cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Actividad hipocolesterolémica del quitosan extraído de langosta (Panulirus interruptus) /
Creators: name: Cruz Bailon, Silvia
Publisher: name: Universidad Autónoma de Baja California.
Year: 2022
Subjects: subject: QP905 C78 1994

description: Se investigó el efecto hipocolesterolémico del quisotán extraído del carapazón de langosta (Panulirus interruptus) en ratas de la raza Sprague-Dawley, administrado por vía oral durante 21 días a un grupo de 6 ratas; tres grupos restantes fueron alimentados con diferentes dietas, las cuales fueron; una dieta carente de colesterol, una dieta rica en colesterol y una dieta con un hipocolesterolémico comercial (Questran).
Equations of motion for natural orbitals of strongly driven two-electron systems
Creators: name: Rapp, J.
name: Brics, M.
name: Bauer, D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Computational Physics (physics.comp-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Natural orbital theory is a computationally useful approach to the few and many-body quantum problem. While natural orbitals are known and applied since many years in electronic structure applications, their potential for time-dependent problems is being investigated only since recently. Correlated two-particle systems are of particular importance because the structure of the two-body reduced density matrix expanded in natural orbitals is known exactly in this case. However, in the time-dependent case the natural orbitals carry time-dependent phases that allow for certain time-dependent gauge transformations of the first kind. Different phase conventions will, in general, lead to different equations of motion for the natural orbitals. A particular phase choice allows us to derive the exact equations of motion for the natural orbitals of any (laser-) driven two-electron system explicitly, i.e., without any dependence on quantities that, in practice, require further approximations. For illustration, we solve the equations of motion for a model helium system. Besides calculating the spin-singlet and spin-triplet ground states, we show that the linear response spectra and the results for resonant Rabi flopping are in excellent agreement with the benchmark results obtained from the exact solution of the time-dependent Schrödinger equation.
description: 12 pages, 2 figures, REVTeX. Update: Include latest changes made for publishing
Sharp parameter bounds for certain maximal point lenses
Creators: name: Luce, Robert
name: Sète, Olivier
name: Liesen, Jörg
Publisher: name: arXiv
Year: 2013
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Complex Variables (math.CV)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 85A04 30D05 31A05

description: Starting from an $n$-point circular gravitational lens having $3n+1$ images, Rhie (2003) used a perturbation argument to construct an $(n+1)$-point lens producing $5n$ images. In this work we give a concise proof of Rhie's result, and we extend the range of parameters in Rhie's model for which maximal lensing occurs. We also study a slightly different construction given by Bayer and Dyer (2007) arising from the $(3n+1)$-point lens. In particular, we extend their results and give sharp parameter bounds for their lens model. By a substitution of variables and parameters we show that both models are equivalent in a certain sense.
description: Minor typographic corrections
Blind deblurring of hyperspectral document images
Creators: name: Ljubenovic, M.
name: Guzzonato, P.
name: Franceschin, G.
name: Traviglia, A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Most computer vision and machine learning-based approaches for historical document analysis are tailored to grayscale or RGB images and thus, mostly exploit their spatial information. Multispectral (MS) and hyperspectral (HS) images contain, next to the spatial information, much richer spectral information than RGB images (usually spreading beyond the visible spectral range) that can facilitate more effective feature extraction, more accurate classification and recognition, and thus, improved analysis. Although utilization of rich spectral information can improve historical document analysis tremendously, there are still some potential limitations of HS imagery such as camera-induced noise and blur that require a carefully designed preprocessing step. Here, we propose novel blind HS image deblurring methods tailored to document images. We exploit a low-rank property of HS images (i.e., by projecting an HS image to a lower dimensional subspace) and utilize a text tailor image prior to performing a PSF estimation and deblurring of subspace components. The preliminary results show that the proposed approach gives good results over all spectral bands, removing successfully image artefacts introduced by blur and noise and significantly increasing the number of bands that can be used in further analysis.
description: This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 101026453. This work is published in the Lecture Notes in Computer Science book series (LNCS, volume 13373) as part of the Image Analysis and Processing, ICIAP 2022 Workshops
Cosmic Reionization On Computers II. Reionization History and Its Back Reaction on Early Galaxies
Creators: name: Gnedin, Nickolay Y.
name: Kaurov, Alexander A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We compare the results from several sets of cosmological simulations of cosmic reionization, produced under Cosmic Reionization On Computers (CROC) project, with existing observational data on the high-redshift Ly-alpha forest and the abundance of Ly-alpha emitters. We find good consistency with the observational measurements and the previous simulation work. By virtue of having several independent realizations for each set of numerical parameters, we are able to explore the effect of cosmic variance on observable quantities. One unexpected conclusion we are forced into is that cosmic variance is unusually large at z>6, with both our simulations and, most likely, observational measurements are still not fully converged for even such basic quantities as the average Gunn-Peterson optical depth or the volume-weighted neutral fraction. We also find that reionization has little effect on the early galaxies or on global cosmic star formation history, because galaxies whose gas content is affected by photoionization contain no molecular (i.e. star-forming) gas in the first place. In particular, measurements of the faint end of the galaxy luminosity function by JWST are unlikely to provide a useful constraint on reionization.
description: Replaced with the final, accepted for publication in ApJ version. This version significantly extends the first submission
Challenging Beyond-the-Standard-Model Solutions to the Fine-Structure Anomaly in Heavy Muonic Atoms
Creators: name: Beyer, K. A.
name: Valuev, I. A.
name: Keitel, C. H.
name: Tamburini, M.
name: Oreshkina, N. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: The leading-order contribution of a new boson to the muonic fine-structure anomaly, which refers to a discrepancy between the predicted transition energies and spectroscopic measurements of $μ-^{90}$Zr, $μ-^{120}$Sn, and $μ-^{208}$Pb, is investigated. We consider bosons of scalar, vector, pseudoscalar, and pseudovector type. Spin-dependent couplings sourced by pseudoscalars or pseudovectors are disfavoured as solutions to the anomaly due to the nuclei in question having vanishing angular momentum. Spin-independent interactions resulting from scalar or vector exchange are also disfavoured because no parameter space exists to simultaneously fit different atomic states of the same nucleus. Therefore, we conclude that a `Beyond-the-Standard-Model' resolution of the muonic fine-structure anomaly is generally disfavoured, and the first-order solution by a single new boson is excluded.
description: 7 pages including 3 figures and 1 table. 3 pages appendix
Multispectral Image Compression Based on HEVC Using Pel-Recursive Inter-Band Prediction
Creators: name: Meyer, Anna
name: Genser, Nils
name: Kaup, André
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Recent developments in optical sensors enable a wide range of applications for multispectral imaging, e.g., in surveillance, optical sorting, and life-science instrumentation. Increasing spatial and spectral resolution allows creating higher quality products, however, it poses challenges in handling such large amounts of data. Consequently, specialized compression techniques for multispectral images are required. High Efficiency Video Coding (HEVC) is known to be the state of the art in efficiency for both video coding and still image coding. In this paper, we propose a cross-spectral compression scheme for efficiently coding multispectral data based on HEVC. Extending intra picture prediction by a novel inter-band predictor, spectral as well as spatial redundancies can be effectively exploited. Dependencies among the current band and further spectral references are considered jointly by adaptive linear regression modeling. The proposed backward prediction scheme does not require additional side information for decoding. We show that our novel approach is able to outperform state-of-the-art lossy compression techniques in terms of rate-distortion performance. On different data sets, average Bjøntegaard delta rate savings of 82 % and 55 % compared to HEVC and a reference method from literature are achieved, respectively.
description: 6 pages, 4 figures, 1 table; Originally published as conference paper at IEEE MMSP 2020
Specification-Guided Critical Scenario Identification for Automated Driving
Creators: name: Molin, Adam
name: Aguilar, Edgar A.
name: Ničković, Dejan
name: Zhu, Mengjia
name: Bemporad, Alberto
name: Esen, Hasan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: To test automated driving systems, we present a case study for finding critical scenarios in driving environments guided by formal specifications. To that aim, we devise a framework for critical scenario identification, which we base on open-source libraries that combine scenario specification, testing, formal methods, and optimization.
About the Cost of Central Privacy in Density Estimation
Creators: name: Lalanne, Clément
name: Garivier, Aurélien
name: Gribonval, Rémi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We study non-parametric density estimation for densities in Lipschitz and Sobolev spaces, and under central privacy. In particular, we investigate regimes where the privacy budget is not supposed to be constant. We consider the classical definition of central differential privacy, but also the more recent notion of central concentrated differential privacy. We recover the result of Barber and Duchi (2014) stating that histogram estimators are optimal against Lipschitz distributions for the L2 risk, and under regular differential privacy, and we extend it to other norms and notions of privacy. Then, we investigate higher degrees of smoothness, drawing two conclusions: First, and contrary to what happens with constant privacy budget (Wasserman and Zhou, 2010), there are regimes where imposing privacy degrades the regular minimax risk of estimation on Sobolev densities. Second, so-called projection estimators are near-optimal against the same classes of densities in this new setup with pure differential privacy, but contrary to the constant privacy budget case, it comes at the cost of relaxation. With zero concentrated differential privacy, there is no need for relaxation, and we prove that the estimation is optimal.
description: Transactions on Machine Learning Research Journal, 2023
Estructura y características poblacionales del lenguado de California Paralichthys californicus (Ayres), en la Bahía de Todos Santos y el Estero de Punta Banda, durante los meses de abril de 1992 a marzo de 1993 /
Creators: name: Carrillo Cortes, Jose Alejandro
Publisher: name: Universidad Autónoma de Baja California.
Year: 2022
Subjects: subject: QL638.B65 C37 1994

description: Se realizaron 12 muestreos mensuales desde abril de 1992 a marzo de 1993, en la Bahía de Todos Santos y el Estero de Punta Banda.
Measurement of the cross section of high transverse momentum $Z\rightarrow b\bar{b}$ production in proton--proton collisions at $\sqrt{s}=8 TeV$ with the ATLAS Detector
Creators: name: ATLAS Collaboration
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: This Letter reports the observation of a high transverse momentum $Z\rightarrow b\bar{b}$ signal in proton-proton collisions at $\sqrt{s}=8$ TeV and the measurement of its production cross section. The data analysed were collected in 2012 with the ATLAS detector at the LHC and correspond to an integrated luminosity of 19.5 fb$^{-1}$. The $Z\rightarrow b\bar{b}$ decay is reconstructed from a pair of b-tagged jets, clustered with the anti-$k_t$ jet algorithm with $R = 0.4$, that have low angular separation and form a dijet with $p_T > 200$ GeV. The signal yield is extracted from a fit to the dijet invariant mass distribution, with the dominant, multi-jet background mass shape estimated by employing a fully data-driven technique that reduces the dependence of the analysis on simulation. The fiducial cross section is determined to be \[ σ^\mathrm{fid}_{Z\rightarrow b\bar{b}} = 2.02 \pm 0.20 ({\rm stat.}) \pm0.25 ({\rm syst.)}\pm 0.06 ({\rm lumi.}){\rm\,pb} = 2.02 \pm{0.33}{\rm\,pb}, \] in good agreement with next-to-leading-order theoretical predictions.
description: There are 8 pages + the cover page + the author list, (20 pages total), 3 figures, 1 table, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2013-04/
Computational Reproducibility in Metabolite Quantification Applied to Short Echo Time in Vivo MR Spectroscopy
Creators: name: Vila, Gaël
name: Bonnet, Axel
name: Chauveau, Fabien
name: Gaillard, Sophie
name: Durand-Dubief, Françoise
name: Camarasu-Pop, Sorina
name: Ratiney, Helene
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optimization and Control (math.OC)
subject: Methodology (stat.ME)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: In vivo metabolite quantification by short echo time MR spectroscopy is a challenge for which various methods have been proposed. In this study, the reproducibility of quantification outcomes is questioned at three distinct levels: (i) between-software (LCModel and cQUEST), (ii) withinsoftware (with different parameter sets), and (iii) across software executions (when the fitting algorithm uses random seeds, like cQUEST). After running multiple quantification tasks on a dedicated platform (VIP), metrics from Bland-Altman analysis were used to assess the variability of outcomes in signals acquired on a lysolecithin rat model, from a study on demyelination. Results show substantial variations at the three levels, allowing for more potent analyses than from a single parameter set / single software point of view.
О једном поморавском говору
Creators: name: Радић, Првослав
Publisher: name: Zenodo
Year: 2004
Subjects: Софија Милорадовић
Параћинско Поморавље
српски језик
говори

description: Употреба падежних облика у говору Пара- ћинског Поморавља - балканистички и етномиграциони аспект
description: Приказ књиге: Софија Милорадовић, Употреба падежних облика у говору Параћинског Поморавља, Етнографски институт САНУ, Београд 2003, стр. 1–366
Cambios en la linea de playa en la boca del Estero de Punta Banda /
Creators: name: Castillo Valdez, Héctor Francisco
Publisher: name: Universidad Autónoma de Baja California.
Year: 2022
Subjects: subject: Costas||Cambios||México||Baja California||Punta Banda, Estero de||Erosión de playas México Baja California Punta Banda, Esterp de||Oceanología||Geología||Tésis
subject: GB458.85 C38 1995

description: Por medio de la aplicación de técnicas computacionales se definió la línea de playa en la boca del estero de Punta Banda de 8 fotografías aéreas y 1 imagen de satélite, tomadas entre 1970 y 1973.
TR-ARPES Signal in Pumped Semiconductors within Dynamical Projective Operatorial Approach (DPOA)
Creators: name: Eskandari-asl, Amir
name: Avella, Adolfo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this manuscript, after discussing in detail the internals of our recently developed method, the dynamical projective operatorial approach (DPOA), we provide the framework to apply this method to pumped semiconductor lattice systems and, in particular, to study and analyze their electronic excitations and TR-ARPES signal. The expressions for relevant out-of-equilibrium Green's functions and TR-ARPES signal are given within the DPOA framework and, defining a retarded TR-ARPES signal, it is shown that it is possible to obtain an out-of-equilibrium version of the fluctuation-dissipation theorem. We clarify how single- and multi-photon resonances, rigid shifts, band dressings, and different types of sidebands emerge in the TR-ARPES signal. We also propose protocols for evaluating the strength of single- and multi-photon resonances and for assigning the residual excited electronic population at each crystal momentum and band to a specific excitation process. Hamiltonians, where intra- and inter-band transitions are selectively inhibited, are defined and used to analyze the effects on the TR-ARPES signal and the residual electronic excited population. Three relevant cases of light-matter coupling are examined within the dipole gauge: only a local dipole, only the Peierls substitution in the hopping term, and both terms at once. The transient and residual pump effects are studied in detail, including the consequences of the lattice symmetries at different crystal momenta on the TR-ARPES signal. A detailed study of the dependence of the TR-ARPES signal on the probe-pulse characteristics is also reported. To provide a guideline for understanding the complex effects and interplays and the variety of possible physical phenomena without being limited by the characteristics of a single particular real material, we have chosen to study a prototypical pumped two-band semiconductor lattice system.
description: 29 pages, 15 figures, 38 panels
Smooth solutions of the Euler and Navier-Stokes equations from the a posteriori analysis of approximate solutions
Creators: name: Morosi, Carlo
name: Pizzocchero, Livio
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35Q30, 76D03, 76D05

description: The main result of [C. Morosi and L. Pizzocchero, Nonlinear Analysis, 2012] is presented in a variant, based on a C^infinity formulation of the Cauchy problem; in this approach, the a posteriori analysis of an approximate solution gives a bound on the Sobolev distance of any order between the exact and the approximate solution.
description: Author's note. Some overlaps with our previous works arXiv:1402.0487, arXiv:1310.5642, arXiv:1304.2972, arXiv:1203.6865, arXiv:1104.3832, arXiv:1009.2051, arXiv:1007.4412, arXiv:0909.3707, arXiv:0709.1670; these overlaps aim to make the paper self-contained and do not involve the main results. Final version to appear in Nonlinear Analysis
Wigner measures approach to the classical limit of the Nelson model: Convergence of dynamics and ground state energy
Creators: name: Ammari, Zied
name: Falconi, Marco
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We consider the classical limit of the Nelson model, a system of stable nucleons interacting with a meson field. We prove convergence of the quantum dynamics towards the evolution of the coupled Klein-Gordon-Schrödinger equation. Also, we show that the ground state energy level of $N$ nucleons, when $N$ is large and the meson field approaches its classical value, is given by the infimum of the classical energy functional at a fixed density of particles. Our study relies on a recently elaborated approach for mean field theory and uses Wigner measures.
description: 37 pages
Error-tolerant quantum convolutional neural networks for symmetry-protected topological phases
Creators: name: Zapletal, Petr
name: McMahon, Nathan A.
name: Hartmann, Michael J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The analysis of noisy quantum states prepared on current quantum computers is getting beyond the capabilities of classical computing. Quantum neural networks based on parametrized quantum circuits, measurements and feed-forward can process large amounts of quantum data to reduce measurement and computational costs of detecting non-local quantum correlations. The tolerance of errors due to decoherence and gate infidelities is a key requirement for the application of quantum neural networks on near-term quantum computers. Here we construct quantum convolutional neural networks (QCNNs) that can, in the presence of incoherent errors, recognize different symmetry-protected topological phases of generalized cluster-Ising Hamiltonians from one another as well as from topologically trivial phases. Using matrix product state simulations, we show that the QCNN output is robust against symmetry-breaking errors below a threshold error probability and against all symmetry-preserving errors provided the error channel is invertible. This is in contrast to string order parameters and the output of previously designed QCNNs, which vanish in the presence of any symmetry-breaking errors. To facilitate the implementation of the QCNNs on near-term quantum computers, the QCNN circuits can be shortened from logarithmic to constant depth in system size by performing a large part of the computation in classical post-processing. These constant-depth QCNNs reduce sample complexity exponentially with system size in comparison to the direct sampling using local Pauli measurements.
description: 26 pages, 14 figures; Sections II and IX revised in v2; Appendices C and E added in v2; Figures 11 and 12 added in v2
Toward Higher Integration Density in Femtosecond-Laser-Written Programmable Photonic Circuits
Creators: name: Albiero, Riccardo
name: Pentangelo, Ciro
name: Gardina, Marco
name: Atzeni, Simone
name: Ceccarelli, Francesco
name: Osellame, Roberto
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Programmability in femtosecond-laser-written integrated circuits is commonly achieved with the implementation of thermal phase shifters. Recent work has shown how such phase shifters display significantly reduced power dissipation and thermal crosstalk with the implementation of thermal isolation structures. However, the aforementioned phase shifter technology is based on a single gold film, which poses severe limitations on integration density and circuit complexity due to intrinsic geometrical constraints. To increase the compactness, we propose two improvements to this technology. Firstly, we fabricated thermal phase shifters with a photolithography process based on two different metal films, namely chromium for microheaters and copper for contact pads and interconnections. Secondly, we developed a novel curved isolation trench design that, along with a state-of-the-art curvature radius, allows for a significant reduction in the optical length of integrated circuits. As a result, curved Cr-Cu phase shifters provide a compact footprint with low parasitic series resistance and no significant increase in power dissipation (~ 38 mW) and thermal crosstalk (~ 20%). These results pave the way toward the fabrication of femtosecond-laser-written photonic circuits with a steep increase in terms of layout complexity.
Variabilidad anual de la estructura del fitoplancton de red en el área norte de Bahía de Todos Santos Baja California (1990) /
Creators: name: Mosqueda Razo, Claudia Alejandra
Publisher: name: Universidad Autónoma de Baja California.
Year: 2022
Subjects: subject: Fitoplancton marino Ecologia Baja California Todos Santos, Bahia de||Oceanología Biología||Tesis
subject: QK934 M68 1995

description: Se realizó un estudio anual de la diversidad de fitoplancton en dos estaciones localizadas perpendicularmente a la línea de costa en el área norte de Bahía Todos Santos B.C.
Valley- and spin-switch effects in molybdenum disulfide superconducting spin valve
Creators: name: Majidi, Leyla
name: Asgari, Reza
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a hole-doped molybdenum disulfide (MoS$_2$) superconducting spin valve (F/S/F) hybrid structure in which the Andreev reflection process is suppressed for all incoming waves with a determined range of the chemical potential in ferromagnetic (F) region and the cross-conductance in the right F region depends crucially on the configuration of magnetizations in the two F regions. Using the scattering formalism, we find that the transport is mediated purely by elastic electron cotunneling (CT) process in a parallel configuration and changes to the pure crossed Andreev reflection (CAR) process in the low-energy regime, without fixing of a unique parameter, by reversing the direction of magnetization in the right F region. This suggests both valley- and spin-switch effects between the perfect elastic CT and perfect CAR processes and makes the nonlocal charge current to be fully valley- and spin-polarized inside the right F region where the type of the polarizations can be changed by reversing the magnetization direction in the right F region. We further demonstrate that the presence of the strong spin-orbit interaction $λ$ and an additional topological term ($β$) in the Hamiltonian of MoS$_2$ result in an enhancement of the charge conductance of the CT and CAR processes and make them to be present for long lengths of the superconducting region. Besides, we find that the thermal conductance of the structure with a small length of the highly doped superconducting region exhibits linear dependence on the temperature at low temperatures whereas it enhances exponentially at higher temperatures. In particular, we demonstrate that the thermal conductance versus the strength of the exchange field ($h$) in F region displays a maximum value at $h
description: 13 pages, 8 figures
Measuring Trotter error and its application to precision-guaranteed Hamiltonian simulations
Creators: name: Ikeda, Tatsuhiko N.
name: Kono, Hideki
name: Fujii, Keisuke
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Trotterization is the most common and convenient approximation method for Hamiltonian simulations on digital quantum computers, but estimating its error accurately is computationally difficult for large quantum systems. Here, we develop a method for measuring the Trotter error without ancillary qubits on quantum circuits by combining the $m$th- and $n$th-order ($m
description: 11+5 pages, 6+2 figures
Distance-Preserving Graph Compression Techniques
Creators: name: Madani, Amirali
name: Maheshwari, Anil
Publisher: name: arXiv
Year: 2023
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: We study the problem of distance-preserving graph compression for weighted paths and trees. The problem entails a weighted graph $G = (V, E)$ with non-negative weights, and a subset of edges $E^{\prime} \subset E$ which needs to be removed from G (with their endpoints merged as a supernode). The goal is to redistribute the weights of the deleted edges in a way that minimizes the error. The error is defined as the sum of the absolute differences of the shortest path lengths between different pairs of nodes before and after contracting $E^{\prime}$. Based on this error function, we propose optimal approaches for merging any subset of edges in a path and a single edge in a tree. Previous works on graph compression techniques aimed at preserving different graph properties (such as the chromatic number) or solely focused on identifying the optimal set of edges to contract. However, our focus in this paper is on achieving optimal edge contraction (when the contracted edges are provided as input) specifically for weighted trees and paths.
Modeling the neutral hydrogen distribution in the post-reionization Universe: intensity mapping
Creators: name: Villaescusa-Navarro, Francisco
name: Viel, Matteo
name: Datta, Kanan K.
name: Choudhury, T. Roy
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We model the distribution of neutral hydrogen (HI) in the post-reionization era and investigate its detectability in 21 cm intensity mapping with the future SKA radio telescope. We rely on high resolution hydrodynamical N-body simulations. The HI is assigned a-posteriori to the gas particles following two different approaches: a halo-based method in which HI is assigned only to gas particles residing within dark matter halos; a particle-based method that assigns HI to all gas particles using a prescription based on the physical properties of the particles. The HI statistical properties are then compared to the observational properties of Damped Lyman-$α$ Absorbers (DLAs) and of lower column density systems and reasonable good agreement is found for all the cases. Among the halo-based method, we further consider two different schemes that aim at reproducing the observed properties of DLAs by distributing HI inside halos: one of this results in a much higher bias for DLAs, in agreement with recent observations, which boosts the 21 cm power spectrum by a factor $\sim 4$ with respect to the other recipe. We compute the 21 cm power spectrum from the simulated HI distribution and calculate the expected signal for both SKA1-mid and SKA1-low configurations at $2.4 \leq z \leq 4$. We find that SKA will be able to detect the 21 cm power spectrum, in the non-linear regime, up to $k\sim 1\,h$/Mpc for SKA1-mid and $k\sim 5\,h$/Mpc for SKA1-low with 100 hours of observations. We also investigate the perspective of imaging the HI distribution. Our findings indicate that SKA1-low could detect the most massive HI peaks with a signal to noise ratio (SNR) higher than 5 for an observation time of about 1000 hours at $z=4$, for a synthesized beam width of $2'$. Detection at redshifts $z\geqslant2.4$ with SKA1-mid would instead require a much longer observation time to achieve a comparable SNR level.
description: 46 pages, 21 figures; published on JCAP
Did Christiaan Huygens need glasses? A study of Huygens' telescope equations and tables
Creators: name: Pietrow, A. G. M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: History and Philosophy of Physics (physics.hist-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In the later stages of his life, Christiaan Huygens semi-empirically derived a set of relations between the objective focus and diameter, the eyepiece focus, and the magnification that resulted from combining the two lenses. These relations were used by him and his brother to build what he believed were optimized telescopes. When comparing these equations to the ones derived from modern optical principles, Huygens' telescopes were in fact far from optimal. While there are several potential reasons for this discrepancy, one possible reason, explored in this work, is that Huygens might have suffered from a mild case of myopia (or near-sightedness) and that he compensated for this condition by building telescopes that overmagnified by a factor of 3.5. Based on this hypothesis, Huygens' visual acuity is estimated to be around 20/70, which on average corresponds to an optical prescription of -1.5 diopters
description: Published in Notes and Records of the Royal Society
Fluctuation Moments for Regular Functions of Wigner Matrices
Creators: name: Reker, Jana
Publisher: name: arXiv
Year: 2023
Subjects: subject: Probability (math.PR)
subject: Combinatorics (math.CO)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 60B20, 15B52, 46L54

description: We compute the deterministic approximation for mixed fluctuation moments of products of deterministic matrices and general Sobolev functions of Wigner matrices. Restricting to polynomials, our formulas reproduce recent results of [Male, Mingo, Peché, Speicher 2022], showing that the underlying combinatorics of non-crossing partitions and annular non-crossing permutations continue to stay valid beyond the setting of second-order free probability theory. The formulas obtained further characterize the variance in the functional central limit theorem obtained recently in the companion paper [Reker 2023].
description: 52 pages (including appendix), 20 figures
Mechanisms of SiO oxidation: Implications for dust formation
Creators: name: Andersson, Stefan
name: Gobrecht, David
name: Valero, Rosendo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Reactions of SiO molecules have been postulated to initiate efficient formation of silicate dust particles in outflows around dying (AGB) stars. Both OH radicals and H$_2$O molecules can be present in these environments and their reactions with SiO and the smallest SiO cluster, Si$_2$O$_2$, affect the efficiency of eventual dust formation. Rate coefficients of gas-phase oxidation and clustering reactions of SiO, Si$_2$O$_2$ and Si$_2$O$_3$ have been calculated using master equation calculations based on density functional theory calculations. The calculations show that the reactions involving OH are fast. Reactions involving H$_2$O are not efficient routes to oxidation but may under the right conditions lead to hydroxylated species. The reaction of Si$_2$O$_2$ with H$_2$O, which has been suggested as efficient producing Si$_2$O$_3$, is therefore not as efficient as previously thought. If H$_2$O molecules dissociate to form OH radicals, oxidation of SiO and dust formation could be accelerated. Kinetics simulations of oxygen-rich circumstellar environments using our proposed reaction scheme suggest that under typical conditions only small amounts of SiO$_2$ and Si$_2$O$_2$ are formed and that most of the silicon remains as molecular SiO.
description: 10 pages, 13 figures
Molecular weight dependent bimolecular recombination in organic solar cells
Creators: name: Philippa, Bronson
name: Stolterfoht, Martin
name: White, Ronald D.
name: Velusamy, Marrapan
name: Burn, Paul L.
name: Meredith, Paul
name: Pivrikas, Almantas
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Charge carrier recombination is studied in operational organic solar cells made from the polymer:fullerene system PCDTBT:PC71BM (poly[N-9"-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] : [6,6]-phenyl-C$_{70}$-butyric acid methyl ester). A newly developed technique High Intensity Resistance dependent PhotoVoltage (HI-RPV) is presented for reliably quantifying the bimolecular recombination coefficient independently of variations in experimental conditions, thereby resolving key limitations of previous experimental approaches. Experiments are performed on solar cells of varying thicknesses and varying polymeric molecular weights. It is shown that solar cells made from low molecular weight PCDTBT exhibit Langevin recombination, whereas suppressed (non-Langevin) recombination is found in solar cells made with high molecular weight PCDTBT.
Experimental demonstration of separating the waveparticle duality of a single photon with the quantum Cheshire cat
Creators: name: Li, JiaKun
name: Sun, Kai
name: Wang, Yan
name: Hao, ZeYan
name: Liu, ZhengHao
name: Zhou, Jie
name: Fan, XingYan
name: Chen, JingLing
name: Xu, JinShi
name: Li, ChuanFeng
name: Guo, GuangCan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: As a fundamental characteristic of physical entities, waveparticle duality describes whether a microscopic entity exhibits wave or particle attributes depending on the specific experimental setup. This assumption is premised on the notion that physical properties are inseparable from the objective carrier. However, after the concept of the quantum Cheshire cats was proposed, which makes the separation of physical attributes from the entity possible, the premise no longer holds. Furthermore, an experimental demonstration of the separation of the wave and particle attributes inspired by this scenario remains scarce. In this work, we experimentally separated the wave and particle attributes of a single photon by exploiting the quantum Cheshire cat concept for the first time. By applying a weak disturbance to the evolution of the system, we achieve an effect similar to the quantum Cheshire cat and demonstrated the separation of the wave and particle attributes via the extraction of weak values. Our work provides a new perspective for the indepth understanding of waveparticle duality and promotes the application of weak measurements in fundamentals of quantum mechanics.
description: 12 pages,4 figures, published in Light: Science & Applications
End-to-End Reinforcement Learning for Torque Based Variable Height Hopping
Creators: name: Soni, Raghav
name: Harnack, Daniel
name: Isermann, Hannah
name: Fushimi, Sotaro
name: Kumar, Shivesh
name: Kirchner, Frank
Publisher: name: arXiv
Year: 2023
Subjects: subject: Robotics (cs.RO)
subject: Machine Learning (cs.LG)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Legged locomotion is arguably the most suited and versatile mode to deal with natural or unstructured terrains. Intensive research into dynamic walking and running controllers has recently yielded great advances, both in the optimal control and reinforcement learning (RL) literature. Hopping is a challenging dynamic task involving a flight phase and has the potential to increase the traversability of legged robots. Model based control for hopping typically relies on accurate detection of different jump phases, such as lift-off or touch down, and using different controllers for each phase. In this paper, we present a end-to-end RL based torque controller that learns to implicitly detect the relevant jump phases, removing the need to provide manual heuristics for state detection. We also extend a method for simulation to reality transfer of the learned controller to contact rich dynamic tasks, resulting in successful deployment on the robot after training without parameter tuning.
description: Update publication info. Cite as: R. Soni, D. Harnack, H. Isermann, S. Fushimi, S. Kumar and F. Kirchner, "End-to-End Reinforcement Learning for Torque Based Variable Height Hopping," 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Detroit, MI, USA, 2023, pp. 7531-7538, doi: 10.1109/IROS55552.2023.10342187
The Massive Fermion Phase for the U(N) Chern-Simons Gauge Theory in D=3 at Large N
Creators: name: Bardeen, William A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We explore the phase structure of fermions in the U(N) Chern-Simons gauge theory in three dimensions using the large N limit where N is the number of colors and the fermions are taken to be in the fundamental representation of the U(N) gauge group. In the large N limit, the theory retains its classical conformal behavior and considerable attention has been paid to a possible AdS/CFT duality of the theory in the conformal phase. In this paper we present a solution for the massive phase of the fermion theory that is exact to the leading order of 't Hooft's large N expansion. We present evidence for the spontaneous breaking of the exact scale symmetry and analyze the properties of the dilation that appears as the Goldstone boson of scale symmetry breaking.
description: 18 pages, 6 figures; corrected shift in quark bare mass parameter, clarified discussion of the fermion gap equation, various typos, appendix added
Topological Anderson insulating phases in the interacting Haldane model
Creators: name: Silva, Joao S.
name: Castro, Eduardo V.
name: Mondaini, Rubem
name: Vozmediano, María A. H.
name: López-Sancho, M. Pilar
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We analyze the influence of disorder and strong correlations on the topology in two dimensional Chern insulators. A mean field calculation in the half-filled Haldane model with extended Hubbard interactions and Anderson disorder shows that disorder favors topology in the interacting case and extends the topological phase to a larger region of the Hubbard parameters. In the absence of a staggered potential, we find a novel disorder-driven topological phase with Chern number C=1, with co-existence of topology with long range spin and charge orders. More conventional topological Anderson insulating phases are also found in the presence of a finite staggered potential.
О српским граматикама између науке и политике и о неким другим питањима : Поводом питања о месту хрватског језика међу јужнословенским језицима
Creators: name: Радић, Првослав
Publisher: name: Zenodo
Year: 2022
Subjects: српски језик
граматике
наука
политика
лингвистика
српски национални идентитет

description: Да се српска национална свест заиста била успавала код потоњих српских лингвиста, како су давно наслутили поједини српски интелектуалци, потврђује податак да се они нису хтели (или смели) посебно ангажовати око одбране низа суштинских питања везаних за српски језик, почев, на пример, од његовог назвања или утврђивања његовог територијалног домета (дакле и граница са суседним језицима), као и око других кључних питања на које је србистика још у XIX столећу имала свој прилично заокружен одговор.
 Запуштеност српске лингвистичке науке у југословенском периоду у вези с низом суштинских језичких питања (укључујући и она која се тичу српског националног идентитета) као да коначно стиже на наплату. То се на одређени начин испољило и кроз покренуто питање граматика српскога језика и њихових наставних јединица о саставу јужнословенске језичке групе, што се управо тиче и питања територијалног домета српскога језика, око којег су српски лингвисти поново показали нејединство, додуше, не баш спремни да то и јавно покажу.
Solvable random walk model with memory and its relations with Markovian models of anomalous diffusion
Creators: name: Boyer, D.
name: Romo-Cruz, J. C. R.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Motivated by studies on the recurrent properties of animal and human mobility, we introduce a path-dependent random walk model with long range memory for which not only the mean square displacement (MSD) can be obtained exactly in the asymptotic limit, but also the propagator. The model consists of a random walker on a lattice, which, at a constant rate, stochastically relocates at a site occupied at some earlier time. This time in the past is chosen randomly according to a memory kernel, whose temporal decay can be varied via an exponent parameter. In the weakly non-Markovian regime, memory reduces the diffusion coefficient from the bare value. When the mean backward jump in time diverges, the diffusion coefficient vanishes and a transition to an anomalous subdiffusive regime occurs. Paradoxically, at the transition, the process is an anti-correlated Lévy flight. Although in the subdiffusive regime the model exhibits some features of the continuous time random walk with infinite mean waiting time, it belongs to another universality class. If memory is very long-ranged, a second transition takes place to a regime characterized by a logarithmic growth of the MSD with time. In this case the process is asymptotically Gaussian and effectively described as a scaled Brownian motion with a diffusion coefficient decaying as 1/t.
description: 13 pages, 8 figures
Cosmological viable f(R,T) dark energy model: dynamics and stability
Creators: name: Baffou, E. H.
name: Kpadonou, A. V.
name: Rodrigues, M. E.
name: Houndjo, M. J. S.
name: Tossa, J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper we undertake the modified theory of gravity f(R,T) where R and T are the Ricci scalar and the trace of the energy momentum tensor, respectively. Imposing the conservation of the energy momentum tensor, we obtain a model about what dynamics and stability are studied. The stability is developed using the de Sitter and power-law solutions. The results show that the model presents stability for both the de Sitter and power-law solutions. Regarding the dynamics, cosmological solutions are obtained by integrating the background equations for both the low-redshift and High-redshift regimes and are consistent with the observational data.
description: 15 pages, 4 figues