transform on the torus: a group theoretical approachOct 31 2013We construct a Continuous Wavelet Transform (CWT) on the torus $\mathbb T^2$ following a group-theoretical approach based on the conformal group $SO(2,2)$. The Euclidean limit reproduces wavelets on the plane $\mathbb R^2$ with two dilations, which can ... More

Embedding cycles of given length in oriented graphsOct 25 2011Oct 03 2012Kelly, Kuehn and Osthus conjectured that for any l>3 and the smallest number k>2 that does not divide l, any large enough oriented graph G with minimum indegree and minimum outdegree at least \lfloor |V(G)|/k\rfloor +1 contains a directed cycle of length ... More

k-Ordered Hamilton cycles in digraphsJul 11 2007Given a digraph D, the minimum semi-degree of D is the minimum of its minimum indegree and its minimum outdegree. D is k-ordered Hamiltonian if for every ordered sequence of k distinct vertices there is a directed Hamilton cycle which encounters these ... More

On the homotopy type of the space of Sullivan diagramsMay 21 2017We study the homotopy type of the harmonic compactification of the moduli space of a 2-cobordism S with one outgoing boundary component, or equivalently of the space of Sullivan diagrams of type S on one circle. Our results are of two types: vanishing ... More

On Caching with More Users than FilesJan 24 2016Jan 26 2016Caching appears to be an efficient way to reduce peak hour network traffic congestion by storing some content at the user's cache without knowledge of later demands. Recently, Maddah-Ali and Niesen proposed a two-phase, placement and delivery phase, coded ... More

Conjectures on the normal covering number of the finite symmetric and alternating groupsOct 10 2013Let $\gamma(S_n)$ be the minimum number of proper subgroups $H_i$ of the symmetric group $S_n$ such that each element in $S_n$ lies in some conjugate of one of the $H_i.$ In this paper we conjecture that $$\gamma(S_n)=\frac{n}{2}\left(1-\frac{1}{p_1}\right) ... More

Shortest Paths and Convex Hulls in 2D Complexes with Non-Positive CurvatureMar 02 2016Jul 23 2016Globally non-positively curved, or CAT(0), polyhedral complexes arise in a number of applications, including evolutionary biology and robotics. These spaces have unique shortest paths and are composed of Euclidean polyhedra, yet many properties of convex ... More

Are Clusterings of Multiple Data Views Independent?Jan 12 2019In the Pioneer 100 (P100) Wellness Project (Price and others, 2017), multiple types of data are collected on a single set of healthy participants at multiple timepoints in order to characterize and optimize wellness. One way to do this is to identify ... More

Gravitational entropy of black holes and wormholesSep 18 2011Pure thermodynamical considerations to describe the entropic evolution of the universe seem to violate the Second Law of Thermodynamics. This suggests that the gravitational field itself has entropy. In this paper we expand recent work done by Rudjord, ... More

An explanation of remarkable emission line profiles in post-flare coronal rainJul 21 2017We study broad red-shifted emission in chromospheric and transition region lines that appears to correspond to a form of post-flare coronal rain. Profiles of Mg II, C II and Si IV lines were obtained using the IRIS instrument before, during and after ... More

Zero forcing in iterated line digraphsAug 10 2017Oct 23 2018Zero forcing is a propagation process on a graph, or digraph, defined in linear algebra to provide a bound for the minimum rank problem. Independently, zero forcing was introduced in physics, computer science and network science, areas where line digraphs ... More

A Dirac type result on Hamilton cycles in oriented graphsSep 07 2007Jun 04 2008We show that for each \alpha>0 every sufficiently large oriented graph G with \delta^+(G),\delta^-(G)\ge 3|G|/8+ \alpha |G| contains a Hamilton cycle. This gives an approximate solution to a problem of Thomassen. In fact, we prove the stronger result ... More

A note on complete subdivisions in digraphs of large outdegreeMay 07 2006Mader conjectured that for all k there is an integer d(k) such that every digraph of minimum outdegree at least d(k) contains a subdivision of a transitive tournament of order k. In this note we observe that if the minimum outdegree of a digraph is sufficiently ... More

ACQUIRE: an inexact iteratively reweighted norm approach for TV-based Poisson image restorationJul 27 2018We propose a method, called ACQUIRE, for the solution of constrained optimization problems modeling the restoration of images corrupted by Poisson noise. The objective function is the sum of a generalized Kullback-Leibler divergence term and a TV regularizer, ... More

Galton-Watson processes in varying environment and accessibility percolationNov 10 2016Nov 19 2016This paper deals with branching processes in varying environment, namely, whose offspring distributions depend on the generations. We provide sufficient conditions for survival or extinction which rely only on the first and second moments of the offspring ... More

Some characterizations of the quasi-sum production models with proportional marginal rate of substitutionMay 20 2014Jun 30 2015In this note we classify quasi-sum production functions with constant elasticity of production with respect to any factor of production and with proportional marginal rate of substitution.

An algorithm to estimate the vertices of a tetrahedron with uniform random points insideAug 30 2016Using $n$ uniform random points inside an arbitrary tetrahedron, we give an algorithm to estimate its vertices. The accuracy of the algorithm is proved by applying a Monte Carlo simulation technique.

On some graphs associated with the finite alternating groupsDec 23 2014Jul 21 2016Let $P_0(A_n), \widetilde{P}_0(A_n), P_0(\mathcal{T}(A_n))$ and $\mathcal{O}_0(A_n)$ be respectively the proper power graph, the proper quotient power graph, the proper power type graph and the proper order graph of the alternating group $A_n$, for $n\geq ... More

Cauchy theory and exponential stability for inhomogeneous boltzmann equation for hard potentials without cut-offOct 03 2017Apr 23 2018In this paper, we investigate both the problems of Cauchy theory and exponential stability for the inhomogeneous Boltzmann equation without angular cutoff. We only deal with the physical case of hard potentials type interactions (with a moderate angular ... More

Hamilton decompositions of regular tournamentsAug 24 2009Dec 16 2009We show that every sufficiently large regular tournament can almost completely be decomposed into edge-disjoint Hamilton cycles. More precisely, for each \eta>0 every regular tournament G of sufficiently large order n contains at least (1/2-\eta)n edge-disjoint ... More

Cycles Of Given Length In Oriented GraphsJun 05 2008Aug 13 2009We show that for each \ell\geq 4 every sufficiently large oriented graph G with \delta^+(G), \delta^-(G) \geq \lfloor |G|/3 \rfloor +1 contains an \ell-cycle. This is best possible for all those \ell\geq 4 which are not divisible by 3. Surprisingly, for ... More

An exact minimum degree condition for Hamilton cycles in oriented graphsJan 02 2008Apr 10 2008We show that every sufficiently large oriented graph with minimum in- and outdegree at least (3n-4)/8 contains a Hamilton cycle. This is best possible and solves a problem of Thomassen from 1979.

Challenges for Moduli Stabilization and String Cosmology near the ConifoldApr 13 2017This brief article reviews a recently proposed scenario of moduli stabilization constructed in the vicinity of a conifold locus in the complex structure moduli space. We discuss typical features of moduli stabilization due to the logarithmic structure ... More

An algorithm to estimate the vertices of a tetrahedron from uniform random points insideAug 30 2016Aug 18 2017In this paper, we give an algorithm to infer the positions of the vertices of an unknown tetrahedron, given a sample of points which are uniformly distributed within the tetrahedron. The accuracy of the algorithm is demonstrated using some numerical experiments. ... More

The Challenge of Realizing F-term Axion Monodromy Inflation in String TheorySep 24 2014Jan 13 2015A systematic analysis of possibilities for realizing single-field F-term axion monodromy inflation via the flux-induced superpotential in type IIB string theory is performed. In this well-defined setting the conditions arising from moduli stabilization ... More

Energy Demand and Metabolite Partitioning in Spatially Lumped and Distributed Models of Neuron-Astrocyte ComplexDec 18 2014The degrees of freedom of multi-compartment mathematical models for energy metabolism of a neuron-astrocyte complex may offer a key to understand the different ways in which the energetic needs of the brain are met. In this paper we address the problem ... More

Chebyshev-Grüss-type inequalities via discrete oscillationsJan 30 2014The classical form of Gr\"uss' inequality, first published by G. Gr\"{u}ss in 1935, gives an estimate of the difference between the integral of the product and the product of the integrals of two functions. In the subsequent years, many variants of this ... More

Bipartitions of highly connected tournamentsNov 06 2014Feb 01 2015We show that if $T$ is a strongly $10^9k^6\log(2k)$-connected tournament, there exists a partition $A, B$ of $V(T)$ such that each of $T[A]$, $T[B]$ and $T[A,B]$ is strongly $k$-connected. This provides tournament analogues of two partition conjectures ... More

A simple electronic device to experiment with the Hopf bifurcationJan 26 2019We present a simple low-cost electronic circuit that is able to show two different dynamical regimens with oscillations of voltages and with constant values of them. This device is designed as a negative feedback three-node network inspired in the genetic ... More

Vectorized and Parallel Particle Filter SMC Parameter Estimation for Stiff ODEsNov 06 2014Particle filter (PF) sequential Monte Carlo (SMC) methods are very attractive for the estimation of parameters of time dependent systems where the data is either not all available at once, or the range of time constants is wide enough to create problems ... More

Edge-disjoint Hamilton cycles in random graphsApr 22 2011May 08 2013We show that provided $\log^{50} n/n \leq p \leq 1 - n^{-1/4}\log^9 n$ we can with high probability find a collection of $\lfloor \delta(G)/2 \rfloor$ edge-disjoint Hamilton cycles in $G \sim G_{n, p}$, plus an additional edge-disjoint matching of size ... More