Results for "Matthias A. Müller"

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Economic MPC using a Cyclic Horizon with Application to Networked Control SystemsFeb 21 2019In this paper, we analyze an economic model predictive control scheme with terminal region and cost, where the system is optimally operated in a certain subset of the state space. The predictive controller operates with a cyclic horizon, which means that ... More
Economic MPC using a Cyclic Horizon with Application to Networked Control SystemsFeb 21 2019Jun 04 2019In this paper, we analyze an economic model predictive control scheme with terminal region and cost, where the system is optimally operated in a certain subset of the state space. The predictive controller operates with a cyclic horizon, which means that ... More
Data-Driven Model Predictive Control with Stability and Robustness GuaranteesJun 11 2019We propose a robust data-driven model predictive control (MPC) scheme to control linear time-invariant (LTI) systems. The scheme uses an implicit model description based on behavioral systems theory and past measured trajectories. In particular, it does ... More
Confined structures of least bending energyAug 12 2013In this paper we study a constrained minimization problem for the Willmore functional. For prescribed surface area we consider smooth embeddings of the sphere into the unit ball. We evaluate the dependence of the the minimal Willmore energy of such surfaces ... More
Anisotropic particles near surfaces: Self-propulsion and frictionOct 28 2015Nov 04 2015We theoretically study the phenomenon of self-propulsion through Casimir forces in thermal non-equilibrium. Using fluctuational electrodynamics, we derive a formula for the self-propulsion force for an arbitrary small object in two scenarios, i) for the ... More
How to Attack the NP-complete Dag Realization Problem in PracticeMar 16 2012We study the following fundamental realization problem of directed acyclic graphs (dags). Given a sequence S:=(a_1,b_1),...,(a_n, b_n) with a_i, b_i in Z_0^+, does there exist a dag (no parallel arcs allowed) with labeled vertex set V:= {v_1,...,v_n} ... More
Spin-polarizing interferometric beam splitter for free electronsJul 29 2016A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field, splitting the beam ... More
Kapitza-Dirac scattering of electrons from a bichromatic standing laser waveMar 12 2015Aug 05 2016Coherent scattering of an electron beam by the Kapitza-Dirac effect from a standing laser wave which comprises two frequency components is studied. To this end, the Schr\"odinger equation is solved numerically with a suitable ponderomotive potential. ... More
Relative Entropy Bounds on Quantum, Private and Repeater CapacitiesApr 12 2016We find a strong-converse bound on the private capacity of a quantum channel assisted by unlimited two-way classical communication. The bound is based on the max-relative entropy of entanglement and its proof uses a new inequality for the sandwiched R\'{e}nyi ... More
Uniform sampling of undirected and directed graphs with a fixed degree sequenceDec 03 2009Mar 05 2010Many applications in network analysis require algorithms to sample uniformly at random from the set of all graphs with a prescribed degree sequence. We present a Markov chain based approach which converges to the uniform distribution of all realizations ... More
Controlling electron spin dynamics in bichromatic Kapitza-Dirac scattering by the laser field polarizationJan 21 2017May 21 2017Spin-dependent Kapitza-Dirac scattering of electron beams from counterpropagating bichromatic laser waves in various polarization geometries is studied. The corresponding scattering probabilities are obtained by analytical and numerical solutions of the ... More
Spin-polarizing interferometric beam splitter for free electronsJul 29 2016Feb 03 2017A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field, splitting the beam ... More
Multiferroic magnetic spirals induced by random magnetic exchangesOct 03 2016Oct 19 2016Multiferroism can originate from the breaking of inversion symmetry caused by magnetic-spiral order. The usual mechanism for stabilizing a magnetic spiral is competition between magnetic exchange interactions differing by their range and sign, such as ... More
Multiferroic magnetic spirals induced by random magnetic exchangesOct 03 2016Nov 14 2016Multiferroism can originate from the breaking of inversion symmetry caused by magnetic-spiral order. The usual mechanism for stabilizing a magnetic spiral is competition between magnetic exchange interactions differing by their range and sign, such as ... More
Multiferroic magnetic spirals induced by random magnetic exchangesOct 03 2016Multiferroism can originate from the breaking of inversion symmetry caused by magnetic-spiral order. The usual mechanism for stabilizing a magnetic spiral is competition between magnetic exchange interactions differing by their range and sign, such as ... More
Quantum Zeno Dynamics through stochastic protocolsJul 29 2016Quantum Zeno Dynamics is the phenomenon that the observation or strong driving of a quantum system can freeze its dynamics to a subspace, effectively truncating the Hilbert space of the system. It represents the quantum version of the famous flying arrow ... More
Gerbil: A Fast and Memory-Efficient $k$-mer Counter with GPU-SupportJul 22 2016A basic task in bioinformatics is the counting of $k$-mers in genome strings. The $k$-mer counting problem is to build a histogram of all substrings of length $k$ in a given genome sequence. We present the open source $k$-mer counting software Gerbil ... More
SADA: Semantic Adversarial Diagnostic Attacks for Autonomous ApplicationsDec 05 2018Apr 05 2019One major factor impeding more widespread adoption of deep neural networks (DNNs) is their issues with robustness, which is essential for safety critical applications such as autonomous driving. This has motivated much recent work on adversarial attacks ... More
SADA: Semantic Adversarial Diagnostic Attacks for Autonomous ApplicationsDec 05 2018One major factor impeding more widespread adoption of deep neural networks (DNNs) is their issues with robustness, which is essential for safety critical applications such as autonomous driving. This has motivated much recent work on adversarial attacks ... More
Stochastic quantum Zeno-based detection of noise correlationsAug 20 2016A system under constant observation is practically freezed to the measurement subspace. If the system driving is a random classical field, the survival probability of the system in the subspace becomes a random variable described by the Stochastic Quantum ... More
Wind Turbine Model and Observer in Takagi-Sugeno Model StructureJan 31 2014Based on a reduced-order, dynamic nonlinear wind turbine model in Takagi-Sugeno (TS) model structure, a TS state observer is designed as a disturbance observer to estimate the unknown effective wind speed. The TS observer model is an exact representation ... More
Noise-robust quantum sensing via optimal multi-probe spectroscopyJan 30 2018The dynamics of quantum systems are unavoidably influenced by their environment and in turn observing a quantum system (probe) can allow one to measure its environment: Measurements and controlled manipulation of the probe such as dynamical decoupling ... More
Einstein relation for random walk in a one-dimensional percolation modelDec 27 2018We consider random walks on the infinite cluster of a conditional bond percolation model on the infinite ladder graph. In a companion paper, we have shown that if the random walk is pulled to the right by a positive bias $\lambda > 0$, then its asymptotic ... More
Constraining dark energy via baryon acoustic oscillations in the (an)isotropic light-cone power spectrumMay 02 2007Oct 13 2008The measurement of the scale of the baryon acoustic oscillations (BAO) in the galaxy power spectrum as a function of redshift is a promising method to constrain the equation-of-state parameter of the dark energy w. To measure the scale of the BAO precisely, ... More
Heat radiation and transfer for point particles in arbitrary geometriesJun 23 2017Oct 04 2017We study heat radiation and heat transfer for pointlike particles in a system of other objects. Starting from exact many-body expressions found from scattering theory and fluctuational electrodynamics, we find that transfer and radiation for point particles ... More
Depth-controlled Bessel beamsJul 08 2016We present a ring aperture with independently switchable segments for the three-dimensional control of quasi propagation invariant beams. We demonstrate that our liquid crystal design concept preserves coherence and generates the Bessel beam structure. ... More
Resonances in the current-voltage characteristics of a dissipative Josephson junctionAug 10 1995The I-V characteristics of a Josephson junction shunted by an Ohmic resistor shows sharp peaks when levels in neighbouring wells are crossing. We consider the shape and size of these peaks using a double-well model where the wells are given in parabolic ... More
Predictions for deeply virtual Compton scattering on a spin-one targetFeb 28 2002We consider hard leptoproduction of a photon on a spin-one target and give the general azimuthal angular dependence of the differential cross section. Furthermore, we estimate the beam spin asymmetry for an unpolarized deuteron target at HERMES.
On stability of the Kasner solution in quadratic gravityMar 09 2016May 31 2016We consider dynamics of a flat anisotropic Universe filled by a perfect fluid near a cosmological singularity in quadratic gravity. Two possible regimes are described -- the Kasner anisotropic solution and an isotropic "vacuum radiation" solution which ... More
Josephson relation for disordered superfluidsSep 24 2014Feb 10 2015The Josephson sum rule relates the superfluid density to the condensate order parameter, via the infrared residue of the single-particle Green's function. We establish an effective Josephson relation for disordered condensates valid upon ensemble averaging. ... More
Baryonic Strangeness and Related Susceptibilities in QCDMay 30 2006The ratios of off-diagonal to diagonal conserved charge susceptibilities e.g., chi_{BS}/chi_{S}, chi_{QS}/chi_{S}, related to the quark flavor susceptibilities, have proven to be discerning probes of the flavor carrying degrees of freedom in hot strongly ... More
Deeply virtual Compton scattering off nucleiFeb 02 2003Feb 05 2003We consider the hard leptoproduction of a photon off nuclei up to spin-1. As a new result we present here the general azimuthal angular dependence of the differential cross section for a spin-1 target. Its twist-two Fourier coefficients of the interference ... More
Optimal acceptance sampling for modules F and F1 of the European Measuring Instruments DirectiveJan 15 2019Mar 28 2019Acceptance sampling plans offered by ISO 2859-1 are far from optimal under the conditions for statistical verification in modules F and F1 as prescribed by Annex II of the Measuring Instruments Directive (MID) 2014/32/EU, resulting in sample sizes that ... More
Higher twist jet broadening and classical propagationMay 08 2007Feb 25 2008The transverse broadening of jets produced in deep-inelastic scattering (DIS) off a large nucleus is studied in the collinear limit. A class of medium enhanced higher twist corrections are re-summed to calculate the transverse momentum distribution of ... More
Vortex dynamics in disordered type-II superconductorsMay 23 1995A field theoretical method is developed which permits us to study the dynamics of vortices in disordered environments. In particular, we obtain a self-consistent system of equations for disorder averaged quantities. Making use of a Hartree-type approximation, ... More
Optimal acceptance sampling for modules F and F1 of the European Measuring Instruments DirectiveJan 15 2019Acceptance sampling plans offered by ISO 2859-1 are far from optimal under the conditions for statistical verification in modules F and F1 as prescribed by Annex II of the Measuring Instruments Directive (MID) 2014/32/EU, resulting in sample sizes that ... More
Local Equation of State and Velocity Distributions of a Driven Granular GasFeb 04 2004Jul 07 2004We present event-driven simulations of a granular gas of inelastic hard disks with incomplete normal restitution in two dimensions between vibrating walls (without gravity). We measure hydrodynamic quantities such as the stress tensor, density and temperature ... More
Advances in sequential measurement and control of open quantum systemsNov 13 2018Novel concepts, perspectives and challenges in measuring and controlling an open quantum system via sequential schemes are shown. In particular, we discuss how protocols, relying both on repeated quantum measurements and dynamical decoupling control pulses, ... More
Sim4CV: A Photo-Realistic Simulator for Computer Vision ApplicationsAug 19 2017Mar 24 2018We present a photo-realistic training and evaluation simulator (Sim4CV) with extensive applications across various fields of computer vision. Built on top of the Unreal Engine, the simulator integrates full featured physics based cars, unmanned aerial ... More
Diffusion of gelation clusters in the Zimm modelMar 27 2003Oct 09 2003Starting from a Zimm model we study selfdiffusion in a solution of crosslinked monomers. We focus on the effects of the hydrodynamic interaction on the dynamics and the critical behaviour at the sol-gel-point. Hydrodynamic interactions cause the clusters' ... More
General Bayesian theories and the emergence of the exclusivity principleJan 31 2019Feb 07 2019We construct a general Bayesian framework that can be used to organize beliefs and to update them based on outcomes of experiments. The framework includes classical and quantum Bayesian inference, as well as other alternative models of Bayesian reasoning ... More
General Bayesian theories and the emergence of the exclusivity principleJan 31 2019Mar 28 2019We construct a general Bayesian framework that can be used to organize beliefs and to update them when new information becomes available. The framework includes classical, quantum, and other alternative models of Bayesian reasoning that may arise in future ... More
Fisher information from stochastic quantum measurementsJun 16 2016The unavoidable interaction between a quantum system and the external noisy environment can be mimicked by a sequence of stochastic measurements whose outcomes are neglected. Here we investigate how this stochasticity is reflected in the survival probability ... More
When Do Composed Maps Become Entanglement Breaking?Jul 03 2018For many completely positive maps repeated compositions will eventually become entanglement breaking. To quantify this behaviour we develop a technique based on the Schmidt number: If a completely positive map breaks the entanglement with respect to any ... More
Cross-Modal Music Retrieval and Applications: An Overview of Key MethodologiesFeb 12 2019There has been a rapid growth of digitally available music data, including audio recordings, digitized images of sheet music, album covers and liner notes, and video clips. This huge amount of data calls for retrieval strategies that allow users to explore ... More
SplineCNN: Fast Geometric Deep Learning with Continuous B-Spline KernelsNov 24 2017May 23 2018We present Spline-based Convolutional Neural Networks (SplineCNNs), a variant of deep neural networks for irregular structured and geometric input, e.g., graphs or meshes. Our main contribution is a novel convolution operator based on B-splines, that ... More
Can GCNs Go as Deep as CNNs?Apr 07 2019Convolutional Neural Networks (CNNs) achieve impressive results in a wide variety of fields. Their success benefited from a massive boost with the ability to train very deep CNN models. Despite their positive results, CNNs fail to properly address problems ... More
Spin dynamics in Kapitza-Dirac scattering of electrons from bichromatic laser fieldsJun 15 2016Aug 10 2016Kapitza-Dirac scattering of nonrelativistic electrons from counterpropagating bichromatic laser waves of linear polarization is studied. The focus lies on the electronic spin dynamics in the Bragg regime when the laser fields possess a frequency ratio ... More
A Fast Search Algorithm for <m,m,m> Triple Product Property Triples and an Application for 5x5 Matrix MultiplicationMay 01 2013We present a new fast search algorithm for <m,m,m> Triple Product Property (TPP) triples as defined by Cohn and Umans in 2003. The new algorithm achieves a speed-up factor of 40 up to 194 in comparison to the best known search algorithm. With a parallelized ... More
Driving Policy Transfer via Modularity and AbstractionApr 25 2018Dec 13 2018End-to-end approaches to autonomous driving have high sample complexity and are difficult to scale to realistic urban driving. Simulation can help end-to-end driving systems by providing a cheap, safe, and diverse training environment. Yet training driving ... More
Quantum optimal control within the rotating wave approximationFeb 26 2015Mar 06 2015We study the interplay between rotating wave approximation and optimal control. In particular, we show that for a wide class of optimal control problems one can choose the control field such that the Hamiltonian becomes time-independent under the rotating ... More
End-to-end Driving via Conditional Imitation LearningOct 06 2017Mar 02 2018Deep networks trained on demonstrations of human driving have learned to follow roads and avoid obstacles. However, driving policies trained via imitation learning cannot be controlled at test time. A vehicle trained end-to-end to imitate an expert cannot ... More
Many body heat radiation and heat transfer in the presence of a non-absorbing background mediumOct 24 2016Heat radiation and near-field radiative heat transfer can be strongly manipulated by adjusting geometrical shapes, optical properties, or the relative positions of the objects involved. Typically these objects are considered as embedded in vacuum. By ... More
Resonant X-ray Emission and Valence-band Lifetime Broadening in LiNO$_3$May 16 2019X-ray absorption and resonant inelastic x-ray scattering measurements are carried out on lithium nitrate LiNO$_3$. The $\sigma$ orbitals around the nitrogen atoms exhibit a large lifetime effect. Experimentally, this is manifest as an apparent weakening ... More
Dressing the chopped-random-basis optimization: a bandwidth-limited access to the trap-free landscapeJun 15 2015Apr 06 2016In quantum optimal control theory the success of an optimization algorithm is highly influenced by how the figure of merit to be optimized behaves as a function of the control field, i.e. by the control landscape. Constraints on the control field introduce ... More
General Bayesian theories and the emergence of the exclusivity principleJan 31 2019Apr 22 2019We construct a general Bayesian framework that can be used to organize beliefs and to update them when new information becomes available. The framework includes classical, quantum, and other alternative models of Bayesian reasoning that may arise in future ... More
Characterization and Compensation of Network-Level Anomalies in Mixed-Signal Neuromorphic Modeling PlatformsApr 29 2014Feb 10 2015Advancing the size and complexity of neural network models leads to an ever increasing demand for computational resources for their simulation. Neuromorphic devices offer a number of advantages over conventional computing architectures, such as high emulation ... More
Spin transport and spin dephasing in zinc oxideMay 16 2012Aug 27 2012The wide bandgap semiconductor ZnO is interesting for spintronic applications because of its small spin-orbit coupling implying a large spin coherence length. Utilizing vertical spin valve devices with ferromagnetic electrodes (TiN/Co/ZnO/Ni/Au), we study ... More
$\cN = 1$ supersymmetric constraints for evolution kernelsMay 03 1999We provide a complete set of supersymmetric constraints for the anomalous dimensions of the conformal twist-two operators to all orders of perturbation theory. Employing them we derive new relations between the exclusive evolution kernels and apply them ... More
On adapted coordinate systemsJun 07 2007The notion of an adapted coordinate system, introduced by V.I.Arnol'd, plays an important role in the study of asymptotic expansions of oscillatory integrals. In two dimensions, A.N.Varchenko gave sufficient conditions for the adaptness of a given coordinate ... More
Probing generalized parton distributions with electroproduction of lepton pairs off the nucleonJul 30 2003We evaluate the differential cross section for the electroproduction of lepton pairs off a polarized nucleon target in the generalized Bjorken region to leading power accuracy in hard momentum. We discuss the importance of this process for phenomenology ... More
Hard exclusive meson production at next-to-leading orderMay 04 2001May 16 2001We evaluate perturbative next-to-leading order corrections to the hard exclusive leptoproduction of pi+ mesons on a transversely polarized proton target. A model dependent study shows that these corrections can be large. We analyze the scale dependence ... More
Off-forward gluonometryMay 03 2000We explore the deeply virtual Compton scattering process at NLO with the emphasis on the measurement of the tensor gluon skewed distributions. We recalculate the one-loop coefficient function and give two-loop results for anomalous dimensions and exclusive ... More
Superconformal constraints for QCD conformal anomaliesSep 06 2000Anomalous superconformal Ward identities and commutator algebra in N = 1 super-Yang-Mills theory give rise to constraints between the QCD special conformal anomalies of conformal composite operators. We evaluate the superconformal anomalies that appear ... More
$L^p-L^2$ Fourier restriction for hypersurfaces in $\Bbb R^3$: Part IIOct 13 2014This is the second of two articles in which we prove a sharp $L^p-L^2$ Fourier restriction theorem for a large class of smooth, finite type hypersurfaces in R^3, which includes in particular all real-analytic hypersurfaces.
$L^p-L^2$ Fourier restriction for hypersurfaces in $\Bbb R^3$: Part IAug 30 2012Oct 13 2014This is the first of two articles in which we prove a sharp $L^p-L^2$ Fourier restriction theorem for a large class of smooth, finite type hypersurfaces in $\Bbb R^3$, which includes in particular all real-analytic hypersurfaces. The present file is a ... More
Uniform estimates for the Fourier transform of surface carried measures in $\Bbb R^3$ and an application to Fourier restrictionOct 11 2010Let $S$ be a hypersurface in $\Bbb R^3$ which is the graph of a smooth, finite type function $\phi,$ and let $\mu=\rho\, d\si$ be a surface carried measure on $S,$ where $d\si$ denotes the surface element on $S$ and $\rho$ a smooth density with suffiently ... More
Discrete differential calculus, graphs, topologies and gauge theoryApr 19 1994Sep 23 1994Differential calculus on discrete sets is developed in the spirit of noncommutative geometry. Any differential algebra on a discrete set can be regarded as a `reduction' of the `universal differential algebra' and this allows a systematic exploration ... More
Theory and phenomenology of generalized parton distributions: a brief overviewMay 17 2001The generalized parton distributions are non-perturbative objects, which encode information on long distance dynamics in a number of exclusive processes. They are hybrids of conventional parton densities, distribution amplitudes and hadron form factors. ... More
Resummation of target mass corrections in two-photon processes: twist-two sectorFeb 18 2001Feb 22 2001We develop a formalism for the resummation of target mass corrections in off-forward two-photon amplitudes given by a chronological product of electromagnetic currents, arising in e.g. deeply virtual Compton scattering. The method is based on a relation ... More
Nucleon hologram with exclusive leptoproductionJun 28 2002Jul 12 2002Hard exclusive leptoproductions of real photons, lepton pairs and mesons are the most promising tools to unravel the three-dimensional picture of the nucleon, which cannot be deduced from conventional inclusive processes like deeply inelastic scattering. ... More
Condensate deformation and quantum depletion of Bose-Einstein condensates in external potentialsFeb 16 2012Jul 28 2012The one-body density matrix of weakly interacting, condensed bosons in external potentials is calculated using inhomogeneous Bogoliubov theory. We determine the condensate deformation caused by weak external potentials on the mean-field level. The momentum ... More
Disorder and interference: localization phenomenaMay 06 2010Jun 01 2016The specific problem we address in these lectures is the problem of transport and localization in disordered systems, when interference is present, as characteristic for waves, with a focus on realizations with ultracold atoms.
A grand-canonical approach to the disordered Bose gasFeb 17 2014We study the problem of disordered interacting bosons within grand-canonical thermodynamics and Bogoliubov theory. We compute the fractions of condensed and non-condensed particles and corrections to the compressibility and the speed of sound due to interaction ... More
Bogoliubov Theory of Disordered Bose-Einstein CondensatesSep 28 2010May 12 2011We describe interacting bosons at low temperature in spatially correlated random potentials. By a Bogoliubov expansion around the deformed mean-field condensate, the fundamental Hamiltonian for elementary excitations is derived, achieving an analytical ... More
Ends of branching random walks on planar hyperbolic Cayley graphsSep 11 2014We prove that the trace of a transient branching random walk on a planar hyperbolic Cayley graph has a.s. continuum many ends and no isolated end.
Perspectives of superconducting MgB2 for microwave applicationsJul 09 2002We discuss the temperature, frequency, and power-dependent surface resistance of the boride superconductor MgB2 in relation to possible applications for passive microwave devices. The data available in the literature are compared with results for polycrystalline ... More
Overview of deeply virtual Compton scatteringNov 05 2001We give a short overview of recent developments in understanding of the deeply virtual Compton scattering on the proton target.
Twist-three effects in two-photon processesJul 04 2000We give a general treatment of twist-three effects in two-photon reactions. We address the issue of the gauge invariance of the Compton amplitude in generalized Bjorken kinematics and relations of twist-three `transverse' skewed parton distributions to ... More
Exclusive evolution kernels in two-loop order: parity even sectorJun 17 1999We complete the construction of the non-forward evolution kernels in next-to-leading order responsible for the scale dependence of e.g. parity even singlet distribution amplitudes. Our formalism is designed to avoid any explicit two-loop calculations ... More
Resonant two-photon single ionization of two atomsFeb 28 2011Resonant two-photon ionization in a system consisting of two spatially well-separated atoms is studied. Due to two-center electron-electron correlations, the ionization may also proceed through photo-excitation of both atoms with subsequent interatomic ... More
Bogoliubov Excitations of Disordered Bose-Einstein CondensatesJan 25 2011We describe repulsively interacting Bose-Einstein condensates in spatially correlated disorder potentials of arbitrary dimension. The first effect of disorder is to deform the mean-field condensate. Secondly, the quantum excitation spectrum and condensate ... More
On Elo based prediction models for the FIFA Worldcup 2018Jun 05 2018We propose an approach for the analysis and prediction of a football championship. It is based on Poisson regression models that include the Elo points of the teams as covariates and incorporates differences of team-specific effects. These models for ... More
Counting self-avoiding walks on free products of graphsSep 10 2015The connective constant $\mu(G)$ of a graph $G$ is the asymptotic growth rate of the number $\sigma_{n}$ of self-avoiding walks of length $n$ in $G$ from a given vertex. We prove a formula for the connective constant for free products of quasi-transitive ... More
Exclusive electroproduction of lepton pairs as a probe of nucleon structureOct 23 2002Oct 24 2002We suggest the measurement of exclusive electroproduction of lepton pairs as a tool to study inter-parton correlations in the nucleon via generalized parton distributions in the kinematical region where this process is light-cone dominated. We demonstrate ... More
Classical impurities and boundary Majorana zero modes in quantum chainsMar 03 2016We study the response of classical impurities in quantum Ising chains. The Z2 degeneracy they entail renders the existence of two decoupled Majorana modes at zero energy an exact property of a finite system at arbitrary values of its bulk parameters. ... More
Diffusive density profiles in a cold-atom expansion experimentJun 19 2014Sep 16 2014In a recent experiment [McGehee et al., Phys. Rev. Lett. 111, 145303 (2013)], the expansion of non-interacting ultracold fermions was studied in a random speckle potential, and the observed density profiles were interpreted based on 3D Anderson localization. ... More
Bogoliubov theory on the disordered latticeSep 24 2012Mar 14 2013Quantum fluctuations of Bose-Einstein condensates trapped in disordered lattices are studied by inhomogeneous Bogoliubov theory. Weak-disorder perturbation theory is applied to compute the elastic scattering rate as well as the renormalized speed of sound ... More
Random Walks on Directed Covers of GraphsFeb 05 2009Oct 05 2009Directed covers of finite graphs are also known as periodic trees or trees with finitely many cone types. We expand the existing theory of directed covers of finite graphs to those of infinite graphs. While the lower growth rate still equals the branching ... More
Relativistic configuration-interaction calculations of energy levels of the $1s^22l$ and $1s2l2l'$ states in lithium-like ions: carbon through chlorineDec 26 2017We present systematic calculations of energy levels of the $1s^22l$ and $1s2l2l'$ states of ions along the lithium isoelectronic sequence from carbon till chlorine. The calculations are performed by using the relativistic-configuration-interaction method ... More
NLO Exclusive Evolution KernelsJun 13 2000We outline a formalism used for a construction of two-loop flavor singlet exclusive evolution kernels in the MS bar scheme. The approach is based on the known pattern of conformal symmetry breaking in MS bar as well as constraints arising from the superconformal ... More
Reconstruction of non-forward evolution kernelsApr 28 1999Jun 21 1999We develop a framework for the reconstruction of the non-forward kernels which govern the evolution of twist-two distribution amplitudes and off-forward parton distributions beyond leading order. It is based on the knowledge of the special conformal symmetry ... More
Spin effects in deeply virtual Compton scatteringJun 21 2001We consider the azimuthal angle dependence in the cross section of the hard leptoproduction of a photon on a nucleon target. We show that this dependence allows to define observables that isolate the twist-two and twist-three sectors in the deeply virtual ... More
Two-center dielectronic recombination in slow atomic collisionsMay 06 2019A free electron can form a bound state with an atomic center $A$ upon photo emission (radiative recombination). In the presence of a neighboring atom $B$, such a bound state can, under certain conditions, be also formed via resonant transfer of energy ... More
NLO evolution kernels for skewed transversity distributionsAug 01 2000Aug 03 2000We present a calculation of the two-loop evolution kernels of the twist-two transversally polarized quark and linearly polarized gluon skewed parton distributions in the minimal subtraction scheme and discuss a solution of the evolution equations suitable ... More
Theory of deeply virtual Compton scattering on the nucleonDec 07 2001Mar 01 2002We compute the cross section for leptoproduction of the real photon off the nucleon, which is sensitive to the deeply virtual Compton scattering amplitude with power accuracy. Our considerations go beyond the leading twist and involve the complete analysis ... More
Strong Anderson localization in cold atom quantum quenchesNov 10 2013Mar 31 2014Signatures of strong Anderson localization in the momentum distribution of a cold atom cloud after a quantum quench are studied. We consider a quasi one-dimensional cloud initially prepared in a well defined momentum state, and expanding for some time ... More
Resonant single-photon double ionization driven by combined intra- and interatomic electron correlationsJun 19 2019Double ionization of an atom by single-photon absorption in the presence of a neighbouring atom is studied. The latter is, first, resonantly photoexcited and, afterwards, transfers the excitation energy radiationlessly to the other atom, leading to its ... More
Algoritmos Genéticos Aplicado ao Problema de Roteamento de VeículosAug 31 2018Routing problems are often faced by companies who serve costumers through vehicles. Such problems have a challenging structure to optimize, despite the recent advances in combinatorial optimization. The goal of this project is to study and propose optimization ... More
Prospects for fast Rydberg gates on an atom chipApr 14 2011Atom chips are a promising candidate for a scalable architecture for quantum information processing provided a universal set of gates can be implemented with high fidelity. The difficult part in achieving universality is the entangling two-qubit gate. ... More