Results for "Mikael Lindvall"

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Broadband lasers for photo-ionization and repumping of trapped ionsJan 24 2019A frequency-stable, broadband laser is presented for experiments on trapped ions. Since the design is based on widely available semiconductor optical amplifier technology, similar lasers can be realized for virtually any wavelength in the near-infrared, ... More
Model-based Testing of Mobile Systems -- An Empirical Study on QuizUp Android AppJun 01 2016We present an empirical study in which model-based testing (MBT) was applied to a mobile system: the Android client of QuizUp, the largest mobile trivia game in the world. The study shows that traditional MBT approaches based on extended finite-state ... More
Translated Poisson approximation for Markov chainsOct 03 2008The paper is concerned with approximating the distribution of a sum W of n integer valued random variables Y_i, whose distributions depend on the state of an underlying Markov chain X. The approximation is in terms of a translated Poisson distribution, ... More
Metamorphic Detection of Adversarial Examples in Deep Learning Models With Affine TransformationsJul 10 2019Adversarial attacks are small, carefully crafted perturbations, imperceptible to the naked eye; that when added to an image cause deep learning models to misclassify the image with potentially detrimental outcomes. With the rise of artificial intelligence ... More
GQM+Strategies: A Comprehensive Methodology for Aligning Business Strategies with Software MeasurementFeb 03 2014In software-intensive organizations, an organizational management system will not guarantee organizational success unless the business strategy can be translated into a set of operational software goals. The Goal Question Metric (GQM) approach has proven ... More
Dark-state suppression and optimization of laser cooling and fluorescence in a trapped alkaline-earth-metal single ionDec 19 2012We study the formation and destabilization of dark states in a single trapped 88Sr+ ion caused by the cooling and repumping laser fields required for Doppler cooling and fluorescence detection of the ion. By numerically solving the time-dependent density ... More
Linking Software Development and Business Strategy Through MeasurementNov 25 2013Most of today's products and services are software-based. Organizations that develop software want to maintain and improve their competitiveness by controlling software-related risks. To do this, they need to align their business goals with software development ... More
Sur les espaces mesures singuliers II - Etude spectraleDec 13 2004We are mainly interested here in Kazhdan's property T for measured equivalence relations. Among our main results are characterizations of strong ergodicity and Kazhdan's property in terms of the spectra of diffusion operators, associated to random walks ... More
Generalised Ramsey numbers for two sets of cyclesMay 13 2016We determine several generalised Ramsey numbers for two sets $\Gamma_1$ and $\Gamma_2$ of cycles, in particular, all generalised Ramsey numbers $R(\Gamma_1,\Gamma_2)$ such that $\Gamma_1$ or $\Gamma_2$ contains a cycle of length at most $6$, or the shortest ... More
On the Dirac and Pauli operators with several Aharonov-Bohm solenoidsApr 04 2006We study the self-adjoint Pauli operators that can be realized as the square of a self-adjoint Dirac operator and correspond to a magnetic field consisting of a finite number of Aharonov-Bohm solenoids and a regular part, and prove an Aharonov-Casher ... More
Fixed-points in the cone of traces on a C*-algebraMar 29 2018Jan 02 2019Nicolas Monod introduced the class of groups with the fixed-point property for cones, characterized by always admitting a non-zero fixed point whenever acting (suitably) on proper weakly complete cones. He proved that his class of groups contains the ... More
Just-infinite C*-algebras and their invariantsMay 08 2017Dec 28 2017Just-infinite C*-algebras, i.e., infinite dimensional C*-algebras, whose proper quotients are finite dimensional, were investigated in [Grigorchuk-Musat-Rordam, 2016]. One particular example of a just-infinite residually finite dimensional AF-algebras ... More
Phylogenetic distances for neighbour dependent substitution processesDec 10 2008Jan 04 2010We consider models of nucleotidic substitution processes where the rate of substitution at a given site depends on the state of its neighbours. For a wide class of such nonreversible models, we show how to compute consistent, mathematically exact, estimators ... More
The stable and the real rank of Z-absorbing C*-algebrasAug 02 2004Aug 30 2004Suppose that A is a C*-algebra for which A is isomorphic to A tensor Z, where Z is the Jiang-Su algebra: a unital, simple, stably finite, separable, nuclear, infinite dimensional C*-algebra with the same Elliott invariant as the complex numbers. We show ... More
Unpolarized, incoherent repumping light for prevention of dark states in a trapped and laser-cooled single ionJan 23 2013Feb 01 2013Many ion species commonly used for laser-cooled ion trapping studies have a low-lying metastable 2D3/2 state that can become populated due to spontaneous emission from the 2P1/2 excited state. This requires a repumper laser to maintain the ion in the ... More
Normalization and Analytical Fock coefficients of the Laughlin state on the torusMar 27 2015Jul 31 2016We investigate the nature of the plasma analogy for the Laughlin wave function on a torus describing the quantum Hall plateau at $\nu=\frac{1}{q}$. We first establish, as expected, that the plasma is screening if there are no short nontrivial paths around ... More
Massively parallel implementation in Python of a pseudo-spectral DNS code for turbulent flowsJul 01 2016Direct Numerical Simulations (DNS) of the Navier Stokes equations is a valuable research tool in fluid dynamics, but there are very few publicly available codes and, due to heavy number crunching, codes are usually written in low-level languages. In this ... More
The Bruhat order on conjugation-invariant sets of involutions in the symmetric groupFeb 12 2015Let $I_n$ be the set of involutions in the symmetric group $S_n$, and for $A \subseteq \{0,1,\ldots,n\}$, let \[ F_n^A=\{\sigma \in I_n \mid \text{$\sigma$ has $a$ fixed points for some $a \in A$}\}. \] We give a complete characterisation of the sets ... More
Free Energy of ABJM TheoryMar 24 2011The free energy of ABJM theory has previously been computed in the strong and weak coupling limits. In this note, we report on results for the computation of the first non-vanishing quantum correction to the free energy, from the field theory side. The ... More
ILC Beam-Parameters and New PhysicsJul 18 2010A brief overview of the linear collider design is given, with emphasis on the elements of particular importance for the performance. The modifications of the RDR design suggested in the SB2009 proposal are presented, once again with emphasis on those ... More
East-west faults due to planetary contractionJun 30 2010Contraction, expansion and despinning have been common in the past evolution of Solar System bodies. These processes deform the lithosphere until it breaks along faults. The type and orientation of faults are usually determined under the assumption of ... More
Enceladus's crust as a non-uniform thin shell: II tidal dissipationMar 06 2019Tidal heating is the prime suspect behind Enceladus's south polar heating anomaly and global subsurface ocean. No model of internal tidal dissipation, however, can explain at the same time the total heat budget and the focusing of the energy at the south ... More
A simple C*-algebra with a finite and an infinite projectionApr 29 2002Aug 28 2002An example is given of a simple, unital C*-algebra which contains an infinite and a non-zero finite projection. This C*-algebra is also an example of an infinite simple C*-algebra which is not purely infinite. A corner of this C*-algebra is a finite, ... More
On the Aharonov-Casher formula for different self-adjoint extensions of the Pauli operator with singular magnetic fieldFeb 11 2005Two different self-adjoint Pauli extensions describing a spin-1/2 two-dimensional quantum system with singular magnetic field are studied. An Aharonov-Casher type formula is proved for the maximal Pauli extension and it is also checked that this extension ... More
Zero modes for the magnetic Pauli operator in even-dimensional Euclidean spaceOct 22 2007We study the ground state of the Pauli Hamiltonian with a magnetic field in R^(2d). We consider the case where a scalar potential W is present and the magnetic field B is given by $B=2i\partial\bar\partial W$. The main result is that there are no zero ... More
Asymptotic Expansions for Moment Functionals of Perturbed Discrete Time Semi-Markov ProcessesMar 18 2016Apr 26 2016In this paper, we study mixed power-exponential moment functionals of nonlinearly perturbed semi-Markov processes in discrete time. Conditions under which the moment functionals of interest can be expanded in asymptotic power series with respect to the ... More
Asymptotics for Quasi-Stationary Distributions of Perturbed Discrete Time Semi-Markov ProcessesMar 18 2016Apr 26 2016In this paper, we study quasi-stationary distributions of nonlinearly perturbed semi-Markov processes in discrete time. This type of distributions is of interest for the analysis of stochastic systems which have finite lifetimes, but are expected to persist ... More
Algorithmics of DiffractionNov 05 2018Dec 31 2018We discuss novel ways to probe high energy diffraction, first inclusive diffraction and then central exclusive processes at the LHC. Our new Monte Carlo synthesis and analysis framework, Graniitti, includes differential screening, an expendable set of ... More
A spectral-Galerkin turbulent channel flow solver for large-scale simulationsJan 13 2017A fully (pseudo-)spectral solver for direct numerical simulations of large-scale turbulent channel flows is described. The solver utilizes the Chebyshev base functions suggested by J. Shen [SIAM J. Sci. Comput., 16, 1, 1995], that lead to stable and robust ... More
Tidal Love numbers of membrane worlds: Europa, Titan, and CoApr 17 2015May 29 2015Under tidal forcing, icy satellites with subsurface oceans deform as if the surface were a membrane stretched around a fluid layer. `Membrane worlds' is thus a fitting name for these bodies and membrane theory provides the perfect toolbox to predict tidal ... More
Spatial patterns of tidal heatingDec 19 2012In a body periodically strained by tides, heating produced by viscous friction is far from homogeneous. I show here that the distribution of the dissipated power within a spherically stratified body is a linear combination of three angular functions. ... More
On the cylindrically symmetric Einstein-Vlasov systemMar 23 2005For the cylindrically symmetric ''asymptotically flat'' Einstein equations in the case of electro-vacuum it is known that solutions exist globally and also that this class of spacetimes is causally geodesically complete. Hence strong cosmic censorship ... More
The effect of Hall drift on the evolution of magnetic fields in the crusts of neutron starsSep 20 1996We consider the effect of Hall-drift on the evolution of magnetic fields in neutorn star crusts using a finite difference code. Previously, most studies have focused on the situation where the ohmic term dominates the evolution. Here, we investigate the ... More
Well-posedness of time-varying linear systemsApr 28 2019In this paper, we give easily verifiable sufficient conditions for two classes of perturbed linear, passive PDE systems to be well-posed, and we provide an energy inequality for the perturbed systems as well. Our conditions are in terms of smoothness ... More
Sur les espaces mesures singuliers I - Etude metrique-mesureeDec 13 2004Recall Jones-Schmidt theorem that an ergodic measured equivalence relation is strongly ergodic if and only if it has no nontrivial amenable quotient. We give two new characterizations of strong ergodicity, in terms of metric-measured spaces. The first ... More
On low degree regular sequences in group cohomologyOct 11 2006We investigate small $p$-groups with cohomology rings of depth higher than predicted by Duflot's theorem. In these groups, a sampling would suggest several naive conjectures about the degrees of the additional regular sequence elements. We arrive at counterexamples ... More
A purely infinite AH-algebra and an application to AF-embeddabilityMay 28 2002Jan 02 2004We show that there exists a purely infinite AH-algebra. The AH-algebra arises as an inductive limit of C*-algebras of the form C_0([0,1),M_k) and it absorbs the Cuntz algebra O_\infty tensorially. Thus one can reach an O_\infty-absorbing C*-algebra as ... More
On the Inversion of High Energy ProtonMay 29 2019Jun 06 2019Inversion of the K-fold stochastic autoconvolution integral equation is an elementary nonlinear problem, yet there are no de facto methods to solve it with finite statistics. To fix this problem, we introduce a novel inverse algorithm based on a combination ... More
Tides on Europa: the membrane paradigmOct 17 2014Jupiter's moon Europa has a thin icy crust which is decoupled from the mantle by a subsurface ocean. The crust thus responds to tidal forcing as a deformed membrane, cold at the top and near melting point at the bottom. In this paper I develop the membrane ... More
Applying Compression to a Game's Network ProtocolMay 28 2012This report presents the results of applying different compression algorithms to the network protocol of an online game. The algorithm implementations compared are zlib, liblzma and my own implementation based on LZ77 and a variation of adaptive Huffman ... More
Structure of the core of magnetic vortices in d-wave superconductors with a subdominant triplet pairing mechanismMar 18 2011Aug 06 2011The quasiparticle states found in the vortex core of a high-T$_{\rm{c}}$ cuprate superconductor may be probed by scanning tunneling spectroscopy. Results of such experiments have revealed typical spectra that are quite different from what is seen in conventional ... More
Eigenvalue asymptotics of the even-dimensional exterior Landau-Neumann HamiltonianJun 27 2008We study the Schroedinger operator with a constant magnetic field in the exterior of a compact domain in $\mathbb{R}^{2d}$, $d\geq 1$. The spectrum of this operator consists of clusters of eigenvalues around the Landau levels. We give asymptotic formulas ... More
On the modular covariance properties of composite fermions on the torusOct 24 2018In this work we show that the composite fermion construction for the torus geometry is modular covariant. We show that this is the case both before and after projection, and that modular covariance properties are preserved under both exact projection ... More
Shenfun -- automating the spectral Galerkin methodAug 10 2017With the shenfun Python module (github.com/spectralDNS/shenfun) an effort is made towards automating the implementation of the spectral Galerkin method for simple tensor product domains, consisting of (currently) one non-periodic and any number of periodic ... More
SUSY model and dark matter determination in the compressed-spectrum region at the ILCNov 14 2016It is an appealing possibility that the observed dark matter density in the universe can be fully explained by SUSY. The current experimental knowledge indicates that this possibility strongly favors a co-annihilation scenario. In such scenarios, the ... More
Oscillations of neutrinos and mesons in quantum field theorySep 13 2001Oct 15 2002This report deals with the quantum field theory of particle oscillations in vacuum. We first review the various controversies regarding quantum-mechanical derivations of the oscillation formula, as well as the different field-theoretical approaches proposed ... More
Josephson currents through spin-active interfacesAug 04 2000The Josephson coupling of two isotropic s-wave superconductors through a small, magnetically active junction is studied. This is done as a function of junction transparency and of the degree of spin-mixing occurring in the barrier. In the tunneling limit, ... More
On the Inversion of High Energy ProtonMay 29 2019Inversion of the K-fold stochastic autoconvolution integral equation is an elementary nonlinear problem, yet there are no de facto methods to solve it with finite statistics. To fix this problem, we introduce a novel inverse algorithm based on a combination ... More
Computation of Poincare-Betti series for monomial ringsFeb 16 2005The multigraded Poincare-Betti series P_R^k(x_1,...,x_n; t) of a monomial ring k[x_1,...,x_n]/<M> on a finite number of monomial generators has the form (1+tx_1)(1+tx_2)...(1+tx_n)/b_(R,k)(x_1,...,x_n; t), where b_(R,k)(x_1,...,x_n;t) is a polynomial ... More
How to compute $\sum 1/n^2$ by solving trianglesJan 01 2007A new simple geometric method is presented for finding the exact value of $\sum_{n=1}^\infty 1/n^2$.
Quasi-Stationary Asymptotics for Perturbed Semi-Markov Processes in Discrete TimeMar 18 2016We consider a discrete time semi-Markov process where the characteristics defining the process depend on a small perturbation parameter. It is assumed that the state space consists of one finite communicating class of states and, in addition, one absorbing ... More
Almost Sharp Global Well-Posedness for a class of Dissipative and Dispersive Equations on R in Low Regularity Sobolev SpacesSep 12 2014Jan 08 2015In this paper we obtain global well-posedness in low order Sobolev spaces of higher order KdV type equations with dissipation. The result is optimal in the sense that the flow-map is not twice continuously differentiable in rougher spaces. The solution ... More
Crouzeix's conjecture holds for tridiagonal $3\times 3$ matrices with elliptic numerical range centered at an eigenvalueJan 05 2017Dec 23 2017M. Crouzeix formulated the following conjecture in (Integral Equations Operator Theory 48, 2004, 461--477): For every square matrix $A$ and every polynomial $p$, $$ \|p(A)\| \le 2 \max_{z\in W(A)}|p(z)|, $$ where $W(A)$ is the numerical range of $A$. ... More
Spontaneously broken time-reversal symmetry in high-temperature superconductorsNov 04 2014Conventional superconductors are strong diamagnets that through the Meissner effect expel magnetic fields. It would therefore be surprising if a superconducting ground state would support spontaneous magnetics fields. Such time-reversal symmetry broken ... More
Trapping atoms on a transparent permanent-magnet atom chipJan 24 2006Apr 21 2006We describe experiments on trapping of atoms in microscopic magneto-optical traps on an optically transparent permanent-magnet atom chip. The chip is made of magnetically hard ferrite-garnet material deposited on a dielectric substrate. The confining ... More
Surgery on discrete groupsNov 25 2016We study constructions of groups, in particular of groups of intermediate rank, which are accessible to surgery techniques.
Non-closure of quantum correlation matrices and factorizable channels that require infinite dimensional ancillaJun 26 2018Jan 02 2019We show that there exist factorizable quantum channels in each dimension $\ge 11$ which do not admit a factorization through any finite dimensional von Neumann algebra, and do require ancillas of type II$_1$, thus witnessing new infinite-dimensional phenomena ... More
Blackbox computation of $A_\infty$-algebrasJul 24 2008May 27 2009Kadeishvili's proof of the minimality theorem induces an algorithm for the inductive computation of an $A_\infty$-algebra structure on the homology of a dg-algebra. In this paper, we prove that for one class of dg-algebras, the resulting computation will ... More
$Hb\bar{b}$ production in Composite Higgs ModelsMay 08 2013New vector-like quarks with electric charge 2/3 and -1/3 can be singly produced at hadron colliders through the exchange of a color octet vector resonance in models of strong electroweak symmetry breaking. We show that electroweak symmetry breaking effects ... More
On non-negatively curved metrics on open five-dimensional manifoldsFeb 15 2005Let $V^n$ be an open manifold of non-negative sectional curvature with a soul $\Sigma$ of co-dimension two. The universal cover $\tilde N$ of the unit normal bundle $N$ of the soul in such a manifold is isometric to the direct product $M^{n-2}\times R$. ... More
Harnessing the Power of Serverless Runtimes for Large-Scale OptimizationJan 10 2019The event-driven and elastic nature of serverless runtimes makes them a very efficient and cost-effective alternative for scaling up computations. So far, they have mostly been used for stateless, data parallel and ephemeral computations. In this work, ... More
Strongly Self-Absorbing C*-algebras which contain a nontrivial projectionFeb 23 2009It is shown that a strongly self-absorbing C*-algebra is of real rank zero and absorbs the Jiang-Su algebra if it contains a nontrivial projection. We also consider cases where the UCT is automatic for strongly self-absorbing C*-algebras, and K-theoretical ... More
Fast and backward stable transforms between spherical harmonic expansions and bivariate Fourier seriesMay 15 2017Nov 04 2017A rapid transformation is derived between spherical harmonic expansions and their analogues in a bivariate Fourier series. The change of basis is described in two steps: firstly, expansions in normalized associated Legendre functions of all orders are ... More
Symmetric Private Information Retrieval For MDS Coded Distributed StorageOct 14 2016A user wants to retrieve a file from a database without revealing the identity of the file retrieved at the database, which is known as the problem of private information retrieval (PIR). If it is further required that the user obtains no information ... More
Aut(F2) puzzlesOct 28 2014This paper studies Aut(F2) and groups closely related to it from a geometric perspective.
Removing chambers in Bruhat-Tits buildingsMar 24 2010Nov 11 2012We introduce and study a family of countable groups constructed from Euclidean buildings by "removing" suitably chosen subsets of chambers.
Non-closure of quantum correlation matrices and factorizable channels that require infinite dimensional ancillaJun 26 2018Mar 13 2019We show that there exist factorizable quantum channels in each dimension $\ge 11$ which do not admit a factorization through any finite dimensional von Neumann algebra, and do require ancillas of type II$_1$, thus witnessing new infinite-dimensional phenomena ... More
Purely infinite C*-algebras arising from crossed productsJun 07 2010Oct 27 2010We study conditions that will ensure that a crossed product of a C*-algebra by a discrete exact group is purely infinite (simple or non-simple). We are particularly interested in the case of a discrete non-amenable exact group acting on a commutative ... More
Feedback theory extended for proving generation of contraction semigroupsMar 14 2014Nov 06 2015Recently, the following novel method for proving the existence of solutions for certain linear time-invariant PDEs was introduced: The operator associated to a given PDE is represented by a (larger) operator with an internal loop. If the larger operator ... More
Amoebas and coamoebas of linear spacesMay 12 2012Sep 13 2016We give a complete description of amoebas and coamoebas of $k$-dimensional very affine linear spaces in $(\mathbb{C}^*)^{n}$. This include an upper bound of their dimension, and we show that if a $k$-dimensional very affine linear space in $(\mathbb{C}^*)^{n}$ ... More
Discriminant coamoebas through homologyJan 31 2012Aug 02 2012Understanding the complement of the coamoeba of a (reduced) A-discriminant is one approach to studying the monodromy of solutions to the corresponding system of A-hypergeometric differential equations. Nilsson and Passare described the structure of the ... More
A shorter proof of a result by Potapov and Sukochev on Lipschtiz functions on $S^p$May 07 2009In this short note we give a short proof of a recent result by Potapov and Sukochev (arXiv:0904.4095v1), stating that a Lipschitz function on the real line remains Lipschitz on the (self-adjoint part of) non-commutative $L_p$ spaces with $1<p<\infty$. ... More
Rectangular summation of multiple Fourier series and multi-parametric capacityJul 18 2019We consider the class of multiple Fourier series associated with functions in the Dirichlet space of the polydisc. We prove that every such series is summable with respect to unrestricted rectangular partial sums, everywhere except for a set of zero multi-parametric ... More
Axiomatizability of the stable rank of C*-algebrasNov 25 2016We show that the class of C*-algebras with stable rank greater than a given positive integer is axiomatizable in logic of metric structures. As a consequence we show that the stable rank is continuous with respect to forming ultrapowers of C*-algebras, ... More
Operator space valued Hankel matricesSep 28 2009If $E$ is an operator space, the non-commutative vector valued $L^p$ spaces $S^p[E]$ have been defined by Pisier for any $1 \leq p \leq \infty$. In this paper a necessary and sufficient condition for a Hankel matrix of the form $(a_{i+j})_{0 \le i,j}$ ... More
Purely infinite C*-algebras of real rank zeroJun 15 2006Jul 04 2006We show that a separable purely infinite C*-algebra is of real rank zero if and only if its primitive ideal space has a basis consisting of compact-open sets and the natural map K_0(I) -> K_0(I/J) is surjective for all closed two-sided ideals J contained ... More
La propriete de decroissance rapide pour le groupe de WiseNov 11 2012We show that the group of presentation $< a,b,c,s,t\mid c=ab=ba,\, c^2=sas^{-1}=tbt^{-1}>$ (introduced by D. Wise) has the property of rapid decay.
Complete isometries between subspaces of noncommutative Lp-spacesJul 03 2007Dec 04 2007We prove some noncommutative analogues of a theorem by Plotkin and Rudin about isometries between subspaces of Lp-spaces. Let 0<p<\infty, p not an even integer. The main result of this paper states that in the category of unital subspaces of noncommutative ... More
Solutions to the generalized Towers of Hanoi problemApr 19 2012Apr 21 2012The purpose of this paper is to prove the Frame-Stewart algorithm for the generalized Towers of Hanoi problem as well as finding the number of moves required to solve the problem and studying the multitude of optimal solutions. The main idea is to study ... More
Intermediate rank and property RDOct 08 2007Nov 11 2012We introduce concepts of intermediate rank for countable groups that "interpolate" between consecutive values of the classical (integer-valued) rank. Various classes of groups are proved to have intermediate rank behaviors. We are especially interested ... More
Universal properties of group actions on locally compact spacesDec 20 2013Dec 06 2014We study universal properties of locally compact G-spaces for countable infinite groups G. In particular we consider open invariant subsets of the \beta-compactification of G (which is a G-space in a natural way), and their minimal closed invariant subspaces. ... More
Interleaved equivalence of categories of persistence modulesOct 30 2012We demonstrate that an equivalence of categories using $\varepsilon$-interleavings as a fundamental component exists between the model of persistence modules as graded modules over a polynomial ring and the model of persistence modules as modules over ... More
Word Sense Disambiguation using a Bidirectional LSTMJun 11 2016In this paper we present a model that leverages a bidirectional long short-term memory network to learn word sense disambiguation directly from data. The approach is end-to-end trainable and makes effective use of word order. Further, to improve the robustness ... More
A local characterization of Kazhdan projections and applicationsApr 06 2016We give a local characterization of the existence of Kazhdan projections for arbitary families of Banach space representations of a compactly generated locally compact group $G$ and give several applications in terms of stability of rigidity under perturbations. ... More
On M-ideals and o-O type spacesDec 17 2014Sep 15 2015We consider pairs of Banach spaces (M_0, M) such that M_0 is defined in terms of a little-o condition, and M is defined by the corresponding big-O condition. The construction is general and pairs include function spaces of vanishing and bounded mean oscillation, ... More
A local characterization of Kazhdan projections and applicationsApr 06 2016Feb 22 2018We give a local characterization of the existence of Kazhdan projections for arbitary families of Banach space representations of a compactly generated locally compact group $G$. We also define and study a natural generalization of the Fell topology to ... More
Inert Scalar Doublet Asymmetry as Origin of Dark MatterMar 11 2015Jun 01 2015In the inert scalar doublet framework, we analyze what would be the effect of a $B-L$ asymmetry that could have been produced in the Universe thermal bath at high temperature. We show that, unless the "$\lambda_5$" scalar interaction is tiny, this asymmetry ... More
A free product formula for the sofic dimensionAug 03 2013It is proved that if $G=G_1*_{G_3}G_2$ is free product of probability measure preserving $s$-regular ergodic discrete groupoids amalgamated over an amenable subgroupoid $G_3$, then the sofic dimension $s(G)$ satisfies the equality \[ s(G)=\h(G_1^0)s(G_1)+\h(G_2^0)s(G_2)-\h(G_3^0)s(G_3) ... More
Impedance-matched cavity quantum memoryApr 14 2010We consider an atomic frequency comb based quantum memory inside an asymmetric optical cavity. In this configuration it is possible to absorb the input light completely in a system with an effective optical depth of one, provided that the absorption per ... More
Large Thermoelectric Effects and Inelastic Scattering in Unconventional SuperconductorsJul 27 2005The thermoelectric coefficient $\eta(T)$ in unconventional superconductors is enhanced below $T_c$ by intermediate strength impurity scattering that is intrinsically particle-hole asymmetric. We compute $\eta(T)$ for a strong-coupling d-wave superconductor ... More
Mixed state non-Abelian holonomy for subsystemsApr 29 2004Feb 01 2005Non-Abelian holonomy in dynamical systems may arise in adiabatic transport of energetically degenerate sets of states. We examine such a holonomy structure for mixtures of energetically degenerate quantal states. We demonstrate that this structure has ... More
On exactly incompressible DG FEM pressure splitting schemes for the Navier-Stokes equationMar 20 2019We compare three iterative pressure correction schemes for solving the Navier-Stokes equations with a focus on exactly divergence free solution with higher order discontinuous Galerkin discretisations. The investigated schemes are the incremental pressure ... More
Identifying local spatial order using full neighbor counting statisticsMar 05 2019Fluid states of matter can locally exhibit characteristics of the onset of crystalline order. Traditionally this has been theoretically investigated using multi-point correlation functions. However new measurement techniques now allow multiparticle configurations ... More
Approximability of the Vertex Cover Problem in Power Law GraphsApr 04 2012Apr 05 2012In this paper we construct an approximation algorithm for the Minimum Vertex Cover Problem (Min-VC) with an expected approximation ratio of 2-f(beta) for random Power Law Graphs (PLG) in the (alpha,beta)-model of Aiello et. al., where f(beta) is a strictly ... More
Physics of the Interplay Between the Top Quark and the Higgs BosonMar 05 2013Mar 27 2013We discuss some aspects of the interplay between the top quark and the Higgs boson at the LHC. First we describe what indirect information on the top Yukawa coupling can be extracted from measurements in the Higgs sector. We then show that the study of ... More
Factorizable maps and traces on the universal free product of matrix algebrasMar 25 2019We relate factorizable quantum channels on $M_n$, for $n \ge 2$, via their Choi matrix, to certain correlation matrices, which, in turn, are shown to be parametrized by traces on the free unital product $M_n * M_n$. Factorizable maps that admit a finite ... More
Word Sense Disambiguation using a Bidirectional LSTMJun 11 2016Nov 18 2016In this paper we present a clean, yet effective, model for word sense disambiguation. Our approach leverage a bidirectional long short-term memory network which is shared between all words. This enables the model to share statistical strength and to scale ... More
Sketches of a platypus: persistent homology and its algebraic foundationsDec 21 2012Nov 10 2013The subject of persistent homology has vitalized applications of algebraic topology to point cloud data and to application fields far outside the realm of pure mathematics. The area has seen several fundamentally important results that are rooted in choosing ... More
Identification of meteorite source regions in the Solar SystemApr 19 2018Over the past decade there has been a large increase in the number of automated camera networks that monitor the sky for fireballs. One of the goals of these networks is to provide the necessary information for linking meteorites to their pre-impact, ... More
Charged particle tracking without magnetic field: optimal measurement of track momentum by a Bayesian analysis of the multiple measurements of deflections due to multiple scatteringJun 19 2017Jul 03 2017We revisit the precision of the measurement of track parameters (position, angle) with optimal methods in the presence of detector resolution, multiple scattering and zero magnetic field. We then obtain an optimal estimator of the track momentum by a ... More