cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Permutation Meets Parallel Compressed Sensing: How to Relax Restricted Isometry Property for 2D Sparse Signals
Creators: name: Fang, Hao
name: Vorobyov, Sergiy A.
name: Jiang, Hai
name: Taheri, Omid
Publisher: name: arXiv
Year: 2013
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Traditional compressed sensing considers sampling a 1D signal. For a multidimensional signal, if reshaped into a vector, the required size of the sensing matrix becomes dramatically large, which increases the storage and computational complexity significantly. To solve this problem, we propose to reshape the multidimensional signal into a 2D signal and sample the 2D signal using compressed sensing column by column with the same sensing matrix. It is referred to as parallel compressed sensing, and it has much lower storage and computational complexity. For a given reconstruction performance of parallel compressed sensing, if a so-called acceptable permutation is applied to the 2D signal, we show that the corresponding sensing matrix has a smaller required order of restricted isometry property condition, and thus, storage and computation requirements are further lowered. A zigzag-scan-based permutation, which is shown to be particularly useful for signals satisfying a layer model, is introduced and investigated. As an application of the parallel compressed sensing with the zigzag-scan-based permutation, a video compression scheme is presented. It is shown that the zigzag-scan-based permutation increases the peak signal-to-noise ratio of reconstructed images and video frames.
description: 30 pages, 10 figures, 3 tables, submitted to the IEEE Trans. Signal Processing in November 2012
Automated Generation of Shuttling Sequences for a Linear Segmented Ion Trap Quantum Computer
Creators: name: Durandau, Jonathan
name: Wagner, Janis
name: Mailhot, Frédéric
name: Brunet, Charles-Antoine
name: Schmidt-Kaler, Ferdinand
name: Poschinger, Ulrich
name: Bérubé-Lauzière, Yves
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A promising approach for scaling-up trapped-ion quantum computer platforms is by storing multiple trapped-ion qubit sets ('ion crystals') in segmented microchip traps and to interconnect these via physical movement of the ions ('shuttling'). Already for realizing quantum circuits with moderate complexity, the design of suitable qubit assignments and shuttling schedules require automation. Here, we describe and test algorithms which address exactly these tasks. We describe an algorithm for fully automated generation of shuttling schedules, complying to constraints imposed by a given trap structure. Furthermore, we introduce different methods for initial qubit assignment and compare these for random circuit (of up to 20 qubits) and quantum Fourier transform-like circuits, and generalized Toffoli gates of up to 40 qubits each. We find that for quantum circuits which contain a fixed structure, advanced assignment algorithms can serve to reduce the shuttling overhead.
The far emission region of the gamma-ray blazar PKS B1424-418
Creators: name: Tavecchio, F.
name: Pacciani, L.
name: Donnarumma, I.
name: Stamerra, A.
name: Isler, J.
name: MacPherson, E.
name: Urry, C. M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report multi-wavelength (IR-O, UV, X-ray, gamma-ray) data of the flat spectrum radio quasar (FSRQ) PKS B1424-418 (z=1.52) gathered during an active phase in 2013 April . As for a few other cases of FSRQs reported in literature, the detection by the Large Area Telescope onboard Fermi of gamma rays with energy above 10 GeV indicates that the emission likely occurs beyond the highly opaque (tau ~10) broad line region. This conclusion is strengthened by a model fit to the spectral energy distribution, which allows us to locate the emission region even beyond the distance generally assumed for the dusty torus. The consequent large size (~1 pc) inferred for the emission region cannot account for the observed daily-scale variability of the gamma-ray flux. We discuss the possibility that short-term variability results from fast magnetic reconnection events, as proposed in recent works.
description: 5 pages, 3 figures, accepted for publication in MNRAS Letters
Identification of the Long-Sought Common-Envelope Events
Creators: name: Ivanova, N.
name: Justham, S.
name: Nandez, J. L. Avendano
name: Lombardi, J. C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Common-envelope events (CEEs), during which two stars temporarily orbit within a shared envelope, are believed to be vital for the formation of a wide range of close binaries. For decades, the only evidence that CEEs actually occur has been indirect, based on the existence of systems that could not be otherwise explained. Here we propose a direct observational signature of CEE arising from a physical model where emission from matter ejected in a CEE is controlled by a recombination front as the matter cools. The natural range of timescales and energies from this model, as well the expected colors, light-curve shapes, ejection velocities and event rate, match those of a recently-recognized class of red transient outbursts.
description: 6 main and 22 supplemental pages, 5 total figures, one table and 2 movies. This is the authors version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science, vol 339, 2013, http://www.sciencemag.org/content/339/6118/433.abstract
Rings of Frobenius operators
Creators: name: Katzman, Mordechai
name: Schwede, Karl
name: Singh, Anurag K.
name: Zhang, Wenliang
Publisher: name: arXiv
Year: 2013
Subjects: subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: Primary 13A35, Secondary 13C11, 13D45, 13C40

description: Let R be a local ring of prime characteristic. We study the ring of Frobenius operators F(E), where E is the injective hull of the residue field of R. In particular, we examine the finite generation of F(E) over its degree zero component, and show that F(E) need not be finitely generated when R is a determinantal ring; nonetheless, we obtain concrete descriptions of F(E) in good generality that we use, for example, to prove the discreteness of F-jumping numbers for arbitrary ideals in determinantal rings.
Singly-excited resonant open quantum system Tavis-Cummings model with quantum circuit mapping
Creators: name: Marinkovic, Marina Krstic
name: Radulaski, Marina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Computational Physics (physics.comp-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Tavis-Cummings (TC) cavity quantum electrodynamical effects, describing the interaction of $N$ atoms with an optical resonator, are at the core of atomic, optical and solid state physics. The full numerical simulation of TC dynamics scales exponentially with the number of atoms. By restricting the open quantum system to a single excitation, typical of experimental realizations in quantum optics, we analytically solve the TC model with an arbitrary number of atoms with linear complexity. This solution allows us to devise the Quantum Mapping Algorithm of Resonator Interaction with $N$ Atoms (Q-MARINA), an intuitive TC mapping to a quantum circuit with linear space and time scaling, whose $N+1$ qubits represent atoms and a lossy cavity, while the dynamics is encoded through $2N$ entangling gates. Finally, we benchmark the robustness of the algorithm on a quantum simulator and superconducting quantum processors against the quantum master equation solution on a classical computer.
description: 15 pages, 4 figures
Intersubband electroluminescent devices operating in the strong coupling regime
Creators: name: Jouy, Pierre
name: Vasanelli, Angela
name: Todorov, Yanko
name: Sapienza, Luca
name: Colombelli, Raffaele
name: Gennser, Ulf
name: Sirtori, Carlo
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present a detailed study of the electroluminescence of intersubband devices operating in the light-matter strong coupling regime. The devices have been characterized by performing angle resolved spectroscopy that shows two distinct light intensity spots in the momentum-energy phase diagram. These two features of the electroluminescence spectra are associated with photons emitted from the lower polariton branch and from the weak coupling of the intersubband transition with an excited cavity mode. The same electroluminescent active region has been processed into devices with and without the optical microcavity to illustrate the difference between a device operating in the strong and weak coupling regime. The spectra are very well simulated as the product of the polariton optical density of states, and a function describing the energy window in which the polariton states are populated. The voltage evolution of the spectra shows that the strong coupling regime allows the observation of the electroluminescence at energies otherwise inaccessible.
Homologous self-assembled superlattices: What causes their periodic polarity switching? Review, model, and experimental test
Creators: name: Thakur, Varun
name: Benafsha, Dor
name: Turkulets, Yury
name: Azulay, Almog R.
name: Liang, Xin
name: Goldman, Rachel S.
name: Shalish, Ilan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Quantum semiconductor structures are commonly achieved by bandgap engineering that relies on the ability to switch from one semiconductor to another during their growth. Growth of a superlattice is typically demanding technologically. In contrast, accumulated evidence points to a tendency among a certain class of multiple-cation binary oxides to self-assemble spontaneously as superlattice structures. This class has been dubbed the homologous superlattices. For a famous example, when a mixture of indium and zinc is oxidized, the phases of In-O and ZnO separate in an orderly periodic manner, along the ZnO polar axis, with polarity inversion taking place between consecutive ZnO sections. As we review here, the same structure has been observed when the indium was replaced with other metals, and perhaps even in ZnO alone. This peculiar self-assembled structure has been attracting research over the past decade. The purpose of this study is to gain understanding of the physics underlying the formation of this unique structure. Here, we first provide an extensive review of the accumulated literature on these spontaneously-formed structures and then propose an explanation for the long-standing mystery of this intriguing self-assembly in the form of an electrostatic growth phenomenon and test the proposed model on experimental data.
Intrinsic alignments and 3d weak gravitational lensing
Creators: name: Merkel, Philipp M.
name: Schaefer, Bjoern Malte
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In this paper we show how intrinsic alignments can be incorporated consistently in the formalism of 3d weak lensing. We use two different descriptions of the intrinsic galaxy ellipticities, the so-called linear and quadratic model, respectively. For both models we derive the covariance matrix of the intrinsic alignment signal (II-alignments) and GI-alignments (the cross correlation of intrinsic and lensing induced ellipticities). Evaluating the covariance matrices for the linear model numerically and comparing the results to the cosmic shear signal we find that for a low redshift survey the total covariance matrix is dominated by the contributions of the II-alignments. For a Euclid-like survey II-alignments still dominate over GI-alignments but they are more than one order of magnitude smaller than the lensing signal. The shape of the ellipticity covariance matrices is quite different in the k-k'-plane for cosmic shear on the one hand and intrinsic alignments on the other hand. In comparison to lensing both alignment types tend to be rather elongated along the diagonal k=k'. Moreover, for high multipoles (l ~ 100) intrinsic alignments are strongly concentrated along that diagonal.
description: 13 pages, 5 figures, MNRAS accepted
An updated measurement of the Hubble constant from near-infrared observations of Type Ia supernovae
Creators: name: Galbany, Lluís
name: de Jaeger, Thomas
name: Riess, Adam G.
name: Müller-Bravo, Tomás E.
name: Dhawan, Suhail
name: Phan, Kim
name: Stritzinger, Maximillian
name: Karamehmetoglu, Emir
name: Leibundgut, Bruno
name: Peterson, Erik
name: Kenworthy, W. D'Arcy
name: Johansson, Joel
name: Maguire, Kate
name: Jha, Saurabh W.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a measurement of the Hubble constant ($H_0$) using type Ia supernova (SNe Ia) in the near-infrared (NIR) from the recently updated sample of SNe Ia in nearby galaxies with distances measured via Cepheid period-luminosity relations by the SHOES project. We collect public near-infrared photometry of up to 19 calibrator SNe Ia and further 57 SNe Ia in the Hubble flow ($z>0.01$), and directly measure their peak magnitudes in the $J$ and $H$ band by Gaussian processes and spline interpolation. Calibrator peak magnitudes together with Cepheid-based distances are used to estimate the average absolute magnitude in each band, while Hubble-flow SNe are used to constrain the zero-point intercept of the magnitude-redshift relation. Our baseline result of $H_0$ is $72.3\pm1.4$ (stat) $\pm1.4$ (syst) km s$^{-1}$ Mpc$^{-1}$ in the $J$ band and $72.3\pm1.3$ (stat) $\pm1.4$ (syst) km s$^{-1}$ Mpc$^{-1}$ in the $H$ band, where the systematic uncertainties include the standard deviation of up to 21 variations of the analysis, the 0.7\% distance scale systematic from SHOES Cepheid anchors, a photometric zeropoint systematic, and a cosmic variance systematic. Our final measurement represents a measurement with a precision of 2.8\% in both bands. The variant with the largest change in $H_0$ is when limiting the sample to SNe from CSP and CfA programmes, noteworthy because these are the best calibrated, yielding $H_0\sim75$ km s$^{-1}$ Mpc$^{-1}$ in both bands. We demonstrate stretch and reddening corrections are still useful in the NIR to standardize SN Ia NIR peak magnitudes. Based on our results, in order to improve the precision of the $H_0$ measurement with SNe Ia in the NIR in the future, we would need to increase the number of calibrator SNe Ia, be able to extend the Hubble-Lemaître diagram to higher-z, and include standardization procedures to help reducing the NIR intrinsic scatter.
description: 15 pages, 8 figures. Accepted in A&A
An Improved Approximation Algorithm for Quantum Max-Cut
Creators: name: King, Robbie
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We give an approximation algorithm for Quantum Max-Cut which works by rounding an SDP relaxation to an entangled quantum state. The SDP is used to choose the parameters of a variational quantum circuit. The entangled state is then represented as the quantum circuit applied to a product state. It achieves an approximation ratio of 0.582 on triangle-free graphs. The previous best algorithms of Anshu, Gosset, Morenz, and Parekh, Thompson achieved approximation ratios of 0.531 and 0.533 respectively. In addition, we study the EPR Hamiltonian, which we argue is a natural intermediate problem which isolates some key quantum features of local Hamiltonian problems. For the EPR Hamiltonian, we give an approximation algorithm with approximation ratio $1 / \sqrt{2}$ on all graphs.
A Self-consistent Model of the Black Hole Evaporation
Creators: name: Kawai, Hikaru
name: Matsuo, Yoshinori
name: Yokokura, Yuki
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct a self-consistent model which describes a black hole from formation to evaporation including the back reaction from the Hawking radiation. In the case where a null shell collapses, at the beginning the evaporation occurs, but it stops eventually, and a horizon and singularity appear. On the other hand, in the generic collapse process of a continuously distributed null matter, the black hole evaporates completely without forming a macroscopically large horizon nor singularity. We also find a stationary solution in the heat bath, which can be regarded as a normal thermodynamic object.
description: 20 pages, 5 figures
Quantum Corrections to Entropy of Charged Dilatonic Black Holes in Arbitrary Dimensions
Creators: name: Shiraishi, Kiyoshi
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The quantum contribution of a scalar field to entropy of a dilatonic black hole is calculated in the brick wall model by the WKB method and analyzed by a high-temperature expansion. If the cutoff distance from the horizon approaches zero, the leading divergent piece of entropy turns out to be proportional to the "area" of the horizon surface (which has (N-1)-dimensional extension in (N+1)-dimensional space-time) and independent of other properties of black holes even in the case of general dilaton coupling. There is also qualitative argument with the known result of subleading divergence for N=3.
description: 8 pages, no figure
Broadband subwavelength focusing of light using a passive drain
Creators: name: Noh, Heeso
name: Popoff, Sebastien M.
name: Cao, Hui
Publisher: name: arXiv
Year: 2013
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Optical absorption is usually considered deleterious, something to avoid if at all possible. We propose a broadband nanoabsorber that completely eliminates the diffracting wave, resulting in a subwavelength enhancement of the field. Broadband operation is made possible by engineering the dispersion of the complex dielectric function. The local enhancement can be significantly improved compared to the standard plane wave illumination of a metallic nanoparticle. Our numerical simulation shows that an optical pulse as short as 6 fs can be focused to a 11 nm region. Not only the local field, but also its gradient are greatly enhanced, pointing to applications in ultrafast nonlinear spectroscopy, sensing and communication with deep-subwavelength resolution.
Phase Diagram and Approximate Message Passing for Blind Calibration and Dictionary Learning
Creators: name: Krzakala, Florent
name: Mézard, Marc
name: Zdeborová, Lenka
Publisher: name: arXiv
Year: 2013
Subjects: subject: Information Theory (cs.IT)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: We consider dictionary learning and blind calibration for signals and matrices created from a random ensemble. We study the mean-squared error in the limit of large signal dimension using the replica method and unveil the appearance of phase transitions delimiting impossible, possible-but-hard and possible inference regions. We also introduce an approximate message passing algorithm that asymptotically matches the theoretical performance, and show through numerical tests that it performs very well, for the calibration problem, for tractable system sizes.
description: 5 pages
Solutions of the scattering problem in a complete set of Bessel functions with a discrete index
Creators: name: Alhaidari, A. D.
name: Ismail, M. E. H.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We use the tridiagonal representation approach to solve the radial Schrödinger equation for the continuum scattering states of the Kratzer potential. We do the same for a radial power-law potential with inverse-square and inverse-cube singularities. These solutions are written as infinite convergent series of Bessel functions with a discrete index. As physical application of the latter solution, we treat electron scattering off a neutral molecule with electric dipole and electric quadrupole moments.
Narrow-leaved lupine (Lupinus angustifolius L.) as nitrogen source in organic vegetable production systems
Creators: name: Katroschan, Kai-Uwe
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2011
Subjects: subject: Organic vegetable production
subject: Lupinus angustifolius
subject: nitrogen flows
subject: Ökologische Gemüseproduktion
subject: Stickstoffflüsse
subject: Dewey Decimal Classification::600 | Technik::630 | Landwirtschaft, Veterinärmedizin

description: [no abstract]
Nanosecond laser flash photolysis studies for the elucidation of photoinduced processes in different TiO2 photocatalysts
Creators: name: Schneider, Jenny
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2016
Subjects: subject: Titandioxid
subject: Laserblitzphotolyse
subject: transiente Absorptionssiganle
subject: getrappte Ladungsträger
subject: Rekombinationsdynamik
subject: Titanium dioxide
subject: laser flash photolysis
subject: transient absorption signals
subject: trapped charge carriers
subject: recombination dynamics
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: [no abstract]
Bounding the Minimum Time of a Quantum Measurement
Creators: name: Shettell, Nathan
name: Centrone, Federico
name: García-Pintos, Luis Pedro
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Measurements take a singular role in quantum theory. While they are often idealized as an instantaneous process, this is in conflict with all other physical processes in nature. In this Letter, we adopt a standpoint where the interaction with an environment is a crucial ingredient for the occurrence of a measurement. Within this framework, we derive lower bounds on the time needed for a measurement to occur. Our bound scales proportionally to the change in entropy of the measured system, and decreases as the number of of possible measurement outcomes or the interaction strength driving the measurement increases. We evaluate our bound in two examples where the environment is modelled by bosonic modes and the measurement apparatus is modelled by spins or bosons.
Near diffraction limited high-power narrow-linewidth Er3+-doped fiber amplifiers : developments towards laser sources at 1.5 [my]m wavelength for gravitational wave astronomy
Creators: name: Kuhn, Vincent
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2011
Subjects: subject: Lasers
subject: fiber amplifiers
subject: erbium-doped
subject: single-frequency
subject: Laser
subject: Faserverstärker
subject: Erbium-dotiert
subject: einfrequent
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: [no abstract]
Discrete Connections for Geometry Processing
Creators: name: Crane, Keenan Michael
Publisher: name: California Institute of Technology
Year: 2010
Subjects: Computer Science
geometry processing
connections
discrete differential geometry

description: Connections provide a way to compare local quantities defined at different points of a geometric space.  This thesis develops a discrete theory of connections that naturally leads to practical, efficient numerical algorithms for geometry processing.  Our formulation is motivated by real-world applications where meshes may be noisy or coarsely discretized.  Further, because our discrete framework closely parallels the smooth theory, we can draw upon a huge wealth of existing knowledge to develop and interpret mesh processing algorithms.

The main contribution of this thesis is a new algorithm for computing trivial connections on discrete surfaces that are as smooth as possible everywhere but on a set of isolated singularities of given index.  A connection is represented via an angle associated with each dual edge, i.e., a discrete angle-valued 1-form.  These angles are determined by the solution to a linear system, and are globally optimal in the sense that they describe the trivial connection closest to Levi-Civita among all solutions with the prescribed set of singularities.  Relative to previous methods our algorithm is surprisingly simple, and can be implemented using standard operations from mesh processing and linear algebra.  The solution can be used to construct rotationally symmetric direction fields with a prescribed set of singularities and directional constraints, which are essential in applications such as quadrilateral remeshing and texture synthesis.
Some properties of the one-dimensional Lévy crystal
Creators: name: Stickler, B. A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We introduce and discuss the one-dimensional Lévy crystal as a probable candidate for an experimentally accessible realization of space fractional quantum mechanics (SFQM) in a condensed matter environment. The discretization of the space fractional Schrödinger equation with the help of shifted Grünwald-Letnikov derivatives delivers a straight-forward route to define the Lévy crystal of order $α\in (1,2]$. As key ingredients for its experimental identification we study the dispersion relation as well as the density of states for arbitrary $α\in (1,2]$. It is demonstrated that in the limit of small wavenumbers all interesting properties of continuous space SFQM are recovered, while for $α\to 2$ the well-established nearest neighbor one-dimensional tight binding chain arises.
description: submitted to PRE
GINGER
Creators: name: Altucci, Carlo
name: Barchiesi, Francesco Bajardi Emilio
name: Basti, Andrea
name: Beverini, Nicolò
name: Braun, Thomas
name: Carelli, Giorgio
name: Capozziello, Salvatore
name: Ciampini, Donatella
name: Davì, Fabrizio
name: De Luca, Gaetano
name: Devoti, Roberto
name: Di Giovambattista, Rita
name: Di Somma, Giuseppe
name: Di Stefano, Giuseppe
name: Di Virgilio, Angela D. V.
name: Famiani, Daniela
name: Frepoli, Alberto
name: Fuso, Francesco
name: Giorgio, Ivan
name: Govoni, Aladino
name: Lambiase, Gaetano
name: Maccioni, Enrico
name: Marsili, Paolo
name: Mercuri, Alessia
name: Morsani, Fabio
name: Ortolan, Antonello
name: Porzio, Alberto
name: Ruggiero, Matteo Luca
name: Tallini, Marco
name: Tasson, Jay
name: Turco, Emilio
name: Velotta, Raffaele
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: In this paper, we outline the scientific objectives, the experimental layout, and the collaborations envisaged for the GINGER (Gyroscopes IN GEneral Relativity) project. The GINGER project brings together different scientific disciplines aiming at building an array of Ring Laser Gyroscopes (RLGs), exploiting the Sagnac effect, to measure continuously, with sensitivity better than picorad/ s, large bandwidth (ca. 1 kHz), and high dynamic range, the absolute angular rotation rate of the Earth. In the paper, we address the feasibility of the apparatus with respect to the ambitious specifications above, as well as prove how such an apparatus, which will be able to detect strong Earthquakes, very weak geodetic signals, as well as general relativity effects like Lense-Thirring and De Sitter, will help scientific advancements in Theoretical Physics, Geophysics, and Geodesy, among other scientific fields.
description: 21 pages, 9 figures
Negative externalities of pesticide use in the vegetable sub-sector in Kenya
Creators: name: Macharia, Ibrahim Ndegwa
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2010
Subjects: subject: Kenya
subject: pesticide externalities
subject: vegetable production
subject: Kenia
subject: pestizide Externalitäten
subject: Gemüseproduktion
subject: Dewey Decimal Classification::600 | Technik::630 | Landwirtschaft, Veterinärmedizin

description: [no abstract]
Enhanced Gravitational Entanglement via Modulated Optomechanics
Creators: name: Plato, A. Douglas K.
name: Rätzel, Dennis
name: Wan, Chuanqi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The role of entanglement in determining the non-classicality of a given interaction has gained significant traction over the last few years. In particular, as the basis for new experimental proposals to test the quantum nature of the gravitational field. Here we show that the rate of gravity mediated entanglement between two otherwise isolated optomechanical systems can be significantly increased by modulating the optomechanical coupling. This is most pronounced for low mass, high frequency systems - convenient for reaching the quantum regime - and can lead to improvements of several orders of magnitude, as well as a broadening of the measurement window. Nevertheless, significant obstacles still remain. In particular, we find that modulations increase decoherence effects at the same rate as the entanglement improvements. This adds to the growing evidence that the constraint on noise (acting on the position d.o.f) depends only on the particle mass, separation, and temperature of the environment and cannot be improved by novel quantum control. Finally, we highlight the close connection between the observation of quantum correlations and the limits of measurement precision derived via the Cramér-Rao Bound. An immediate consequence is that probing superpositions of the gravitational field places similar demands on detector sensitivity as entanglement verification.
description: 31 pages, 4 figures
Flux-balance laws in scalar self-force theory
Creators: name: Grant, Alexander M.
name: Moxon, Jordan
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The motion of a radiating point particle can be represented by a series of geodesics whose "constants" of motion evolve slowly with time. The evolution of these constants of motion can be determined directly from the self-force equations of motion. In the presence of spacetime symmetries, the situation simplifies: there exist not only constants of motion conjugate to these symmetries, but also conserved currents whose fluxes can be used to determine their evolution. Such a relationship between point-particle motion and fluxes of conserved currents is a flux-balance law. However, there exist constants of motion that are not related to spacetime symmetries, the most notable example of which is the Carter constant in the Kerr spacetime. In this paper, we first present a new approach to flux-balance laws for spacetime symmetries, using the techniques of symplectic currents and symmetry operators, which can also generate more general conserved currents. We then derive flux-balance laws for all constants of motion in the Kerr spacetime, using the fact that the background, geodesic motion is integrable. For simplicity, we restrict derivations in this paper to the scalar self-force problem. While generalizing the discussion in this paper to the gravitational case will be straightforward, there will be additional complications in turning these results into a practical flux-balance law in this case.
description: 15+3 pages, 1 figure; v2: corrected typos and added appendix and figure, "matches" published version
Optimizing for an arbitrary Schrödinger cat state
Creators: name: Krauss, Matthias G.
name: Koch, Christiane P.
name: Reich, Daniel M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We derive a set of functionals for optimization towards an arbitrary cat state and demonstrate their application by optimizing the dynamics of a Kerr-nonlinear Hamiltonian with two-photon driving. The versatility of our framework allows us to adapt our functional towards optimization of maximally entangled cat states, applying it to a Jaynes-Cummings model. We identify the strategy of the obtained control fields and determine the quantum speed limit as a function of the cat state's excitation. Finally, we extend our optimization functionals to open quantum system dynamics and apply it to the Jaynes-Cummings model with decay on the oscillator. For strong dissipation and large cat radii, we find a change in the control strategy compared to the case without dissipation. Our results highlight the power of optimal control with functionals specifically crafted for complex physical tasks and the versatility of the quantum optimal control toolbox for practical applications in the quantum technologies.
title: Missbrauch – die Verspottung der Freiheit
Creators: name: Wustmans, Hildegard
Publisher: name: Universität Graz
Year: 2019

description: Die MHG-Studie hat es für alle Welt öffentlich gemacht: Sexueller Missbrauch ist ein ungeheuerlicher Tatbestand. Inzwischen kommt immer öfterauch die Form des spirituellen Missbrauchs zu Gehör. Der Beitrag blickt auf das Phänomen des spirituellen Missbrauchs, beschreibt dahinterstehende Muster und fragt nach pastoralen und strukturellen Antworten, um Übergriffe so gut es geht zu verhindern.
description: The MHG study revealed for all the world to see that sexual abuse is an undeniable and pervasive fact. Increasingly, there are also discussions about spiritual abuse. This article investigates the reality of spiritual abuse, uncovers underlying
patterns and seeks to find pastoral and structural answers that can help prevent abuse.
description: geistliche Begleitung; geistlicher/spiritueller Missbrauch; loci theologici proprii/loci theologici alieni; Muster des Missbrauchs; Doris Wagner
description: Limina, 2(2), 152-163
New immunisation strategies via mucosal routes : comparative analysis of sublingual, intravaginal and intranasal immunisation
Creators: name: Scholz, Kirsten
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2012
Subjects: subject: Mucosal vaccination strategies
subject: adjuvants
subject: Th17 cells
subject: Mukosale Vakzinierungsstrategien
subject: Adjuvantien
subject: Th17-Zellen
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: [no abstract]
AGN feedback works both ways
Creators: name: Zinn, Peter-Christian
name: Middelberg, Enno
name: Norris, Ray P.
name: Dettmar, Ralf-Jürgen
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Simulations of galaxy growth need to invoke strong negative feedback from active galactic nuclei (AGN) to suppress the formation of stars and thus prevent the over-production of very massive systems. While some observations provide evidence for such negative feedback, other studies find either no feedback, or even positive feedback, with increased star formation associated with higher AGN luminosities. Here we report an analysis of several hundred AGN and their host galaxies in the Chandra Deep Field South using X-ray and radio data for sample selection. Combined with archival far infrared data as a reliable tracer of star formation activity in the AGN host galaxies, we find that AGN with pronounced radio jets exhibit a much higher star formation rate than the purely X-ray selected ones, even at the same X-ray luminosities. This difference implies that positive AGN feedback plays an important role, too, and therefore has to be accounted for in all future simulation work. We interpret this to indicate that the enhanced star formation rate of radio selected AGN arises because of jet-induced star formation, as is hinted by the different jet powers among our AGN samples, while the suppressed star formation rate of X-ray selected AGN is caused by heating and photo-dissociation of molecular gas by the hot AGN accretion disc.
description: 21 pages, 9 figures, 3 tables, accepted for publication by ApJ
New approaches in squeezed light generation : quantum states of light with GHz squeezing bandwidth and squeezed light generation via the cascaded Kerr effect
Creators: name: Ast, Stefan
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2015
Subjects: subject: Squeezed light
subject: quantum key distribution
subject: cascaded Kerr effect
subject: entanglement
subject: second harmonic generation
subject: Gequetschtes Licht
subject: Quantenschlüsselverteilung
subject: kaskadierter Kerr-effekt
subject: Verschränkung
subject: Frequenzverdoppelung
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: [no abstract]
Entanglement of annihilation photons
Creators: name: Ivashkin, Alexander
name: Abdurashitov, Dzhonrid
name: Baranov, Alexander
name: Guber, Fedor
name: Morozov, Sergey
name: Musin, Sultan
name: Strizhak, Alexander
name: Tkachev, Igor
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We present the results of a new experimental study of the quantum entanglement of photon pairs produced in positron-electron annihilation at rest. The experimental setup includes a system of Compton polarimeters to measure the Compton scattering of annihilation photons in entangled and decoherent states. Decoherent states are prepared by pre-scattering of one of the initial photons prior to measurements in polarimeters. For the first time, a direct comparison of the polarization correlations of annihilation photons in the entangled and thus prepared separable states has been carried out. The angular distributions of scattered photons turned out to be the same in both quantum states, which is an unexpected discovery for the quantum-entangled positron emission tomography. Moreover, the correlation function in the Bell's inequality is also the same for entangled and separable states. It follows that, despite numerous measurements in a series of experiments, there is still no experimental proof of the entanglement of annihilation photons. These results are in line with recent theoretical predictions of an identical Compton scattering cross-section for entangled and specific mixed separable quantum states and cast doubt on the universality of the Bell's theorem for testing the entanglement and nonlocality in quantum theory.
description: 12 pages, 8 figures
Cosmology and gravitational waves in the Nordstrom-Vlasov system, a laboratory for Dark Energy
Creators: name: Corda, Christian
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We discuss a cosmological solution of the system which was originally introduced by Calogero and is today popularly known as "Nordstrom-Vlasov system". Although the model is un-physical, its cosmological solution results interesting for the same reasons for which the Nordstrom-Vlasov system was originally introduced in the framework of galactic dynamics. In fact, it represents a theoretical laboratory where one can rigorously study some problems, like the importance of the gravitational waves in the dynamics, which at the present time are not well understood within the physical model of the Einstein-Vlasov system. As the cosmology of the Nordstrom-Vlasov system is founded on a scalar field, a better understanding of the system is important also in the framework of the Dark Energy problem. In fact, various attempts to achieve Dark Energy by using scalar fields are present in the literature. In the solution an analytical expression for the time dependence of the cosmological evolution of the Nordstrom's scalar field is also released.This analytical expression is unknown in the literature of the Nordstrom-Vlasov system. Based on their importance, the propagation of gravitational waves in the Nordstrom-Vlasov system and their effects on test masses are also discussed.
description: 11 pages, invited contribution accepted for publication by New Adv. Phys. To appear in Issue 7(1) 2013 on Dark Energy
Nitric oxide in the olfactory epithelium
Creators: name: Schmachtenberg, Oliver
Publisher: name: Hannover : Universität
Year: 2001
Subjects: subject: Nitric oxide
subject: olfactory receptor neuron
subject: NADPH diaphorase
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: [no abstract]
STAP: Sequencing Task-Agnostic Policies
Creators: name: Agia, Christopher
name: Migimatsu, Toki
name: Wu, Jiajun
name: Bohg, Jeannette
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Advances in robotic skill acquisition have made it possible to build general-purpose libraries of learned skills for downstream manipulation tasks. However, naively executing these skills one after the other is unlikely to succeed without accounting for dependencies between actions prevalent in long-horizon plans. We present Sequencing Task-Agnostic Policies (STAP), a scalable framework for training manipulation skills and coordinating their geometric dependencies at planning time to solve long-horizon tasks never seen by any skill during training. Given that Q-functions encode a measure of skill feasibility, we formulate an optimization problem to maximize the joint success of all skills sequenced in a plan, which we estimate by the product of their Q-values. Our experiments indicate that this objective function approximates ground truth plan feasibility and, when used as a planning objective, reduces myopic behavior and thereby promotes long-horizon task success. We further demonstrate how STAP can be used for task and motion planning by estimating the geometric feasibility of skill sequences provided by a task planner. We evaluate our approach in simulation and on a real robot. Qualitative results and code are made available at https://sites.google.com/stanford.edu/stap.
description: Video: https://drive.google.com/file/d/1zp3qFeZLACNPsGLLP7p6q9X1tuA_PGEo/view. Project page: https://sites.google.com/stanford.edu/stap. 12 pages, 7 figures. In proceedings of the IEEE International Conference on Robotics and Automation (ICRA) 2023. The first two authors contributed equally
New insights from behavioral economics in developing countries
Creators: name: Liebenehm, Sabine
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2015
Subjects: subject: Attitudes towards risk and time
subject: poverty
subject: risk management
subject: shocks
subject: Southeast Asia
subject: West Africa
subject: Armut
subject: Risiko- und Zeitpräferenzen
subject: Risikomanagement
subject: Schocks
subject: Südostasien
subject: Westafrika
subject: Dewey Decimal Classification::300 | Sozialwissenschaften, Soziologie, Anthropologie::330 | Wirtschaft

description: [no abstract]
Analytic continuations of the Horn $H_1$ and $H_5$ functions
Creators: name: Bera, Souvik
name: Pathak, Tanay
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Analysis of PDEs (math.AP)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The analytic continuations (ACs) of the double variable Horn $H_1$ and $H_5$ functions have been derived for the first time using the automated symbolic $\textit{Mathematica}$ package $\texttt{Olsson.wl}$. The use of Pfaff-Euler transformations have been emphasised to derive AC to cover regions which are otherwise not possible. The corresponding region of convergence (ROC) is obtained using its companion package $\texttt{ROC2.wl}$. A $\textit{Mathematica}$ package $\texttt{HornH1H5.wl}$, containing all the derived ACs and the associated ROCs, along with a demonstration file of the same is made publicly available in https://github.com/souvik5151/Horn_H1_H5 .
description: Minor changes, Journal version
Markov-modulated marked Poisson processes for modelling disease dynamics based on medical claims data
Creators: name: Mews, Sina
name: Surmann, Bastian
name: Hasemann, Lena
name: Elkenkamp, Svenja
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applications (stat.AP)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: We explore Markov-modulated marked Poisson processes (MMMPPs) as a natural framework for modelling patients' disease dynamics over time based on medical claims data. In claims data, observations do not only occur at random points in time but are also informative, i.e. driven by unobserved disease levels, as poor health conditions usually lead to more frequent interactions with the healthcare system. Therefore, we model the observation process as a Markov-modulated Poisson process, where the rate of healthcare interactions is governed by a continuous-time Markov chain. Its states serve as proxies for the patients' latent disease levels and further determine the distribution of additional data collected at each observation time, the so-called marks. Overall, MMMPPs jointly model observations and their informative time points by comprising two state-dependent processes: the observation process (corresponding to the event times) and the mark process (corresponding to event-specific information), which both depend on the underlying states. The approach is illustrated using claims data from patients diagnosed with chronic obstructive pulmonary disease (COPD) by modelling their drug use and the interval lengths between consecutive physician consultations. The results indicate that MMMPPs are able to detect distinct patterns of healthcare utilisation related to disease processes and reveal inter-individual differences in the state-switching dynamics.
Organic glasses: cluster structure of the random energy landscape
Creators: name: Novikov, S. V.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: An appropriate model for the random energy landscape in organic glasses is a spatially correlated Gaussian field. We calculated the distribution of the average value of a Gaussian random field in a finite domain. The results of the calculation demonstrate a strong dependence of the width of the distribution on the spatial correlations of the field. Comparison with the simulation results for the distribution of the size of the cluster indicates that the distribution of an average field could serve as a useful tool for the estimation of the asymptotic behavior of the distribution of the size of the clusters for "deep" clusters where value of the field on each site is much greater than the rms disorder. We also demonstrate significant modification of the properties of energetic disorder in organic glasses at the vicinity of the electrode.
description: 4 pages, 2 figures
Numerical simulations of delamination in fibre reinforced plastic shell structures using XFEM
Creators: name: Yazdani, Saleh
Publisher: name: Hannover : Institut für Kontinuumsmechanik, Leibniz Universität Hannover
Year: 2016
Subjects: subject: Delamination
subject: shell
subject: XFEM
subject: cohesive zone model
subject: buckling
subject: Schale
subject: erweiterte Finite-Elemente-Methode
subject: Kohäsivzonenmodell
subject: Beulen
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: [no abstract]