bluuebunny/crossref_metadata_2025_split huggingface dataset:
C

n
-symmetric Chern insulators
Authors: Han Ying , He Ai-Lei 
Published: March 2021

Abstract
Chern insulators (CIs) have attracted great interests for the realization of quantum Hall states without external magnetic field. Recently, CIs have been studied on various curved lattices, such as the cone-like lattices and the fullerenes. However, few works were reported how to identify curved-CIs and explore their topological phase transitions (TPTs). In this paper, we systemically investigate the curved-CIs with arbitrary n-fold rotational symmetry on cone-like and saddle-like lattices (also dubbed as C

n
-symmetric CIs), by ‘cutting and gluing’ unit sectors with a disk geometry. These C

n
-symmetric CIs can be identified based on the chiral edge states, the real-space Chern number and the quantized conductance. Here, we propose two ways to calculate the real-space Chern number, the Kitaev’s formula and the local Chern marker. Furthermore, the TPTs of curved CIs are explored by tuning staggered flux and on-site mass.
Radiation risks of lymphoma and multiple myeloma incidence in the updated NRRW-3 cohort in the UK: 1955–2011
Authors: Hunter Nezahat , Haylock Richard 
Published: March 2021

Abstract
The effect of external radiation on lymphoma, including non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL) and multiple myeloma (MM) incidence was evaluated in the National Registry for Radiation Workers based upon the third analysis cohort but with an additional 10 years of follow-up. The study includes 172 452 workers, of whom (90%) were men with 5.25 million person-years of follow-up from 1955 through to the end of 2011. A total of 711 cases of NHL, 113 cases of HL and 279 cases of MM were registered. Poisson regression was used to estimate the excess relative risk per unit of cumulative exposure to ionising radiation. A statistically significant association was found between radiation dose and the incidence of NHL and MM. There was no evidence of radiation associated excess risk for HL. The reported associations are based on a very small proportion of exposed workers, in particular among workers with cumulative doses above 0.5 Sv so should be treated with caution, further investigations are necessary to confirm our results.
Standardization of histogram- and gray-level co-occurrence matrices-based radiomics in the presence of blur and noise
Authors: Gang Grace J , Deshpande Radhika , Stayman J Webster 
Published: March 2021

Abstract
Radiomics have been extensively investigated as quantitative biomarkers that can enhance the utility of imaging studies and aid the clinical decision making process. A major challenge to the clinical translation of radiomics is their variability as a result of different imaging and reconstruction protocols. In this work, we present a novel radiomics standardization framework capable of modeling and recovering the underlying radiomic feature in images that have been corrupted by the effects of spatial resolution and noise. We focus on two classes of radiomics based on pixel value distributions—i.e. histograms and gray-level co-occurrence matrices (GLCMs). We developed a model that predicts these distributions in the presence of system blur and noise, and used that model to invert these physical effects and recover the underlying distributions. Specifically, the effect of blur on histogram and GLCM is highly image-dependent, while additive noise convolves the histogram/GLCM of the noiseless image with those of the noise. The recovery method therefore consists of two deconvolution operations: the first in the image domain to remove the effect of system blur, the second in the histogram/GLCM domain to remove the effect of noise. The performance of the proposed recovery strategy was investigated using a set of texture phantoms and an emulated computed tomography imaging chain with a range of realistic blur and noise levels. The proposed method was able to obtain histogram and GLCM estimates that closely resemble the ground truth. The method performed well across imaging conditions and significantly lowered the variability associated with different imaging protocols. This improvement also translated to better classification accuracy, where recovered radiomic values result in greater separation of radiomic clusters for two different texture phantoms as compared to values derived from the original blurred and noisy images. In summary, the novel radiomics standardization framework demonstrates high potential for mitigating radiomic variability as a result of the imaging system and can potentially be integrated as a preprocessing step towards more robust and reproducible radiomic models.
Emergent mesoscopic quantum vortex and Planckian dissipation in the strange metal phase
Authors: Li Rong , She Zhen-Su 
Published: March 2021

Abstract
A major puzzle of condensed-matter physics is the physics behind the linear-in-temperature law of resistivity in many exotic metallic systems, including cuprates, pnictides, and heavy fermions. In this work, we propose, based on a symmetry-breaking analysis, that the strange metal phase is a novel emergent mesoscopic quantum state, beyond Landau’s quasiparticle excitation, which is composed of fluctuating vortices. The model predicts, in a straightforward way, the local magnetic field with a correlation time determined by the Coulomb potential, validated by observations of dynamic muon spin relaxation rates in both 3d cuprates and 5d iridate without fitting parameter. Furthermore, the model resolves the underlying quantum mechanism of the Planckian dissipation in terms of carrier scattering by fluctuating vortex, which predicts a scattering rate proportional to the vortex density, thus deriving both linear-in temperature and linear-in field laws, with a universal scattering coefficient validated by data of several dozens of samples for cuprates and iron pnictides. These findings offer a new phenomenology for non-Fermi liquid in strongly correlated materials.
Persistent currents in Bose–Bose mixtures after an interspecies interaction quench
Authors: Spehner D , Morales-Molina L , Reyes S A 
Published: March 2021

Abstract
We study the persistent currents and interspecies entanglement generation in a Bose–Bose mixture formed by two atomic gases (hereafter labeled by the letters A and B) trapped in a one-dimensional ring lattice potential with an artificial gauge field after a sudden quench from zero to strong interactions between the two gases. Assuming that the strength of these interactions is much larger than the single species energies and that the gas A is initially in the Mott-insulator regime, we show that the current of the gas B is reduced with respect to its value prior the interaction quench. Averaging fast oscillations out, the relative decrease of this current is independent of the initial visibility and Peierls phase of the gas B and behaves quadratically with the visibility of the gas A. The second Rényi entropy of the reduced state measuring the amount of entanglement between the two gases is found to scale linearly with the number of sites and to be proportional to the relative decrease of the current.
A numerical study of the entropy generation and heat transfer rate of airflow around a NACA 0015 airfoil subjected to an external magnetic field
Authors: Saffarzadeh Hamed , Djavareshkian Mohammad Hassan 
Published: March 2021

Abstract
In the present study, the thermal Lattice Boltzmann Technique is combined with the Ghost Fluid method to simulate the flow and heat transfer rate around a NACA 0015 airfoil in the presence of an external magnetic field source. It is tried to investigate the mutual effects of the Hartmann and Reynolds numbers as well as the magnetic field angle and the attack angle of the airfoil on the flow and heat transfer characteristics. Besides, the total entropy generation rate of the system was studied through its main components, i.e. entropy generation rate due to friction, heat transfer, and Magneto Hydrodynamics. Therefore, the tests were carried out for various Re and Ha numbers, plus different magnetic field angles and airfoil attack angles, and their influence on the active parameters which are Cd, Cl, and Nu, along with the entropy generation rate of the system, were recorded. The results revealed that with an increment of the Re number the Cd and Cl graphs drop, but the Nu value raises. Also, the total entropy generation rate of the system is at its maximum around γ = 60.
Terahertz flat-top broadband defect modes generated in periodically undulated waveguides
Authors: Zhang Kun , Fan Ya-Xian , Xu Lan-Lan , Liu Ting , Liu Huan , Tao Zhi-Yong 
Published: March 2021

Abstract
We propose a tunable flat-top broadband defect mode in the terahertz (THz) frequency range by inserting multiple defects into a periodic waveguide with undulated tube walls. When introducing a defect into periodic structures, we can achieve a defect mode with a very sharp transmission peak in the forbidden band due to the local resonance effect. Here, in the proposed multi-defect structure, we find a broadband defect mode with a bandwidth of 38.3 GHz appearing in the transmission spectrum, which is over 21 times that of the traditional defect mode. The simulations reveal that the broadband defect mode is caused by the competition between Bragg scattering and local resonances in multiple defect mode coupling. The bandwidth and center frequency of this broadband defect mode can be manipulated by altering the number and size of defects, which could be applied in various THz systems as functional devices.
Minimum variance estimation of statistical anisotropy via galaxy survey
Authors: Shiraishi Maresuke , Okumura Teppei , Akitsu Kazuyuki 
Published: March 2021

Abstract
We consider the benefits of measuring cosmic statistical anisotropy from redshift-space correlators of the galaxy number density fluctuation and the peculiar velocity field without adopting the plane-parallel (PP) approximation. Since the correlators are decomposed using the general tripolar spherical harmonic (TripoSH) basis, we can deal with wide-angle contributions untreatable by the PP approximation, and at the same time, target anisotropic signatures can be cleanly extracted. We, for the first time, compute the covariance of the TripoSH decomposition coefficient and the Fisher matrix to forecast the detectability of statistical anisotropy. The resultant expression of the covariance is free from nontrivial mixings between each multipole moment caused by the PP approximation and hence the detectability is fully optimized. Compared with the analysis under the PP approximation, the superiority in detectability is always confirmed, and it is highlighted, especially in the cases that the shot noise level is large and that target statistical anisotropy has a blue-tilted shape in Fourier space. The application of the TripoSH-based analysis to forthcoming all-sky survey data could result in constraints on anisotropy comparable to or tighter than the current cosmic microwave background ones.
Resonant sub-GeV Dirac dark matter
Authors: Bernreuther Elias , Heeba Saniya , Kahlhoefer Felix 
Published: March 2021

Abstract
We study the phenomenology and detection prospects of a sub-GeV Dirac dark matter candidate with resonantly enhanced annihilations via a dark photon mediator. The model evades cosmological constraints on light thermal particles in the early universe while simultaneously being in reach of current and upcoming terrestrial experiments. We conduct a global analysis of the parameter space, considering bounds from accelerator and direct detection experiments, as well as those arising from Big Bang Nucleosynthesis, the Cosmic Microwave Background and dark matter self-interactions. We also extend our discussion to the case of a dark matter subcomponent. We find that large regions of parameter space remain viable even for the case of a moderate resonant enhancement, and demonstrate the complementarity of different experimental strategies for further exploring this scenario.
Generating rotating spacetime in Ricci-based gravity: naked singularity as a black hole mimicker
Authors: Shao Wei-Hsiang , Chen Che-Yu , Chen Pisin 
Published: March 2021

Abstract
Motivated by the lack of rotating solutions sourced by matter in General Relativity as well as in modified gravity theories, we extend a recently discovered exact rotating solution of the minimal Einstein-scalar theory to its counterpart in Eddington-inspired Born-Infeld gravity coupled to a Born-Infeld scalar field.

This is accomplished with the implementation of a well-developed mapping between solutions of Ricci-Based Palatini theories of gravity and General Relativity.

The new solution is parametrized by the scalar charge and the Born-Infeld coupling constant apart from the mass and spin of the compact object.

Compared to the spacetime prior to the mapping, we find that the high-energy modifications at the Born-Infeld scale are able to suppress but not remove the curvature divergence of the original naked null singularity.

Depending on the sign of the Born-Infeld coupling constant, these modifications may even give rise to an additional timelike singularity exterior to the null one.

In spite of that, both of the naked singularities before and after the mapping are capable of casting shadows, and as a consequence of the mapping relation, their shadows turn out to be identical as seen by a distant observer on the equatorial plane.

Even though the scalar field induces a peculiar oblateness to the appearance of the shadow with its left and right endpoints held fixed, the closedness condition for the shadow contour sets a small upper bound on the absolute value of the scalar charge, which leads to observational features of the shadow closely resembling those of a Kerr black hole.
Searching for extremal spots
in Planck lensing maps
Authors: Jakubec Clemens , Sullivan Raelyn M. , Scott Douglas 
Published: March 2021

Abstract
A great deal of attention has been given to the so-called Cold Spot in maps of the cosmic microwave background (CMB) temperature.
We present a similar analysis, searching for extremal spots in the CMB lensing convergence and lensing potential maps from the Planck 2018 data release.
We perform a multi-scale and multi-filter analysis using the first three members of the Mexican-hat wavelet family to search for extremal features of different shapes and sizes. Although an initial analysis appears to show the existence of some extremal spots at scales below about 5, we conclude, after marginalising over all scales and filters, that no significant features are detected in the lensing maps. We conclude that in terms of maxima and minima of various sizes, the lensing data have similar statistical properties to Gaussian simulations.
The impact of new d(p,γ)3 rates on Big Bang Nucleosynthesis
Authors: Yeh Tsung-Han , Olive Keith A. , Fields Brian D. 
Published: March 2021

Abstract
We consider the effect on Big Bang Nucleosynthesis (BBN) of new measurements of the
d(p,γ)3 cross section by the LUNA Collaboration. These have an important effect on the primordial abundance of D/H which is also sensitive to the baryon density at the time of BBN.
We have re-evaluated the thermal rate for this reaction, using
a world average of cross section data, which we describe with
model-independent polynomials; our results are in good agreement with a similar
analysis by LUNA.
We then perform a full likelihood analysis
combining BBN and Planck cosmic microwave background (CMB) likelihood chains
using the new rate combined with previous measurements and compare with the results using previous rates. Concordance between BBN and CMB measurements of the anisotropy spectrum using the old rates was excellent. The predicted deuterium abundance at the Planck value of the baryon density was (D/H)BBN+CMB
old = (2.57 ± 0.13) × 10−5 which can be compared with the value determined from quasar absorption systems (D/H)obs = (2.55 ± 0.03) × 10−5. Using the new rates we find (D/H)BBN+CMB = (2.51 ± 0.11) × 10−5.
We thus find consistency among BBN theory, deuterium and 4 observations, and the CMB, when using reaction rates fit in our data-driven approach. We also find that the new reaction data tightens the constraints on the number of relativistic degrees of freedom during BBN, giving the effective number of light neutrino species Nν = 2.880 ± 0.144 in good agreement with the Standard Model of particle physics.
Finally, we note that the observed deuterium abundance continues to be more precise than the BBN+CMB prediction, whose error budget is now
dominated by d(d,n)3 and d(d,p)3 H.
More broadly, it is clear that the details of
the treatment of nuclear reactions and their uncertainty have become critical for BBN.
Towards real-life EEG applications: novel superporous hydrogel-based semi-dry EEG electrodes enabling automatically ‘charge–discharge’ electrolyte
Authors: Li Guangli , Wang Sizhe , Li Mingzhe , Duan Yanwen Y 
Published: March 2021

Abstract

Objective. A novel polyacrylamide/polyvinyl alcohol superporous hydrogel (PAAm/PVA SPH)-based semi-dry electrode was constructed for capturing electroencephalogram (EEG) signals at the hairy scalp, showing automatically ‘charge–discharge’ electrolyte concept in EEG electrode development. Approach. In this regard, PAAm/PVA SPH was polymerized in-situ in the hollow electrode cavity by freezing polymerization, which acted as a dynamic reservoir of electrolyte fluid. The SPH can be completely ‘charged’ with electrolyte fluid, such as saline, in just a few seconds and can be ‘discharged’ through a few tiny pillars into the scalp at a desirable rate. In this way, an ideal local skin hydration effect was achieved at electrode–skin contact sites, facilitating the bioelectrical signal pathway and significantly reducing electrode–skin impedance. Moreover, the electrode interface effectively avoids short circuit and inconvenient issues. Main results. The results show that the semi-dry electrode displayed low and stable contact impedance, showing non-polarization properties with low off-set potential and negligible potential drift. The average temporal cross-correlation coefficient between the semi-dry and conventional wet electrodes was 0.941. Frequency spectra also showed almost identical responses with anticipated neural electrophysiology responses. Significance. Considering prominent advantages such as a rapid setup, robust signal, and user-friendliness, the new concept of semi-dry electrodes shows excellent potential in emerging real-life EEG applications.
Poor man’s scaling:
XYZ
Coqblin–Schrieffer model revisited
Authors: Kogan Eugene , Shi Zheng 
Published: March 2021

Abstract
We derive the third-order poor man’s scaling equation for a generic Hamiltonian describing a quantum impurity embedded into an itinerant electron gas. We show that the XYZ Coqblin–Schrieffer model introduced by one of us earlier is algebraically renormalizable in the sense that the form of the Hamiltonian is preserved along the scaling trajectory, write down the scaling equations for the model, and analyze the renormalization group flows in the cases of both constant and pseudogap densities of states.
Tuning Ginzburg–Landau theory to quantitatively study thin ferromagnetic materials
Authors: Guruciaga Pamela C , Caballero Nirvana , Jeudy Vincent , Curiale Javier , Bustingorry Sebastian 
Published: March 2021

Abstract
Along with experiments, numerical simulations are key to gaining insight into the underlying mechanisms governing domain wall motion in thin ferromagnetic systems. However, a direct comparison between numerical simulation of model systems and experimental results still represents a great challenge. Here, we present a tuned Ginzburg–Landau model to quantitatively study the dynamics of domain walls in quasi two-dimensional ferromagnetic systems with perpendicular magnetic anisotropy. This model incorporates material and experimental parameters and the micromagnetic prescription for thermal fluctuations, allowing us to perform material-specific simulations and at the same time recover universal features. We show that our model quantitatively reproduces previous experimental velocity-field data in the archetypal perpendicular magnetic anisotropy Pt/Co/Pt ultra-thin films in the three dynamical regimes of domain wall motion (creep, depinning and flow). In addition, we present a statistical analysis of the domain wall width parameter, showing that our model can provide detailed nano-scale information while retaining the complex behavior of a statistical disordered model.
Correlation between mathematical creative thinking ability and mathematical creative thinking disposition in geometry
Authors: Yanty Putri Nasution Eline , Yulia Putri , Seprina Anggraini Reri , Putri Rahmi , Sari Maila 
Published: March 2021

Abstract
Mathematics educators commonly believe that an open-ended approach could facilitate students to build their creative thinking ability and its disposition, especially in geometry. This research belongs to a quasi-experiment that used a non-equivalent control group design. The purpose of this research was to analyze the correlation between creative thinking ability and creative thinking disposition through an open-ended learning approach toward area and volume of flat geometrical objects problems. Two classes are selected as the sample, they are the control group and experiment group. The open-ended approach was used in the experiment group then direct instruction in the control group. The population is all of the eighth-grade students at one of the junior high school in Bandung, West Java, Indonesia. This study used to test and non-test as the research instruments. The test instrument was a creative thinking ability test while the non-test instrument was a questionnaire. These instruments were given after the learning process then analyzed by using Bivariate Correlation through SPSS. According to the analysis results, the finding is: the correlation coefficient between creative thinking ability and creative thinking disposition is at the middle level. The conclusion is there is a significant correlation between students’ creative thinking ability and students’ creative thinking disposition.
Application of the CGVRP model and the 0-1 linear programming determines the RASKIN (subsidized rice) distribution route
Authors: Hermanto Koko , Ruskartina Eki , Gunawan  
Published: March 2021

Abstract
Distribution is one of the important aspects to run a business or enterprise. BULOG is a state-own enterprise that operates in the food security sector. One of its services is to distribute RASKIN (subsidized rice) to all district in Indonesia. Sumbawa is one of the big district in Indonesia has a BULOG Regional sub-division to distr So far, the distribution of Raskin carried out by BULOG in the district of Sumbawa still relies on the experience of drivers in distributing RASKIN to destination villages and the application of the heuristic method has never been applied to optimize distribution routes, considering that a large number of distribution areas creates many combinations of distribution channels. This study aims to propose the optimal distribution route for RASKIN for BULOG in Sumbawa district, Alas warehouse so that the distribution time and costs can be more optimal. In this study, this problem was solved using the Cluster General Vehicle Routing Problem (CGVRP) model and the 0-1 linear programming. The result shows that only 3 of 4 vehicles can be used to distribute RASKIN, whereas previously, BULOG use 4 vehicles. The total route of the three vehicles is 206.52 miles.