Results for "Magnus V. Persson"

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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
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 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
The ALMA-PILS survey: The sulphur connection between protostars and comets: IRAS 16293-2422 B and 67P/Churyumov-GerasimenkoFeb 08 2018The evolutionary past of our Solar System can be pieced together by comparing analogous low-mass protostars with remnants of our Protosolar Nebula - comets. Sulphur-bearing molecules may be unique tracers of the joint evolution of the volatile and refractory ... More
Atomistic modelling of friction of Cu and Au nanoparticles adsorbed on grapheneFeb 26 2013Nov 22 2013We present classical molecular dynamics calculations of the behavior of copper and gold nanoparticles on a graphene sheet, sheared with a constant applied force $F_{\rm a}$. The force $F_{\rm s}$ acting on the particle from the substrate depends on the ... More
Generalized phonon-assisted Zener tunneling in indirect semiconductors with non-uniform electric fields : a rigorous approachApr 19 2011Jun 24 2011A general framework to calculate the Zener current in an indirect semiconductor with an externally applied potential is provided. Assuming a parabolic valence and conduction band dispersion, the semiconductor is in equilibrium in the presence of the external ... More
A Triple Protostar System Formed via Fragmentation of a Gravitationally Unstable DiskOct 26 2016Binary and multiple star systems are a frequent outcome of the star formation process, and as a result, almost half of all sun-like stars have at least one companion star. Theoretical studies indicate that there are two main pathways that can operate ... More
Band Gap Modulation of SrTiO3 upon CO2 AdsorptionMay 15 2017CO2 chemisorption on SrTiO3(001) surfaces is studied using ab initio calculations in order to establish new chemical sensing mechanisms. We find that CO2 adsorption opens the material band gap, however, while the adsorption on the TiO2-terminated surface ... 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
Velocity dependence of friction of confined polymersNov 18 2009We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate, and (b) polymer sliding on polymer. We discuss ... More
Effective Viscosity of Confined HydrocarbonsJan 24 2012We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity \mu eff for nanometer-thin films depends linearly on the logarithm ... 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
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
The Pimsner-Voiculescu sequence for coactions of compact Lie groupsApr 25 2010Mar 02 2011The Pimsner-Voiculescu sequence is generalized to a Pimsner-Voiculescu tower describing the $KK$-category equivariant with respect to coactions of a compact Lie group satisfying the Hodgkin condition. A dual Pimsner-Voiculescu tower is used to show that ... 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
The role of grain boundary scattering in reducing the thermal conductivity of polycrystalline XNiSn (X = Hf, Zr, Ti) half-Heusler alloysJul 13 2017Oct 11 2017Thermoelectric application of half-Heusler compounds suffers from their fairly high thermal conductivities. Insight into how effective various scattering mechanisms are in reducing the thermal conductivity of fabricated XNiSn compounds (X = Hf, Zr, Ti, ... 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.
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.
Tailoring electronic properties of multilayer phosphorene by siliconizationOct 22 2017Dec 04 2017Controlling a thickness dependence of electronic properties for two-dimensional (2d) materials is among primary goals for their large-scale applications. Herein, employing a first-principles computational approach, we predict that Si interaction with ... 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
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
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.
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
Enabling accurate first-principle calculations of electronic properties with a corrected k.p schemeJul 05 2016Mar 22 2017A computationally inexpensive k.p-based interpolation scheme is developed that can extend the eigenvalues and momentum matrix elements of a sparsely sampled k-point grid into a densely sampled one. Dense sampling, often required to accurately describe ... More
Plurisubharmonic Approximation and Boundary Values of Plurisubharmonic FunctionsNov 05 2012We study the problem of approximating plurisubharmonic functions on a bounded domain $\Omega$ by continuous plurisubharmonic functions defined on neighborhoods of $\bar\Omega$. It turns out that this problem can be linked to the problem of solving a Dirichlet ... 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
Contact mechanics: relation between interfacial separation and loadJun 19 2007I study the contact between a rigid solid with a randomly rough surface and an elastic block with a flat surface. I derive a relation between the (average) interfacial separation $u$ and the applied normal squeezing pressure $p$. I show that for non-adhesive ... More
Rubber friction and tire dynamicsJul 16 2010We propose a simple rubber friction law, which can be used, e.g., in models of tire (and vehicle) dynamics. The friction law is tested by comparing numerical results to the full rubber friction theory (B.N.J. Persson, J. Phys.: Condensed Matter 18, 7789 ... More
Rubber friction: role of the flash temperatureMay 10 2006When a rubber block is sliding on a hard rough substrate, the substrate asperities will exert time-dependent deformations of the rubber surface resulting in viscoelastic energy dissipation in the rubber, which gives a contribution to the sliding friction. ... More
On Shrinking Targets for Piecewise Expanding Interval MapsJun 26 2014May 26 2015For a map $T \colon [0,1] \to [0,1]$ with an invariant measure $\mu$, we study, for a $\mu$-typical $x$, the set of points $y$ such that the inequality $|T^n x - y| < r_n$ is satisfied for infinitely many $n$. We give a formula for the Hausdorff dimension ... 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
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
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
Independent resolutions for totally disconnected dynamical systems II: C*-algebraic caseApr 24 2014We develop the notion of independent resolutions for crossed products attached to totally disconnected dynamical systems. If such a crossed product admits an independent resolution of finite length, then its K-theory can be computed (at least in principle) ... 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
Independent resolutions for totally disconnected dynamical systems I: Algebraic caseApr 24 2014Sep 22 2014This is the first out of two papers on independent resolutions for totally disconnected dynamical systems. In the present paper, we discuss independent resolutions from an algebraic point of view. We also present applications to group homology and cohomology. ... 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.
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
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.
Lack of diamagnetism and the Little-Parks effectMay 19 2014When a superconducting sample is submitted to a sufficiently strong external magnetic field, the superconductivity of the material is lost. In this paper we prove that this effect does not, in general, take place at a unique value of the external magnetic ... 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
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
Coaction functorsMay 13 2015Mar 31 2016A certain type of functor on a category of coactions of a locally compact group on C*-algebras is introduced and studied. These functors are intended to help in the study of the crossed-product functors that have been recently introduced in relation to ... 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
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
Hecke C*-algebras and semidirect productsNov 17 2006Apr 11 2008We analyze Hecke pairs (G,H) and the associated Hecke algebra when G is a semidirect product N x Q and H = M x R for subgroups M of N and R of Q with M normal in N. Conditions are given in terms of N, Q, M, and R which are equivalent to the Hecke condition ... More
Generalised Hecke algebras and C^*-completionsSep 14 2006Oct 03 2007For a Hecke pair $(G, H)$ and a finite-dimensional representation $\sigma$ of $H$ on $V_\sigma$ with finite range we consider a generalised Hecke algebra $\H_\sigma(G, H)$, which we study by embedding the given Hecke pair in a Schlichting completion $(G_\sigma, ... More
Exact large ideals of B(G) are downward directedAug 02 2015Mar 29 2016We prove that if E and F are large ideals of B(G) for which the associated coaction functors are exact, then the same is true for the intersection of E and F. We also give an example of a coaction functor whose restriction to the maximal coactions does ... More
Cavity electromagnetically induced transparency and all-optical switching using ion Coulomb crystalsFeb 24 2011The control of one light field by another, ultimately at the single photon level, is a challenging task which has numerous interesting applications within nonlinear optics and quantum information science. Due to the extremely weak direct interactions ... More
Quantum nonlinear lattices and coherent state vectorsJan 13 2000Quantized nonlinear lattice models are considered for two different classes, boson and fermionic ones. The quantum discrete nonlinear Schroedinger model (DNLS) is our main objective, but its so called modified discrete nonlinear (MDNLS) version is also ... More
Dynamic Iterative PursuitJun 12 2012For compressive sensing of dynamic sparse signals, we develop an iterative pursuit algorithm. A dynamic sparse signal process is characterized by varying sparsity patterns over time/space. For such signals, the developed algorithm is able to incorporate ... More
Combined modeling of sparse and dense noise for improvement of Relevance Vector MachineJan 12 2015Using a Bayesian approach, we consider the problem of recovering sparse signals under additive sparse and dense noise. Typically, sparse noise models outliers, impulse bursts or data loss. To handle sparse noise, existing methods simultaneously estimate ... More
Trends in Ferromagnetism in Mn doped dilute III-V alloys from a density functional perspectiveMay 12 2009Mn doping in dilute III-V alloys has been examined as a route to enhance ferromagnetic stability. Strong valence band bowing is expected at the dilute limit, implying a strong modification of the ferromagnetic stability upon alloying, with even an increase ... 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
Finite element convergence for the time-dependent Joule heating problem with mixed boundary conditionsJan 30 2018We prove strong convergence for a large class of finite element methods for the time-dependent Joule heating problem in three spatial dimensions with mixed boundary conditions on Lipschitz domains. We consider conforming subspaces for the spatial discretization ... More
Estimation of mass thickness response of embedded aggregated silica nanospheres from high angle annular dark-field scanning transmission electron micrographsAug 27 2013In this study we investigate the functional behavior of the intensity in high-angle annular dark field (HAADF) scanning transmission electron micrograph (STEM) images. The model material is a silica particle (20 nm) gel at 5 wt%. By assuming that the ... More
Near-field radiative heat transfer between closely spaced graphene and amorphous SiO$_2$Sep 02 2014We study the near-field radiative energy transfer between graphene and an amorphous SiO$_2$ substrate. In comparison with the existing theories of near-field radiative heat transfer our theory takes into account that the free carriers in graphene are ... More
Adhesion between elastic solids with randomly rough surfaces: comparison of analytical theory with molecular dynamics simulationsDec 22 2011The adhesive contact between elastic solids with randomly rough, self affine fractal surfaces is studied by molecular dynamics (MD) simulations. The interfacial binding energy obtained from the simulations of nominally flat and curved surfaces is compared ... More
Fluid squeeze-out between rough surfaces: comparison of theory with experimentFeb 07 2011We study the time dependency of the (average) interfacial separation between an elastic solid with a flat surface and a rigid solid with a randomly rough surface, squeezed together in a fluid. We use an analytical theory describing the fluid flow factors, ... More
Casimir-Lifshitz forces and radiative heat transfer between moving bodiesMay 24 2010Dec 23 2010Recently Philbin et al. (New J. Phys. 11 (2009) 033035; arXiv:0904.2148v3) presented a new theory of the van der Waals friction. Contrary to the previous theories they claimed that there is no "quantum friction" at zero temperature. We show that this ... More
Radiative heat transfer between nanostructuresMay 22 2006We simplify the formalism of Polder and Van Hove [Phys.Rev.B {\bf 4}, 3303(1971)], which was developed to calculate the heat transfer between macroscopic and nanoscale bodies of arbitrary shape, dispersive and adsorptive dielectric properties. In the ... More
Theory of adhesion: role of surface roughnessMay 13 2014We discuss how surface roughness influence the adhesion between elastic solids. We introduce a Tabor number which depends on the length scale or magnification, and which gives information about the nature of the adhesion at different length scales. We ... More
Theory of the interaction forces and the heat transfer between moving bodies mediated by the fluctuating electromagnetic fieldJul 07 2008May 05 2010Within the framework of unified approach we study the Casimir-Lifshitz interaction, the van der Waals friction force and the radiative heat transfer at nonequilibrium conditions, when the interacting bodies are at different temperatures, and they move ... More
Van der Waals Frictional Drag induced by Liquid Flow in Low- Dimensional SystemsJul 07 2008We study the van der Waals frictional drag force induced by liquid flow in low-dimensional systems (2D and 1D electron systems, and 2D and 1D channels with liquid). We find that for both 1D and 2D systems, the frictional drag force induced by liquid flow ... More
Frictional drag between quantum wells mediated by fluctuating electromagnetic fieldMay 22 2006We use the theory of the fluctuating electromagnetic field to calculate the frictional drag between nearby two-and three dimensional electron systems. The frictional drag results from coupling via a fluctuating electromagnetic field, and can be considered ... More
Field Galaxy Evolution Since Z~1 from a Sample of QSO Absorption-Selected GalaxiesOct 06 1994We present some of the results of a large survey aimed at establishing the properties of galaxies selected by their having produced detectable Mg~II $\lambda\lambda 2796$, 2803 absorption in the spectra of background QSOs. The present sample covers the ... More
Automatic Observer Script for StarCraft: Brood War Bot Games (technical report)May 01 2015This short report describes an automated BWAPI-based script developed for live streams of a StarCraft Brood War bot tournament, SSCAIT. The script controls the in-game camera in order to follow the relevant events and improve the viewer experience. We ... 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
Leak-rate of seals: comparison of theory with experimentApr 20 2009Seals are extremely useful devices to prevent fluid leakage. We present experimental results for the leak-rate of rubber seals, and compare the results to a novel theory, which is based on percolation theory and a recently developed contact mechanics ... More
Adsorbate induced enhancement of electrostatic non-contact frictionMay 22 2006We study the non-contact friction between an atomic force microscope tip and a metal substrate in the presence of bias voltage. The friction is due to energy losses in the sample created by the electromagnetic field from the oscillating charges induced ... More
Role of semi core levels in determining the band-gaps of semiconductors: First-principles calculations with model HamiltoniansJun 04 2007First principle calculations based on LDA/GGA approximation for the exchange functional underestimate the position of the semi core 3d levels in GaX (X = N, P and As) semiconductors. A self-interaction correction scheme within the LDA+U/GGA+U approximation ... More
Multiscale differential Riccati equations for linear quadratic regulator problemsJun 14 2017We 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