Results for "Mihai Budiu"

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Hillview: A trillion-cell spreadsheet for big dataJul 10 2019Hillview is a distributed spreadsheet for browsing very large datasets that cannot be handled by a single machine. As a spreadsheet, Hillview provides a high degree of interactivity that permits data analysts to explore information quickly along many ... More
Packet Transactions: High-level Programming for Line-Rate SwitchesDec 16 2015Jan 30 2016Many algorithms for congestion control, scheduling, network measurement, active queue management, security, and load balancing require custom processing of packets as they traverse the data plane of a network switch. To run at line rate, these data-plane ... More
Intermediate disorder limits for multi-layer semi-discrete directed polymersSep 01 2016We show that the partition function of the multi-layer semi-discrete directed polymer converges in the intermediate disorder regime to the partition function for the multi-layer continuum polymer introduced by O'Connell and Warren. This verifies, modulo ... More
The generalization of A. E. Kennelly theory of complex representation of the electrical quantities in sinusoidal periodic regime to the one and three-phase electric quantities in non-sinusoidal periodic regimeFeb 12 2010In this paper, a new mathematical method of electrical circuits calculus is proposed based on the theory of the complex linear operators in matrix form. The newly proposed method generalizes the theory of complex representation of electrical quantities ... More
Realization of conditionally monotone independence and monotone products of completely positive mapsNov 06 2009The paper gives an operator algebras model for the conditional monotone independence, introduced by T. Hasebe. The construction is used to prove an embedding result for the N. Muraki's monotone product of C*-algebras. Also, the formulas from the definition ... More
Design of Log-Map / Max-Log-Map DecoderMar 25 2009The process of turbo-code decoding starts with the formation of a posteriori probabilities (APPs) for each data bit, which is followed by choosing the data-bit value that corresponds to the maximum a posteriori (MAP) probability for that data bit. Upon ... More
A new proof for the multiplicative property of the boolean cumulants with applications to operator-valued caseApr 14 2008Apr 15 2008The paper presents several combinatorial properties of the boolean cumulants. A corollary is a new proof of the multiplicative property of the boolean cumulant series that can be easily adapted for the case of boolean independence with amalgamation over ... More
Solving the Hamiltonian path problem with a light-based computerAug 10 2007In this paper we propose a special computational device which uses light rays for solving the Hamiltonian path problem on a directed graph. The device has a graph-like representation and the light is traversing it by following the routes given by the ... More
Orbifolds in Numerical RelativityMar 13 2006Apr 17 2006Numerical Relativity has been using orbifolds for a long time, although they appear under different names in the literature. We review orbifolds previously used in simulations also discuss some that have not been used yet but are likely to be useful in ... More
Sync-Rank: Robust Ranking, Constrained Ranking and Rank Aggregation via Eigenvector and Semidefinite Programming SynchronizationApr 05 2015We consider the classic problem of establishing a statistical ranking of a set of n items given a set of inconsistent and incomplete pairwise comparisons between such items. Instantiations of this problem occur in numerous applications in data analysis ... More
A triangular gap of size two in a sea of dimers in a $90^\circ$ angle with mixed boundary conditions, and a heat flow conjecture for the general caseMar 04 2014We consider a triangular gap of side two in a $90^\circ$ angle on the triangular lattice with mixed boundary conditions: a constrained, zig-zag boundary along one side, and a free lattice line boundary along the other. We study the interaction of the ... More
Higher genus curves on toric varietiesJan 11 2001Given a smooth and projective curve C and a smooth and projective toric variety X, we first describe a compactification of the space of morphisms from C to X representing a fixed homology class, and after we study the intersection theory on this variety. ... More
Scattering of antiplane elastic waves by two-dimensional periodic arrays of cracksFeb 06 2013In the context of elastic wave propagation in damaged solids, an analytical approach for scattering of antiplane waves by two-dimensional periodic arrays of cracks is developed. Before considering the study of arrays of cracks, the scattering of an antiplane ... More
Hidden symmetries in a gauge covariant approach, Hamiltonian reduction and oxidationSep 26 2011Hidden symmetries in a covariant Hamiltonian formulation are investigated involving gauge covariant equations of motion. The special role of the Stackel-Killing tensors is pointed out. A reduction procedure is used to reduce the original phase space to ... More
Action-angle variables for geodesic motions in Sasaki-Einstein spaces $Y^{p,q}$Nov 04 2016We use the action-angle variables to describe the geodesic motions in the $5$-dimensional Sasaki-Einstein spaces $Y^{p,q}$. This formulation allows us to study thoroughly the complete integrability of the system. We find that the Hamiltonian involves ... More
Macroscopically separated gaps in dimer coverings of Aztec rectanglesMay 12 2014In this paper we determine the interaction of diagonal defect clusters in regions of an Aztec rectangle that scale to arbitrary points on its symmetry axis (in earlier work we treated the case when this point was the center of the scaled Aztec rectangle). ... More
Decorated Young Tableaux and the Poissonized Robinson-Schensted ProcessApr 15 2014Apr 29 2015We introduce an object called a decorated Young tableau that slightly extends the notion of a standard Young tableau. This object can equivalently be viewed as a continuous time trajectory of Young diagrams or as a non-intersecting line ensemble. The ... More
A note on the strong formulation of stochastic control problems with model uncertaintyFeb 18 2014Apr 08 2014We consider a Markovian stochastic control problem with model uncertainty. The controller (intelligent player) observes only the state, and, therefore, uses feed-back (closed-loop) strategies. The adverse player (nature) who does not have a direct interest ... More
Bounds on the Heat Kernel under the Ricci FlowOct 27 2010We establish an estimate for the fundamental solution of the heat equation on a closed Riemannian manifold $M$ of dimension at least 3, evolving under the Ricci flow. The estimate depends on some constants arising from a Sobolev imbedding theorem. Considering ... More
A Lower Bound for Succinct Rank QueriesJul 06 2009The rank problem in succinct data structures asks to preprocess an array A[1..n] of bits into a data structure using as close to n bits as possible, and answer queries of the form rank(k) = Sum_{i=1}^k A[i]. The problem has been intensely studied, and ... More
Rotational invariance of quadromer correlations on the hexagonal latticeFeb 23 2005In 1963 Fisher and Stephenson \cite{FS} conjectured that the monomer-monomer correlation on the square lattice is rotationally invariant. In this paper we prove a closely related statement on the hexagonal lattice. Namely, we consider correlations of ... More
The scaling limit of the correlation of holes on the triangular lattice with periodic boundary conditionsJan 28 2005Oct 24 2007We define the correlation of holes on the triangular lattice under periodic boundary conditions and study its asymptotics as the distances between the holes grow to infinity. We prove that the joint correlation of an arbitrary collection of lattice-triangular ... More
Extremal solutions of the two-dimensional $L$-problem of moments, IIDec 18 1995All extremal solutions of the truncated $L$-problem of moments in two real variables , with support contained in a given compact set, are described as characteristic functions of semi-algebraic sets given by a single polynomial inequality. An exponential ... More
Algebraic properties of G-groupoidsDec 30 2015The main purpose of this paper is to give a new definition for the notion of group-groupoid. Also, several basic properties of group-groupoids are established.
Strongly anisotropic diffusion problems; asymptotic analysisOct 23 2012The subject matter of this paper concerns anisotropic diffusion equations: we consider heat equations whose diffusion matrix have disparate eigenvalues. We determine first and second order approximations, we study the well-posedness of them and establish ... More
Correlation of a macroscopic dent in a wedge with mixed boundary conditionsJun 05 2019As part of our ongoing work on the enumeration of symmetry classes of lozenge tilings of hexagons with certain four-lobed structures removed from their center, we consider the case of the tilings which are both vertically and horizontally symmetric. In ... More
Some remarks on Myers theorem for Finsler manifoldsMay 22 2014The standard Bonnet-Myers theorem says that if the Ricci scalar of a Riemannian manifold is bounded below by a positive number, then the manifold is compact. Moreover, a bound of its diameter is pointed out. The theorem was extended to Finsler manifolds. ... More
Splitting criteria for vector bundles induced by restrictions to divisorsJan 28 2015Sep 18 2015In this article we deduce criteria for the splitting and the triviality of vector bundles, by restricting them to partially ample divisors. This allows to study the problem of splitting on the total space of fibre bundles. The statements are illustrated ... More
Subvarieties with partially ample normal bundleMay 16 2018We show that local complete intersection subvarieties of smooth projective varieties, which have partially ample normal bundle, possess the G2-property. This generalizes results of Hartshorne and B\u{a}descu-Schneider.
A Fock Space Model for Addition and Multiplication of C-free Random VariablesDec 19 2010The paper presents a Fock space model suitable for constructions of c-free algebras. Immediate applications are direct proofs for the properties of the c-free R- and S-transforms.
Vector bundles on projective varieties which split along q-ample subvarietiesOct 05 2014Mar 04 2015Let Y be a subvariety of a smooth projective variety X, and V a vector bundle on X. Given that the restriction of V to Y splits into a direct sum of line bundles, we ask whether V splits on X. I answer this question in affirmative if holds: Y is a q-ample ... More
Stochastic Perron's method and elementary strategies for zero-sum differential gamesMay 22 2013Feb 18 2014We develop here the Stochastic Perron Method in the framework of two-player zero-sum differential games. We consider the formulation of the game where both players play, symmetrically, feed-back strategies (as in [CR09] or [PZ12]) as opposed to the Elliott-Kalton ... More
Splitting criteria for vector bundles on minuscule homogeneous varietiesMar 04 2015I prove that a vector bundle on a minuscule homogeneous variety splits into a direct sum of line bundles if and only if its restriction to the union of two-dimensional Schubert subvarieties splits. A case-by-case analysis is done.
Ultrametric fixed points in reduced axiomatic systemsApr 17 2015Apr 22 2015The Brezis-Browder ordering principle [Advances Math., 21 (1976), 355-364] is used to get a proof, in the reduced axiomatic system (ZF-AC+DC), of a fixed point result [in the complete axiomatic system (ZF)] over Cantor complete ultrametric spaces due ... More
PPF dependent fixed points in A-closed Razumikhin classesMay 18 2014The PPF dependent fixed point result in algebraically closed Razumikhin classes due to Agarwal et al [Fixed Point Theory Appl., 2013, 2013:280] is identical with its constant class counterpart; and this, in turn, is reducible to a fixed point principle ... More
Implicit contractive maps in ordered metric spacesMay 03 2013Further extensions are given to the fixed point result (for implicit contractions) due to Altun and Simsek [Fixed Point Th. Appl., Volume 2010, Article ID 621469]. Some connections with related statements in the area due to Agarwal, El-Gebeily and O'Regan ... More
Weakly contractive maps in altering metric spacesFeb 16 2013Oct 08 2013The weakly contractive metric type fixed point result in Berinde [Nonlinear Anal. Forum, 9 (2004), 45-53] is "almost" covered by the related altering metric one due to Khan et al [Bull. Austral. Math. Soc., 30 (1984), 1-9]. Further extensions of these ... More
Ran-Reurings theorems in ordered metric spacesMar 27 2011Jun 27 2011The Ran-Reurings fixed point theorem [Proc. Amer. Math. Soc., 132 (2004), 1435-1443] is but a particular case of Maia's [Rend. Sem. Mat. Univ. Padova, 40 (1968), 139-143]. A "functional" version of this last result is then provided, in a convergence-metric ... More
Semi-stable vector bundles on fibred varietiesSep 02 2013Jun 08 2014Let $\pi:Y\to X$ be a surjective morphism between two irreducible, smooth complex projective varieties with ${\rm dim}Y>{\rm dim}X >0$. We consider polarizations of the form $L_c=L+c\cdot\pi^*A$ on $Y$, with $c>0$, where $L,A$ are ample line bundles on ... More
Complements of hypersurfaces, variation maps and minimal models of arrangementsFeb 07 2014We prove the minimality of the CW-complex structure for complements of hyperplane arrangements in $\mathbb C^n$ by using the theory of Lefschetz pencils and results on the variation maps within a pencil of hyperplanes. This also provides a method to compute ... More
A gravity term from spontaneous symmetry breakingJan 02 2014In this model, the gravity term in the Lagrangean comes from spontaneous symmetry breaking of an additional scalar quadruplet field $\Upsilon$. The resulting gravitational field is approximate to one of the models of coframe gravity with parameters $\rho_1 ... More
Shell model analysis of competing mechanism to the double-beta decay of $^{48}$CaOct 24 2012Dec 31 2012Background: Neutrinoless double beta decay, if observed, would reveal physics beyond the Standard Model (SM) of particle physics, namely it would prove that neutrinos are Majoran fermions and that the lepton number is not conserved. Purpose: The analysis ... More
Killing forms on the five-dimensional Einstein-Sasaki Y(p,q) spacesJul 11 2012Oct 16 2012We present the complete set of Killing-Yano tensors on the five-dimensional Einstein-Sasaki Y(p,q) spaces. Two new Killing-Yano tensors are identified, associated with the complex volume form of the Calabi-Yau metric cone. The corresponding hidden symmetries ... More
Local volumes on normal algebraic varietiesMay 16 2011In this paper we study a notion of volume for Cartier divisors on arbitrary blow-ups of normal complex algebraic varieties of dimension greater than one, with a distinguished point. We apply this to study a volume for normal isolated singularities, generalizing ... More
Higher order first integrals of motion in a gauge covariant Hamiltonian frameworkOct 19 2009Dec 07 2009The higher order symmetries are investigated in a covariant Hamiltonian formulation. The covariant phase-space approach is extended to include the presence of external gauge fields and scalar potentials. The special role of the Killing-Yano tensors is ... More
Output Width Signal Control In Asynchronous Digital Systems Using Monostable CircuitsApr 23 2009In present paper, I propose a method for resolving the timing delays for output signals from an asynchronous sequential system. It will be used an example of an asynchronous sequential system that will set up an output signal when an input signal will ... More
Symmetry classes of spanning trees of Aztec diamonds and perfect matchings of odd squares with a unit holeOct 24 2007We say that two graphs are similar if their adjacency matrices are similar matrices. We show that the square grid $G_n$ of order $n$ is similar to the disjoint union of two copies of the quartered Aztec diamond $QAD_{n-1}$ of order $n-1$ with the path ... More
The emergence of the electrostatic field as a Feynman sum in random tilings with holesOct 24 2007Jan 13 2009We consider random lozenge tilings on the triangular lattice with holes $Q_1,...,Q_n$ in some fixed position. For each unit triangle not in a hole, consider the average orientation of the lozenge covering it. We show that the scaling limit of this discrete ... More
Generalized Runge-Lenz Vector in Taub-Nut Spinning SpaceJul 18 1994The generalized Killing equations and the symmetries of Taub-NUT spinning space are investigated. For spinless particles the Runge-Lenz vector defines a constant of motion directly, whereas for spinning particles it now requires a non-trivial contribution ... More
Gradient estimates for the heat equation under the Ricci-Harmonic Map flowAug 31 2013The paper establishes a series of gradient estimates for positive solutions to the heat equation on a manifold $M$ evolving under the Ricci flow, coupled with the harmonic map flow between $M$ and a second manifold $N$. We prove Li-Yau type Harnack inequalities ... More
The interaction of collinear gaps of arbitrary charge in a two dimensional dimer systemFeb 06 2012The correlation of gaps in dimer systems was introduced in 1963 by Fisher and Stephenson, who looked at the interaction of two monomers generated by the rigid exclusion of dimers on the closely packed square lattice. In previous work we considered the ... More
The Dirac equation in curved spacetimes using coordinate-free notationJun 07 2010Sep 16 2013The Dirac equation in curved spacetimes is formulated using coordinate-free notation. A Lagrangean density which corresponds to the subject equation is presented. The subject equation is invariant under a local rotation of the coframe. The current is ... More
Farey Statistics in Time n^{2/3} and Counting Primitive Lattice Points in PolygonsAug 01 2007Nov 02 2007We present algorithms for computing ranks and order statistics in the Farey sequence, taking time O (n^{2/3}). This improves on the recent algorithms of Pawlewicz [European Symp. Alg. 2007], running in time O (n^{3/4}). We also initiate the study of a ... More
CodeketsNov 16 2005To every binary linear [n,k]-code C we associate a quantum state ("codeket") belonging to the n-th tensor power of the 2-dimensional complex Hilbert space associated to the spin 1/2 particle. We completely characterize the expectation values of the products ... More
Harnack inequalities for the curve shortening flowNov 01 2015We offer an algorithmic approach for determining Harnack quantities for the curve shortening flow and we show how, following this procedure, one can obtain Hamilton's Harnack inequality for this flow $\kappa_t + \frac{1}{2t}\kappa \geq \frac{\kappa_s^2}{\kappa}$, ... More
Rethinking the ExperimentDec 07 2016The crisis in the reproducibility of experiments invites a re-evaluation of methods of inquiry and validation procedures. The text challenges current assumptions of knowledge acquisition and introduces G-complexity for defining decidable vs. non-decidable ... More
A Non-commutative analogue of Gaussian Hilbert SpacesApr 22 2005The paper gives analogues of some starting results in the theory of Gaussian Hilbert Spaces for semicircular distributed random variables. The transition from the commutative to the free frame is done considering matrices of increasing dimension and utilizing ... More
Duality of Euler data for affine varietiesJun 21 2005We compare the Euler-Poincar\'e characteristic to the global Euler obstruction, in case of singular affine varieties, and point out a certain duality among their expressions in terms of strata of a Whitney stratification.
Plane partitions I: a generalization of MacMahon's formulaAug 04 1998Oct 29 2004The number of plane partitions contained in a given box was shown by MacMahon to be given by a simple product formula. By a simple bijection, this formula also enumerates lozenge tilings of hexagons of side-lengths $a,b,c,a,b,c$ (in cyclic order) and ... More
Symmetries of shamrocks IV: The self-complementary caseJun 05 2019In this paper we enumerate the centrally symmetric lozenge tilings of a hexagon with a shamrock removed from its center. Our proof is based on a variant of Kuo's graphical condensation method in which only three of the four involved vertices are on the ... More
Variational Principles in Fang Uniform SpacesJun 18 2010Feb 09 2013The vectorial Zhu-Li Variational Principle (ZLVP) in Fang uniform spaces is in the logical segment between the Brezis-Browder ordering principle (BB) and Ekeland's Variational Principle (EVP); hence, it is equivalent with both BB and EVP. In particular, ... More
Metrizable linear connections in a Lie algebroidMar 09 2010A linear connection $D$ in a Lie algebroid is said to be metrizable if there exists a Riemannian metric $h$ in the Lie algebroid such that $Dh=0$. Conditions for the linear connection $D$ to be metrizable are investigated.
Asymptotic free independence and entry permutations for Gaussian random matricesDec 04 2018The paper presents conditions on entry permutations that induce asymptotic freeness when acting on Gaussian random matrices. The class of permutations described includes the matrix transpose, as well as entry permutations relevant in Quantum Information ... More
Poisson geometry of the Maxwell-Bloch top system and stability problemJan 03 2014Dynamics of Maxwell-Bloch top system, that includes Maxwell-Bloch and Lorenz-Hamilton equations as particular cases, is studied in the framework Poisson geometry. Constants of motion as well as the relation of solution to that of pendulum are presented. ... More
Quotients of affine spaces for actions of reductive groupsDec 14 2004In this paper we study actions of reductive groups on affine spaces. We prove that there is a fan structure on the space of characters of the group, which parameterizes the possible invariant quotients. In the second half of the paper we study various ... More
GW Invariants and Invariant QuotientsOct 03 2000Jan 19 2001The article investigates the following question: given a projective variety X acted on by a connected and reductive group G, which is the relationship between the Gromov-Witten invariants of X and those of X//G? In this study we shall also try to give ... More
Constraints on exact Lagrangians in cotangent bundles of manifolds fibred over the circleOct 02 2007Sep 11 2008We give topological obstructions to the existence of a closed exact Lagrangian submanifold in the cotangent bundle of a closed manifold M which is the total space of a fibration over the circle. For instance we show that the fundamental group of such ... More
Strong exceptional sequences of vector bundles on certain Fano varietiesJun 18 2009In an unpublished preprint, A. King conjectured that there are tilting bundles over projective varieties which are obtained as invariant quotients of affine spaces for linear actions of reductive groups. The goal of this paper is to give further examples ... More
On martingale problems with continuous-time mixing and values of zero-sum games without Isaacs conditionJul 17 2013Apr 15 2014We consider a zero-sum stochastic differential game over elementary mixed feed-back strategies. These are strategies based only on the knowledge of the past state, randomized continuously in time from a sampling distribution which is kept constant in ... More
Contractive maps in locally transitive relational metric spacesAug 12 2013Dec 05 2013Some fixed point results are given for a class of Meir-Keeler contractive maps acting on metric spaces endowed with locally transitive relations. Technical connections with the related statements due to Berzig et al [Abstr. Appl. Anal., Volume 2013, Article ... More
An optical solution for the set splitting problemDec 02 2017We describe here an optical device, based on time-delays, for solving the set splitting problem which is well-known NP-complete problem. The device has a graph-like structure and the light is traversing it from a start node to a destination node. All ... More
The Entity Registry System. From concept to deploymentAug 02 2016The entity registry system (ERS) is a decentralized entity registry that can be used to replace the Web as a platform for publishing linked data when the latter is not available. In developing countries, where off-line is the default mode of operation, ... More
Another dual of MacMahon's theorem on plane partitionsSep 21 2015In this paper we introduce a counterpart structure to the shamrocks studied in the paper "A dual of Macmahon's theorem on plane partitions" by M. Ciucu and C. Krattenthaler (Proc. Natl. Acad. Sci. USA, vol. 110 (2013), 4518-4523), which, just like the ... More
Generalisation of Helmholtz-Thevenin theorem to three-phase electrical circuitsJun 04 2009The scope of this paper is to determine the generalized form for equivalent tension generator theorem (Helmholtz-Thevenin theorem) for three-phase electrical circuit. Any complicated electrical power systems we can reduce depending on any three-phase ... More
The unitary theory of the electrical powersApr 07 2009General physics approach is applied to analysis of power components in electrical systems under sinusoidal and non-sinusoidal conditions. Physical essence of active, reactive and distorting powers are determinate. It is shown that the all three powers ... More
Fermion on Curved Spaces, Symmetries, and Quantum AnomaliesSep 28 2006Nov 29 2006We review the geodesic motion of pseudo-classical spinning particles in curved spaces. Investigating the generalized Killing equations for spinning spaces, we express the constants of motion in terms of Killing-Yano tensors. Passing from the spinning ... More
Staggering of the Nuclear Charge Radii in a Superfluid Model with Good Particle NumberOct 05 1994A simple superfluid model with an effective four body interaction of monopole pairing type is used to explain the staggering of the charge radii in the isotope chains. The contribution of deformation and of the particle number projection are analyzed ... More
Unifying the Landscape of Cell-Probe Lower BoundsOct 19 2010We show that a large fraction of the data-structure lower bounds known today in fact follow by reduction from the communication complexity of lopsided (asymmetric) set disjointness. This includes lower bounds for: * high-dimensional problems, where the ... More
Perfect matchings and perfect powersJan 28 2005Feb 23 2005In the last decade there have been many results about special families of graphs whose number of perfect matchings is given by perfect or near perfect powers. In this paper we present an approach that allows proving them in a unified way. We use this ... More
A random tiling model for two dimensional electrostaticsMar 28 2003Oct 29 2004We consider triangular holes on the hexagonal lattice and we study their interaction when the rest of the lattice is covered by dimers. More precisely, we analyze the joint correlation of these triangular holes in a ``sea'' of dimers. We determine the ... More
Global equisingularity of families of affine hypersurfacesMay 18 1998We consider an equisingularity problem for polynomial families of affine hypersurfaces $X_\tau \subset \bC^n$. We show that the constancy of the global polar invariants $\gamma^* (X_\tau)$ is equivalent to the $t$-equisingularity at infinity, an asymptotic-type ... More
Banach Lie algebroidsMar 05 2010First, we extend the notion of second order differential equations (SODE) on a smooth manifold to anchored Banach vector bundles. Then we define the Banach Lie algebroids as Lie algebroids structures modeled on anchored Banach vector bundles and prove ... More
An elementary method for the fidel codification of texts written in Romanian language (O metodă elementară pentru codificarea fidelă a textelor scrise în limba română)Mar 01 2018In this paper an elementary (cryptographic system) for the codification and decodification of texts written in Romanian language is presented. This method is based on the alphabet A and the 7x7-Square. The theme presented is at the interference between ... More
Noncontractible loops of symplectic embeddings between convex toric domainsSep 11 2018Given two 4-dimensional ellipsoids whose symplectic sizes satisfy a specified inequality, we prove that a certain loop of symplectic embeddings between the two ellipsoids is noncontractible. The statement about symplectic ellipsoids is a particular case ... More
Families of toric varietiesJul 16 2002The goal of this paper is to define families of toric varieties and to study their properties. These families are locally trivial fibrations over some base, whose fibres are isomorphic to a fixed complete toric variety. The study is motivated by the occurence ... More
Freeness with amalgamation, limit theorems and S-transform in non-commutative probability spaces of type BAug 31 2007Oct 14 2007The present material addresses several problems left open in the Trans. AMS paper " Non-crossing cumulants of type B" of P. Biane, F. Goodman and A. Nica. The main result is that a type B non-commutative probability space can be studied in the framework ... More
Asymptotic equisingularity and topology of complex hypersurfacesMay 18 1998Nov 27 2017We consider an equisingularity problem for polynomial families of affine hypersurfaces $X_\tau \subset \mathbb C^n$ with (at worst) isolated singularities. We show that the constancy of the global polar invariants $\gamma^* (X_\tau)$ is equivalent to ... More
The vanishing neighbourhood of non-isolated singularitiesNov 25 2004Dec 23 2004We study the vanishing neighbourhood of non-isolated singularities of functions on singular spaces by associating a general linear function. We use the carrousel monodromy in order to show how to get a better control over the attaching of thimbles. For ... More
Centrally symmetric tilings of fern-cored hexagonsJun 07 2019In this paper we enumerate the centrally symmetric lozenge tilings of a hexagon with a fern removed from its center. The proof is based on a variant of Kuo's graphical condensation method. An unexpected connection with the total number of tilings is established~---~when ... More
Self-similar carpets over finite fieldsAug 07 2007Some linear dynamical systems over finite fields are studied and the self-similar character of their development is proved. Connections with aperiodic tilings, Delanoy numbers and other topics are also proved. The prime fields F_p have a canonical presentation ... More
Vanishing cycles of pencils of hypersurfacesApr 08 2002Jun 13 2003We prove an extended Lefschetz principle for a large class of pencils of hypersurfaces having isolated singularities, possibly in the axis, and show that the module of vanishing cycles is generated by the images of certain variation maps.
About the surjectivity of the Wahl map of nodal curves on K3 surfacesDec 12 2013Apr 05 2015I correct an error in my article arXiv:0911.5474, concerning the non-surjectivity of the Wahl map of nodal curves on K3 surfaces. I prove that a modification of the Wahl map is indeed non-surjective for nodal curves with a low number of nodes, on arbitrary ... More
Modular properties of nodal curves on K3 surfacesNov 29 2009In this paper we partially address two issues: - The first is a rigidity property for pairs (S,C) consisting of a general projective K3 surface S, and a curve C obtained as the normalization of a nodal, hyperplane section of S. We prove that a non-trivial ... More
Seshadri constants for curve classesJul 23 2017Sep 07 2018We develop a local positivity theory for movable curves on projective varieties similar to the classical Seshadri constants of nef divisors. We give analogues of the Seshadri ampleness criterion, of a characterization of the augmented base locus of a ... More
Dynamical systems with double recursion are undecidableOct 10 2007A primitive type of two-dimensional dynamic system is introduced. It is shown that there is no decision procedure able to answer if such a dynamical system is ultimately zero.
Nonlinear Versions of a Vector Maximal PrincipleMay 12 2010Jul 21 2011Some nonlinear extensions of the vector maximality statement established by Goepfert, Tammer and Zalinescu [Nonl. Anal., 39 (2000), 909-922] are given. Basic instruments for these are the Brezis-Browder ordering principle [Advances Math., 21 (1976), 355-364] ... More
Vector bundles on projective varieties whose restriction to ample subvarieties splitJan 19 2014Sep 18 2015We systematically study the splitting of vector bundles on a smooth, projective variety, whose restriction to the zero locus of a regular section of an ample vector bundle splits. First, we find ampleness and genericity conditions which ensure that the ... More
Stability analysis and control chaos for fractional 5D Maxwell-Bloch modelFeb 21 2018In this paper we investigate the dynamical behavior of fractional differential system associated to 5D Maxwell-Bloch model in terms of fractional Caputo derivatives.
Asymptotic Perron's method and simple Markov Strategies in stochastic games and controlFeb 27 2014Feb 19 2015We introduce a modification of Perron's method, where semi-solutions are considered in a carefully defined asymptotic sense. With this definition, we can show, in a rather elementary way, that in a zero-sum game or a control problem (with or without model ... More
Function contractive maps in triangular symmetric spacesNov 17 2012Oct 31 2013Some fixed point results are given for a class of functional contractions acting on (reflexive) triangular symmetric spaces. Technical connections with the corresponding theories over (standard) metric and partial metric spaces are also being established. ... More