Results for "Magnus V. Persson"

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Shrinking targets in parametrised familiesMar 03 2016May 03 2016We consider certain parametrised families of piecewise expanding maps on the interval, and estimate and sometimes calculate the Hausdorff dimension of the set of parameters for which the orbit of a fixed point has a certain shrinking target property. ... More
Clusters of eigenvalues for the magnetic Laplacian with Robin conditionJun 04 2014We study the Schr\"{o}dinger operator with a constant magnetic field in the exterior of a compact domain in euclidean space. Functions in the domain of the operator are subject to a boundary condition of the third type (a magnetic Robin condition). In ... More
A recent accretion burst in the low-mass protostar IRAS 15398-3359: ALMA imaging of its related chemistryDec 03 2013Low-mass protostars have been suggested to show highly variable accretion rates through-out their evolution. Such changes in accretion, and related heating of their ambient envelopes, may trigger significant chemical variations on different spatial scales ... More
Linking interstellar and cometary O$_2$: a deep search for $^{16}$O$^{18}$O in the solar-type protostar IRAS 16293--2422May 31 2018Recent measurements carried out at comet 67P/C-G with the ${\it Rosetta}$ probe revealed that molecular oxygen, O$_2$, is the fourth most abundant molecule in comets. Models show that O$_2$ is likely of primordial nature, coming from the interstellar ... More
Energy, phonon, and dynamic stability criteria of 2d materialsJan 22 2019Jan 28 2019First-principles calculations have become a powerful tool to exclude the Edisonian approach in search of novel 2d materials. However, no universal first-principles criteria to examine the realizability of hypothetical 2d materials have been established ... More
Evaluation of Phosphorene as Anode Material for Na-ion Batteries from First PrinciplesJan 11 2015We systematically evaluate the prospects of a novel 2D nanomaterial, phosphorene, as anode for Na-ion batteries. Using first-principles calculations, we determine the Na adsorption energy, specific capacity and Na diffusion barriers on monolayer phosphorene. ... More
Noble gas as a functional dopant in ZnO: Delocalization of the oxygen vacancy statesJan 01 2019Owing to fully occupied orbitals, noble gases are considered to be chemically inert and to have limited effect on materials properties under normal conditions. However, using first-principles calculations, we demonstrate herein that the insertion of noble ... More
Warm water deuterium fractionation in IRAS 16293-2422 - The high-resolution ALMA and SMA viewNov 28 2012Measuring the water deuterium fractionation in the inner warm regions of low-mass protostars has so far been hampered by poor angular resolution obtainable with single-dish ground- and space-based telescopes. Observations of water isotopologues using ... More
Subarcsecond resolution observations of warm water towards three deeply embedded low-mass protostarsMar 22 2012Water is present during all stages of star formation: as ice in the cold outer parts of protostellar envelopes and dense inner regions of circumstellar disks, and as gas in the envelopes close to the protostars, in the upper layers of circumstellar disks ... More
An invariant of link cobordisms from Khovanov homologyJun 28 2002Dec 23 2004In [Duke Math. J. 101 (1999) 359-426], Mikhail Khovanov constructed a homology theory for oriented links, whose graded Euler characteristic is the Jones polynomial. He also explained how every link cobordism between two links induces a homomorphism between ... More
Statistical and knowledge supported visualization of multivariate dataAug 31 2010In the present work we have selected a collection of statistical and mathematical tools useful for the exploration of multivariate data and we present them in a form that is meant to be particularly accessible to a classically trained mathematician. We ... More
Shared matings in $V_2$Dec 22 2016Jan 09 2017We give a new constructive method to prove existence of shared matings in the special class $V_2$ consisting of rational maps with a super-attracting $2$-cycle (up to M\"obius conjugacy). The proof does not use Thurston's Theorem on branched coverings ... More
Operator-valued pseudo-differential operators and the twisted index pairingNov 26 2010Nov 10 2011The notion of pseudo-differential operators with coefficients in a continuous trace algebra over a manifold are introduced and their index theory is studied. The algebra of principal symbols in this calculus provides an abstract Poincar\'e dual to the ... More
Another Proof of a Lemma by L. SheppNov 20 2014We give a new proof of a lemma by L. Shepp, that was used in connection to random coverings of a circle.
Inhomogeneous potentials, Hausdorff dimension and shrinking targetsNov 13 2017Oct 12 2018Generalising a construction of Falconer, we consider classes of $G_\delta$-subsets of $\mathbb{R}^d$ with the property that sets belonging to the class have large Hausdorff dimension and the class is closed under countable intersections. We relate these ... More
Random iterated function systems with smooth invariant densitiesMar 17 2009We consider some random iterated function systems on the interval and show that the invariant measure has density in $\mathcal{C}^\infty$. To prove this we use some techniques for contractions in cone metrics, applied to the transfer operator.
On the dependency of rubber friction on the normal force or load: theory and experimentDec 04 2015In rubber friction studies it is often observed that the kinetic friction coefficient {\mu} depends on the nominal contact pressure p. We discuss several possible origins of the pressure dependency of {\mu}: (a) saturation of the contact area (and friction ... More
Detection of glycolaldehyde towards the solar-type protostar NGC1333 IRAS2AFeb 03 2015Glycolaldehyde is a key molecule in the formation of biologically relevant molecules such as ribose. We report its detection with the Plateau de Bure interferometer towards the Class 0 young stellar object NGC1333 IRAS2A, which is only the second solar-type ... More
Influence of Behavioral Models on Multiuser Channel CapacityJan 05 2015Apr 09 2015In order to characterize the channel capacity of a wavelength channel in a wavelength-division multiplexed (WDM) system, statistical models are needed for the transmitted signals on the other wavelengths. For example, one could assume that the transmitters ... More
Hochschild cohomology of ring objects in monoidal categoriesMay 03 2016We define the Hochschild complex and cohomology of a ring object in a monoidal category enriched over abelian groups. We interpret the cohomology groups and prove that the cohomology ring is graded-commutative.
Growth and decay of discrete nonlinear Schroedinger breathers interacting with internal modes or standing-wave phononsFeb 11 2000We investigate the long-time evolution of weakly perturbed single-site breathers (localized stationary states) in the discrete nonlinear Schroedinger (DNLS) equation. The perturbations we consider correspond to time-periodic solutions of the linearized ... More
Reticulation-visible networksAug 21 2015Jun 25 2017Let $X$ be a finite set, $\mathcal N$ be a reticulation-visible network on $X$, and $\mathcal T$ be a rooted binary phylogenetic tree. We show that there is a polynomial-time algorithm for deciding whether or not $\mathcal N$ displays $\mathcal T$. Furthermore, ... More
Entire functions with Julia sets of positive measureApr 08 2009Let f be a transcendental entire function for which the set of critical and asymptotic values is bounded. The Denjoy-Carleman-Ahlfors theorem implies that if the set of all z for which |f(z)|>R has N components for some R>0, then the order of f is at ... More
Distance-dependent sign-reversal in the Casimir-Lifshitz torqueJan 03 2018The Casimir-Lifshitz torque between two biaxially polarizable anisotropic planar slabs is shown to exhibit a non-trivial sign-reversal in its rotational sense. The critical distance $a_c$ between the slabs that marks this reversal is characterized by ... More
Inverse semigroup C*-algebras associated with left cancellative semigroupsFeb 27 2012Mar 09 2012To each discrete left cancellative semigroup $S$ one may associate a certain inverse semigroup $I_l(S)$, often called the left inverse hull of $S$. We show how the full and the reduced C*-algebras of $I_l(S)$ are related to the full and reduced semigroup ... More
Newton maps as matings of cubic polynomialsAug 18 2014In this paper we prove existence of matings between a large class of renormalizable cubic polynomials with one fixed critical point and another cubic polynomial having two fixed critical points. The resulting mating is a Newton map. Our result is the ... More
Rolling friction for hard cylinder and sphere on viscoelastic solidAug 26 2010We calculate the friction force acting on a hard cylinder or spherical ball rolling on a flat surface of a viscoelastic solid. The rolling friction coefficient depends non-linearly on the normal load and the rolling velocity. For a cylinder rolling on ... More
A generalized finite element method for linear thermoelasticityApr 01 2016We propose and analyze a generalized finite element method designed for linear quasistatic thermoelastic systems with spatial multiscale coefficients. The method is based on the local orthogonal decomposition technique introduced by M{\aa}lqvist and Peterseim ... More
Stability of large scale chromomagnetic fields in the early universeJun 10 1998Sep 20 1998It is well known that Yang-Mills theory in vacuum has a perturbative instability to spontaneously form a large scale magnetic field (the Savvidy mechanism) and that a constant field is unstable so that a possible ground state has to be inhomogenous over ... More
The absolute continuity of the invariant measure of random iterated function systems with overlapsMar 12 2009We consider iterated function systems on the interval with random perturbation. Let $Y_\epsilon$ be uniformly distributed in $[1- \epsilon, 1 + \epsilon]$ and let $f_i \in C^{1+\alpha}$ be contractions with fixpoints $a_i$. We consider the iterated function ... More
Non-typical points for $β$-shiftsApr 27 2010Feb 08 2013We study sets of nontypical points under the map $f_\beta \mapsto \beta x $ mod 1, for non-integer $\beta$ and extend our results from [F\"arm, Persson, Schmeling, 2010] in several directions. In particular we prove that sets of points whose forward orbit ... More
A note on approximation of plurisubharmonic functionsSep 15 2016We extend a recent result of Avelin, Hed, and Persson about approximation of functions $u$ that are plurisubharmonic on a domain $\Omega$ and continuous on $\bar\Omega$, with functions that are plurisubharmonic on (shrinking) neighborhoods of $\bar\Omega$. ... More
Bernoulli Convolutions and 1D DynamicsJan 27 2015We describe a family $\phi_{\lambda}$ of dynamical systems on the unit interval which preserve Bernoulli convolutions. We show that if there are parameter ranges for which these systems are piecewise convex, then the corresponding Bernoulli convolution ... More
Rotationally-supported disks around Class I sources in Taurus: disk formation constraintsDec 19 2013(Abridged) Disks are observed around pre-main sequence stars, but how and when they form is still heavily debated. While disks around young stellar objects have been identified through thermal dust emission, spatially and spectrally resolved molecular ... More
On the elastic energy and stress correlation in the contact between elastic solids with randomly rough surfacesMay 06 2008When two elastic solids with randomly rough surfaces are brought in contact, a very inhomogeneous stress distribution sigma(x) will occur at the interface. Here I study the elastic energy and the correlation function <sigma(q)sigma(-q)>, where sigma(q) ... More
Multiscale techniques for parabolic equationsApr 30 2015We use the local orthogonal decomposition technique to derive a generalized finite element method for linear and semilinear parabolic equations with spatial multiscale diffusion coefficient. We consider nonsmooth initial data and a backward Euler scheme ... More
A Sparse and High-Order Accurate Line-Based Discontinuous Galerkin Method for Unstructured MeshesApr 06 2012Oct 05 2012We present a new line-based discontinuous Galerkin (DG) discretization scheme for first- and second-order systems of partial differential equations. The scheme is based on fully unstructured meshes of quadrilateral or hexahedral elements, and it is closely ... More
Discreteness-Induced Oscillatory Instabilities of Dark SolitonsNov 05 1998We reveal that even weak inherent discreteness of a nonlinear model can lead to instabilities of the localized modes it supports. We present the first example of an oscillatory instability of dark solitons, and analyse how it may occur for dark solitons ... More
Applying geometric K-cycles to fractional indicesNov 07 2012Apr 29 2014A geometric model for twisted $K$-homology is introduced. It is modeled after the Mathai-Melrose-Singer fractional analytic index theorem in the same way as the Baum-Douglas model of $K$-homology was modeled after the Atiyah-Singer index theorem. A natural ... More
Core Structure and Non-Abelian Reconnection of Defects in a Biaxial Nematic Spin-2 Bose-Einstein CondensateNov 29 2016We calculate the energetic structure of defect cores and propose controlled methods to imprint a nontrivially entangled vortex pair that undergoes non-Abelian vortex reconnection in a biaxial nematic spin-2 condensate. For a singular vortex, we find three ... More
Nearly Optimal Bounds for Distributed Wireless Scheduling in the SINR ModelApr 27 2011Apr 30 2014We study the wireless scheduling problem in the SINR model. More specifically, given a set of $n$ links, each a sender-receiver pair, we wish to partition (or \emph{schedule}) the links into the minimum number of slots, each satisfying interference constraints ... More
Wireless Capacity With Arbitrary Gain MatrixAug 04 2011Given a set of wireless links, a fundamental problem is to find the largest subset that can transmit simultaneously, within the SINR model of interference. Significant progress on this problem has been made in recent years. In this note, we study the ... More
On Fell bundles over inverse semigroups and their left regular representationsNov 09 2016We prove a version of Wordingham's theorem for left regular representations in the setting of Fell bundles of inverse semigroups and use this result to discuss the various associated cross sectional C*-algebras.
Rapid mixing of subset Glauber dynamics on graphs of bounded tree-widthFeb 17 2011Motivated by the `subgraphs world' view of the ferromagnetic Ising model, we develop a general approach to studying mixing times of Glauber dynamics based on subset expansion expressions for a class of graph polynomials. With a canonical paths argument, ... More
The Compact Discontinuous Galerkin (CDG) Method for Elliptic ProblemsFeb 13 2007Sep 15 2008We present a compact discontinuous Galerkin (CDG) method for an elliptic model problem. The problem is first cast as a system of first order equations by introducing the gradient of the primal unknown, or flux, as an additional variable. A standard discontinuous ... More
Anisotropic contribution to the van der Waals and the Casimir-Polder energies for CO$_2$ and CH$_4$ molecules near surfaces and thin filmsJun 04 2015In order to understand why carbon dioxide (CO$_2$) and methane (CH$_4$) molecules interact differently with surfaces, we investigate the Casimir-Polder energy of a linearly polarizable CO$_2$ molecule and an isotropically polarizable CH$_4$ molecule in ... More
Lifshitz interaction can promote ice growth at water-silica interfacesApr 05 2017At air-water interfaces, the Lifshitz interaction by itself does not promote ice growth. On the contrary, we find that the Lifshitz force promotes the growth of an ice film, up to 1-8 nm thickness, near silica-water interfaces at the triple point of water. ... More
A measure theoretic approach to linear inverse atmospheric dispersion problemsMay 28 2013Sep 17 2014Using measure theoretic arguments, we provide a general framework for describing and studying the general linear inverse dispersion problem where no a priori assumptions on the source function has been made. We investigate the source-sensor relationship ... More
Footprints and footprint analysis for atmospheric dispersion problemsSep 18 2014Footprint analysis, also known as the study of Influence areas, is a first order method for solving inverse atmospheric dispersion problems. We revisit the concept of footprints giving a rigorous definition of the concept (denoted posterior footprints ... More
The Spectrum of Volterra-type integration operators on generalized Fock spacesSep 04 2015We describe the spectrum of certain integration operators acting on general- ized Fock spaces.
On the semi-classical analysis of the groundstate energy of the Dirichlet Pauli operatorMay 13 2016Jun 02 2016We discuss the results of a recent paper by Ekholm, Kova\v{r}\'ik and Portmann in connection with a question of C. Guillarmou about the semiclassical expansion of the lowest eigenvalue of the Pauli operator with Dirichlet conditions. We exhibit connections ... More
On the asymptotics of the scenery flowSep 06 2013Various notions of "zooming in" on measures exist in the literature and the scenery flow is one of them. It is of interest to describe the joint asymptotics of the scenery flows generated by a measure and the measure transported by a local diffeomorphism. ... More
ALMA observations of the kinematics and chemistry of disc formationMay 06 2014May 12 2014Context: The R CrA cloud hosts a handful of Class 0/I low-mass young stellar objects. The chemistry and physics at scales $>500$ AU in this cloud are dominated by the irradiation from the nearby Herbig Be star R CrA. The luminous large-scale emission ... More
Imaging the water snowline in a protostellar envelope with H$^{13}$CO$^+$Jan 08 2018Snowlines are key ingredients for planet formation. Providing observational constraints on the locations of the major snowlines is therefore crucial for fully connecting planet compositions to their formation mechanism. Unfortunately, the most important ... More
A Study of Energy and Locality Effects using Space-filling CurvesJun 20 2016The cost of energy is becoming an increasingly important driver for the operating cost of HPC systems, adding yet another facet to the challenge of producing efficient code. In this paper, we investigate the energy implications of trading computation ... More
Metric Construction, Stopping Times and Path CouplingNov 08 2005Nov 22 2005In this paper we examine the importance of the choice of metric in path coupling, and the relationship of this to \emph{stopping time analysis}. We give strong evidence that stopping time analysis is no more powerful than standard path coupling. In particular, ... More
KAM tori in 1D random discrete nonlinear Schrödinger model?Jul 12 2010We suggest that KAM theory could be extended for certain infinite-dimensional systems with purely discrete linear spectrum. We provide empirical arguments for the existence of square summable infinite-dimensional invariant tori in the random discrete ... More
Space-Constrained Interval SelectionFeb 20 2012Mar 11 2015We study streaming algorithms for the interval selection problem: finding a maximum cardinality subset of disjoint intervals on the line. A deterministic 2-approximation streaming algorithm for this problem is developed, together with an algorithm for ... More
Vertex coloring acyclic digraphs and their corresponding hypergraphsJun 11 2007We consider vertex coloring of an acyclic digraph $\Gdag$ in such a way that two vertices which have a common ancestor in $\Gdag$ receive distinct colors. Such colorings arise in a natural way when bounding space for various genetic data for efficient ... More
Complete identification of alkali sites in ion conducting lithium silicate glasses: a computer study of ion dynamicsJan 14 2003Jul 09 2003The available sites for ions in a typical disordered ionic conductor are determined. For this purpose we devised a straightforward algorithm which via cluster analysis identifies these sites from long time ionic trajectories below the glass transition. ... More
Path Coupling Using Stopping Times and Counting Independent Sets and Colourings in HypergraphsJan 06 2005Apr 02 2005We give a new method for analysing the mixing time of a Markov chain using path coupling with stopping times. We apply this approach to two hypergraph problems. We show that the Glauber dynamics for independent sets in a hypergraph mixes rapidly as long ... More
Tensor-product coaction functorsDec 03 2018For a discrete group $G$, we develop a `$G$-balanced tensor product' of two coactions $(A,\delta)$ and $(B,\epsilon)$, which takes place on a certain subalgebra of the maximal tensor product $A\otimes_{\max} B$. Our motivation for this is that we are ... More
Control of Multi-Agent Systems with Finite Time Control Barrier Certificates and Temporal LogicAug 07 2018In this paper, a method to synthesize controllers using finite time convergence control barrier functions guided by linear temporal logic specifications for continuous time multi-agent dynamical systems is proposed. Finite time convergence to a desired ... More
Asynchronous Multi-Agent Primal-Dual OptimizationJun 07 2016We present a framework for asynchronously solving nonlinear optimization problems over networks of agents which are augmented by the presence of a centralized cloud computer. This framework uses a Tikhonov-regularized primal-dual approach in which the ... More
Empirical Big Data Research: A Systematic Literature MappingSep 10 2015Background: Big Data is a relatively new field of research and technology, and literature reports a wide variety of concepts labeled with Big Data. The maturity of a research field can be measured in the number of publications containing empirical results. ... More
Exotic group C*-algebras in noncommutative dualityNov 21 2012Aug 30 2013We show that for a locally compact group G there is a one-to-one correspondence between G-invariant weak*-closed subspaces E of the Fourier-Stieltjes algebra B(G) containing B_r(G) and quotients C*_E(G) of C*(G) which are intermediate between C*(G) and ... More
Modeling surface roughness scattering in metallic nanowiresJun 09 2015Sep 14 2015Ando's model provides a rigorous quantum-mechanical framework for electron-surface roughness scattering, based on the detailed roughness structure. We apply this method to metallic nanowires and improve the model introducing surface roughness distribution ... More
Analytic solution of Ando's surface roughness model with finite domain distribution functionsSep 29 2015Ando's surface roughness model is applied to metallic nanowires and extended beyond small roughness size and infinite barrier limit approximations for the wavefunction overlaps, such as the Prange-Nee approximation. Accurate and fast simulations can still ... More
On the speed of convergence of Newton's method for complex polynomialsFeb 11 2012Aug 25 2014We investigate Newton's method for complex polynomials of arbitrary degree $d$, normalized so that all their roots are in the unit disk. For each degree $d$, we give an explicit set $\mathcal{S}_d$ of $3.33d\log^2 d(1 + o(1))$ points with the following ... More
Latent modeling of flow cytometry cell populationsFeb 13 2015Flow cytometry is a widespread single-cell measurement technology with a multitude of clinical and research applications. Interpretation of flow cytometry data is hard; the instrumentation is delicate and can not render absolute measurements, hence samples ... More
Scheduling Refresh Queries for Keeping Results from a SPARQL Endpoint Up-to-Date (Extended Version)Aug 29 2016Many datasets change over time. As a consequence, long-running applications that cache and repeatedly use query results obtained from a SPARQL endpoint may resubmit the queries regularly to ensure up-to-dateness of the results. While this approach may ... More
Voluntary Retreat for Decentralized Interference Reduction in Robot SwarmsDec 05 2018In densely-packed robot swarms operating in confined regions, spatial interference -- which manifests itself as a competition for physical space -- forces robots to spend more time navigating around each other rather than performing the primary task. ... More
Permissive Barrier Certificates for Safe Stabilization Using Sum-of-squaresFeb 24 2018Motivated by the need to simultaneously guarantee safety and stability of safety-critical dynamical systems, we construct permissive barrier certificates in this paper that explicitly maximize the region where the system can be stabilized without violating ... More
Fast simulated annealing in $\R^d$ and an application to maximum likelihood estimationSep 13 2006Using classical simulated annealing to maximise a function $\psi$ defined on a subset of $\R^d$, the probability $\p(\psi(\theta\_n)\leq \psi\_{\max}-\epsilon)$ tends to zero at a logarithmic rate as $n$ increases; here $\theta\_n$ is the state in the ... More
Smale space C*-algebras have nonzero projectionsJan 29 2019The main result of the present paper is that the stable and unstable C*-algebras associated to a mixing Smale space always contain nonzero projections. This gives a positive answer to a question of the first listed author and Karen Strung and has implications ... More
Heat transfer between weakly coupled systems: Graphene on a-SiO2Jul 22 2010We study the heat transfer between weakly coupled systems with flat interface. We present a simple analytical result which can be used to estimate the heat transfer coefficient. As an application we consider the heat transfer between graphene and amorphous ... More
Resonant photon tunneling enhancement of the radiative heat transferMay 23 2006We study the dependence of the heat transfer between two semi-infinite solids on the dielectric properties of the bodies. We show that the heat transfer at short separation between the solids may increase by many order of magnitude when the surfaces are ... More
The effect of surface roughness on the adhesion of elastic solidsApr 10 2001We study the influence of surface roughness on the adhesion of elastic solids. Most real surfaces have roughness on many different length scales, and this fact is taken into account in our analysis. We consider in detail the case when the surface roughness ... More
The Puzzling Collapse of Electronic Sliding Friction on a Superconductor SurfaceMay 05 1998In a recent paper [Phys. Rev. Lett. 80 (1998) 1690], Krim and coworkers have observed that the friction force, acting on a thin physisorbed layer of N_2 sliding on a lead film, abruptly decreases by a factor of ~2 when the lead film is cooled below its ... More
Viscoelastic contact mechanics between randomly rough surfacesJun 27 2014We present exact numerical results for the friction force and the contact area for a viscoelastic solid (rubber) in sliding contact with hard, randomly rough substrates. The rough surfaces are self-affine fractal with roughness over several decades in ... More
Theory of the leak-rate of sealsMay 06 2008Seals are extremely useful devices to prevent fluid leakage. However, the exact mechanism of roughness induced leakage is not well understood. We present a theory of the leak-rate of seals, which is based on percolation theory and a recently developed ... More
Contact mechanics: contact area and interfacial separation from small contact to full contactMar 28 2008We present a molecular dynamics study of the contact between a rigid solid with a randomly rough surface and an elastic block with a flat surface. The numerical calculations mainly focus on the contact area and the interfacial separation from small contact ... More
Resonant photon tunneling enhancement of the van der Waals frictionMay 22 2006We study the van der Waals friction between two flat metal surfaces in relative motion. For good conductors we find that normal relative motion gives a much larger friction than for parallel relative motion. The friction may increase by many order of ... More
Surfaces with triple pointsOct 16 2000In this paper we compute upper bounds for the number of ordinary triple points on a hypersurface in $P^3$ and give a complete classification for degree six (degree four or less is trivial, and five is elementary). But the real purpose is to point out ... More
Approximation and Bounded Plurisubharmonic Exhaustion Functions Beyond Lipschitz DomainsOct 26 2012Using techniques from the analysis of PDEs to study the boundary behaviour of functions on domains with low boundary regularity, we extend results by Forna\ae{}ss-Wiegerinck (1989) on plurisubharmonic approximation and by Demailly (1987) on the existence ... More
Reverse Cauchy--Schwarz inequalities for positive C*-valued sesquilinear formsMay 25 2009We prove two new reverse Cauchy--Schwarz inequalities of additive and multiplicative types in a space equipped with a positive sesquilinear form with values in a C*-algebra. We apply our results to get some norm and integral inequalities. As a consequence, ... More
Multiscale differential Riccati equations for linear quadratic regulator problemsJun 14 2017Jun 18 2018We consider approximations to the solutions of differential Riccati equations in the context of linear quadratic regulator problems, where the state equation is governed by a multiscale operator. Similarly to elliptic and parabolic problems, standard ... More
3D sub-nanoscale imaging of unit cell doubling due to octahedral tilting and cation modulation in strained perovskite thin filmsOct 17 2018Oct 24 2018Determining the 3-dimensional crystallography of a material with sub-nanometre resolution is essential to understanding strain effects in epitaxial thin films. A new scanning transmission electron microscopy imaging technique is demonstrated that visualises ... More
Massive MIMO with 1-bit ADCApr 30 2014We investigate massive multiple-input-multiple output (MIMO) uplink systems with 1-bit analog-to-digital converters (ADCs) on each receiver antenna. Receivers that rely on 1-bit ADC do not need energy-consuming interfaces such as automatic gain control ... More
On Hardy q-inequalitiesMar 25 2014Some q-analysis variants of Hardy type inequalities of the form \int_0^b (x^{\alpha-1} \int_0^x t^{-\alpha} f(t) d_qt)^p d_qx \leq C \int_0^b f^p(t) d_qt with sharp constant C are proved and discussed. A similar result with the Riemann-Liouville operator ... More
Quantum Vavilov-Cherenkov radiation from shearing two transparent dielectric platesNov 20 2015Dec 11 2015Using a fully relativistic theory we study the quantum Vavilov-Cherenkov radiation and quantum friction occurring during relative sliding of the two transparent dielectric plates with the refractive index $n$. These phenomena occur above the threshold ... More
Surface roughness induced electric field enhancement and triboluminescenceJul 12 2010The separation of solids in adhesive contact, or the fracture of solid bodies, often results in the emission of high energy photons, e.g., visible light and X-rays. This is believed to be related to charge separation. We propose that the emission of high ... More
Adsorbate vibrational mode enhancement of radiative heat transferMay 23 2006We show that the radiative heat transfer between two solid surfaces at short separation may increase by many order of magnitude when the surfaces are covered by adsorbates. In this case the heat transfer is determined by resonant photon tunneling between ... More
Non-contact friction between nanostructuresMay 22 2006We calculate the van der Waals friction between two semi-infinite solids in normal relative motion and find a drastic difference in comparison with the parallel relative motion. The case of the good conductors is investigated in details both within the ... More
Quantum field theory of the van der Waals frictionMay 19 2006The van der Waals friction between two semi-infinite solids, and between a small neutral particle and semi-infinite solid is reconsidered on the basis of thermal quantum field theory in the Matsubara formulation. The calculation of the friction to linear ... More
Comment on "Fully covariant radiation force on a polarizable particle"May 11 2014Jul 22 2014Recently Pieplow and Henkel (PH) (NJP \textbf{15} (2013) 023027) presented a new fully covariant theory of the Casimir friction force acting on small neutral particle moving parallel to flat surface. We compare results of this theory with results which ... More
Near-field radiative heat transfer and van der Waals friction between closely spaced graphene and amorphous SiO$_2$Dec 23 2010We study the radiative heat transfer and the van der Waals friction between graphene and an amorphous SiO$_2$ substrate. We study the surface phonon-polaritons contribution to the low-field mobility as a function of temperature and of carrier density. ... More
Fluid squeeze-out between solids with rough surfacesApr 07 2010We study the fluid squeeze-out from the interface between an elastic solid with a flat surface and a rigid solid with a randomly rough surface. As an application we discuss fluid squeeze-out between a tire tread block and a road surface. Some implications ... More
Frictional Drag induced in Low- Dimensional Systems by Brownian Motion of Ions in Liquid FlowOct 28 2009Oct 30 2009We study the frictional drag force in low-dimensional systems (2D-electron and 2D-liquid systems) mediated by a fluctuating electromagnetic field which originate from Brownian motion of ions in liquid. The analysis is focused on the [2D-system-2D-system], ... More
Comment on "No quantum friction between uniformly moving plates"Apr 23 2009May 14 2009Quite recently Philbin et al present new theory of the van der Waals friction at zero temperature. Contrary to the previous theory they claimed that there is no "quantum friction" due to quantum fluctuation of the electromagnetic field between two parallel ... More