cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Low-carbon optimal dispatch of integrated energy system considering demand response under the tiered carbon trading mechanism
Creators: name: Wang, Limeng
name: Liu, Xuemeng
name: Li, Yang
name: Chang, Duo
name: Ren, Xing
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In the operation of the integrated energy system (IES), considering further reducing carbon emissions, improving its energy utilization rate, and optimizing and improving the overall operation of IES, an optimal dispatching strategy of integrated energy system considering demand response under the stepped carbon trading mechanism is proposed. Firstly, from the perspective of demand response (DR), considering the synergistic complementarity and flexible conversion ability of multiple energy sources, the lateral time-shifting and vertical complementary alternative strategies of electricity-gas-heat are introduced and the DR model is constructed. Secondly, from the perspective of life cycle assessment, the initial quota model of carbon emission allowances is elaborated and revised. Then introduce a tiered carbon trading mechanism, which has a certain degree of constraint on the carbon emissions of IES. Finally, the sum of energy purchase cost, carbon emission transaction cost, equipment maintenance cost and demand response cost is minimized, and a low-carbon optimal scheduling model is constructed under the consideration of safety constraints. This model transforms the original problem into a mixed integer linear problem using Matlab software, and optimizes the model using the CPLEX solver. The example results show that considering the carbon trading cost and demand response under the tiered carbon trading mechanism, the total operating cost of IES is reduced by 5.69% and the carbon emission is reduced by 17.06%, which significantly improves the reliability, economy and low carbon performance of IES.
description: Accepted by Electric Power Construction [in Chinese]
Dark linear seesaw mechanism
Creators: name: Batra, A.
name: Câmara, H. B.
name: Joaquim, F. R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We propose a minimal model where a dark sector, odd under a $\mathcal{Z}_2$ discrete symmetry, is the seed of lepton number violation in the neutrino sector at the loop level, in the context of the linear seesaw mechanism. Neutrino mass suppression stems from a naturally small scalar potential coupling which breaks the lepton number symmetry softly. The fact that we consider (dark) Dirac vector-like neutral leptons, prevents the appearance of other mass terms that could contribute to neutrino masses via alternative mechanisms. We study the dark-matter phenomenology of the model, focusing on the case in which the stable particle is the lightest neutral scalar arising from the dark scalar sector. Prospects for testing our framework with the results of current and future lepton flavour violation searches are also discussed.
description: 13 LaTeX pages, 3 figures
One- and two-particle correlation functions in the cluster perturbation theory for cuprates
Creators: name: Kuz'min, V. I.
name: Nikolaev, S. V.
name: Korshunov, M. M.
name: Ovchinnikov, S. G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Physics of high-$T_c$ superconducting cuprates is obscured by the effect of strong electronic correlations. One way to overcome the problem is to seek for an exact solution at least within the small cluster and expand it to the whole crystal. Such an approach is in the heart of the cluster perturbation theory (CPT). Here we develop CPT for the dynamic spin and charge susceptibilities (spin-CPT and charge-CPT), within which the correlation effects are explicitly taken into account by the exact diagonalization. We apply spin-CPT and charge-CPT to the effective two-band Hubbard model for the cuprates obtained from the three-band Emery model and calculate one- and two-particle correlation functions, namely, spectral function and spin and charge susceptibilities. Doping dependence of the spin susceptibility was studied within spin-CPT and CPT-RPA that is the CPT generalization of the random phase approximation (RPA). Both methods produce the low energy response at four incommensurate wave vectors in qualitative agreement to the results of the inelastic neutron scattering on overdoped cuprates.
description: 14 pages, 8 figures
Dynamic Range in the C.elegans Brain Network
Creators: name: Antonopoulos, Chris G.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: We study external, electrical perturbations and their responses in the brain dynamic network of the \textit{Caenorhabditis elegans} soil worm, given by the connectome of its large somatic nervous system. Our analysis is inspired by a realistic experiment where one stimulates externally specific parts of the brain and studies the persistent neural activity triggered in other cortical regions. In this work, we perturb groups of neurons that form communities, identified by the walktrap community detection method, by trains of stereotypical electrical Poissonian impulses and study the propagation of neural activity to other communities by measuring the corresponding dynamic ranges and Steven law exponents. We show that when one perturbs specific communities, keeping the rest unperturbed, the external stimulations are able to propagate to some of them but not to all. There are also perturbations that do not trigger any response. We found that this depends on the initially perturbed community. Finally, we relate our findings for the former cases with low neural synchronization, self-criticality and large information flow capacity, and interpret them as the ability of the brain network to respond to external perturbations when it works at criticality and its information flow capacity becomes maximal.
description: 9 pages, 6 figures, accepted for publication in Chaos: An Interdisciplinary Journal of Nonlinear Science
Validation, Verification, and Testing (VVT) of future RISC-V powered cloud infrastructures: the Vitamin-V Horizon Europe Project perspective
Creators: name: Alonso, Marti
name: Andreu, David
name: Canal, Ramon
name: Di Carlo, Stefano
name: Chenet, Cristiano
name: Costa, Juanjo
name: Girones, Andreu
name: Gizopoulos, Dimitris
name: Karakostas, Vasileios
name: Otero, Beatriz
name: Papadimitriou, George
name: Rodriguez, Eva
name: Savino, Alessandro
Publisher: name: arXiv
Year: 2023
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Vitamin-V is a project funded under the Horizon Europe program for the period 2023-2025. The project aims to create a complete open-source software stack for RISC-V that can be used for cloud services. This software stack is intended to have the same level of performance as the x86 architecture, which is currently dominant in the cloud computing industry. In addition, the project aims to create a powerful virtual execution environment that can be used for software development, validation, verification, and testing. The virtual environment will consider the relevant RISC-V ISA extensions required for cloud deployment. Commercial cloud systems use hardware features currently unavailable in RISC-V virtual environments, including virtualization, cryptography, and vectorization. To address this, Vitamin-V will support these features in three virtual environments: QEMU, gem5, and cloud-FPGA prototype platforms. The project will focus on providing support for EPI-based RISC-V designs for both the main CPUs and cloud-important accelerators, such as memory compression. The project will add the compiler (LLVM-based) and toolchain support for the ISA extensions. Moreover, Vitamin-V will develop novel approaches for validating, verifying, and testing software trustworthiness. This paper focuses on the plans and visions that the Vitamin-V project has to support validation, verification, and testing for cloud applications, particularly emphasizing the hardware support that will be provided.
Evolution of segmented strings
Creators: name: Gubser, Steven S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: I explain how to evolve segmented strings in de Sitter and anti-de Sitter spaces of any dimension in terms of forward-directed null displacements. The evolution is described entirely in terms of discrete hops which do not require a continuum spacetime. Moreover, the evolution rule is purely algebraic, so it can be defined not only on ordinary real de Sitter and anti-de Sitter, but also on the rational points of the quadratic equations that define these spaces. For three-dimensional anti-de Sitter space, a simpler evolution rule is possible that descends from the Wess-Zumino-Witten equations of motion. In this case, one may replace three-dimensional anti-de Sitter space by a non-compact discrete subgroup of SL(2,R) whose structure is related to the Pell equation. A discrete version of the BTZ black hole can be constructed as a quotient of this subgroup. This discrete black hole avoids the firewall paradox by a curious mechanism: even for large black holes, there are no points inside the horizon until one reaches the singularity.
description: 37 pages, 3 figures
Systematic Error Estimation for Chemical Reaction Energies
Creators: name: Simm, Gregor N.
name: Reiher, Markus
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Computational Physics (physics.comp-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: For the theoretical understanding of the reactivity of complex chemical systems accurate relative energies between intermediates and transition states are required. Despite its popularity, density functional theory (DFT) often fails to provide sufficiently accurate data, especially for molecules containing transition metals. Due to the huge number of intermediates that need to be studied for all but the simplest chemical processes, DFT is to date the only method that is computationally feasible. Here, we present a Bayesian framework for DFT that allows for error estimation of calculated properties. Since the optimal choice of parameters in present-day density functionals is strongly system dependent, we advocate for a system-focused re-parameterization. While, at first sight, this approach conflicts with the first-principles character of DFT that should make it in principle system independent, we deliberately introduce system dependence because we can then assign a stochastically meaningful error to the system-dependent parametrization that makes it non-arbitrary. By re-parameterizing a functional that was derived on a sound physical basis to a chemical system of interest we obtain a functional that yields reliable confidence intervals for reaction energies. We demonstrate our approach at the example of catalytic nitrogen fixation.
description: 26 pages, 9 figures, 3 tables
Collective depinning and sliding of a quantum Wigner solid in a 2D electron system
Creators: name: Melnikov, M. Yu.
name: Shashkin, A. A.
name: Huang, S. -H.
name: Liu, C. W.
name: Kravchenko, S. V.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report the observation of two-threshold voltage-current characteristics accompanied by a peak of broadband current noise between the two threshold voltages in the insulating state at low densities in the 2D electron system in ultra-high mobility SiGe/Si/SiGe heterostructures. The observed results can be described by a phenomenological theory of the collective depinning of elastic structures, which naturally generates a peak of a broadband current noise between the dynamic and static thresholds and changes to sliding of the solid over a pinning barrier above the static threshold. This gives compelling evidence for the electron solid formation in this electron system and shows the generality of the effect for different classes of electron systems.
description: As published
Effect of Cauchy noise on a network of quadratic integrate-and-fire neurons with non-Cauchy heterogeneities
Creators: name: Pyragas, Viktoras
name: Pyragas, Kestutis
Publisher: name: arXiv
Year: 2023
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Biological sciences

description: We analyze the dynamics of large networks of pulse-coupled quadratic integrate-and-fire neurons driven by Cauchy noise and non-Cauchy heterogeneous inputs. Two types of heterogeneities defined by families of $q$-Gaussian and flat distributions are considered. Both families are parametrized by an integer $n$, so that as $n$ increases, the first family tends to a normal distribution, and the second tends to a uniform distribution. For both families, exact systems of mean-field equations are derived and their bifurcation analysis is carried out. We show that noise and heterogeneity can have qualitatively different effects on the collective dynamics of neurons.
description: 9 pages, 5 figures
Indoor Positioning based on Active Radar Sensing and Passive Reflectors: Concepts & Initial Results
Creators: name: Schlachter, Pascal
name: Yu, Zhibin
name: Iqbal, Naveed
name: Wu, Xiaofeng
name: Hinderer, Sven
name: Yang, Bin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Robotics (cs.RO)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: To navigate reliably in indoor environments, an industrial autonomous vehicle must know its position. However, current indoor vehicle positioning technologies either lack accuracy, usability or are too expensive. Thus, we propose a novel concept called local reference point assisted active radar positioning, which is able to overcome these drawbacks. It is based on distributing passive retroreflectors in the indoor environment such that each position of the vehicle can be identified by a unique reflection characteristic regarding the reflectors. To observe these characteristics, the autonomous vehicle is equipped with an active radar system. On one hand, this paper presents the basic idea and concept of our new approach towards indoor vehicle positioning and especially focuses on the crucial placement of the reflectors. On the other hand, it also provides a proof of concept by conducting a full system simulation including the placement of the local reference points, the radar-based distance estimation and the comparison of two different positioning methods. It successfully demonstrates the feasibility of our proposed approach.
description: Accepted as a work-in-progress paper at the 13th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2023)
Small-scale dynamos: From idealized models to solar and stellar applications
Creators: name: Rempel, Matthias
name: Bhatia, Tanayveer
name: Rubio, Luis Bellot
name: Korpi-Lagg, Maarit J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this article we review small-scale dynamo processes that are responsible for magnetic field generation on scales comparable to and smaller than the energy carrying scales of turbulence. We provide a review of critical observation of quiet Sun magnetism, which have provided strong support for the operation of a small-scale dynamo in the solar photosphere and convection zone. After a review of basic concepts we focus on numerical studies of kinematic growth and non-linear saturation in idealized setups, with special emphasis on the role of the magnetic Prandtl number for dynamo onset and saturation. Moving towards astrophysical applications we review convective dynamo setups that focus on the deep convection zone and the photospheres of solar-like stars. We review the critical ingredients for stellar convection setups and discuss their application to the Sun and solar-like stars including comparison against available observations.
description: 54 pages, 10 figures, submitted to Space Science Reviews
Spatial adiabatic passage: a review of recent progress
Creators: name: Menchon-Enrich, Ricard
name: Benseny, Albert
name: Ahufinger, Verònica
name: Greentree, Andrew D.
name: Busch, Thomas
name: Mompart, Jordi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Adiabatic techniques are known to allow for engineering quantum states with high fidelity. This requirement is currently of large interest, as applications in quantum information require the preparation and manipulation of quantum states with minimal errors. Here we review recent progress on developing techniques for the preparation of spatial states through adiabatic passage, particularly focusing on three state systems. These techniques can be applied to matter waves in external potentials, such as cold atoms or electrons, and to classical waves in waveguides, such as light or sound.
description: Review article, 34 pages, 27 figures
The Polynomial Form of the Scattering Equations is an H-Basis
Creators: name: Bosma, Jorrit
name: Sogaard, Mads
name: Zhang, Yang
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We prove that the polynomial form of the scattering equations is a Macaulay H-basis. We demonstrate that this H-basis facilitates integrand reduction and global residue computations in a way very similar to using a Gröbner basis, but circumvents the heavy computation of the latter. As an example, we apply the H-basis to prove the conjecture that the dual basis of the polynomial scattering equations must contain one constant term.
description: 6 pages
Functional Renormalisation Group analysis of Tensorial Group Field Theories on $\mathbb{R}^d$
Creators: name: Geloun, Joseph Ben
name: Martini, Riccardo
name: Oriti, Daniele
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Rank-d Tensorial Group Field Theories are quantum field theories defined on a group manifold $G^{\times d}$, which represent a non-local generalization of standard QFT, and a candidate formalism for quantum gravity, since, when endowed with appropriate data, they can be interpreted as defining a field theoretic description of the fundamental building blocks of quantum spacetime. Their renormalisation analysis is crucial both for establishing their consistency as quantum field theories, and for studying the emergence of continuum spacetime and geometry from them. In this paper, we study the renormalisation group flow of two simple classes of TGFTs, defined for the group $G=\mathbb{R}$ for arbitrary rank, both without and with gauge invariance conditions, by means of functional renormalisation group techniques. The issue of IR divergences is tackled by the definition of a proper thermodynamic limit for TGFTs. We map the phase diagram of such models, in a simple truncation, and identify both UV and IR fixed points of the RG flow. Encouragingly, for all the models we study, we find evidence for the existence of a phase transition of condensation type.
description: 43 pages, 9 figures
Can neural networks count digit frequency?
Creators: name: Khandelwal, Padmaksh
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: In this research, we aim to compare the performance of different classical machine learning models and neural networks in identifying the frequency of occurrence of each digit in a given number. It has various applications in machine learning and computer vision, e.g. for obtaining the frequency of a target object in a visual scene. We considered this problem as a hybrid of classification and regression tasks. We carefully create our own datasets to observe systematic differences between different methods. We evaluate each of the methods using different metrics across multiple datasets.The metrics of performance used were the root mean squared error and mean absolute error for regression evaluation, and accuracy for classification performance evaluation. We observe that decision trees and random forests overfit to the dataset, due to their inherent bias, and are not able to generalize well. We also observe that the neural networks significantly outperform the classical machine learning models in terms of both the regression and classification metrics for both the 6-digit and 10-digit number datasets. Dataset and code are available on github.
description: Code and Datasets: https://github.com/PadmakshKhandelwal/Can-neural-networks-count
On the scaling behaviour of an integrable spin chain with ${\cal Z}_r$ symmetry
Creators: name: Kotousov, Gleb A.
name: Lukyanov, Sergei L.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The subject matter of this work is a 1D quantum spin - $\frac{1}{2}$ chain associated with the inhomogeneous six-vertex model possessing an additional ${\cal Z}_r$ symmetry. The model is studied in a certain parametric domain, where it is critical. Within the ODE/IQFT approach, a class of ordinary differential equations and a quantization condition are proposed which describe the scaling limit of the system. Some remarkable features of the CFT underlying the critical behaviour are observed. Among them is an infinite degeneracy of the conformal primary states and the presence of a continuous component in the spectrum in the case of even $r$.
description: 31 pages, 8 figures, 2 tables
Student understanding of quantum mechanics at the beginning of graduate instruction
Creators: name: Singh, Chandralekha
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: A survey was developed to probe student understanding of quantum mechanics at the beginning of graduate instruction. The survey was administered to 202 physics graduate students enrolled in first-year quantum mechanics courses from seven universities at the beginning of the first semester. We also conducted one-on-one interviews with fifteen graduate or advanced undergraduate students who had just completed a course in which all the content on the survey was covered. Although students from some universities performed better on average than others, we found that students share universal difficulties understanding the concepts of quantum mechanics. The difficulties were often due to over-generalizations of concepts learned in one context to other contexts where they are not directly applicable. Difficulties in distinguishing between closely related concepts and making sense of the formalism of quantum mechanics were common. The results of this study can sensitize instructors of first-year graduate quantum physics to some of the difficulties students are likely to face.
description: 11 pages, PACS: 01.40Fk,01.40.gb,01.40G-,1.30.Rr, Keywords: physics education research, quantum mechanics, teaching, learning, pedagogy, student difficulties. arXiv admin note: substantial text overlap with arXiv:1504.02056, arXiv:1602.05616
K. Alex Müller: Science between ferroelectricity and superconductivity
Creators: name: Kremer, R. K.
name: Bussmann-Holder, A.
name: Keller, H.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: K. Alex Müller started his scientific career in 1958 when he was about thirty-one years old. After his wife passed away and being in his nineties, his interest in physics gradually faded. In those years shortly before he passed away, on January 9, 2023, he was no longer interested in superconductivity or ferroelectricity, he had become essentially devoted to philosophy and psychology. It is of note that altogether his research in physics comprised sixty years of activity. Almost in the middle of this period, he was awarded the Nobel Prize in Physics for the discovery of high-temperature superconductivity in ceramic copper oxides in 1987. This discovery made him truly famous. While most researchers are familiar with his Nobel Prize work, many are not aware of the fact that K. Alex Müller was already an acclaimed scientist before that and highly respected in the field of perovskite oxides, ferroelectricity, structural phase transitions, Jahn-Teller physics, electron paramagnetic resonance (EPR) and, especially so in the properties of SrTiO3.
description: 13 pages, 7 figures, 1 table
Trichopria lewisi Nixon 1940
Creators: name: Notton, David G.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Mymaridae
Trichopria
Trichopria lewisi

description: Trichopria lewisi Nixon, 1940: 59, fig. 1a-d.
Valid name
Trichopria lewisi Nixon, 1940.
Summary of types
Holotype ♀, BMNH number 9.706, by original designation. Paratypes 24♀♀, ♂.
Primary type data
Type; Kenya Colony/ Kabete/ Ex Glossina / brevipalpis &/ G. fuscipleuris/ Dr E.A.Lewis; Trichopria / lewisi Nixon / ♀ type 1940; Pres. by/ Imp. Inst. Ent./ B.M.1940-181.
Type locality
Kenya, Kabete.
Remarks
Although Nixon mentioned 24 ♀♀ and 1 ♂ as paratypes, there are 63 ♀♀ and 3 ♂♂ specimens labelled as paratypes, so it is not clear which are Nixon’s original paratypes. While the error in labelling paratypes is unfortunate, it is not likely to be a problem, as the holotype is certainly recognised and all the type specimens appear to be the same species. Nixon’s preparation of the male genitalia is missing. The holotype is mounted on a card point and is entire. It is worth noting a singular feature of the male of this species which was not recorded by Nixon: the male head is truncate behind, and the genal pubescence is long, and, unlike other Trichopria, turned back to form a row from the top to the bottom of the gena, defining a vertical channel behind each gena, between the back of the head and the pronotum. By analogy with the observed mating behaviour of other Trichopria it is predicted that this channel is used to constrain the female antenna during courtship.
description: Published as part of Notton, David G., 2014, A catalogue of the types of Diapriinae (Hymenoptera, Diapriidae) at the Natural History Museum, London, pp. 1-123 in European Journal of Taxonomy 75 on page 93, DOI: 10.5852/ejt.2014.75, http://zenodo.org/record/3862773
Formation of high-order acoustic Bessel beams by spiral diffraction gratings
Creators: name: Jiménez, Noé
name: Picó, Rubén
name: Sánchez-Morcillo, Víctor
name: Romero-García, Vicent
name: García-Raffi, Lluis M.
name: Staliunas, Kestutis
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' spiral diffraction grating is theoretically, numerically and experimentally reported in this work. These beams are propagation-invariant solutions of the Helmholtz equation and are characterized by an azimuthal variation of the phase along its annular spectrum producing an acoustic vortex in the near field. In our system, the scattering of plane acoustic waves by the spiral grating leads to the formation of the acoustic vortex with zero pressure on-axis and the angular phase dislocations characterized by the spiral geometry. The order of the generated Bessel beam and, as a consequence, the size of the generated vortex can be fixed by the number of arms in the spiral diffraction grating. The obtained results allow to obtain Bessel beams with controllable vorticity by a passive device, which has potential applications in low-cost acoustic tweezers and acoustic radiation force devices.
Thermal features of Heisenberg antiferromagnets on edge- versus corner-sharing triangular-based lattices: A message from spin waves
Creators: name: Yamamoto, Shoji
name: Ohara, Jun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We construct modified spin-wave thermodynamics for frustrated noncollinear antiferromagnets for the first time. The well-known modified spin-wave theory for collinear antiferromagnets diagonalizes a bosonic Hamiltonian subject to the constraint that the total staggered magnetization be zero. Applying this scheme as it is to frustrated noncollinear antiferromagnets ends in a poor thermodynamics, missing the optimal ground state and breaking the local U(1) rotational symmetry. We find a new double-constraint modification scheme to overcome this difficulty, which is tuned especially to frustrated spiral magnets but spontaneously goes back to the standard single-constraint condition at the onset of a collinear Néel-ordered classical ground state. We apply this new scheme to triangular-based polyhedral and planar antiferromagnets with particular interest in a possible contrast between edge- versus corner-sharing geometries. Under such circumstances that very few methods are available to calculate finite-temperature properties of frustrated noncollinear quantum magnets in the thermodynamic limit, our newly developed modified spin-wave theory predicts that the specific heat of the kagome-lattice Heisenberg antiferromagnet in the corner-sharing geometry remains having both mid-temperature broad maximum and low-temperature narrow peak in the thermodynamic limit, while the specific heat of the triangular-lattice Heisenberg antiferromagnet in the edge-sharing geometry retains a low-temperature sharp peak followed by a mid-temperature weak anormaly in the thermodynamic limit.
description: New robust modified spin-wave thermodynamics for various frustrated noncollinear Heisenberg antiferromagnets in the triangular-based geometry; 52 pages including 8 figures
Gravity modes on rapidly rotating accreting white dwarfs and their variation after dwarf novae
Creators: name: Kumar, Praphull
name: Townsley, Dean M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Accreting white dwarfs in Cataclysmic variables (CVs) show short-period (tens of minutes) brightness variations that are consistent with non-radial oscillations similar to gravity (g) modes observed in isolated white dwarfs (WDs). GW Librae, a dwarf nova, was the first CV in which non-radial oscillations were observed and continues to be the best studied accreting WD displaying these pulsations. Unlike isolated WDs, accreting WDs rotate rapidly, with spin periods comparable to or shorter than typical low-order oscillation periods. Accreting WDs also have a different relationship between their interior temperature and surface temperature. The surface temperature of an accreting WD varies on a months to year timescale between dwarf novae accretion events, allowing study of how this temperature change effects g-mode behavior. Here we show results from adiabatic seismological calculations for accreting WDs, focusing on low-order ($\ell=1$) modes. We demonstrate how g-modes vary in response to temperature changes in the subsurface layers due to a dwarf nova accretion event. These calculations include rotation non-perturbatively, required by the high spin rate. We discuss the thermal history of these accreting WDs, and compare the seismological properties with and without rotation. Comparison of $g$-mode frequencies to observed objects may allow inference of features of the structure of the WD such as mass, surface abundance, accretion history, and more. The variation of mode frequencies during cooling after an outburst provides a novel method of identifying modes.
description: 18 pages, 13 figures, Accepted to ApJ
Ligand spheres in asymmetric hetero Diels-Alder reactions catalyzed by Cu(II) box complexes: experiment and modeling
Creators: name: Umamaheswari, V.
name: Cias, Pawel
name: Pöppl, Andreas
name: Kaupp, Martin
name: Gescheidt, Georg
Publisher: name: Technische Universität Berlin
Year: 2014
Subjects: subject: 540 Chemie und zugeordnete Wissenschaften

description: Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
description: This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
description: The stereoselective hetero Diels–Alder reaction between ethyl glyoxylate and cyclohexadiene catalyzed by [Cu(II)t-Bu-(box)](OTf)2 was investigated. The reaction was performed step-by-step and the geometry of the Cu(II) complexes formed in the course of the catalysis was analysed by EPR spectroscopy, advanced pulsed EPR methods (ENDOR, and HYSCORE) and DFT calculations. Our results show that one triflate counterion is directly coordinated to Cu(II) during the catalytic process (axial position). This leads to penta-coordinated Cu(II) complexes. Solvent molecules are able to alter the geometry of the Cu(II) complexes although their coordination is weak. These findings provide an explanation for the solvent and counterion effects observed in many catalytic reactions.
Helping Students Learn Quantum Mechanics for Quantum Computing
Creators: name: Singh, Chandralekha
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: Quantum information science and technology is a rapidly growing interdisciplinary field drawing researchers from science and engineering fields. Traditional instruction in quantum mechanics is insufficient to prepare students for research in quantum computing because there is a lack of emphasis in the current curriculum on quantum formalism and dynamics. We are investigating the difficulties students have with quantum mechanics and are developing and evaluating quantum interactive learning tutorials (QuILTs) to reduce the difficulties. Our investigation includes interviews with individual students and the development and administration of free-response and multiple-choice tests. We discuss the implications of our research and development project on helping students learn quantum mechanics relevant for quantum computing.
description: 4 pages, PACS: 1.40Fk,01.40.gb,01.40G-, Keywords: physics education research, pedagogy, teaching, learning, quantum mechanics, Proceedings of the 2006 Physics Education Research Conference, Syracuse, NY, AIP Conference Proceedings, Melville New York 883, 42-45, (2007)
Charging of small grains in a space plasma: Application to Jovian stream particles
Creators: name: Dzhanoev, A. R.
name: Schmidt, J.
name: Liu, X.
name: Spahn, F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Most theoretical investigations of dust charging processes in space have treated the current balance condition as independent of grain size. However, for small grains, as they are often observed in space environments, a dependence on grain size is expected due to secondary electron emission (SEE). Here, by the term "small" we mean a particle size comparable to the typical penetration depth for given primary electron energy. The results are relevant for the dynamics of small, charged dust particles emitted by the volcanic moon Io, which form the Jovian dust streams. We revise the theory of charging of small (sub-micron sized) micrometeoroids to take into account a high production of secondary electrons for small grains immersed in an isotropic flux of electrons. We apply our model to obtain an improved estimate for the charge of the dust streams leaving the Jovian system, detected by several spacecraft. For the Jupiter plasma environment we derive the surface potential of grains composed of NaCl (believed to be the major constituent of Jovian dust stream particles) or silicates. For small particles the potential depends on grain size and the secondary electron current induces a sensitivity to material properties. As a result of the small particle effect, the estimates for the charging times and for the fractional charge fluctuations of NaCl grains obtained using our general approach to SEE give results qualitatively different from the analogous estimates derived from the traditional approach to SEE. We find that for the charging environment considered in this paper field emission does not limit the charging of NaCl grains.
description: 7 pages, 9 figures; second revision submitted to A&A
KURVS: The outer rotation curve shapes and dark matter fractions of $z \sim 1.5 $ star-forming galaxies
Creators: name: Puglisi, Annagrazia
name: Dudzevičiūtė, Ugnė
name: Swinbank, Mark
name: Gillman, Steven
name: Tiley, Alfred L.
name: Bower, Richard G.
name: Cirasuolo, Michele
name: Cortese, Luca
name: Glazebrook, Karl
name: Harrison, Chris
name: Ibar, Edo
name: Molina, Juan
name: Obreschkow, Danail
name: Oman, Kyle A.
name: Schaller, Matthieu
name: Shankar, Francesco
name: Sharples, Ray M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present first results from the KMOS Ultra-deep Rotation Velocity Survey (KURVS), aimed at studying the outer rotation curves shape and dark matter content of 22 star-forming galaxies at $z\sim1.5$. These galaxies represent `typical' star-forming discs at $z \sim 1.5$, being located within the star-forming main sequence and stellar mass-size relation with stellar masses $9.5\leqslant$log$(M_{\star}/\mathrm{M_{\odot}})\leqslant11.5$. We extract individual rotation curves out to 4 times the effective radius, on average, or $\sim 10-15$ kpc. Most rotation curves are flat or rising between three- and six-disc scale radii. Only three objects with dispersion-dominated dynamics ($v_{\rm rot}/σ_0\sim0.2$) have declining outer rotation curves at more than 5$σ$ significance. After accounting for seeing and pressure support, the nine rotation-dominated discs with $v_{\rm rot}/σ_0\geqslant1.5$ have average dark matter fractions of $50 \pm 20\%$ at the effective radius, similar to local discs. Together with previous observations of star-forming galaxies at cosmic noon, our measurements suggest a trend of declining dark matter fraction with increasing stellar mass and stellar mass surface density at the effective radius. Simulated EAGLE galaxies are in quantitative agreement with observations up to log$(M_{\star}R_{\rm eff}^{-2}/\mathrm{M_{\odot}kpc^{-2}}) \sim 9.2$, and over-predict the dark matter fraction of galaxies with higher mass surface densities by a factor of $\sim 3$. We conclude that the dynamics of typical rotationally-supported discs at $z \sim 1.5$ is dominated by dark matter from effective radius scales, in broad agreement with cosmological models. The tension with observations at high stellar mass surface density suggests that the prescriptions for baryonic processes occurring in the most massive galaxies (such as bulge growth and quenching) need to be reassessed.
description: 23 pages, 9 figures. Resubmitted to MNRAS after addressing the referee's comments. Abstract slightly modified to compile with the arXiv formatting
Observation of Enhanced Dynamic ΔG effect near Ferromagnetic Resonance Frequency
Creators: name: Hu, Wenbin
name: Wang, Yudi
name: Huang, Mingxian
name: Zhang, Huaiwu
name: Bai, Feiming
Publisher: name: arXiv
Year: 2023
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The field-dependence elastic modulus of magnetostrictive films, also called ΔE or ΔG effect, is crucial for ultrasensitive magnetic field sensors based on surface acoustic waves (SAWs). In spite of a lot of successful demonstrations, rare attention was paid to the frequency-dependence of ΔE or ΔG effect. In current work, shear horizontal-type SAW delay lines coated with a thin FeCoSiB layer have been studied at various frequencies upon applying magnetic fields. The change of shear modulus of FeCoSiB has been extracted by measuring the field-dependent phase shift of SAWs. It is found that the ΔG effect is significantly enhanced at high-order harmonic frequencies close to the ferromagnetic resonance frequency, increasing by ~82% compared to that at the first SAW mode (128 MHz). In addition, the smaller the effective damping factor of magnetostrictive layer, the more pronounced ΔG effect can be obtained, which is explained by our proposed dynamic magnetoelastic coupling model.
Large-scale and Efficient Texture Mapping Algorithm via Loopy Belief Propagation
Creators: name: ling, Xiao
name: Qin, Rongjun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Texture mapping as a fundamental task in 3D modeling has been well established for well-acquired aerial assets under consistent illumination, yet it remains a challenge when it is scaled to large datasets with images under varying views and illuminations. A well-performed texture mapping algorithm must be able to efficiently select views, fuse and map textures from these views to mesh models, at the same time, achieve consistent radiometry over the entire model. Existing approaches achieve efficiency either by limiting the number of images to one view per face, or simplifying global inferences to only achieve local color consistency. In this paper, we break this tie by proposing a novel and efficient texture mapping framework that allows the use of multiple views of texture per face, at the same time to achieve global color consistency. The proposed method leverages a loopy belief propagation algorithm to perform an efficient and global-level probabilistic inferences to rank candidate views per face, which enables face-level multi-view texture fusion and blending. The texture fusion algorithm, being non-parametric, brings another advantage over typical parametric post color correction methods, due to its improved robustness to non-linear illumination differences. The experiments on three different types of datasets (i.e. satellite dataset, unmanned-aerial vehicle dataset and close-range dataset) show that the proposed method has produced visually pleasant and texturally consistent results in all scenarios, with an added advantage of consuming less running time as compared to the state of the art methods, especially for large-scale dataset such as satellite-derived models.
description: 13 Figures
Gaussian process deconvolution
Creators: name: Tobar, Felipe
name: Robert, Arnaud
name: Silva, Jorge F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Let us consider the deconvolution problem, that is, to recover a latent source $x(\cdot)$ from the observations $\mathbf{y} = [y_1,\ldots,y_N]$ of a convolution process $y = x\star h + η$, where $η$ is an additive noise, the observations in $\mathbf{y}$ might have missing parts with respect to $y$, and the filter $h$ could be unknown. We propose a novel strategy to address this task when $x$ is a continuous-time signal: we adopt a Gaussian process (GP) prior on the source $x$, which allows for closed-form Bayesian nonparametric deconvolution. We first analyse the direct model to establish the conditions under which the model is well defined. Then, we turn to the inverse problem, where we study i) some necessary conditions under which Bayesian deconvolution is feasible, and ii) to which extent the filter $h$ can be learnt from data or approximated for the blind deconvolution case. The proposed approach, termed Gaussian process deconvolution (GPDC) is compared to other deconvolution methods conceptually, via illustrative examples, and using real-world datasets.
description: Accepted at Proceedings of the Royal Society A
Non-Abelian Vortex in Four Dimensions as a Critical String on a Conifold
Creators: name: Koroteev, Peter
name: Shifman, Mikhail
name: Yung, Alexei
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Non-Abelian vortex strings supported in a certain four-dimensional N=2 Yang-Mills theory with fundamental matter were shown arXiv:1502.00683 to become critical superstrings. In addition to translational moduli non-Abelian string under consideration carries orientational and size moduli. Their dynamics is described by two-dimensional sigma model whose target space is a tautological bundle over the complex projective space. For the N=2 theory with the $U(2)$ gauge group and four fundamental hypermultiplets there are six orientational and size moduli. After combining with four translational moduli they form a ten-dimensional target space required for a superstring to be critical. For the theory in question the target space of the sigma model is C^2 x Y_6, where Y_6 is a conifold. We study closed string states which emerge in four dimensions (4D) and identify them with hadrons of the 4D bulk N=2 theory. It turns out that most of the states arising from the ten-dimensional graviton spectrum are non-dynamical in 4D. We find a single dynamical massless hypermultiplet associated with the deformation of the complex structure of the conifold. We interpret this degree of freedom as a monopole-monopole baryon of the 4D theory (at strong coupling).
description: One figure, 37 pages