Results for "Sebastian Acosta"

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A control approach to recover the wave speed (conformal factor) from one measurementJan 27 2014Jan 08 2015In this paper we consider the problem of recovering the conformal factor in a conformal class of Riemannian metrics from the boundary measurement of one wave field. More precisely, using boundary control operators, we derive an explicit equation satisfied ... More
High order surface radiation conditions for time-harmonic waves in exterior domainsFeb 23 2017We formulate a new family of high order on-surface radiation conditions to approximate the outgoing solution to the Helmholtz equation in exterior domains. Motivated by the pseudo-differential expansion of the Dirichlet-to-Neumann operator developed by ... More
Multiwave imaging in an enclosure with variable wave speedJan 30 2015Apr 10 2015In this paper we consider the mathematical model of thermo- and photo-acoustic tomography for the recovery of the initial condition of a wave field from knowledge of its boundary values. Unlike the free-space setting, we consider the wave problem in a ... More
Source estimation with incoherent waves in random waveguidesAug 08 2014Feb 24 2015We study an inverse source problem for the acoustic wave equation in a random waveguide. The goal is to estimate the source of waves from measurements of the acoustic pressure at a remote array of sensors. The waveguide effect is due to boundaries that ... More
Time reversal for radiative transport with applications to inverse and control problemsApr 10 2013Aug 03 2013In this paper we develop a time reversal method for the radiative transport equation to solve two problems: an inverse problem for the recovery of an initial condition from boundary measurements, and the exact boundary controllability of the transport ... More
Recovery of Pressure and Wave Speed for Photoacoustic Imaging under a Condition of Relative UncertaintyMay 14 2019In this paper, we study the photoacoustic tomography problem for which we seek to recover both the initial state of the pressure field and the wave speed of the medium from the knowledge of a single boundary measurement. The goal is to propose practical ... More
Recovery of the absorption coefficient in radiative transport from a single measurementAug 21 2013Feb 14 2015In this paper, we investigate the recovery of the absorption coefficient from boundary data assuming that the region of interest is illuminated at an initial time. We consider a sufficiently strong and isotropic, but otherwise unknown initial state of ... More
Photoacoustic imaging taking into account thermodynamic attenuationFeb 04 2016Aug 24 2016In this paper we consider a mathematical model for photoacoustic imaging which takes into account attenuation due to thermodynamic dissipation. The propagation of acoustic (compressional) waves is governed by a scalar wave equation coupled to the heat ... More
Spherical CR Dehn SurgerySep 15 2015Consider a three dimensional cusped spherical $\mathrm{CR}$ manifold $M$ and suppose that the holonomy representation of $\pi_1(M)$ can be deformed in such a way that the peripheral holonomy is generated by a non-parabolic element. We prove that, in this ... More
FJRW-Rings and Landau-Ginzburg Mirror Symmetry in Two DimensionsJun 04 2009For any non-degenerate, quasi-homogeneous hypersurface singularity W and an admissible group of diagonal symmetries G, Fan, Jarvis, and Ruan have constructed a cohomological field theory which is a candidate for the mathematical structure behind the Landau-Ginzburg ... More
The DtN nonreflecting boundary condition for multiple scattering problems in the half-planeDec 28 2013The multiple-Dirichlet-to-Neumann (multiple-DtN) non-reflecting boundary condition is adapted to acoustic scattering from obstacles embedded in the half-plane. The multiple-DtN map is coupled with the method of images as an alternative model for multiple ... More
Contact Interactions at the LHCSep 17 2007Contact interactions offer a general framework for describing a new interaction with a scale above the energy scale probed. These interactions can occur if the Standard Model particles are composite or if new heavy particles are exchanged. The discovery ... More
On the dimension of discrete valuations of k((X1,...,Xn))Nov 15 2000Let $v$ be a rank-one discrete valuation of the field $k((\X))$. We know, after \cite{Bri2}, that if $n=2$ then the dimension of $v$ is 1 and if $v$ is the usual order function over $k((\X))$ its dimension is $n-1$. In this paper we prove that, in the ... More
Groups definable in Presburger arithmeticMar 31 2019We determine all groups definable in Presburger arithmetic, up to a finite index subgroup.
Rank one discrete valuations of $k((X_1,...X_n))$Oct 31 2000Dec 16 2002In this paper we study the rank one discrete valuations of $k((X_1,... ,X_n))$ whose center in $k\lcor\X\rcor$ is the maximal ideal $(\X)$. In sections 2 to 6 we give a construction of a system of parametric equations describing such valuations. This ... More
On the multi-frequency inverse source problem in heterogeneous mediaDec 28 2013The inverse source problem where an unknown source is to be identified from the knowledge of its radiated wave is studied. The focus is placed on the effect that multi-frequency data has on establishing uniqueness. In particular, it is shown that data ... More
Spin-polarization control driven by a Rashba-type effect breaking the mirror symmetry in two-dimensional dual topological insulatorsNov 27 2018Jan 12 2019Three-dimensional topological insulators protected by both the time reversal (TR) and mirror symmetries were recently predicted and observed. Two-dimensional materials featuring this property and their potential for device applications have been less ... More
Numerical method of characteristics for one-dimensional blood flowNov 20 2014Mar 27 2015Mathematical modeling at the level of the full cardiovascular system requires the numerical approximation of solutions to a one-dimensional nonlinear hyperbolic system describing flow in a single vessel. This model is often simulated by computationally ... More
Liouvillian Propagators, Riccati Equation and Differential Galois TheoryApr 21 2013Jun 13 2013In this paper a Galoisian approach to build propagators through Riccati equations is presented. The main result corresponds to the relationship between the Galois integrability of the linear Schr\"odinger equation and the virtual solvability of the differential ... More
Liouvillian Solutions of Schrödinger Equation with Polynomial Potentials using Gröbner BasisOct 22 2018May 12 2019The main aim of this paper is the presentation of a new methodology to obtain Liouvillian solutions of stationary one dimensional Schr\"odinger equation with quasi-solvable polynomial potentials through the using of differential Galois theory and Gr\"obner ... More
Differential Galois Groups and Representation of Quivers for Seismic Models with Constant Hessian of Square of SlownessDec 13 2016The trajectory of energy is modeled by the solution of the Eikonal equation, which can be solved by solving a Hamiltonian system. This system is amenable of treatment from the point view of the theory of Differential Algebra. In particular, by Morales-Ramis ... More
XPath Node Selection over Grammar-Compressed TreesNov 21 2013XML document markup is highly repetitive and therefore well compressible using grammar-based compression. Downward, navigational XPath can be executed over grammar-compressed trees in PTIME: the query is translated into an automaton which is executed ... More
Fast and Tiny Structural Self-Indexes for XMLDec 28 2010XML document markup is highly repetitive and therefore well compressible using dictionary-based methods such as DAGs or grammars. In the context of selectivity estimation, grammar-compressed trees were used before as synopsis for structural XPath queries. ... More
A basis of $\R ^n$ with good isometric properties and some applications to denseness of norm attaining operatorsNov 20 2018We characterize real Banach spaces $Y$ such that the pair $(\ell_\infty ^n, Y)$ has the Bishop-Phelps-Bollob\'as property for operators. To this purpose it is essential the use of an appropriate basis of the domain space $\R^n$. As a consequence of the ... More
On an analogue of a Brauer theorem for fusion categoriesMar 16 2015In this paper we prove an analogue of Brauer's theorem for faithful objects in fusion categories. Other notions, such as the order and the index associated to faithful objects of fusion categories are also discussed. We show that the index of a faithful ... More
Resolutions for unit groups of ordersSep 28 2016We present a general algorithm for constructing a free resolution for unit groups of orders in semisimple rational algebras. The approach is based on computing a contractible $G$-complex employing the theory of minimal classes of quadratic forms and Opgenorth's ... More
Equivalence Problems for Tree Transducers: A Brief SurveyMay 22 2014The decidability of equivalence for three important classes of tree transducers is discussed. Each class can be obtained as a natural restriction of deterministic macro tree transducers (MTTs): (1) no context parameters, i.e., top-down tree transducers, ... More
Continuity of discrete homomorphisms of diffeomorphism groupsJul 16 2013Jul 15 2016Let $M$ and $N$ be two closed $C^{\infty}$ manifolds and let $\text{Diff}_c(M)$ denote the group of $C^{\infty}$ diffeomorphisms isotopic to the identity. We prove that any (discrete) group homomorphism between $\text{Diff}_c(M)$ and $\text{Diff}_c(N)$ ... More
Theoretical overview of b->s hadronic decaysFeb 10 2010A wealth of data on hadronic b -> s transitions is available from the B-factories and will be improved at the LHCb experiment and possible future super-B-factories. I review the theory of these decays as it pertains to the search for physics beyond the ... More
SUSY beyond minimal flavour violationOct 29 2007Dec 06 2007We review aspects of the phenomenology of the MSSM with non-minimal flavour violation, including a discussion of important constraints and the sensitivity to fundamental scales.
Saturation in central-forward jet production in p-Pb collisions at LHCDec 20 2012We show that saturation can manifest itself in central-forward dijet production in p-A collisions. In spite of large transverse momenta of the jets, the almost back-to-back dijet configurations are able to probe gluon density at low x and low kt. We perform ... More
Particle Filters in Robotics (Invited Talk)Dec 12 2012This presentation will introduce the audience to a new, emerging body of research on sequential Monte Carlo techniques in robotics. In recent years, particle filters have solved several hard perceptual robotic problems. Early successes were limited to ... More
Introduction to Measurement Space and Application to Operationally Useful Entanglement and Mode EntanglementApr 27 2010Aug 28 2010We introduce the idea that the knowable quantum reality depends not only on the state but also on measurements. Mathematically, we map the states from the ordinary Hilbert space into new states in what we call the measurement space. The state vectors ... More
Cluster Transformations from Bipartite Field TheoriesJan 02 2013Oct 17 2013Bipartite field theories (BFTs) are a new class of 4d N=1 quantum field theories defined by bipartite graphs on bordered Riemann surfaces. In this paper we derive, purely in terms of the gauge theory, the cluster transformations of face weights under ... More
Experimental Challenges of the European Strategy for Particle PhysicsSep 30 2013Oct 07 2013In planning for the Phase II upgrades of CMS and ATLAS major considerations are: 1)being able to deal with degradation of tracking and calorimetry up to the radiation doses to be expected with an integrated luminosity of 3000 $fb^{-1}$ and 2)maintaining ... More
Neutron Production and Zero Degree Calorimeter Acceptance at LHCDec 22 2009May 10 2010We calculate cross sections for the far forward LHC detectors to be used for luminosity measurement. A simple model, based on a parametrization of available inclusive neutron data and the assumption that 2 arm rates in non-diffractive events are uncorrelated, ... More
Diffractive J/$ψ$ production in Ultraperipheral AuAu Collisions at RHICOct 31 2005We report on the first measurement of diffractive J/psi production in Ultraperipheral Au+Au collisions at \sqrt{s_{NN}}=200 GeV.
MusicMood: Predicting the mood of music from song lyrics using machine learningNov 01 2016Sentiment prediction of contemporary music can have a wide-range of applications in modern society, for instance, selecting music for public institutions such as hospitals or restaurants to potentially improve the emotional well-being of personnel, patients, ... More
Brackets, Sigma Models and Integrability of Generalized Complex StructuresSep 04 2006Nov 27 2008It is shown how derived brackets naturally arise in sigma-models via Poisson- or antibracket, generalizing a recent observation by Alekseev and Strobl. On the way to a precise formulation of this relation, an explicit coordinate expression for the derived ... More
Derived Brackets from Super-Poisson BracketsMar 08 2007The relation between Poisson brackets in supersymmetric one or two-dimensional sigma-models and derived brackets is summarized.
Relative tensor triangular Chow groups, singular varieties and localizationOct 01 2015We extend the scope of Balmer's tensor triangular Chow groups to compactly generated triangulated categories $\mathcal{K}$ that only admit an action by a compactly-rigidly generated tensor triangulated category $\mathcal{T}$ as opposed to having a compatible ... More
Coupled intertwiner dynamics: A toy model for coupling matter to spin foam modelsJun 15 2015Sep 17 2015The universal coupling of matter and gravity is one of the most important features of general relativity. In quantum gravity, in particular spin foams, matter couplings have been defined in the past, yet the mutual dynamics, in particular if matter and ... More
Intersection products for tensor triangular Chow groupsMay 28 2015We show that under favorable circumstances, one can construct an intersection product on the Chow groups of a tensor triangulated category $\mathcal{T}$ (as defined by Balmer) which generalizes the usual intersection product on a non-singular algebraic ... More
Why Is Dual-Pivot Quicksort Fast?Nov 03 2015Sep 28 2016I discuss the new dual-pivot Quicksort that is nowadays used to sort arrays of primitive types in Java. I sketch theoretical analyses of this algorithm that offer a possible, and in my opinion plausible, explanation why (a) dual-pivot Quicksort is faster ... More
Post-Newtonian dynamics at order 1.5 in the Vlasov-Maxwell systemFeb 13 2006We study the dynamics of many charges interacting with the Maxwell field. The particles are modeled by means of non-negative distribution functions $f^+$ and $f^-$ representing two species of charged matter with positive and negative charge, respectively. ... More
Universality of ac-conduction in anisotropic disordered systems: An effective medium approximation studyFeb 03 2004Apr 12 2005Anisotropic disordered system are studied in this work within the random barrier model. In such systems the transition probabilities in different directions have different probability density functions. The frequency-dependent conductivity at low temperatures ... More
Machine learning-assisted discovery of GPCR bioactive ligandsDec 16 2018While G-protein coupled receptors (GPCRs) constitute the largest class of membrane proteins, structures and endogenous ligands of a large portion of GPCRs remain unknown. Due to the involvement of GPCRs in various signaling pathways and physiological ... More
On Kesten's Multivariate Choquet-Deny LemmaFeb 21 2013Mar 14 2014Let $d >1$ and $(A_n)_{n \ge 1}$ be a sequence of independent identically distributed random matrices with nonnegative entries and no zero column. This induces a Markov chain $M_n = A_n M_{n-1}$ on the cone of d-vectors with nonnegative entries. We study ... More
Conformally Flat Circle Bundles over SurfacesFeb 26 2009We classify conformally flat Riemannian $3-$manifolds which possesses a free isometric $S^1-$action.
Toric Poisson Ideals in Cluster AlgebrasSep 15 2010Feb 29 2012This paper investigates the Poisson geometry associated to a cluster algebra over the complex numbers, and its relationship to compatible torus actions. We show, under some assumptions, that each Noetherian cluster algebra has only finitely many torus ... More
Totally geodesic submanifolds of the exceptional Riemannian symmetric spaces of rank 2Sep 08 2008The present article is the final part of a series on the classification of the totally geodesic submanifolds of the irreducible Riemannian symmetric spaces of rank 2. After this problem has been solved for the 2-Grassmannians in my previous papers cited ... More
Properties of the Dirac spectrum on three dimensional lens spacesApr 13 2015Aug 14 2015We present a spectral rigidity result for the Dirac operator on lens spaces. More specifically, we show that each homogeneous lens space and each three dimensional lens space $L(q;p)$ with $q$ prime is completely characterized by its Dirac spectrum in ... More
Recurrence and Transience for Branching Random Walks in an iid Random EnvironmentJun 02 2006We give three different criteria for transience of a Branching Markov Chain. These conditions enable us to give a classification of Branching Random Walks in Random Environment (BRWRE) on Cayley Graphs in recurrence and transience. This classification ... More
Hölder-Zygmund Estimates for Degenerate Parabolic SystemsJul 19 2013We consider energy solutions of the inhomogeneous parabolic $p$-Laplacien system $\partial_t u-\text{div}(|D u|^{p-2}D u)=-\text{div} g$. We show in the case $p\geq 2$ that if the right hand side $g$ is locally in $L^\infty(\text{BMO})$, then $u$ is locally ... More
Discrete knot energiesMar 08 2016The present chapter gives an overview on results for discrete knot energies. These discrete energies are designed to make swift numerical computations and thus open the field to computational methods. Additionally, they provide an independent, geometrically ... More
For which positive $p$ is the integral Menger curvature $\mathcal{M}_{p}$ finite for all simple polygons?Feb 02 2012In this brief note we show that the integral Menger curvature $\mathcal{M}_{p}$ is finite for all simple polygons if and only if $p\in (0,3)$. For the intermediate energies $\mathcal{I}_{p}$ and $\mathcal{U}_{p}$ we obtain the analogous result for $p\in ... More
A characterisation of inner product spaces by the maximal circumradius of spheresFeb 02 2012We give a new characterisation of inner product spaces amongst normed vector spaces in terms of the maximal cirumradius of spheres. It turns out that a normed vector space $(X,\norm{\cdot})$ with $\dim X\geq 2$ is an inner product space if and only if ... More
The third cohomology group classifies crossed module extensionsNov 15 2009Sep 29 2010We give an elementary proof of the well-known fact that the third cohomology group H^3(G, M) of a group G with coefficients in an abelian G-module M is in bijection to the set Ext^2(G, M) of equivalence classes of crossed module extensions of G with M. ... More
A spectral curve approach to Lawson symmetric CMC surfaces of genus 2Sep 14 2012Apr 11 2013Minimal and CMC surfaces in $S^3$ can be treated via their associated family of flat $\SL(2,\C)$-connections. In this the paper we parametrize the moduli space of flat $\SL(2,\C)$-connections on the Lawson minimal surface of genus 2 which are equivariant ... More
From ADM to Brane-World chargesOct 12 2000We first recall a covariant formalism used to compute conserved charges in gauge invariant theories. We then study the case of gravity for two different boundary conditions, namely spatial infinity and a Brane-World boundary. The new conclusion of this ... More
Scalar Curvature Estimates by Parallel Alternating TorsionSep 28 2007We generalize Llarull's scalar curvature comparison to Riemannian manifolds admitting metric connections with parallel and alternating torsion and having a nonnegative curvature operator on 2-vectors. As a byproduct, we show that Euler number and signature ... More
Bernoulli Percolation on random TessellationsSep 15 2016We generalize the standard site percolation model on the $d$-dimensional lattice to a model on random tessellations of $\mathbb R^d$. We prove the uniqueness of the infinite cluster by adapting the Burton-Keane argument \cite{burton1989density}, develop ... More
Equivalences between localisations of categories provided by replacementsOct 09 2018We give a characterisation of functors whose induced functor on the level of localisations is an equivalence and where the isomorphism inverse is induced by some kind of replacements such as projective resolutions or cofibrant replacements.
Group theoretical independence of $\ell$-adic Galois representationsJan 17 2017Let $K/\mathbb{Q}$ be a finitely generated field of characteristic zero and $X/K$ a smooth projective variety. Fix $q\in\mathbb{N}$. For every prime number $\ell$ let $\rho_\ell$ be the representation of $\mathrm{Gal}(K)$ on the \'etale cohomology group ... More
A spectral theory for simply periodic solutions of the sinh-Gordon equationJul 29 2016In this work a spectral theory for 2-dimensional, simply periodic, complex-valued solutions u of the sinh-Gordon equation is developed. Spectral data for such solutions are defined (following Hitchin and Bobenko) and the space of spectral data is described ... More
On the irreducible representations of generalized quantum doublesFeb 20 2012A description of all the irreducible representations of generalized quantum doubles associated to skew pairings of semisimple Hopf algebras is given. In particular a description of the irreducible representations of semisimple Drinfeld doubles is obtained. ... More
Backward-Backward Splitting in Hadamard SpacesSep 23 2013Sep 30 2013The backward-backward algorithm is a tool for finding minima of a regularization of the sum of two convex functions in Hilbert spaces. We generalize this setting to Hadamard spaces and prove the convergence of an error-tolerant version of the backward-backward ... More
Mellin moments of heavy flavor contributions to F_2(x,Q^2) at NNLOOct 16 2009This thesis is concerned with the calculation of fixed moments of the O(a_s^3) heavy flavor contributions to the Wilson coefficients of the structure function F_2(x,Q^2) in the limit Q^2 >> m^2, neglecting power corrections. The massive Wilson coefficients ... More
Accurate variational electronic structure calculations with the density matrix renormalization groupMay 06 2014During the past 15 years, the density matrix renormalization group (DMRG) has become increasingly important for ab initio quantum chemistry. The underlying matrix product state (MPS) ansatz is a low-rank decomposition of the full configuration interaction ... More
Supersymmetry beyond minimal flavour violationAug 14 2008Nov 18 2008We review the sources and phenomenology of non-minimal flavour violation in the MSSM. We discuss in some detail the most important theoretical and experimental constraints, as well as promising observables to look for supersymmetric effects at the LHC ... More
On strategies for determination and characterization of the underlying eventSep 04 2010Sep 22 2010We discuss the problem of the separation and description of the underlying event (UE) within two existing approaches to UE measurement: the "traditional" method, widely used at Tevatron, and a recently proposed jet-area/median method. A simple toy model ... More
Bipartite Field Theories: from D-Brane Probes to Scattering AmplitudesJul 03 2012Dec 20 2012We introduce and initiate the investigation of a general class of 4d, N=1 quiver gauge theories whose Lagrangian is defined by a bipartite graph on a Riemann surface, with or without boundaries. We refer to such class of theories as Bipartite Field Theories ... More
Depth Two Hopf Subalgebras of Semisimple Hopf algebrasJul 18 2008Let H be a finite dimensional semisimple Hopf algebra over an algebraically closed field of characteristic zero. In this note we give a short proof of the fact that a Hopf subalgebra of H is a depth two subalgebra if and only if it is normal Hopf subalgebra. ... More
Categorical Hopf kernels and representations of semisimple Hopf algebrasOct 11 2010In the category of semisimple Hopf algebras the Hopf kernels introduced by Andruskiewitsch and Devoto in \cite{AD} coincide with kernels of representation as introduced in \cite{Bker}. Some new results concerning the normality of kernels are also presented. ... More
The Chordal Loewner Equation and Monotone Probability TheoryMay 21 2016Jun 21 2016In [5], O. Bauer interpreted the chordal Loewner equation in terms of non-commutative probability theory. We follow this perspective and identify the chordal Loewner equations as the non-autonomous versions of evolution equations for semigroups in monotone ... More
Second-order perturbation theory for 3He and pd scattering in pionless EFTSep 11 2016This work implements pionless effective field theory with the two-nucleon system expanded around the unitarity limit at second order perturbation theory. The expansion is found to converge well. All Coulomb effects are treated in perturbation theory, ... More
A Projection to the Pure Spinor SpaceFeb 02 2012This article is based on a talk given at the Memorial Conference for Maximilian Kreuzer at the ESI in Vienna and contains a compact summary of a recent collaboration with P.A. Grassi. A non-linear projection from the space of SO(10) Weyl spinors to the ... More
The burnside problem for $\text{Diff}_{\text{Vol}}(\mathbb{S}^2)$Jul 15 2016Let $S$ be a closed surface and $\text{Diff}_{\text{Vol}}(S)$ be the group of volume preserving diffeomorphisms of $S$. A finitely generated group $G$ is periodic of bounded exponent if there exists $k \in \mathbb{N}$ such that every element of $G$ has ... More
Distributed Event-based State EstimationNov 16 2015An event-based state estimation approach for reducing communication in a networked control system is proposed. Multiple distributed sensor-actuator-agents observe a dynamic process and sporadically exchange their measurements and inputs over a bus network. ... More
H1 Diffractive Structure Function Measurements and QCD FitsDec 15 2004Measurements of diffractive structure functions in ep collisions and diffractive parton densities extracted from QCD fits are presented.
Asymptotic Rasmussen InvariantFeb 12 2007We use simple properties of the Rasmussen invariant of knots to study its asymptotic behaviour on the orbits of a smooth volume preserving vector field on a compact domain in the 3-space. A comparison with the asymptotic signature allows us to prove that ... More
Constructing equivariant vector bundles via the BGG correspondenceOct 17 2017We describe a strategy for the construction of finitely generated $G$-equivariant $\mathbb{Z}$-graded modules $M$ over the exterior algebra for a finite group $G$. By an equivariant version of the BGG correspondence, $M$ defines an object $\mathcal{F}$ ... More
Polylogarithmic Cuts in Models of V^0Mar 25 2013Mar 29 2013We study initial cuts of models of weak two-sorted Bounded Arithmetics with respect to the strength of their theories and show that these theories are stronger than the original one. More explicitly we will see that polylogarithmic cuts of models of $\mathbf{V}^0$ ... More
A constructive approach to Freyd categoriesDec 10 2017In this paper we give an algorithmic description of Freyd categories that subsumes and enhances the usual approach to finitely presented modules in computer algebra. The upshot is a constructive approach to finitely presented functors that only relies ... More
Graphs with degree complete labelingJun 14 2017In 2006 Qian [J. Qian, Degree complete graphs; Discrete Mathematics 306 (2006), 533--537] introduced the concept of degree complete graphs for labeled graphs. He also gave a characterization of these graphs in terms of two forbidden subgraphs. Furthermore, ... More
Fourier multipliers on weighted $L^p$ spacesMar 18 2014May 13 2014The paper provides a complement to the classical results on Fourier multipliers on $L^p$ spaces. In particular, we prove that if $q\in (1,2)$ and a function $m:\mathbb{R} \rightarrow \mathbb{C}$ is of bounded $q$-variation uniformly on the dyadic intervals ... More
Poisson Ideals in Cluster Algebras and the Spectra of Quantized Coordinate RingsJul 14 2011Oct 31 2012We describe the Poisson ideals and attached symplectic geometry of a cluster algebra with compatible Poisson structure. We apply these results to determine the spectrum of a quantum cluster algebra. As an application, we describe the topology on the spectra ... More
Closed function sets on groups of prime orderOct 22 2018We give a full description of all sets of functions on the group $(\mathbb{ Z}_p, +)$ of prime order which are closed under the composition with the clone generated by $+$ from both sides. Thereby, we also get a description of all iterative algebras on ... More
Spontaneous CP Violation and the Strong CP Problem in Left-Right Symmetric TheoriesAug 06 2018We study spontaneous CP violation as a solution to the strong CP problem in left-right symmetric theories. The discrete CP symmetry is broken by a complex vacuum expectation value of a right-handed Higgs doublet. Heavy vector-like down-type quarks mix ... More
Global instability of wing shock buffetJun 19 2018Shock buffet on wings encountered in edge-of-the-envelope transonic flight remains an unresolved and disputed flow phenomenon, challenging both fundamental fluid mechanics and applied aircraft aerodynamics. The question of global instability leading to ... More
Top-quark pair production in association with a $Z$ boson in the 4$\ell$ channel with the ATLAS experimentJan 14 2019Jan 24 2019The cross section of the $t\bar{t}Z$~and $t\bar{t}W$~processes are measured in a simultaneous fit using 36.1 $\text{fb}^{-1}$ of of proton--proton collisions at a centre-of-mass energy of $\sqrt{s}=13$ TeV recorded by the ATLAS experiment at the LHC. ... More
The unitarity expansion for light nucleiDec 13 2018I is argued here that (at least light) nuclei may reside in a sweet spot: bound weakly enough to be insensitive to the details of the interaction, but dense enough to be insensitive to the exact values of the large two-body scattering lengths as well. ... More
Equivariant Quantizations of Symmetric AlgebrasOct 12 2008Dec 09 2008Let g be a Lie bialgebra and let V be a finite-dimensional g-module. We study deformations of the symmetric algebra of V which are equivariant with respect to an action of the quantized enveloping algebra of g. In particular we investigate such quantizations ... More
R-Matrix Poisson Algebras and Their DeformationsJun 03 2007We classify in this paper Poisson structures on modules over semisimple Lie algebras arising from classical r-matrices. We then study their quantizations and the relation to classical invariant theory.
Quadratic-time Algorithm for the String Constrained LCS ProblemJun 30 2011The problem of finding a longest common subsequence of two main sequences with some constraint that must be a substring of the result (STR-IC-LCS) was formulated recently. It is a variant of the constrained longest common subsequence problem. As the known ... More
Validation of credit default probabilities via multiple testing proceduresJun 25 2010We apply multiple testing procedures to the validation of estimated default probabilities in credit rating systems. The goal is to identify rating classes for which the probability of default is estimated inaccurately, while still maintaining a predefined ... More
Morse theory and higher torsion invariants IIMay 20 2003Let p: M -> B be a family of compact manifolds equipped with a unitarily flat vector bundle F -> M. We generalize Igusa's higher Franz-Reidemeister torsion \tau(M/B;F) to the case that the fibre-wise cohomology H^*(M/B;F) -> B carries a parallel metric. ... More
Non-Coexistence of Infinite Clusters in Two-Dimensional Dependent Site PercolationMar 04 2011Jul 20 2011This paper presents three results on dependent site percolation on the square lattice. First, there exists no positively associated probability measure on {0,1}^{Z^2} with the following properties: a) a single infinite 0cluster exists almost surely, b) ... More
Invariance Principle for the Random Conductance Model with dynamic bounded ConductancesFeb 03 2012Oct 11 2012We study a continuous time random walk X in an environment of dynamic random conductances. We assume that the conductances are stationary ergodic, uniformly bounded and bounded away from zero and polynomially mixing in space and time. We prove a quenched ... More
Sharpness of the phase transition and lower bounds for the critical intensity in continuum percolation on $\mathbb{R}^d$Jul 21 2016We consider the Boolean model $Z$ on $\mathbb{R}^d$ with random compact grains, i.e. $Z := \bigcup_{i \in \mathbb{N}} (X_i + Z_i)$ where $\eta_t := \{X_1, X_2, \dots\}$ is a Poisson point process of intensity $t$ and $(Z_1, Z_2, \dots)$ is an i.i.d. sequence ... More