cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Modular Hamiltonians of excited states, OPE blocks and emergent bulk fields
Creators: name: Sárosi, Gábor
name: Ugajin, Tomonori
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the entanglement entropy and the modular Hamiltonian of slightly excited states reduced to a ball shaped region in generic conformal field theories. We set up a formal expansion in the one point functions of the state in which all orders are explicitly given in terms of integrals of multi-point functions along the vacuum modular flow, without a need for replica index analytic continuation. We show that the quadratic order contributions in this expansion can be calculated in a way expected from holography, namely via the bulk canonical energy for the entanglement entropy, and its variation for the modular Hamiltonian. The bulk fields contributing to the canonical energy are defined via the HKLL procedure. In terms of CFT variables, the contribution of each such bulk field to the modular Hamiltonian is given by the OPE block corresponding to the dual operator integrated along the vacuum modular flow. These results do not rely on assuming large $N$ or other special properties of the CFT and therefore they are purely kinematic.
description: 40 pages, 2 figures. v3: some typos corrected, references added, extended discussion on convergence and holographic interpretation
How Do Academic Medicine Pathways Differ for Underrepresented Trainees and Physicians? A Critical Scoping Review
Creators: name: Russel, Sarah M.
name: Wright, Sarah T.
name: Carter, Taylor M.
name: Hirshfield, Laura E.
Publisher: name: Wolters Kluwer
Year: 2023

description:
PURPOSE: Academic medicine faces difficulty recruiting and retaining a diverse workforce. The proportion of medical students who are underrepresented in medicine (URiM) is smaller than the proportion of URiM's in the general population, and these numbers worsen with each step up the academic medicine ladder. Previously known as the "leaky pipeline," this phenomenon may be better understood as disparate "pathways with potholes," which acknowledges the different structural barriers that URiM trainees and faculty face in academic medicine. This critical scoping review analyzed current literature to determine what variables contribute to the inequitable "pathways and potholes" URiM physicians experience in academic medicine. METHOD: The authors combined scoping review methodology with a critical lens. The comprehensive search strategy used terms about academic medicine, underrepresented groups, and leaving academic medical careers. One reviewer conducted screening, full text review, and data extraction while in consultation with members of the research team. Data extraction focused on themes related to pathways and potholes, such as attrition, recruitment, and retention in academic medicine. Themes were iteratively merged, and quality of contribution to the field and literature gaps were noted. RESULTS: Included papers clustered into attrition, recruitment, and retention. Those pertaining to attrition noted that URiM faculty are less likely to get promoted even when controlling for scholarly output, and a hostile work environment may exacerbate attrition. Recruitment and retention strategies were most effective when multi-pronged approaches changed every step of the recruitment and promotion processes. CONCLUSIONS: These studies provide examples of various "potholes" that can affect representation in academic medicine of URiM trainees and faculty. However, only a few studies examined the link between isolating and hostile work environments, the so-called "chilly climate," and attrition from academic medicine. Understanding these concepts is key to producing the most effective interventions to improve diversity in medicine.
Glueball spectrum from $N_f=2$ lattice QCD study on anisotropic lattices
Creators: name: Sun, Wei
name: Gui, Long-Cheng
name: Chen, Ying
name: Gong, Ming
name: Liu, Chuan
name: Liu, Yu-Bin
name: Liu, Zhaofeng
name: Ma, Jian-Ping
name: Zhang, Jian-Bo
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The lowest-lying glueballs are investigated in lattice QCD using $N_f=2$ clover Wilson fermion on anisotropic lattices. We simulate at two different and relatively heavy quark masses, corresponding to physical pion mass of $m_π\sim 938$ MeV and $650$ MeV. The quark mass dependence of the glueball masses have not been investigated in the present study. Only the gluonic operators built from Wilson loops are utilized in calculating the corresponding correlation functions. In the tensor channel, we obtain the ground state mass to be 2.363(39) GeV and 2.384(67) GeV at $m_π\sim 938$ MeV and $650$ MeV, respectively. In the pseudoscalar channel, when using the gluonic operator whose continuum limit has the form of $ε_{ijk}TrB_iD_jB_k$, we obtain the ground state mass to be 2.573(55) GeV and 2.585(65) GeV at the two pion masses. These results are compatible with the corresponding results in the quenched approximation. In contrast, if we use the topological charge density as field operators for the pseudoscalar, the masses of the lowest state are much lighter (around 1GeV) and compatible with the expected masses of the flavor singlet $q\bar{q}$ meson. This indicates that the operator $ε_{ijk}TrB_iD_jB_k$ and the topological charge density couple rather differently to the glueball states and $q\bar{q}$ mesons. The observation of the light flavor singlet pseudoscalar meson can be viewed as the manifestation of effects of dynamical quarks. In the scalar channel, the ground state masses extracted from the correlation functions of gluonic operators are determined to be around 1.4-1.5 GeV, which is close to the ground state masses from the correlation functions of the quark bilinear operators. In all cases, the mixing between glueballs and conventional mesons remains to be further clarified in the future.
description: 14 pages, 8 figures, 9 tables; typos fixed, minor modifications, match the published version
Gravitational Waves, baryon asymmetry of the universe and electric dipole moment in the CP-violating NMSSM
Creators: name: Bian, Ligong
name: Guo, Huai-Ke
name: Shu, Jing
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work, we make the first study of electroweak baryogenesis (EWBG) based on the LHC data in the CP-violating next-to-minimal supersymmetric model (NMSSM) where a strongly first order electroweak phase transition (EWPT) is obtained in the general complex Higgs potential. With representative benchmark points which pass the current LEP and LHC constraints, we demonstrate the structure of EWPT for those points and how a strongly first order EWPT is obtained in the complex NMSSM where the resulting gravitational wave production properties are found to be within the reaches of future space-based interferometers like BBO and Ultimate-DECIGO. We further calculate the generated baryon asymmetries where the CP violating sources are (1): higgsino-singlino dominated, (2): higgsino-gaugino dominated or (3): from both sources. It is shown that all three representing scenarios could evade the strong constraints set by various electric dipole moments (EDM) searches where cancellations among the EDM contributions occur at the tree level (higgsino-singlino dominated) or loop level (higgsino-gaugino dominated). The 125 GeV SM like Higgs can be either the second lightest neutral Higgs $H_2$ or the third lightest neutral Higgs $H_3$. Finally, we comment on the future direct and indirect probe of CPV in the Higgs sector from the collider and EDM experiments.
description: 17 pages, 5 figures
Characterizing the zenithal night sky brightness in large territories: How many samples per square kilometer are needed?
Creators: name: Bará, Salvador
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: A recurring question arises when trying to characterize, by means of measurements or theoretical calculations, the zenithal night sky brightness throughout a large territory: how many samples per square kilometer are needed? The optimum sampling distance should allow reconstructing, with sufficient accuracy, the continuous zenithal brightness map across the whole region, whilst at the same time avoiding unnecessary and redundant oversampling. This paper attempts to provide some tentative answers to this issue, using two complementary tools: the luminance structure function and the Nyquist-Shannon spatial sampling theorem. The anaysis of several regions of the world, based on the data from the New world atlas of artificial night sky brightness (Falchi et al 2016, Sci. Adv. 2, e1600377) suggests that, as a rule of thumb, about one measurement per square kilometer could be sufficient for determining the zenithal night sky brightness of artificial origin at any point in a region to within 0.1 magV/arcsec2 (in the root-mean-square sense) of its true value in the Johnson-Cousins V band. The exact reconstruction of the zenithal night sky brightness maps from samples taken at the Nyquist rate seems to be considerably more demanding.
description: Accepted version, Monthly Notices of the Royal Astronomical Society
On perfect clustering of high dimension, low sample size data
Creators: name: Sarkar, Soham
name: Ghosh, Anil K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences
subject: 62H30

description: Popular clustering algorithms based on usual distance functions (e.g., Euclidean distance) often suffer in high dimension, low sample size (HDLSS) situations, where concentration of pairwise distances has adverse effects on their performance. In this article, we use a dissimilarity measure based on the data cloud, called MADD, which takes care of this problem. MADD uses the distance concentration phenomenon to its advantage, and as a result, clustering algorithms based on MADD usually perform better for high dimensional data. Using theoretical and numerical results, we amply demonstrate it in this article. We also address the problem of estimating the number of clusters. This is a very challenging problem in cluster analysis, and several algorithms have been proposed for it. We show that many of these existing algorithms have superior performance in high dimensions when MADD is used instead of the Euclidean distance. We also construct a new estimator based on penalized Dunn index and prove its consistency in the HDLSS asymptotic regime, where the sample size remains fixed and the dimension grows to infinity. Several simulated and real data sets are analyzed to demonstrate the importance of MADD for cluster analysis of high dimensional data.
Entanglement Entropy in Integrable Field Theories with Line Defects I. Topological Defect
Creators: name: Jiang, Yunfeng
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper and a companion one, we study the effect of integrable line defects on entanglement entropy in massive integrable field theories in 1+1 dimensions. The current paper focuses on topological defects that are purely transmissive. Using the form factor bootstrap method, we show that topological defects do not affect the the entanglement entropy in the UV limit and modify slightly the leading exponential correction in the IR. This conclusion holds for both unitary and non-unitary field theories. In contrast, non-topological defects affect the entanglement entropy more significantly both in UV and IR limit and will be studied in the companion paper.
description: 30 pages, references added, typos corrected
Sutured Manifolds and Polynomial Invariants from Higher Rank Bundles
Creators: name: Daemi, Aliakbar
name: Xie, Yi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Geometric Topology (math.GT)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 57R58, 57R57, 57M27

description: For each integer $N\geq 2$, Mariño and Moore defined generalized Donaldson invariants by the methods of quantum field theory, and made predictions about the values of these invariants. Subsequently, Kronheimer gave a rigorous definition of generalized Donaldson invariants using the moduli spaces of anti-self-dual connections on hermitian vector bundles of rank $N$. In this paper, Mariño and Moore's predictions are confirmed for simply connected elliptic surfaces without multiple fibers and certain surfaces of general type in the case that $N=3$. The primary motivation is to study 3-manifold instanton Floer homologies which are defined by higher rank bundles. In particular, the computation of the generalized Donaldson invariants are exploited to define a Floer homology theory for sutured 3-manifolds.
description: 105 pages, 5 figures. v2: exposition of gluing theory results improved, typos and minor mistakes fixed
Dynamics in quantum Ising chain driven by inhomogeneous transverse magnetization
Creators: name: Bhattacharyya, Sirshendu
name: Dasgupta, Subinay
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the dynamics caused by transport of transverse magnetization in one dimensional transverse Ising chain at zero temperature. We observe that a class of initial states having product structure in fermionic momentum-space and satisfying certain criteria, produce spatial variation in transverse magnetization. Starting from such a state, we obtain the transverse magnetization analytically and then observe its dynamics in presence of a homogeneous constant field $Γ$. In contradiction with general expectation, whatever be the strength of the field, the magnetization of the system does not become homogeneous even after infinite time. At each site, the dynamics is associated with oscillations having two different timescales. The envelope of the larger timescale oscillation decays algebraically with an exponent which is invariant for all such special initial states. The frequency of this oscillation varies differently with external field in ordered and disordered phases. The local magnetization after infinite time also characterizes the quantum phase transition.
description: 7 pages, 4 figures
The induced motion of a probe coupled to a bath with random resettings
Creators: name: Maes, Christian
name: Thiery, Thimothée
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider a probe linearly coupled to the center of mass of a nonequilibrium bath. We study the induced motion on the probe for a model where a resetting mechanism is added to an overdamped bath dynamics with quadratic potentials. The fact that each bath-particle is at random times being reset to a fixed position is known for optimizing diffusive search strategies, but here stands for the nonequilibrium aspect of the bath. In the large bath scaling limit the probe is governed by an effective Langevin equation. Depending on the value of the parameters, there appear three regimes: (i) an equilibrium-like regime but with a reduced friction and an increased effective temperature; (ii) a regime where the noise felt by the probe is continuous but nonGaussian and exhibits fat-tails; (iii) a regime with a nonGaussian noise exhibiting power-law distributed jumps. The model thus represents an exactly solvable case for the origin of nonequilibrium probe dynamics.
description: 17 pages, 4 figures; v2: refs updated, published version
The complexity of Boolean surjective general-valued CSPs
Creators: name: Fulla, Peter
name: Uppman, Hannes
name: Zivny, Stanislav
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computational Complexity (cs.CC)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences
subject: F.2.0

description: Valued constraint satisfaction problems (VCSPs) are discrete optimisation problems with a $(\mathbb{Q}\cup\{\infty\})$-valued objective function given as a sum of fixed-arity functions. In Boolean surjective VCSPs, variables take on labels from $D=\{0,1\}$ and an optimal assignment is required to use both labels from $D$. Examples include the classical global Min-Cut problem in graphs and the Minimum Distance problem studied in coding theory. We establish a dichotomy theorem and thus give a complete complexity classification of Boolean surjective VCSPs with respect to exact solvability. Our work generalises the dichotomy for $\{0,\infty\}$-valued constraint languages (corresponding to surjective decision CSPs) obtained by Creignou and Hébrard. For the maximisation problem of $\mathbb{Q}_{\geq 0}$-valued surjective VCSPs, we also establish a dichotomy theorem with respect to approximability. Unlike in the case of Boolean surjective (decision) CSPs, there appears a novel tractable class of languages that is trivial in the non-surjective setting. This newly discovered tractable class has an interesting mathematical structure related to downsets and upsets. Our main contribution is identifying this class and proving that it lies on the borderline of tractability. A crucial part of our proof is a polynomial-time algorithm for enumerating all near-optimal solutions to a generalised Min-Cut problem, which might be of independent interest.
description: v5: small corrections and improved presentation
Entanglement Entropy in Integrable Field Theories with Line Defects II. Non-topological Defect
Creators: name: Jiang, Yunfeng
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: This is the second part of two papers where we study the effect of integrable line defects on bipartite entanglement entropy in integrable field theories. In this paper, we consider non-topological line defects in Ising field theory. We derive an infinite series expression for the entanglement entropy and show that both the UV and IR limits of the bulk entanglement entropy are modified by the line defect. In the UV limit, we give an infinite series expression for the coefficient in front of the logarithmic divergence and the exact defect $g$-function. By tuning the defect to be purely transmissive and reflective, we recover correctly the entanglement entropy of the bulk and with integrable boundary.
description: 30 pages, references added, typos corrected, publication version
The irreversible thermodynamics of curved lipid membranes
Creators: name: Sahu, Amaresh
name: Sauer, Roger A.
name: Mandadapu, Kranthi K.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: Cell Behavior (q-bio.CB)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The theory of irreversible thermodynamics for arbitrarily curved lipid membranes is presented here. The coupling between elastic bending and irreversible processes such as intra-membrane lipid flow, intra-membrane phase transitions, and protein binding and diffusion is studied. The forms of the entropy production for the irreversible processes are obtained, and the corresponding thermodynamic forces and fluxes are identified. Employing the linear irreversible thermodynamic framework, the governing equations of motion along with appropriate boundary conditions are provided.
description: 62 pages, 4 figures
Time-frequency analysis of ship wave patterns in shallow water: modelling and experiments
Creators: name: Pethiyagoda, Ravindra
name: Moroney, Timothy J.
name: MacFarlane, Gregor J.
name: Binns, Jonathan R.
name: McCue, Scott W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: A spectrogram of a ship wake is a heat map that visualises the time-dependent frequency spectrum of surface height measurements taken at a single point as the ship travels by. Spectrograms are easy to compute and, if properly interpreted, have the potential to provide crucial information about various properties of the ship in question. Here we use geometrical arguments and analysis of an idealised mathematical model to identify features of spectrograms, concentrating on the effects of a finite-depth channel. Our results depend heavily on whether the flow regime is subcritical or supercritical. To support our theoretical predictions, we compare with data taken from experiments we conducted in a model test basin using a variety of realistic ship hulls. Finally, we note that vessels with a high aspect ratio appear to produce spectrogram data that contains periodic patterns. We can reproduce this behaviour in our mathematical model by using a so-called two-point wavemaker. These results highlight the role of wave interference effects in spectrograms of ship wakes.
description: 14 pages, 7 figures
Obtaining time-dependent multi-dimensional dividing surfaces using Lagrangian descriptors
Creators: name: Feldmaier, Matthias
name: Junginger, Andrej
name: Main, Jörg
name: Wunner, Günter
name: Hernandez, Rigoberto
Publisher: name: arXiv
Year: 2017
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: Dynamics between reactants and products are often mediated by a rate-determining barrier and an associated dividing surface leading to the transition state theory rate. This framework is challenged when the barrier is time-dependent because its motion can give rise to recrossings across the fixed dividing surface. A non-recrossing time-dependent dividing surface can nevertheless be attached to the TS trajectory resulting in recrossing-free dynamics. We extend the formalism---constructed using Lagrangian Descriptors---to systems with additional bath degrees of freedom. The propagation of reactant ensembles provides a numerical demonstration that our dividing surface is recrossing-free and leads to exact TST rates.
description: 55 pages, 4 figures, 66 references
Sensing Noncollinear Magnetism at the Atomic Scale Combining Magnetic Exchange and Spin-Polarized Imaging
Creators: name: Hauptmann, Nadine
name: Gerritsen, Jan W.
name: Wegner, Daniel
name: Khajetoorians, Alexander A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Storing and accessing information in atomic-scale magnets requires magnetic imaging techniques with single-atom resolution. Here, we show simultaneous detection of the spin-polarization and exchange force, with or without the flow of current, with a new method, which combines scanning tunneling microscopy and non-contact atomic force microscopy. To demonstrate the application of this new method, we characterize the prototypical nano-skyrmion lattice formed on a monolayer of Fe/Ir(111). We resolve the square magnetic lattice by employing magnetic exchange force microscopy, demonstrating its applicability to non-collinear magnetic structures, for the first time. Utilizing distance-dependent force and current spectroscopy, we quantify the exchange forces in comparison to the spin-polarization. For strongly spin-polarized tips, we distinguish different signs of the exchange force which we suggest arises from a change in exchange mechanisms between the probe and a skyrmion. This new approach may enable both non-perturbative readout combined with writing by current-driven reversal of atomic-scale magnets.
Deep Learning for Determination of Properties of Semidilute Polymer Solutions
Creators: name: Jacobs, Michael
name: Sayko, Ryan
name: Dobrynin, Andrey V.
name: Dominijanni, Marissa
Publisher: name: American Chemical Society (ACS)
Year: 2023

description:
The ability to predict polymer solution viscosity is essential for polymer characterization and processing. Here, we use a synergistic approach combining the scaling theory of polymer solutions and convolutional neural network (CNN) models to obtain system-specific parameters and describe semidilute solution viscosity in the unentangled and entangled solution regimes. The scaling approach relies on the existence of a characteristic microscopic length scalethe solution correlation length (correlation blob size) ξwhich uniquely defines macroscopic solution properties. It is based on a relationship between the solution correlation length ξ = lg ν/B and the number of monomers g per correlation volume for polymers with the monomer projection length l. The system-specific set of parameters B g, B th, and 1 in the corresponding solution regime with the scaling exponent ν = 0.588, 0.5, and 1, respectively. Applying two CNN models, we obtained the sets B g and B th from the solution specific viscosity, ηsp, as a function of concentration, c, and weight-average degree of polymerization, N w. The CNN was trained on theoretically generated datasets converted to sparse images representing the normalized specific viscosity ηsp/N w (cl 3)1/(3ν–1) in the unentangled Rouse regime. The trained CNN was utilized in automated data analysis of the solution viscosity of polystyrene, poly­(ethylene oxide), poly­(methyl methacrylate), poly­(acrylonitrile-co-itaconic acid), cellulose, sodium hyaluronate, hydroxypropyl methyl cellulose, methyl cellulose, hydroxypropyl cellulose, cellulose tris­(phenyl carbamate), xanthan gum, galactomannan, and sodium κ-carrageenan in water, organic solvents, and ionic liquids. This approach produced values of the B-parameters with mean absolute percentage differences of less than 6% from the corresponding values determined by the manual data analysis. The B-parameters are then used to obtain the packing number P e defining the onset of entanglements in polymer solutions and to describe semidilute solution viscosity as a function of concentration and N w.
Stability for gains from large investors' strategies in M1/J1 topologies
Creators: name: Becherer, Dirk
name: Bilarev, Todor
name: Frentrup, Peter
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Finance (q-fin.MF)
subject: Probability (math.PR)
subject: FOS: Economics and business
subject: FOS: Mathematics
subject: 60H10, 60H20, 60G17, 91G99, 93E20

description: We prove continuity of a controlled SDE solution in Skorokhod's $M_1$ and $J_1$ topologies and also uniformly, in probability, as a non-linear functional of the control strategy. The functional comes from a finance problem to model price impact of a large investor in an illiquid market. We show that $M_1$-continuity is the key to ensure that proceeds and wealth processes from (self-financing) càdlàg trading strategies are determined as the continuous extensions for those from continuous strategies. We demonstrate by examples how continuity properties are useful to solve different stochastic control problems on optimal liquidation and to identify asymptotically realizable proceeds.
description: Some important corrections
title: „Das wird man ja wohl noch sagen dürfen“?
title: Zum Umgang mit Verschwörungstheorien und extremistischen Aussagen in Schule und Unterricht
titleType: Subtitle
Creators: name: Dittgen, Michell W.
name: Drewes, Oliver
Publisher: name: Universität Trier
Year: 2023
Subjects: subject: Unterricht
valueUri: http://d-nb.info/gnd/4062005-0
subject: Radikalismus
valueUri: http://d-nb.info/gnd/4048171-2
subject: Verschwörungstheorie
valueUri: http://d-nb.info/gnd/4138784-3

description: Sie haben eine spannende politische Diskussion in der Klasse. Das Gros Ihrer Schüler*innen ist wach, interessiert und engagiert. Alles läuft prima. Doch dann passiert's: Einer oder eine von ihnen stellt – absichtlich oder unreflektiert – eine extremistische oder verschwörungstheoretische Aussage in den Raum. Und nun?
Long-range topological insulators and weakened bulk-boundary correspondence
Creators: name: Lepori, L.
name: Dell'Anna, L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We formalize the appearance of new types of insulators in long-range (LR) fermionic systems. These phases are not included in the "ten-fold way classification" (TWC) for the short-range (SR) topological insulators. This conclusion is obtained studying at first specific one-dimensional LR examples, in particular their phase diagrams and contents in symmetries and entanglement. The purely long-range phases (LRP) are signaled by the violation of the area-law for the Von Neumann entropy and by corresponding peculiar distributions for the entanglement spectrum (ES). The origin of the deviations from the TWC is analyzed from a more general point of view and in any dimension. In particular, it is found related with a particular type of divergences occurring in the spectrum, due to the LR couplings. A satisfying characterization for the LRP can be achieved at least for one-dimensional systems, as well as the connected definition of a nontrivial topology, provided a careful evaluation of the LR contributions. Our results lead to reconsider the definition of correlation length in LR systems. The same analysis also allows to infer, at least for one-dimensional models, the weakening of the bulk-boundary correspondence, due to the important correlations between bulk and edges, and consequently to clarify the nature of the massive edge states appearing in the topological LR. The emergence of this peculiar edge structure is signaled by the bulk ES. The stability of the LRP against finite-size effects, relevant in current experiments, and against local disorder is discussed, showing that the latter ingredient can even strengthen the effect of the LR couplings. Finally, we analyze the entanglement content of the paradigmatic LR Ising spin chain, inferring again important deviations from the SR regime, and the limitations of bulk-boundary (tensor-network based) approaches to classify LR spin models.
Optimal Output Consensus of High-Order Multi-Agent Systems with Embedded Technique
Creators: name: Tang, Yutao
name: Deng, Zhenhua
name: Hong, Yiguang
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this paper, we study an optimal output consensus problem for a multi-agent network with agents in the form of multi-input multi-output minimum-phase dynamics. Optimal output consensus can be taken as an extended version of the existing output consensus problem for higher-order agents with an optimization requirement, where the output variables of agents are driven to achieve a consensus on the optimal solution of a global cost function. To solve this problem, we first construct an optimal signal generator, and then propose an embedded control scheme by embedding the generator in the feedback loop. We give two kinds of algorithms based on different available information along with both state feedback and output feedback, and prove that these algorithms with the embedded technique can guarantee the solvability of the problem for high-order multi-agent systems under standard assumptions.
description: 23 page, 5 figures, accepted by IEEE Transactions on Cybernetics
Closed Superstring Field Theory and its Applications
Creators: name: de Lacroix, Corinne
name: Erbin, Harold
name: Kashyap, Sitender Pratap
name: Sen, Ashoke
name: Verma, Mritunjay
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We review recent developments in the construction of heterotic and type II string field theories and their various applications. These include systematic procedures for determining the shifts in the vacuum expectation values of fields under quantum corrections, computing renormalized masses and S-matrix of the theory around the shifted vacuum and a proof of unitarity of the S-matrix. The S-matrix computed this way is free from all divergences when there are more than 4 non-compact space-time dimensions, but suffers from the usual infrared divergences when the number of non-compact space-time dimensions is 4 or less.
description: review article, LaTeX, 137 pages; v2: references updated, other minor changes
Ising anyonic topological phase of interacting Fermions in one dimension
Creators: name: Guther, Kai
name: Lang, Nicolai
name: Büchler, Hans Peter
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study a microscopic model of interacting fermions in a ladder setup, where the total number of particles is conserved. At a special point, the ground state is known and gives rise to a topological state of matter with edge modes obeying the statistics of Ising anyons. Using a combination of bosonization as well as full scale numerical density-matrix renormalization group analysis, we map out the full phase diagram. We nd that the topological phase survives in an extended parameter regime. Remarkably, an additional symmetry is required to protect the topological phase.
description: 9 pages, 5 figures
Engineering Algorithms for Dynamic and Time-Dependent Route Planning
Creators: name: Zeitz, Tim
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2022

description: Efficiently computing shortest paths is an essential building block of many mobility applications, most prominently route planning/navigation devices and applications. In this thesis, we apply the algorithm engineering methodology to design algorithms for route planning in dynamic (for example, considering real-time traffic) and time-dependent (for example, considering traffic predictions) problem settings. We build on and extend the popular Contraction Hierarchies (CH) speedup technique. With a few minutes of preprocessing, CH can optimally answer shortest path queries on continental-sized road networks with tens of millions of vertices and edges in less than a millisecond, i.e. around four orders of magnitude faster than Dijkstra’s algorithm. CH already has been extended to dynamic and time-dependent problem settings. However, these adaptations suffer from limitations. For example, the time-dependent variant of CH exhibits prohibitive memory consumption on large road networks with detailed traffic predictions. This thesis contains the following key contributions: First, we introduce CH-Potentials, an A*-based routing framework. CH-Potentials computes optimal distance estimates for A* using CH with a lower bound weight function derived at preprocessing time. The framework can be applied to any routing problem where appropriate lower bounds can be obtained. The achieved speedups range between one and three orders of magnitude over Dijkstra’s algorithm, depending on how tight the lower bounds are. Second, we propose several improvements to Customizable Contraction Hierarchies (CCH), the CH adaptation for dynamic route planning. Our improvements yield speedups of up to an order of magnitude. Further, we augment CCH to efficiently support essential extensions such as turn costs, alternative route computation and point-of-interest queries. Third, we present the first space-efficient, fast and exact speedup technique for time-dependent routing. Compared to the previous time-dependent variant of CH, our technique requires up to 40 times less memory, needs at most a third of the preprocessing time, and achieves only marginally slower query running times. Fourth, we generalize A* and introduce time-dependent A* potentials. This allows us to design the first approach for routing with combined live and predicted traffic, which achieves interactive running times for exact queries while allowing live traffic updates in a fraction of a minute. Fifth, we study extended problem models for routing with imperfect data and routing for truck drivers and present efficient algorithms for these variants. Sixth and finally, we present various complexity results for non-FIFO time-dependent routing and the extended problem models.
Peeling Property of Bondi-Sachs metrics for nonzero Cosmological Constant
Creators: name: Xie, Fangquan
name: Zhang, Xiao
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In this paper, we show that the peeling property still holds for Bondi-Sachs metrics with nonzero cosmological constant under the boundary condition given by Sommerfeld's radiation condition together with three nontrivial $Λ$-independent functions $B$, $a$, $b$. This should indicate the new boundary condition is natural. Moreover, we construct some nonstationary vacuum Bondi-Sachs metrics without Bondi news, which Newmann-Penrose quantities fall faster than usual. This provides a new feature of gravitational waves for nonzero cosmological constant.
description: 12 pages, final version, to appear in Science China Mathematics
Bispectrum Inversion with Application to Multireference Alignment
Creators: name: Bendory, Tamir
name: Boumal, Nicolas
name: Ma, Chao
name: Zhao, Zhizhen
name: Singer, Amit
Publisher: name: arXiv
Year: 2017
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We consider the problem of estimating a signal from noisy circularly-translated versions of itself, called multireference alignment (MRA). One natural approach to MRA could be to estimate the shifts of the observations first, and infer the signal by aligning and averaging the data. In contrast, we consider a method based on estimating the signal directly, using features of the signal that are invariant under translations. Specifically, we estimate the power spectrum and the bispectrum of the signal from the observations. Under mild assumptions, these invariant features contain enough information to infer the signal. In particular, the bispectrum can be used to estimate the Fourier phases. To this end, we propose and analyze a few algorithms. Our main methods consist of non-convex optimization over the smooth manifold of phases. Empirically, in the absence of noise, these non-convex algorithms appear to converge to the target signal with random initialization. The algorithms are also robust to noise. We then suggest three additional methods. These methods are based on frequency marching, semidefinite relaxation and integer programming. The first two methods provably recover the phases exactly in the absence of noise. In the high noise level regime, the invariant features approach for MRA results in stable estimation if the number of measurements scales like the cube of the noise variance, which is the information-theoretic rate. Additionally, it requires only one pass over the data which is important at low signal-to-noise ratio when the number of observations must be large.
Ansicht der Gebirgkette über Zürich : aus dem Beckenhof nach der Natur gezeichnet
Creators: name: [s.n.]
Publisher: name: [s.n.]
Year: 1787
Subjects: Zürich

description: [David Hess ?]
description: Vergleiche: David Hess:  Ansicht der Gebirgkette über Zürich, circa 1808, Signatur: S Z Zürich VI 40
Does universal controllability of physical systems prohibit thermodynamic cycles?
Creators: name: Janzing, Dominik
name: Wocjan, Pawel
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Here we study the thermodynamic cost of computation and control using 'physically universal' cellular automata or Hamiltonians. The latter were previously defined as systems that admit the implementation of any desired transformation on a finite target region by first initializing the state of the surrounding and then letting the system evolve according to its autonomous dynamics. This way, one obtains a model of control where each region can play both roles the controller or the system to be controlled. In physically universal systems every degree of freedom is indirectly accessible by operating on the remaining degrees of freedom. In a nutshell, the thermodynamic cost of an operation is then given by the size of the region around the target region that needs to be initialized. In the meantime, physically universal CAs have been constructed by Schaeffer (in two dimensions) and Salo & Törmä (in one dimension). Here we show that in Schaeffer's CA the cost for implementing $n$ operations grows linearly in $n$, while operating in a thermodynamic cycle requires sublinear growth to ensure zero cost *per operation* in the limit $n\to\infty$. Although this particular result need not hold for general physically universal CAs, this strong notion of universality does imply a certain kind of instability of information, which could result in lower bounds on the cost of protecting information from its noisy environment. The technical results of the paper are sparse and quite simple. The contribution of the paper is mainly conceptual and consists in illustrating the type of thermodynamic questions raised by models of control that rely on the concept of physical universality.
description: 19 pages, 7 figures
Instabilities and spin-up behaviour of a rotating magnetic field driven flow in a rectangular cavity
Creators: name: Galindo, V.
name: Nauber, R.
name: Räbiger, D.
name: Franke, S.
name: Beyer, H.
name: Büttner, L.
name: Czarske, J.
name: Eckert, S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: This study presents numerical simulations and experiments considering the flow of an electrically conducting fluid inside a cube driven by a rotating magnetic field (RMF). The investigations are focused on the spin-up, where a liquid metal (GaInSn) is suddenly exposed to an azimuthal body force generated by the RMF, and the subsequent flow development. The numerical simulations rely on a semi-analytical expression for the induced electromagnetic force density in an electrically conducting medium inside a cuboid container with insulating walls. Velocity distributions in two perpendicular planes are measured using a novel dual-plane, two-component ultrasound array Doppler velocimeter (UADV) with continuous data streaming, enabling long term measurements for investigating transient flows. This approach allows to identify the main emerging flow modes during the transition from a stable to unstable flow regimes with exponentially growing velocity oscillations using the Proper Orthogonal Decomposition (POD) method. Characteristic frequencies in the oscillating flow regimes are determined in the super critical range above the critical magnetic Taylor number $Ta_c \approx 1.26 \times 10^5$, where the transition from the steady double vortex structure of the secondary flow to an unstable regime with exponentially growing oscillations is detected. The mean flow structures and the temporal evolution of the flow predicted by the numerical simulations and observed in experiments are in very good agreement.
description: 34 pages, 25 figures, submitted to Physics of Fluids
Mutual Uncertainty, Conditional Uncertainty and Strong Sub-Additivity
Creators: name: Sazim, Sk
name: Adhikari, Satyabrata
name: Pati, Arun K.
name: Agrawal, Pankaj
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce a new concept called as the mutual uncertainty between two observables in a given quantum state which enjoys similar features like the mutual information for two random variables. Further, we define the conditional uncertainty as well as conditional variance and show that conditioning on more observable reduces the uncertainty. Given three observables, we prove a 'strong sub-additivity' relation for the conditional uncertainty under certain condition. As an application, we show that using the conditional variance one can detect bipartite higher dimensional entangled states. The efficacy of our detection method lies in the fact that it gives better detection criteria than most of the existing criteria based on geometry of the states. Interestingly, we find that for $N$-qubit product states, the mutual uncertainty is exactly equal to $N-\sqrt{N}$, and if it is other than this value, the state is entangled. We also show that using the mutual uncertainty between two observables, one can detect non-Gaussian steering where Reid's criteria fails to detect. Our results may open up a new direction of exploration in quantum theory and quantum information using the mutual uncertainty, conditional uncertainty and the strong sub-additivity for multiple observables.
description: 9 pages, 1 figure. V3: Contains new results: a) a new entanglement detection criteria and b) a new steering criteria. Accepted for publication in Phys. Rev. A (2018)
Direct observation of giant binding energy modulation of exciton complexes in monolayer MoSe$_2$
Creators: name: Gupta, Garima
name: Kallatt, Sangeeth
name: Majumdar, Kausik
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Screening due to surrounding dielectric medium reshapes the electron-hole interaction potential and plays a pivotal role in deciding the binding energies of strongly bound exciton complexes in quantum confined monolayers of transition metal dichalcogenides (TMDs). However, owing to strong quasi-particle bandgap renormalization in such systems, a direct quantification of estimated shifts in binding energy in different dielectric media remains elusive using optical studies. In this work, by changing the dielectric environment, we show a conspicuous photoluminescence (PL) peak shift at low temperature for higher energy excitons (2s, 3s, 4s, 5s) in monolayer MoSe$_2$, while the 1s exciton peak position remains unaltered - a direct evidence of varying compensation between screening induced exciton binding energy modulation and quasi-particle bandgap renormalization. The estimated modulation of binding energy for the 1s exciton is found to be 58.6% (70.5% for 2s, 78.9% for 3s, 85% for 4s) by coating an Al$_2$O$_3$ layer on top, while the corresponding reduction in quasi-particle bandgap is estimated to be 248 meV. Such a direct evidence of large tunability of the binding energy of exciton complexes as well as the bandgap in monolayer TMDs holds promise of novel device applications.
description: 19 pages including supplemental information