cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Multi-Pass Optically Pumped Rubidium Atomic Magnetometer with Free Induction Decay
Creators: name: Zhang, Lulu
name: Yang, Yongbiao
name: Zhao, Ni
name: He, Jun
name: Wang, Junmin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A free-induction-decay (FID) type optically-pumped rubidium atomic magnetometer driven by a radio-frequency (RF) magnetic field is presented in this paper. Influences of parameters, such as the temperature of rubidium vapor cell, the power of pump beam, and the strength of RF magnetic field and static magnetic field on the amplitude and the full width at half maximum (FWHM) of the FID signal, have been investigated in the time domain and frequency domain. At the same time, the sensitivities of the magnetometer for the single-pass and the triple-pass probe beam cases have been compared by changing the optical path of the interaction between probe beam and atomic ensemble. Compared with the sensitivity of ~21.2 pT/Hz^(1/2) in the case of the single-pass probe beam, the amplitude of FID signal in the case of the triple-pass probe beam has been significantly enhanced, and the sensitivity has been improved to ~13.4 pT/Hz^(1/2). The research in this paper provids a reference for the subsequent study of influence of different buffer gas pressure on the FWHM and also a foundation for further improving the sensitivity of FID rubidium atomic magnetometer by employing a~polarization-squeezed light as probe beam, to achieve a sensitivity beyond the photo-shot-noise level.
description: sensors,2022,22(19):7598
АЛИ САФИЙ ҲАЁТИ ВА МЕРОСИ ҲАҚИДА
Creators: name: Мавлянов, У.Н.
name: Тангирбердиев, Ш.
Publisher: name: Zenodo
Year: 2025

description: Мақолада темурийлар ренессансининг етук алломаларидан бири бўлган Фахруддин Али Сафийнинг ҳаёти ва илмий мероси тадқиқ этилган. Мутафаккир ҳаётининг асосий босқичлари, асарлари рўйхати ва уларнинг асосий мазмуни манбалар ҳамда замонавий тадқиқотлар асосида ёритилган.
Self-Supervised Learning for Data Scarcity in a Fatigue Damage Prognostic Problem
Creators: name: Akrim, Anass
name: Gogu, Christian
name: Vingerhoeds, Rob
name: Salaün, Michel
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (stat.ML)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: With the increasing availability of data for Prognostics and Health Management (PHM), Deep Learning (DL) techniques are now the subject of considerable attention for this application, often achieving more accurate Remaining Useful Life (RUL) predictions. However, one of the major challenges for DL techniques resides in the difficulty of obtaining large amounts of labelled data on industrial systems. To overcome this lack of labelled data, an emerging learning technique is considered in our work: Self-Supervised Learning, a sub-category of unsupervised learning approaches. This paper aims to investigate whether pre-training DL models in a self-supervised way on unlabelled sensors data can be useful for RUL estimation with only Few-Shots Learning, i.e. with scarce labelled data. In this research, a fatigue damage prognostics problem is addressed, through the estimation of the RUL of aluminum alloy panels (typical of aerospace structures) subject to fatigue cracks from strain gauge data. Synthetic datasets composed of strain data are used allowing to extensively investigate the influence of the dataset size on the predictive performance. Results show that the self-supervised pre-trained models are able to significantly outperform the non-pre-trained models in downstream RUL prediction task, and with less computational expense, showing promising results in prognostic tasks when only limited labelled data is available.
Experimental demonstration of graph-state quantum secret sharing
Creators: name: Bell, B. A.
name: Markham, D.
name: Herrera-Martí, D. A.
name: Marin, A.
name: Wadsworth, W. J.
name: Rarity, J. G.
name: Tame, M. S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Distributed quantum communication and quantum computing offer many new opportunities for quantum information processing. Here networks based on highly nonlocal quantum resources with complex entanglement structures have been proposed for distributing, sharing and processing quantum information. Graph states in particular have emerged as powerful resources for such tasks using measurement-based techniques. We report an experimental demonstration of graph-state quantum secret sharing, an important primitive for a quantum network. We use an all-optical setup to encode quantum information into photons representing a five-qubit graph state. We are able to reliably encode, distribute and share quantum information between four parties. In our experiment we demonstrate the integration of three distinct secret sharing protocols, which allow for security and protocol parameters not possible with any single protocol alone. Our results show that graph states are a promising approach for sophisticated multi-layered protocols in quantum networks.
Nucleon axial form factors from two-flavour Lattice QCD
Creators: name: Junnarkar, P. M.
name: Capitani, S.
name: Djukanovic, D.
name: von Hippel, G.
name: Hua, J.
name: Jäger, B.
name: Meyer, H. B.
name: Rae, T. D.
name: Wittig, H.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We present preliminary results on the axial form factor $G_A(Q^2)$ and the induced pseudoscalar form factor $G_P(Q^2)$ of the nucleon. A systematic analysis of the excited-state contributions to form factors is performed on the CLS ensemble `N6' with $m_π= 340 \ \text{MeV}$ and lattice spacing $a \sim 0.05 \ \text{fm}$. The relevant three-point functions were computed with source-sink separations ranging from $t_s \sim 0.6 \ \text{fm}$ to $t_s \sim \ 1.4 \ \text{fm}$. We observe that the form factors suffer from non-trivial excited-state contributions at the source-sink separations available to us. It is noted that naive plateau fits underestimate the excited-state contributions and that the method of summed operator insertions correctly accounts for these effects.
description: 7 pages, 12 figures; talk presented at Lattice 2014 -- 32nd International Symposium on Lattice Field Theory, 23-28 June, 2014, Columbia University New York, NY
DIFAI: Diverse Facial Inpainting using StyleGAN Inversion
Creators: name: Yoon, Dongsik
name: Kwak, Jeong-gi
name: Li, Yuanming
name: Han, David
name: Ko, Hanseok
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Image inpainting is an old problem in computer vision that restores occluded regions and completes damaged images. In the case of facial image inpainting, most of the methods generate only one result for each masked image, even though there are other reasonable possibilities. To prevent any potential biases and unnatural constraints stemming from generating only one image, we propose a novel framework for diverse facial inpainting exploiting the embedding space of StyleGAN. Our framework employs pSp encoder and SeFa algorithm to identify semantic components of the StyleGAN embeddings and feed them into our proposed SPARN decoder that adopts region normalization for plausible inpainting. We demonstrate that our proposed method outperforms several state-of-the-art methods.
description: ICIP 2022
Suppression of inclusive J/$\mathbfψ$ and $\mathbfψ$(2S) production in p-Pb collisions with ALICE at the LHC
Creators: name: Paul, Biswarup
Publisher: name: arXiv
Year: 2014
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The ALICE Collaboration has studied inclusive J/$ψ$ and $ψ$(2S) production in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV with the Muon Spectrometer. The measurement was performed at forward (2.03 $
description: 2 pages, 5 figures, Proceedings of Symposium on Nuclear Physics, BHU, Varanasi, India, December 8-12, 2014
Stability analysis and simulations of coupled bulk-surface reaction-diffusion systems
Creators: name: Madzvamuse, Anotida
name: Chung, Andy H. W.
name: Venkataraman, Chandrasekhar
Publisher: name: arXiv
Year: 2015
Subjects: subject: Analysis of PDEs (math.AP)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Mathematics
subject: FOS: Biological sciences

description: In this article we formulate new models for coupled systems of bulk-surface reaction-diffusion equations on stationary volumes. The bulk reaction-diffusion equations are coupled to the surface reaction-diffusion equations through linear Robin-type boundary conditions. We then state and prove the necessary conditions for diffusion-driven instability for the coupled system. Due to the nature of the coupling between bulk and surface dynamics, we are able to decouple the stability analysis of the bulk and surface dynamics. Under a suitable choice of model parameter values, the bulk reaction-diffusion system can induce patterning on the surface independent of whether the surface reaction-diffusion system produces or not, patterning. On the other hand, the surface reaction-diffusion system can not generate patterns everywhere in the bulk in the absence of patterning from the bulk reaction-diffusion system. For this case, patterns can only be induced in regions close to the surface membrane. Various numerical experiments are presented to support our theoretical findings. Our most revealing numerical result is that, Robin-type boundary conditions seem to introduce a boundary layer coupling the bulk and surface dynamics.
description: 21 pages, 5 figures
SOAR TESS Survey. I. Sculpting of TESS Planetary Systems by Stellar Companions
Creators: name: Law, N.
name: Mang, J.
name: Mann, A.W.
name: Ziegler, C.
name: Briceno, C.
name: Tokovinin, A.
Publisher: name: IOP Publishing Ltd
Year: 2020

description: The Transiting Exoplanet Survey Satellite (TESS) is finding transiting planet candidates around bright, nearby stars across the entire sky. The large field of view, however, results in low spatial resolution; therefore, multiple stars contribute to almost every TESS light curve. High angular resolution imaging can detect the previously unknown companions to planetary candidate hosts that dilute the transit depths, lead to host star ambiguity, and, in some cases, are the source of false-positive transit signals. We use speckle imaging on the Southern Astrophysical Research (SOAR) telescope to search for companions to 542 TESS planet candidate hosts in the southern sky. We provide correction factors for the 117 systems with resolved companions due to photometric contamination. The contamination in TESS due to close binaries is similar to that found in surveys of Kepler planet candidates. For the solar-type population, we find a deep deficit of close binary systems with projected stellar separations less than 100 au among planet candidate hosts (44 observed binaries compared to 124 expected based on field binary statistics). The close binary suppression among TESS planet candidate hosts is similar to that seen for the more distant Kepler population. We also find a large surplus of TESS planet candidates in wide binary systems detected in both SOAR and Gaia DR2 (119 observed binaries compared to 77 expected). These wide binaries almost exclusively host giant planets, however, suggesting that orbital migration caused by perturbations from the stellar companion may lead to planet-planet scattering and suppress the population of small planets in wide binaries. Both trends are also apparent in the M dwarf planet candidate hosts.
Searches for continuous gravitational waves from neutron stars: A twenty-year retrospective
Creators: name: Wette, Karl
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Seven years after the first direct detection of gravitational waves, from the collision of two black holes, the field of gravitational wave astronomy is firmly established. A first detection of continuous gravitational waves from rapidly-spinning neutron stars could be the field's next big discovery. I review the last twenty years of efforts to detect continuous gravitational waves using the LIGO and Virgo gravitational wave detectors. I summarise the model of a continuous gravitational wave signal, the challenges to finding such signals in noisy data, and the data analysis algorithms that have been developed to address those challenges. I present a quantitative analysis of 297 continuous wave searches from 80 papers, published from 2003 to 2022, and compare their sensitivities and coverage of the signal model parameter space.
description: 45 pages, 10 figures, 3 tables. Invited review for special issue of Astroparticle Physics: 'Gravitational Waves and Multi-messenger Astrophysics'. A machine-readable version of Table A.3 is provided in the ancillary files
Disclosing Early Excited State Relaxation Events in Prototypical Linear Carbon Chains
Creators: name: Kabaciński, Piotr
name: Marabotti, Pietro
name: Serafini, Patrick
name: Fazzi, Daniele
name: Cerullo, Giulio
name: Casari, Carlo S.
name: Zavelani-Rossi, Margherita
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Chemical Physics (physics.chem-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: One-dimensional (1D) linear nanostructures comprising sp-hybridized carbon atoms, as derivatives of the prototypical allotrope known as carbyne, are predicted to possess outstanding mechanical, thermal, and electronic properties. Despite recent advances in the synthesis, their chemical and physical properties are still poorly understood. Here, we investigate the photophysics of a prototypical polyyne (i.e., 1D chain with alternating single and triple carbon bonds), as the simplest model of finite carbon wire and as a prototype of sp-carbon-based chains. We perform transient absorption experiments with high temporal resolution (<30 fs) on monodispersed hydrogen-capped hexayne H$-$(C$\equiv$C)$_6-$H synthesized by laser ablation in liquid. With the support of detailed computational studies based on ground state density functional theory (DFT) and excited state time-dependent (TD)-DFT calculations, we provide a comprehensive description of the excited state relaxation processes at early times following photoexcitation. We show that the internal conversion from a bright high-energy singlet excited state to a low-lying singlet dark state is ultrafast and takes place with a 200-fs time constant, followed by thermalization on the picosecond timescale and decay of the low-energy singlet state with hundreds of picoseconds time constant. We also show that the timescale of these processes does not depend on the end groups capping the sp-carbon chain. The understanding of the primary photo-induced events in polyynes is of key importance both for fundamental knowledge and for potential optoelectronic and light-harvesting applications of low dimensional nanostructured carbon-based materials.
description: 24 pages, 6 figures
EVR-CB-001: An Evolving, Progenitor, White Dwarf Compact Binary Discovered with the Evryscope
Creators: name: Law, N.M.
name: Bauer, E.
name: Barlow, B.N.
name: Kupfer, T.
name: Howard, W.S.
name: Corbett, H.T.
name: Glazier, A.
name: Corcoran, K.A.
name: Ratzloff, J.K.
name: Geier, S.
Publisher: name: Institute of Physics Publishing
Year: 2019

description: We present EVR-CB-001, the discovery of a compact binary with an extremely low-mass (0.21 ± 0.05M o) helium core white dwarf progenitor (pre-He WD) and an unseen low-mass (0.32 ± 0.06M o) helium white dwarf (He WD) companion. He WDs are thought to evolve from the remnant helium-rich core of a main-sequence star stripped during the giant phase by a close companion. Low-mass He WDs are exotic objects (only about 0.2% of WDs are thought to be less than 0.3 M o), and are expected to be found in compact binaries. Pre-He WDs are even rarer, and occupy the intermediate phase after the core is stripped, but before the star becomes a fully degenerate WD and with a larger radius (≈0.2R o) than a typical WD. The primary component of EVR-CB-001 (the pre-He WD) was originally thought to be a hot subdwarf (sdB) star from its blue color and under-luminous magnitude, characteristic of sdBs. The mass, temperature (T eff = 18,500 ± 500 K), and surface gravity () solutions from this work are lower than values for typical hot subdwarfs. The primary is likely to be a post-red-giant branch, pre-He WD contracting into a He WD, and at a stage that places it nearest to sdBs on color-magnitude and T eff-log(g) diagrams. EVR-CB-001 is expected to evolve into a fully double degenerate, compact system that should spin down and potentially evolve into a single hot subdwarf star. Single hot subdwarfs are observed, but progenitor systems have been elusive.
Incorporating Spontaneous Reporting System Data to Aid Causal Inference in Longitudinal Healthcare Data
Creators: name: Reps, Jenna
name: Aickelin, Uwe
Publisher: name: arXiv
Year: 2015
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: Inferring causality using longitudinal observational databases is challenging due to the passive way the data are collected. The majority of associations found within longitudinal observational data are often non-causal and occur due to confounding. The focus of this paper is to investigate incorporating information from additional databases to complement the longitudinal observational database analysis. We investigate the detection of prescription drug side effects as this is an example of a causal relationship. In previous work a framework was proposed for detecting side effects only using longitudinal data. In this paper we combine a measure of association derived from mining a spontaneous reporting system database to previously proposed analysis that extracts domain expertise features for causal analysis of a UK general practice longitudinal database. The results show that there is a significant improvement to the performance of detecting prescription drug side effects when the longitudinal observation data analysis is complemented by incorporating additional drug safety sources into the framework. The area under the receiver operating characteristic curve (AUC) for correctly classifying a side effect when other data were considered was 0.967, whereas without it the AUC was 0.923 However, the results of this paper may be biased by the evaluation and future work should overcome this by developing an unbiased reference set.
description: IEEE International Conference of Data Mining: The Fifth Workshop on Biological Data Mining and its Applications in Healthcare, 2014
EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
Creators: name: Fors, O.
name: Ratzloff, J.K.
name: Ser, D.D.
name: Glazier, A.
name: Corbett, H.
name: Haislip, J.
name: Law, N.M.,
name: Howard, W.S.
Publisher: name: Institute of Physics Publishing
Year: 2019

description: We search for superflares from 4068 cool stars in 2+ yr of Evryscope photometry, focusing on those with high-cadence data from both Evryscope and the Transiting Exoplanet Survey Satellite (TESS). The Evryscope array of small telescopes observed 575 flares from 284 stars, with a median energy of 1034.0 erg. Since 2016, Evryscope has enabled the detection of rare events from all stars observed by TESS through multi-year, high-cadence continuous observing. We report around twice the previous largest number of 1034 erg high-cadence flares from nearby cool stars. We find eight flares with amplitudes of 3+ g′ magnitudes, with the largest reaching 5.6 mag and releasing 1036.2 erg. We observe a 1034 erg superflare from TOI-455 (LTT 1445), a mid-M with a rocky planet candidate. We measure the superflare rate per flare-star and quantify the average flaring of active stars as a function of spectral type, including superflare rates, flare frequency distributions, and typical flare amplitudes in g′. We confirm superflare morphology is broadly consistent with magnetic reconnection. We estimate starspot coverage necessary to produce superflares, and hypothesize maximum allowed superflare energies and waiting times between flares corresponding to 100% coverage of the stellar hemisphere. We observe decreased flaring at high Galactic latitudes. We explore the effects of superflares on ozone loss to planetary atmospheres: we observe one superflare with sufficient energy to photodissociate all ozone in an Earth-like atmosphere in one event. We find 17 stars that may deplete an Earth-like atmosphere via repeated flaring. Of the 1822 stars around which TESS may discover temperate rocky planets, we observe 14.6% ± 2% emit large flares.
Stirring in massive, young debris discs from spatially resolved Herschel images
Creators: name: Moór, A.
name: Kóspál, Á.
name: Ábrahám, P.
name: Apai, D.
name: Balog, Z.
name: Grady, C.
name: Henning, Th.
name: Juhász, A.
name: Kiss, Cs.
name: Krivov, A. V.
name: Pawellek, N.
name: Szabó, Gy. M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: A significant fraction of main-sequence stars are encircled by dusty debris discs, where the short-lived dust particles are replenished through collisions between planetesimals. Most destructive collisions occur when the orbits of smaller bodies are dynamically stirred up, either by the gravitational effect of locally formed Pluto-sized planetesimals (self-stirring scenario), or via secular perturbation caused by an inner giant planet (planetary stirring). The relative importance of these scenarios in debris systems is unknown. Here we present new Herschel Space Observatory imagery of 11 discs selected from the most massive and extended known debris systems. All discs were found to be extended at far-infrared wavelengths, five of them being resolved for the first time. We evaluated the feasibility of the self-stirring scenario by comparing the measured disc sizes with the predictions of the model calculated for the ages of our targets. We concluded that the self-stirring explanation works for seven discs. However, in four cases, the predicted pace of outward propagation of the stirring front, assuming reasonable initial disc masses, was far too low to explain the radial extent of the cold dust. Therefore, for HD 9672, HD 16743, HD 21997, and HD 95086, another explanation is needed. We performed a similar analysis for ß Pic and HR 8799, reaching the same conclusion. We argue that planetary stirring is a promising possibility to explain the disk properties in these systems. In HR 8799 and HD 95086 we may already know the potential perturber, since their known outer giant planets could be responsible for the stirring process. Our study demonstrates that among the largest and most massive debris discs self-stirring may not be the only active scenario, and potentially planetary stirring is responsible for destructive collisions and debris dust production in a number of systems.
description: Accepted for publication in MNRAS, 22 pages, 7 figures, 6 tables (abstract abridged due to arXiv requirements)
Thermal fluctuations and stiffening of heterogeneous fluid membranes
Creators: name: Banerjee, Tirthankar
name: Basu, Abhik
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We study the effects of thermal fluctuations on symmetric tensionless heterogeneous (two-component) fluid membranes in a simple minimal model. Close to the critical point $T_c$ of the associated miscibility phase transition of the composition and for sufficiently strong curvature-composition interactions, mediated through a composition-dependent bending modulus, thermal fluctuations lead to enhancement of the effective bending modulus. Thus, the membrane conformation fluctuations will be {\em suppressed} near $T_c$, in comparison with a pure fluid membrane, for which thermal fluctuations are known to reduce the effective bending modulus at all non-zero temperatures.
description: 8 pages, 5 figures, accepted in Physical Review E
Quantum Monte Carlo study of Doppler broadening of positron annihilation radiation in semiconductors and insulators
Creators: name: Simula, Kristoffer
name: Härkönen, Jan
name: Zhelezova, Iuliia
name: Drummond, Neil
name: Tuomisto, Filip
name: Makkonen, Ilja
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Positron annihilation in solid state matter can be utilized to detect and identify open-volume defects. The momentum distribution of the annihilation radiation is an important observable in positron-based measurements, and can reveal information on the chemical surroundings of the defect sites. In this work we present a variational quantum Monte Carlo method for simulation of the momentum densities of annihilating electron-positron pairs in semiconductors and insulators. We study finite-size effects, effects of lattice vibrations, and different levels of trial wave functions. Small simulation cells and simple wave function forms are found to be sufficient for accurate calculations in simulation of pristine lattices, enabling cheap accumulation of results. We compare calculated predictions of the Doppler broadening of the 511-keV 2γ annihilation line of the in aluminium nitride and silicon against experimental data measured from reference samples. Our results achieve better agreement with experiments in the these materials than conventional state-of-the-art methods, and proves that direct modeling of the electron-positron correlations is important for a supporting theory of positron annihilation sprectroscopies
description: 10 pages, 4 figures
Local Limit Theorems in some Random models from Number Theory
Creators: name: Giuliano, Rita
name: Weber, Michel
Publisher: name: arXiv
Year: 2015
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: Primary: 60F15, 60G50, Secondary: 60F05

description: We study the local limit theorem for weighted sums of Bernoulli variables. We show on examples that this is an important question in the general theory of the local limit theorem, and which turns up to be not well explored. The examples we consider arise from standard random models used in arithmetical number theory. We next use the characteristic function method to prove new local limit theorems for weighted sums of Bernoulli variables. Further, we give an application of the almost sure local limit theorem to a representation problem in additive number theory due to Burr, using an appropriate random model. We also give a simple example showing that the local limit theorem, in its standard form, fails to be sharp enough for estimating the probability $P\{S_n\in E\}$ for infinite sets of integers $E$, already in the simple case where $S_n$ is a sum of $n$ independent standard Bernoulli random variables and $E$ an arithmetic progression.
description: 16 pages
How does a thermal binary crystal break under shear?
Creators: name: Horn, Tobias
name: Löwen, Hartmut
Publisher: name: arXiv
Year: 2014
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: When exposed to strong shearing, the particles in a crystal will rearrange and ultimately, the crystal will break by forming large nonaffine defects. Even for the initial stage of this process, only little effort has been devoted to the understanding of the breaking process on the scale of the individual particle size for thermalized mixed crystals. Here, we explore the shear-induced breaking for an equimolar two-dimensional binary model crystal with a high interaction asymmetry between the two different species such that the initial crystal has an intersecting square sublattice of the two constituents. Using Brownian dynamics computer simulations, we show that the combination of shear and thermal fluctuations leads to a characteristic hierarchical breaking scenario where initially, the more strongly coupled particles are thermally distorted, paving the way for the weakly coupled particles to escape from their cage. This in turn leads to mobile defects which may finally merge, proliferating a cascade of defects, which triggers the final breakage of the crystal. This scenario is in marked contrast to the breakage of one-component crystals close to melting. Moreover, we explore the orientational dependence of the initial shear direction relative to the crystal orientation and compare this to the usual melting scenario without shear. Our results are verifiable in real-space experiments of superparamagnetic colloidal mixtures at a pending air-water interface in an external magnetic field where the shear can be induced by an external laser field.
description: 11 pages, 14 figures
Newtonian cosmology and Evolution of kappa-deformed universe
Creators: name: Harikumar, E.
name: Sreekumar, Harsha
name: Panja, Suman Kumar
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Considering space--time to be non-commutative, we study the evolution of the universe employing the approach of Newtonian cosmology. Generalizing the conservation of energy and the first law of thermodynamics to $κ$-deformed space--time, we derive the modified Friedmann equations, valid up to the first order, in the deformation parameter. Analyzing these deformed equations, we derive the time evolution of the scale factor in cases of radiation-dominated, matter-dominated, and vacuum (energy)-dominated universes. We show that the rate of change of the scale factor in all three situations is modified by the non-commutativity of space--time, and this rate depends on the sign of the deformation parameter, indicating a possible explanation for the observed Hubble tension. We undertake this investigation for two different realizations of non-commutative space--time coordinates. In both cases, we also argue for the existence of bounce in the evolution of the universe.
description: Revised,18 pages, 6 figures
Asymptotic freedom using a gluon mass as a regulator
Creators: name: Galvez-Viruet, J. J.
name: Gomez-Rocha, M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Front-Form Hamiltonian dynamics provides a framework in which QCD's vacuum is simple and states are boost invariant. However, canonical expressions are divergent and must be regulated in order to establish well-defined eigenvalue problems. The Renormalization Group Procedure for Effective Particles (RGPEP) provides a systematic way of finding counterterms and obtaining regulated Hamiltonians. Among its achievements is the description of asymptotic freedom, with a running coupling constant defined as the coefficient in front of the three gluon-vertex operators in the regulated Hamiltonian. However, the obtained results need a deeper understanding, since the coupling exhibits a finite dependence on the regularization functions, at least at the third-order term in the perturbative expansion. Here we present a similar derivation using a different regularization scheme based on massive gluons. The procedure can be extended to incorporate contributions from virtual fermions.
description: 7 pages, 6 figures, proceedings of ConfXV
One-way propagation of light in Born-Infeld-like metamaterials
Creators: name: De Lorenci, Vitorio A.
name: Pereira, Jonas P.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose and investigate a family of nonlinear metamaterials in which light rays propagate just in one direction -- one-way propagation. Furthermore, we argue how such nonlinear media could provide an analog model for investigating the Born-Infeld Lagrangian in the realm of fields larger than its scale field.
description: 7 pages, 2 figures
The Elusive Majority of Young Moving Groups. I. Young Binaries and Lithium-rich Stars in the Solar Neighborhood
Creators: name: Hinkley, S.
name: Riaz, B.
name: Law, N.M.
name: Bowler, B.P.
name: Shkolnik, E.L.
name: Gizis, J.E.
name: Riddle, R.
name: Baranec, C.
name: Shah, V.S.
name: Ziegler, C.
name: Liu, M.C.
Publisher: name: Institute of Physics Publishing
Year: 2019

description: Young stars in the solar neighborhood serve as nearby probes of stellar evolution and represent promising targets to directly image self-luminous giant planets. We have carried out an all-sky search for late-type (≈K7-M5) stars within 100 pc selected primarily on the basis of activity indicators from the Galaxy Evolution Explorer and ROSAT. Approximately 2000 active and potentially young stars are identified, of which we have followed up over 600 with low-resolution optical spectroscopy and over 1000 with diffraction-limited imaging using Robo-AO at the Palomar 1.5 m telescope. Strong lithium is present in 58 stars, implying ages spanning ≈10-200 Myr. Most of these lithium-rich stars are new or previously known members of young moving groups including TWA, β Pic, Tuc-Hor, Carina, Columba, Argus, AB Dor, Upper Centaurus Lupus, and Lower Centaurus Crux; the rest appear to be young low-mass stars without connections to established kinematic groups. Over 200 close binaries are identified down to 0.″2 - the vast majority of which are new - and will be valuable for dynamical mass measurements of young stars with continued orbit monitoring in the future.
Beyond Thomas--Fermi analysis of the density profiles of a miscible two-component Bose--Einstein condensate
Creators: name: Polo, J.
name: Mason, P.
name: Sridhar, S.
name: Billam, T. P.
name: Ahufinger, V.
name: Gardiner, S. A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We investigate a harmonically trapped two-component Bose--Einstein condensate within the miscible regime, close to its boundaries, for different ratios of effective intra- and inter-species interactions. We derive analytically a universal equation for the density around the different boundaries in one, two and three dimensions, for both the coexisting and spatially separated regimes. We also present a general procedure to solve the Thomas--Fermi approximation in all three spatial dimensionalities, reducing the complexity of the Thomas--Fermi problem for the spatially separated case in one and three dimensions to a single numerical inversion. Finally, we analytically determine the frontier between the two different regimes of the system.
description: 9 pages, 3 figures
Bosonization, Duality, and the $C$-Theorem in the Non-Abelian Thirring Model
Creators: name: Santos, Rodrigo Corso B.
name: Hernaski, Carlos A.
name: Gomes, Pedro R. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We revisit the two dimensional non-Abelian Thirring model in order to investigate its fixed point structure and the corresponding renormalization group (RG) flow. For this purpose we discuss the bosonization of the model, and we present different, but of course equivalent, bosonic versions of the theory. The bosonic theories are illuminating in that they exhibit the fixed points in a manifest way, and also possess a remarkable strong/weak duality that sheds light on the fixed point structure of the theory. We study the RG flow through the computation of the Zamolodchikov $C$-function and of the $β$-function in the large-level limit. Within this framework, we discuss how close to the infrared fixed point the RG flow can reach, since this point is strictly unachievable due to an emergent gauge invariance.
description: 33 pages, 2 figures, journal version, comments are welcome!
TESS Spots a Compact System of Super-Earths around the Naked-eye Star HR 858
Creators: name: Kielkopf, J.
name: Addison, B.
name: Clark, J.T.
name: Crossfield, I.
name: Ricker, G.R.
name: Zhang, H.
name: Zhou, G.
name: Latham, D.W.
name: Siverd, R.J.
name: Winn, J.N.
name: Jenkins, J.M.
name: Wittenmyer, R.
name: Dittmann, J.A.
name: Becker, J.C.
name: Ziegler, C.A.
name: Dynes, S.
name: Vanderburg, A.
name: Rodriguez, J.E.
name: Horner, J.
name: Plavchan, P.
name: Stassun, K.
name: Vanderspek, R.K.
name: Quinn, S.N.
name: Tinney, C.G.
name: Rowden, P.
name: Rabus, M.
name: Caldwell, D.A.
name: Kreidberg, L.
name: Law, N.
name: Pearce, L.A.
name: Bieryla, A.
name: Mann, A.W.
name: Seager, S.
name: Guerrero, N.
name: Smith, J.C.
name: Briceño, C.
name: Brown, T.M.
name: Kane, S.R.
name: Rose, M.E.
name: Burt, J.A.
name: Kraus, A.L.
name: Fulton, B.J.
name: Huang, C.X.
name: Morton, T.D.
name: Bowler, B.P.
name: Okumura, J.
name: Mengel, M.W.
name: Harbeck, D.
name: Wright, D.J.
name: Burke, C.J.
name: Shporer, A.
Publisher: name: Institute of Physics Publishing
Year: 2019

description: Transiting Exoplanet Survey Satellite (TESS) observations have revealed a compact multiplanet system around the sixth-magnitude star HR 858 (TIC 178155732, TOI 396), located 32 pc away. Three planets, each about twice the size of Earth, transit this slightly evolved, late F-type star, which is also a member of a visual binary. Two of the planets may be in mean motion resonance. We analyze the TESS observations, using novel methods to model and remove instrumental systematic errors, and combine these data with follow-up observations taken from a suite of ground-based telescopes to characterize the planetary system. The HR 858 planets are enticing targets for precise radial velocity observations, secondary eclipse spectroscopy, and measurements of the Rossiter-McLaughlin effect.
Relation between the escort average in microcanonical ensemble and the escort average in canonical ensemble in the Tsallis statistics
Creators: name: Ishihara, Masamichi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We studied the escort averages in microcanonical and canonical ensembles in the Tsallis statistics of entropic parameter $q>1$. The quantity $(q-1)$ is the measure of the deviation from the Boltzmann-Gibbs statistics. We derived the relation between the escort average in the microcanonical ensemble and the escort average in the canonical ensemble. Conditions arise by requiring that the integrals appeared in the canonical ensemble do not diverge. A condition is the relation between the heat capacity $C_V^{\mathrm{CE}}$ at constant volume in the canonical ensemble and the entropic parameter $q$: $0 < (q-1) C_V^{\mathrm{CE}} < 1$. This condition gives the known condition when $C_V^{\mathrm{CE}}$ equals the number of ingredients $N$. With the derived relation, we calculated the energy, the energy fluctuation, and the difference between the canonical ensemble and the microcanonical ensemble in the expectation value of the square of Hamiltonian. The difference between the microcanonical ensemble and the canonical ensemble in energy is small because of the condition. The heat capacity $C_V^{\mathrm{CE}}$ and the quantity $(q-1)$ are related to the energy fluctuation and the difference. It was shown that the magnitude of the relative difference $|(S^{\mathrm{CE}}_{\mathrm{R}q}-S^{\mathrm{ME}}_{\mathrm{R}q})/S^{\mathrm{ME}}_{\mathrm{R}q}|$ is small when the number of free particles is large, where $S^{\mathrm{ME}}_{\mathrm{R}q}$ is the Rényi entropy in the microcanonical ensemble and $S^{\mathrm{CE}}_{\mathrm{R}q}$ is the Rényi entropy in the canonical ensemble. The similar result was also obtained for the Tsallis entropy.
description: 12 pages
HD 2685 b: A hot Jupiter orbiting an early F-type star detected by TESS
Creators: name: Ségransan, D.
name: Pepe, F.
name: Osip, D.
name: Doty, J.
name: Sedaghati, E.
name: Relles, H.
name: Ziegler, C.
name: Tenenbaum, P.
name: Jenkins, J.M.
name: Nielsen, L.D.
name: Cruz, B.
name: Paredes, L.A.
name: Sarkis, P.
name: Matthews, E.
name: Furész, G.
name: Bayliss, D.
name: Henning, T.
name: Lovis, C.
name: Haworth, K.
name: Matson, R.
name: Schlieder, J.
name: Turner, O.
name: Vanderburg, A.
name: Law, N.M.
name: Brahm, R.
name: Jones, M.I.
name: Bakos, G.
name: Howell, S.
name: Latham, D.W.
name: Jordán, A.
name: Dittmann, J.
name: Christiansen, J.L.
name: Mann, A.W.
name: Gonzales, E.
name: Henry, T.
name: Hodari-Sadiki, J.
name: Suc, V.
name: Winn, J.N.
name: Marmier, M.
name: Tokovinin, A.
name: Udry, S.
name: Davies, M.
name: Smith, J.C.
name: Bouchy, F.
name: Crossfield, I.
name: Seager, S.
name: Laughlin, G.
name: Collins, K.A.
name: Shporer, A.
name: Wang, S.
name: Espinoza, N.
name: Beichman, C.
name: Ciardi, D.
Publisher: name: EDP Sciences
Year: 2019

description: We report on the confirmation of a transiting giant planet around the relatively hot (Teff = 6801 ± 76 K) star HD 2685, whose transit signal was detected in Sector 1 data of NASA's TESS mission. We confirmed the planetary nature of the transit signal using Doppler velocimetric measurements with CHIRON, CORALIE, and FEROS, as well as using photometric data obtained with the Chilean-Hungarian Automated Telescope and the Las Cumbres Observatory. From the joint analysis of photometry and radial velocities, we derived the following parameters for HD 2685 b: P = 4.12688-0.00004+0.00005 days, e = 0.091-0.047+0.039, MP = 1.17 ± 0.12 MJ, and RP =1.44 ± 0.05 RJ. This system is a typical example of an inflated transiting hot Jupiter in a low-eccentricity orbit. Based on the apparent visual magnitude (V = 9.6 mag) of the host star, this is one of the brightest known stars hosting a transiting hot Jupiter, and it is a good example of the upcoming systems that will be detected by TESS during the two-year primary mission. This is also an excellent target for future ground- and space-based atmospheric characterization as well as a good candidate for measuring the projected spin-orbit misalignment angle through the Rossiter-McLaughlin effect.
A projection hybrid high order finite volume/finite element method for incompressible turbulent flows
Creators: name: Busto, Saray
name: Ferrin, Jose Luis
name: Toro, Eleuterio F.
name: Vazquez-Cendon, Maria Elena
Publisher: name: arXiv
Year: 2023
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: In this paper the projection hybrid FV/FE method presented in Busto et al. 2014 is extended to account for species transport equations. Furthermore, turbulent regimes are also considered thanks to the $k-\varepsilon$ model. Regarding the transport diffusion stage new schemes of high order of accuracy are developed. The CVC Kolgan-type scheme and ADER methodology are extended to 3D. The latter is modified in order to profit from the dual mesh employed by the projection algorithm and the derivatives involved in the diffusion term are discretized using a Galerkin approach. The accuracy and stability analysis of the new method are carried out for the advection-diffusion-reaction equation. Within the projection stage the pressure correction is computed by a piecewise linear finite element method. Numerical results are presented, aimed at verifying the formal order of accuracy of the scheme and to assess the performance of the method on several realistic test problems.
description: arXiv admin note: text overlap with arXiv:1802.10585
Global Energetics of Solar Flares: II. Thermal Energies
Creators: name: Aschwanden, M. J.
name: Boerner, P.
name: Ryan, D.
name: Caspi, A.
name: McTiernan, J. M.
name: Warren, H. P.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the second part of a project on the global energetics of solar flares and CMEs that includes about 400 M- and X-class flares observed with AIA/SDO during the first 3.5 years of its mission. In this Paper II we compute the differential emission measure (DEM) distribution functions and associated multi-thermal energies, using a spatially-synthesized Gaussian DEM forward-fitting method. The multi-thermal DEM function yields a significantly higher (by an average factor of $\approx 14$), but more comprehensive (multi-)thermal energy than an isothermal energy estimate from the same AIA data. We find a statistical energy ratio of $E_{th}/E_{diss} \approx 2\%-40\%$ between the multi-thermal energy $E_{th}$ and the magnetically dissipated energy $E_{diss}$, which is an order of magnitude higher than the estimates of Emslie et al.~2012. For the analyzed set of M and X-class flares we find the following physical parameter ranges: $L=10^{8.2}-10^{9.7}$ cm for the length scale of the flare areas, $T_p=10^{5.7}-10^{7.4}$ K for the DEM peak temperature, $T_w=10^{6.8}-10^{7.6}$ K for the emission measure-weighted temperature, $n_p=10^{10.3}-10^{11.8}$ cm$^{-3}$ for the average electron density, $EM_p=10^{47.3}-10^{50.3}$ cm$^{-3}$ for the DEM peak emission measure, and $E_{th}=10^{26.8}-10^{32.0}$ erg for the multi-thermal energies. The deduced multi-thermal energies are consistent with the RTV scaling law $E_{th,RTV} = 7.3 \times 10^{-10} \ T_p^3 L_p^2$, which predicts extremal values of $E_{th,max} \approx 1.5 \times 10^{33}$ erg for the largest flare and $E_{th,min} \approx 1 \times 10^{24}$ erg for the smallest coronal nanoflare. The size distributions of the spatial parameters exhibit powerlaw tails that are consistent with the predictions of the fractal-diffusive self-organized criticality model combined with the RTV scaling law.
description: Accepted for publication in ApJ, 2015-Feb-18 (in press)