Results for "Jan-Niklas Schmidt"

total 17376took 0.11s
The Fate of the Higgs Mode in a Trapped Dipolar SupersolidJul 22 2019We theoretically investigate the spectrum of elementary excitations of a trapped dipolar quantum gas across the BEC-supersolid phase transition. Our calculations reveal the existence of distinct Higgs and Nambu-Goldstone modes that emerge from the softening ... More
Transient supersolid properties in an array of dipolar quantum dropletsJan 23 2019Mar 08 2019We study theoretically and experimentally the emergence of supersolid properties in a dipolar Bose-Einstein condensate. The theory reveals a ground state phase diagram with three distinct regimes - a regular Bose-Einstein condensate, incoherent and coherent ... More
Anisotropic Superfluid Behavior of a Dipolar Bose-Einstein CondensateApr 12 2018Jul 18 2018We present transport measurements on a dipolar superfluid using a Bose-Einstein condensate of Dy-162 with strong magnetic dipole-dipole interactions. By moving an attractive laser beam through the condensate we observe an anisotropy in superfluid flow. ... More
The low-energy Goldstone mode in a trapped dipolar supersolidJun 11 2019A supersolid is a counter-intuitive state of matter that combines the frictionless flow of a superfluid with the crystal-like periodic density modulation of a solid. Since the first prediction in the 1950s, experimental efforts to realize this state have ... More
Magnetic catalysis and inverse magnetic catalysis in QCDFeb 27 2015May 13 2015We investigate the effects of strong magnetic fields on the QCD phase structure at vanishing density by solving the gluon and quark gap equations, and by studying the dynamics of the quark scattering with the four-fermi coupling. The chiral crossover ... More
Realization of Shor's Algorithm at Room TemperatureJun 10 2017Shor's algorithm can find prime factors of a large number more efficiently than any known classical algorithm. Understanding the properties that gives the speedup is essential for a general and scalable construction. Here we present a realization of Shor's ... More
Quantum Simulation Logic, Oracles, and the Quantum AdvantageMay 13 2019Query complexity is a common tool for comparing quantum and classical computation, and it has produced many examples of how quantum algorithms differ from classical ones. Here we investigate in detail the role that oracles play for the advantage of quantum ... More
Efficient classical simulation of the Deutsch-Jozsa and Simon's algorithmsAug 20 2015Mar 05 2018A long-standing aim of quantum information research is to understand what gives quantum computers their advantage. This requires separating problems that need genuinely quantum resources from those for which classical resources are enough. Two examples ... More
Efficient classical simulation of the Deutsch-Jozsa algorithmJun 15 2015Sep 10 2015In 1985, David Deutsch challenged the Church-Turing thesis by stating that his quantum model of computation "could, in principle, be built and would have many remarkable properties not reproducible by any Turing machine". While this is thought to be true ... More
Quantum correlations in dilute dipolar quantum droplets beyond the extended Gross-Pitaevskii equationApr 23 2019Dipolar quantum droplets are exotic quantum objects that are self-bound due to the subtle balance of attraction, repulsion and quantum correlations. Here we present a systematic study of the critical atom number of these self-bound droplets, comparing ... More
Developing Artificial Herders Using JasonDec 31 2009This paper gives an overview of a proposed strategy for the "Cows and Herders" scenario given in the Multi-Agent Programming Contest 2009. The strategy is to be implemented using the Jason platform, based on the agent-oriented programming language Agent-Speak. ... More
HotBox: Testing Temperature Effects in Sensor NetworksDec 06 2014Low-power wireless networks, especially in outside deployments, are exposed to a wide range of temperatures. The detrimental effect of high temperatures on communication quality is well known. To investigate these influences under controlled conditions, ... More
Multi-Agent Programming Contest 2010 - The Jason-DTU TeamOct 01 2010We provide a brief description of the Jason-DTU system, including the methodology, the tools and the team strategy that we plan to use in the agent contest.
Smooth Wilson Loops in N=4 Non-Chiral SuperspaceJun 23 2015Nov 25 2015We consider a supersymmetric Wilson loop operator for 4d N=4 super Yang-Mills theory which is the natural object dual to the AdS_5 x S^5 superstring in the AdS/CFT correspondence. It generalizes the traditional bosonic 1/2 BPS Maldacena-Wilson loop operator ... More
One-Loop Superconformal and Yangian Symmetries of Scattering Amplitudes in N=4 Super Yang-MillsFeb 09 2010Apr 21 2010Recently it has been argued that tree-level scattering amplitudes in N=4 Yang-Mills theory are uniquely determined by a careful study of their superconformal and Yangian symmetries. However, at one-loop order these symmetries are known to become anomalous ... More
Master formula for one-loop renormalization of bosonic SMEFT operatorsApr 16 2019Using background-field method and super-heat-kernel expansion, we derive a master formula for the one-loop UV divergences of the bosonic dimension-6 operators in Standard Model Effective Field Theory (SMEFT). This approach reduces the calculation of all ... More
Existence and uniqueness of global classical solutions to a two species cancer invasion haptotaxis modelApr 26 2017We consider a haptotaxis cancer invasion model that includes two families of cancer cells. Both families, migrate on the extracellular matrix and proliferate. Moreover the model describes an epithelial-to-mesenchymal-like transition between the two families, ... More
Integrability of Smooth Wilson Loops in N=4 SuperspaceSep 17 2015Nov 20 2015We perform a detailed study of the Yangian symmetry of smooth supersymmetric Maldacena-Wilson loops in planar N=4 super Yang-Mills theory. This hidden symmetry extends the global superconformal symmetry present for these observables. A gauge-covariant ... More
Angular Analysis of \boldmath $Λ_b\to Λ_c (\to Λ π)\ell\barν$Jul 29 2019We revisit the decay $\Lambda_b^0\to \Lambda_c^+ \ell^-\bar\nu$ ($\ell = e,\mu,\tau$) with a subsequent two-body decay $\Lambda_c^+ \to \Lambda^0 \pi^+$ in the Standard Model and in generic New Physics models. The decay's joint four-differential angular ... More
Solving $k$-means on High-dimensional Big DataFeb 15 2015May 28 2015In recent years, there have been major efforts to develop data stream algorithms that process inputs in one pass over the data with little memory requirement. For the $k$-means problem, this has led to the development of several $(1+\varepsilon)$-approximations ... More
The Gaussian entropy of fermionic systemsApr 18 2012Nov 05 2012We consider the entropy and decoherence in fermionic quantum systems. By making a Gaussian Ansatz for the density operator of a collection of fermions we study statistical 2-point correlators and express the entropy of a system fermion in terms of these ... More
Consistent simulation of capacitive radio-frequency discharges and external matching networksApr 16 2018External matching networks are crucial and necessary for operating capacitively coupled plasmas in order to maximize the absorbed power. Experiments show that external circuits in general heavily interact with the plasma in a nonlinear way. This interaction ... More
Sparse Proteomics Analysis - A compressed sensing-based approach for feature selection and classification of high-dimensional proteomics mass spectrometry dataJun 11 2015Nov 26 2016Background: High-throughput proteomics techniques, such as mass spectrometry (MS)-based approaches, produce very high-dimensional data-sets. In a clinical setting one is often interested in how mass spectra differ between patients of different classes, ... More
Normal-state properties of the antiperovskite oxide Sr$_{3-x}$SnO revealed by $^{119}$Sn-NMRSep 25 2018We have performed $^{119}$Sn-NMR measurements on the antiperovskite oxide superconductor Sr$_{3-x}$SnO to investigate how its normal state changes with the Sr deficiency. A two-peak structure was observed in the NMR spectra of all the measured samples. ... More
Particle-in-Cell/Test-Particle Simulations of Technological Plasmas: Sputtering Transport in Capacitive Radio Frequency DischargesJul 14 2016The paper provides a tutorial to the conceptual layout of a self-consistently coupled Particle-In-Cell/Test-Particle model for the kinetic simulation of sputtering transport in capacitively coupled plasmas at low gas pressures. It explains when a kinetic ... More
Gaussian covariance matrices for anisotropic galaxy clustering measurementsSep 14 2015Jan 07 2016Measurements of the redshift-space galaxy clustering have been a prolific source of cosmological information in recent years. Accurate covariance estimates are an essential step for the validation of galaxy clustering models of the redshift-space two-point ... More
An exact solution of the Dirac equation with CP violationJan 17 2013We consider Yukawa theory in which the fermion mass is induced by a Higgs like scalar. In our model the fermion mass exhibits a temporal dependence, which naturally occurs in the early Universe setting. Assuming that the complex fermion mass changes as ... More
On Yangian Symmetry in Planar N=4 SYMApr 30 2010Apr 10 2011Planar N=4 supersymmetric Yang-Mills theory appears to be perturbatively integrable. This work reviews integrability in terms of a Yangian algebra and compares the application to the problems of anomalous dimensions and scattering amplitudes.
Discovery of VHE Gamma-ray Emission from the Starburst Galaxy M82Dec 18 2009Dec 23 2009The galaxy M82 has long been considered a promising target for VHE gamma-ray observations because of the compact starburst region in its core. Theoretical predictions have suggested it should be detectable by ground-based imaging Cherenkov telescopes ... More
Electricity Theft Detection using Machine LearningAug 19 2017Non-technical losses (NTL) in electric power grids arise through electricity theft, broken electric meters or billing errors. They can harm the power supplier as well as the whole economy of a country through losses of up to 40% of the total power distribution. ... More
Hadronic Production of Gamma Rays and Starburst GalaxiesOct 01 2008The Milky Way has been estabished to emit gamma rays. These gamma rays are presumably dominated by decays of neutral pions, although inverse Compton scatterings and bremsstrahlung also contribute. It is plausible that other galaxies can be diffuse sources ... More
The su(2|3) Undynamic Spin ChainJul 01 2008Apr 17 2009The integrable spin chain found in perturbative planar N=4 supersymmetric gauge theory is dynamic. Here we propose a reformulation which removes the dynamic effects in order to make the model more accessible to an algebraic treatment.
Higher-Loop Integrability in N=4 Gauge TheorySep 14 2004Oct 28 2004The dilatation operator measures scaling dimensions of local operator in a conformal field theory. Algebraic methods of constructing the dilatation operator in four-dimensional N=4 gauge theory are reviewed. These led to the discovery of novel integrable ... More
The Dilatation Operator of N=4 Super Yang-Mills Theory and IntegrabilityJul 30 2004Oct 22 2005The dilatation generator measures the scaling dimensions of local operators in a conformal field theory. In this thesis we consider the example of maximally supersymmetric gauge theory in four dimensions and develop and extend techniques to derive, investigate ... More
On the Scattering Phase for AdS_5 x S^5 StringsJun 22 2006Feb 05 2007We propose a phase factor of the worldsheet S-matrix for strings on AdS_5 x S^5 apparently solving Janik's crossing relation.
The su(2|3) Dynamic Spin ChainOct 28 2003Dec 09 2003The complete one-loop, planar dilatation operator of the N=4 superconformal gauge theory was recently derived and shown to be integrable. Here, we present further compelling evidence for a generalisation of this integrable structure to higher orders of ... More
The Complete One-Loop Dilatation Operator of N=4 Super Yang-Mills TheoryJul 01 2003Feb 27 2011We continue the analysis of hep-th/0303060 in the one-loop sector and present the complete psu(2,2|4) dilatation operator of N=4 Super Yang-Mills theory. This operator generates the matrix of one-loop anomalous dimensions for all local operators in the ... More
Review of AdS/CFT Integrability, Chapter VI.1: Superconformal SymmetryDec 17 2010Mar 20 2011Aspects of the D=4, N=4 superconformal symmetry relevant to the AdS/CFT duality and integrability are reviewed. These include the Lie superalgebra psu(2,2|4), its representations, conformal transformations and correlation functions in N=4 super Yang-Mills ... More
Superconductivity in the antiperovskite Dirac-metal oxide Sr$_3$SnOApr 21 2016Feb 24 2017Oxides with perovskite-based structures have been known as essential materials for fascinating phenomena such as high-temperature and unconventional superconductivity. Discoveries of these oxide superconductors have driven the science community to vastly ... More
The Analytic Bethe Ansatz for a Chain with Centrally Extended su(2|2) SymmetryOct 09 2006Jan 02 2007We investigate the integrable structure of spin chain models with centrally extended su(2|2) and psu(2,2|4) symmetry. These chains have their origin in the planar AdS/CFT correspondence, but they also contain the one-dimensional Hubbard model as a special ... More
An SU(1|1)-Invariant S-Matrix with Dynamic RepresentationsNov 01 2005Nov 07 2005The spin chains originating from large-N conformal gauge theories are of a special kind: The Hamiltonian is not invariant under the symmetry algebra, it is rather a part of it. This leads to interesting properties within the asymptotic Bethe ansatz. Here ... More
Spin Chain for Quantum StringsSep 03 2004Sep 14 2004We review and compare the integrable structures in N=4 gauge theory and string theory on AdS5xS5. Recently, Bethe ansaetze for gauge theory/weak coupling and string theory/strong coupling were proposed to describe scaling dimensions in the su(2) subsector. ... More
The su(2|2) Dynamic S-MatrixNov 07 2005Sep 19 2006We derive and investigate the S-matrix for the su(2|3) dynamic spin chain and for planar N=4 super Yang-Mills. Due to the large amount of residual symmetry in the excitation picture, the S-matrix turns out to be fully constrained up to an overall phase. ... More
Study of Higgs Production in Fermionic Decay Channels at CMSJul 22 2013In these proceedings to the LHCP conference 2013 results are presented on the study of the Higgs-like particle at a mass of 125 GeV decaying into final states consisting of either $\tau^+\tau^-$, or a $b\bar{b}$ quark pair, based on the full statistics ... More
Higher loops, integrability and the near BMN limitAug 11 2003In this note we consider higher-loop contributions to the planar dilatation operator of N=4 SYM in the su(2) subsector of two complex scalar fields. We investigate the constraints on the form of this object due to interactions of two excitations in the ... More
The S-Matrix of AdS/CFT and Yangian SymmetryApr 03 2007Mar 27 2008We review the algebraic construction of the S-matrix of AdS/CFT. We also present its symmetry algebra which turns out to be a Yangian of the centrally extended su(2|2) superalgebra.
Large Deviations of the Estimated Cumulative Hazard RateJul 03 2019Survivorship analysis allows to statistically analyze situations that can be modeled as waiting times to an event. These waiting times are characterized by the cumulative hazard rate, which can be estimated by the Nelson-Aalen estimator or diverse confidence ... More
The Classical Trigonometric r-Matrix for the Quantum-Deformed Hubbard ChainFeb 05 2010Apr 03 2011The one-dimensional Hubbard model is an exceptional integrable spin chain which is apparently based on a deformation of the Yangian for the superalgebra gl(2|2). Here we investigate the quantum-deformation of the Hubbard model in the classical limit. ... More
T-Duality, Dual Conformal Symmetry and Integrability for Strings on AdS_5 x S^5Mar 03 2009In recent years two intriguing observations have been made for N=4 super Yang-Mills theory and for superstrings on AdS5xS5: In the planar limit the computation of the spectrum is vastly simplified by the apparent integrability of the models. Furthermore, ... More
BMN Operators and Superconformal SymmetryNov 05 2002Mar 17 2003Implications of N=4 superconformal symmetry on Berenstein-Maldacena-Nastase (BMN) operators with two charge defects are studied both at finite charge J and in the BMN limit. We find that all of these belong to a single long supermultiplet explaining a ... More
Conditional Densities and Simulations of Inhomogeneous Poisson Point Processes: The R package "IPPP"Jan 30 2019May 20 2019A number of numeric approaches to simulate Poisson point processes with arbitrary event rates are presented and implemented for R. They include the simulation of the number of points and their location as well as the determination of conditional probability ... More
A generic method for equipping arbitrary rf discharge simulation frameworks with external lumped element circuitsFeb 06 2019External electric circuits attached to radio-frequency plasma discharges are essential for the power transfer into the discharge and are, therefore, a key element for plasma operation. Many plasma simulations, however, simplify or even neglect the external ... More
Finite Element simulation of radiation losses in photonic crystal fibersNov 14 2007In our work we focus on the accurate computation of light propagation in finite size photonic crystal structures with the finite element method (FEM). We discuss how we utilize numerical concepts like high-order finite elements, transparent boundary conditions ... More
Kardar-Parisi-Zhang Universality of the Nagel-Schreckenberg ModelJul 01 2019Dynamical universality classes are distinguished by their dynamical exponent $z$ and unique scaling functions encoding space-time asymmetry for, e.g. slow-relaxation modes or the distribution of time-integrated currents. So far the universality class ... More
Evaluation of the citation matching algorithms of CWTS and iFQ in comparison to Web of ScienceJul 13 2015The results of bibliometric studies provided by bibliometric research groups, e.g. the Centre for Science and Technology Studies (CWTS) and the Institute for Research Information and Quality Assurance (iFQ), are often used in the process of research assessment. ... More
On the Yang-Mills two-loop effective action with wordline methodsDec 01 2008We derive the two-loop effective action for covariantly constant field strength of pure Yang-Mills theory in the presence of an infrared scale. The computation is done in the framework of the worldline formalism, based on a generalization procedure of ... More
On modal analysis of laminated glass: Usability of simplified methods and enhanced effective thicknessJan 03 2018This paper focuses on the modal analysis of laminated glass beams. In these multilayer elements, the stiff glass plates are connected by compliant interlayers with frequency/temperature-dependent behavior. The aim of our study is (i) to assess whether ... More
Adaptive Finite Element Method for Simulation of Optical Nano StructuresNov 14 2007We discuss realization, properties and performance of the adaptive finite element approach to the design of nano-photonic components. Central issues are the construction of vectorial finite elements and the embedding of bounded components into the unbounded ... More
Symplectic structure of N=1 supergravity with anomalies and Chern-Simons termsMay 29 2007Sep 11 2007The general actions of matter-coupled N=1 supergravity have Peccei-Quinn terms that may violate gauge and supersymmetry invariance. In addition, N=1 supergravity with vector multiplets may also contain generalized Chern-Simons terms. These have often ... More
Uncertainty Modeling and Analysis of the European XFEL Cavities Manufacturing ProcessJun 21 2019This paper reports on comprehensive efforts on uncertainty quantification and global sensitivity analysis for accelerator cavity design. As a case study object the TESLA shaped superconducting cavities, as produced for the European X-ray Free Electron ... More
On Vertex- and Empty-Ply Proximity DrawingsAug 30 2017Sep 07 2017We initiate the study of the vertex-ply of straight-line drawings, as a relaxation of the recently introduced ply number. Consider the disks centered at each vertex with radius equal to half the length of the longest edge incident to the vertex. The vertex-ply ... More
On linear representation of $\ast$-regular rings having representable ortholattice of projectionsNov 04 2018This paper aims at the following results: \begin{enumerate} \item The class of all $*$-regular rings forms a variety. \item A subdirectly irreducible $*$-regular ring $R$ is faithfully representable (i.e. isomorphic to a subring of an endomorphisms ring ... More
On the Geometry of Null Polygons in Full N=4 SuperspaceMar 02 2012Mar 23 2012We discuss various formulations of null polygons in full, non-chiral N=4 superspace in terms of spacetime, spinor and twistor variables. We also note that null polygons are necessarily fat along fermionic directions, a curious fact which is compensated ... More
Tomography scheme for two spin-1/2 qubits in a double quantum dotApr 10 2013We present a scheme for full quantum state tomography tailored for two spin qubits in a double quantum dot. A set of 15 quantum states allows to determine the density matrix in this two-qubit space by projective measurement. In this paper we choose a ... More
Generation of mesoscopic superpositions of a binary Bose-Einstein condensate in a slightly asymmetric double wellJul 27 2007A previous publication [Europhysics Letters 78, 10009 (2007)] suggested to coherently generate mesoscopic superpositions of a two-component Bose-Einstein condensate in a double well under perfectly symmetric conditions. However, already tiny asymmetries ... More
Conformal regularization of Einstein's field equationsApr 14 2005Jul 15 2005To study asymptotic structures, we regularize Einstein's field equations by means of conformal transformations. The conformal factor is chosen so that it carries a dimensional scale that captures crucial asymptotic features. By choosing a conformal orthonormal ... More
Consistent boundary conditions for cosmological topologically massive gravity at the chiral pointAug 19 2008Oct 28 2010We show that cosmological topologically massive gravity at the chiral point allows not only Brown-Henneaux boundary conditions as consistent boundary conditions, but slightly more general ones which encompass the logarithmic primary found in 0805.2610 ... More
Parameterization of the Angular Distribution of Gamma Rays Produced by p-p Interaction in Astronomical EnvironmentSep 03 2007Dec 12 2007We present the angular distribution of gamma rays produced by proton-proton interactions in parameterized formulae to facilitate calculations in astrophysical environments. The parameterization is derived from Monte Carlo simulations of the up-to-date ... More
Constructing phase space distributions with internal symmetriesJan 29 2019Feb 22 2019We discuss an ab initio world-line approach to constructing phase space distributions in systems with internal symmetries. Starting from the Schwinger-Keldysh real time path integral in quantum field theory, we derive the most general extension of the ... More
Springer MotivesDec 12 2018We show that the motive of a Springer fiber is pure Tate. We then consider a category of equivariant Springer motives on the nilpotent cone and construct an equivalence to the derived category of graded modules over the graded affine Hecke algebra.
Enhancing nanomechanical squeezing by atomic interactions in a hybrid atom-optomechanical systemNov 13 2018In a hybrid atom-optomechanical system, the optical coupling of a mechanical mode of a nanomembrane in an optical cavity with a distant interacting atom gas permits highly non-classical quantum many-body states. We show that the mechanical mode can be ... More
Caching in the Clouds: Optimized Dynamic Cache Instantiation in Content Delivery SystemsMar 11 2018By caching content at geographically distributed servers, content delivery applications can achieve scalability and reduce wide-area network traffic. However, each deployed cache has an associated cost. When the request rate from the local region is sufficiently ... More
Solutions of martingale problems for Lévy-type operators and stochastic differential equations driven by Lévy processes with discontinuous coefficientsAug 08 2012We show the existence of L\'evy-type stochastic processes in one space dimension with characteristic triplets that are either discontinuous at thresholds, or are stable-like with stability index functions for which the closures of the discontinuity sets ... More
Worst-case Bounds and Optimized Cache on $M^{th}$ Request Cache Insertion Policies under Elastic ConditionsDec 18 2018Cloud services and other shared third-party infrastructures allow individual content providers to easily scale their services based on current resource demands. In this paper, we consider an individual content provider that wants to minimize its delivery ... More
Well-posedness of renormalized solutions for a stochastic $p$-Laplace equation with $L^1$-initial dataAug 29 2019We consider a $p$-Laplace evolution problem with stochastic forcing on a bounded domain $D\subset\mathbb{R}^d$ with homogeneous Dirichlet boundary conditions for $1<p<\infty$. The additive noise term is given by a stochastic integral in the sense of It\^{o}. ... More
Graded and Geometric Parabolic Induction for Category $\mathcal{O}$Mar 01 2016Sep 13 2018We prove that the parabolic induction functor on BGG-category $\mathcal{O}$ associated to a complex reductive Lie algebra is gradable, that is, lifts to graded category $\mathcal{O}$ as constructed by Beilinson-Ginzburg-Soergel. Graded category $\mathcal{O}$ ... More
Optimization of electron pumping by harmonic mixingDec 21 2010Mar 22 2011For a symmetric bridge coupled to infinite leads, in the presence of a dipole-coupled external ac-field with harmonic mixing, we solve the Schr\"odinger equation in the time-domain using open boundary conditions as well as in the energy-domain using Floquet ... More
Gravity duals for logarithmic conformal field theoriesDec 30 2009Mar 09 2010Logarithmic conformal field theories with vanishing central charge describe systems with quenched disorder, percolation or dilute self-avoiding polymers. In these theories the energy momentum tensor acquires a logarithmic partner. In this talk we address ... More
Comment on "Motion of a helical vortex filament in superfluid 4He under the extrinsic form of the local induction approximation"Oct 01 2013We comment on the paper by Van Gorder ["Motion of a helical vortex filament in superfluid ${}^4$He under the extrinsic form of the local induction approximation", Phys. Fluids 25, 085101 (2013)]. We point out that the flow of the normal fluid component ... More
Construction of Lax Connections by ExponentiationJul 13 2012We propose a method for constructing the Lax connection of two-dimensional relativistic integrable sigma models on coset spaces by means of exponentiation of a suitable operator. We derive a simple quadratic relation that this operator must satisfy for ... More
Long-Range PSU(2,2|4) Bethe Ansaetze for Gauge Theory and StringsApr 25 2005Sep 26 2005We generalize various existing higher-loop Bethe ansaetze for simple sectors of the integrable long-range dynamic spin chain describing planar N=4 Super Yang-Mills Theory to the full psu(2,2|4) symmetry and, asymptotically, to arbitrary loop order. We ... More
Optimal Topological Test for Degeneracies of Real HamiltoniansOct 03 2003Jan 09 2004We consider adiabatic transport of eigenstates of real Hamiltonians around loops in parameter space. It is demonstrated that loops that map to nontrivial loops in the space of eigenbases must encircle degeneracies. Examples from Jahn-Teller theory are ... More
Yangian Algebra and Correlation Functions in Planar Gauge TheoriesApr 24 2018Jul 02 2018In this work we consider colour-ordered correlation functions of the fields in integrable planar gauge theories such as N=4 supersymmetric Yang-Mills theory with the aim to establish Ward-Takahashi identities corresponding to Yangian symmetries. To this ... More
Had You Looked Where I'm Looking: Cross-user Similarities in Viewing Behavior for 360$^{\circ}$ Video and Caching ImplicationsJun 24 2019The demand and usage of 360$^{\circ}$ video services are expected to increase. However, despite these services being highly bandwidth intensive, not much is known about the potential value that basic bandwidth saving techniques such as server or edge-network ... More
A flexible multidimensional rectangular mesh administration and refinement technique with application in cancer invasion modelsJun 19 2017We present a mesh-structure data administration technique for the bookkeeping of adaptive mesh refinement, in particular h-refinement, of rectangular parallelepiped meshes. Our technique is a unified approach for 1-, 2- and 3D domains, that can be extended ... More
World-line formulation of chiral kinetic theory in topological background gauge fieldsDec 11 2017In heavy-ion collisions, an interesting question of phenomenological relevance is how the chiral imbalance generated at early times persists through a fluctuating background of sphalerons in addition to other "non-anomalous" interactions with the QGP. ... More
Universal Quantum Computing with Spin and ValleyMar 22 2012We investigate a two-electron double quantum dot with both spin and valley degrees of freedom as they occur in graphene, carbon nanotubes, or silicon, and regard the 16-dimensional space with one electron per dot as a four-qubit logic space. In the spin-only ... More
Scaling property of the critical hopping parameters for the Bose-Hubbard modelSep 17 2009Recently precise results for the boundary between the Mott insulator phase and the superfluid phase of the homogeneous Bose-Hubbard model have become available for arbitrary integer filling factor g and any lattice dimension d > 1. We use these data for ... More
Searching for degeneracies of real Hamiltonians using homotopy classification of loops in SO($n$)Jun 15 2004Jan 25 2005Topological tests to detect degeneracies of Hamiltonians have been put forward in the past. Here, we address the applicability of a recently proposed test [Phys. Rev. Lett. {\bf 92}, 060406 (2004)] for degeneracies of real Hamiltonian matrices. This test ... More
Bose-Einstein condensates in a double well: mean-field chaos and multi-particle entanglementNov 07 2008A recent publication [Phys. Rev. Lett. 100, 140408 (2008)] shows that there is a relation between mean-field chaos and multi-particle entanglement for BECs in a periodically shaken double well. 'Schrodinger-cat' like mesoscopic superpositions in phase-space ... More
Instability in cosmological topologically massive gravity at the chiral pointMay 19 2008Oct 22 2009We consider cosmological topologically massive gravity at the chiral point with positive sign of the Einstein-Hilbert term. We demonstrate the presence of a negative energy bulk mode that grows linearly in time. Unless there are physical reasons to discard ... More
Coulomb Branches of Star-Shaped QuiversAug 15 2018Dec 07 2018We study the Coulomb branches of 3d N=4 `star-shaped' quiver gauge theories and their deformation quantizations, by applying algebraic techniques that have been developed in the mathematics and physics literature over the last few years. The algebraic ... More
Finite-frequency noise of interacting single-electron emitters: spectroscopy with higher noise harmonicsMay 08 2018We derive the symmetrized current-noise spectrum of a quantum dot, which is weakly tunnel-coupled to an electron reservoir and driven by a slow time-dependent gate voltage. This setup can be operated as an on-demand emitter of single electrons into a ... More
A Fault-Tolerant Sequentially Consistent DSM With a Compositional Correctness ProofAug 08 2016We present the SC-ABD algorithm that implements sequentially consistent distributed shared memory (DSM). The algorithm tolerates that less than half of the processes are faulty (crash-stop). Compared to the multi-writer ABD algorithm, SC-ABD requires ... More
Optimizing electrically controlled echo sequences for the exchange-only qubitOct 14 2015Recently, West and Fong [New J. Phys. 14, 083002 (2012)] introduced an echo scheme for an exchange-only qubit, which relies entirely on the exchange-interaction. Here, we compare two different exchange-based sequences and two optimization strategies, ... More
Asymptotic scaling behavior of self-avoiding walks on critical percolation clustersSep 11 2014We study self-avoiding walks on three-dimensional critical percolation clusters using a new exact enumeration method. It overcomes the exponential increase in computation time by exploiting the clusters' fractal nature. We enumerate walks of over $10^4$ ... More
On Mean Field Limits for Dynamical SystemsJul 11 2013Sep 04 2015We present a purely probabilistic proof of propagation of molecular chaos for $N$-particle systems in dimension $3$ with interaction forces scaling like $1/\vert q\vert^{\lambda}$ with $\lambda<2$ and cut-off at $q = N^{-1/3}$. The proof yields a Gronwall ... More
Coherently controlled entanglement generation in a binary Bose-Einstein condensateFeb 09 2007Considering a two-component Bose-Einstein condensate in a double-well potential, a method to generate a Bell state consisting of two spatially separated condensates is suggested. For repulsive interactions, the required tunnelling control is achieved ... More
Quantum Deformations of the One-Dimensional Hubbard ModelFeb 06 2008May 21 2008The centrally extended superalgebra psu(2|2)xR^3 was shown to play an important role for the integrable structures of the one-dimensional Hubbard model and of the planar AdS/CFT correspondence. Here we consider its quantum deformation U_q(psu(2|2)xR^3) ... More
Variational Multi-Phase Segmentation using High-Dimensional Local FeaturesFeb 26 2019We propose a novel method for multi-phase segmentation of images based on high-dimensional local feature vectors. While the method was developed for the segmentation of extremely noisy crystal images based on localized Fourier transforms, the resulting ... More