bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of atomic Pauli potentials and their large-Z limit
Authors: Redd Jeremy J. , Cancio Antonio C. 
Published: October 2021

Modeling the Pauli energy, the contribution to the kinetic energy caused by Pauli statistics, without using orbitals is the open problem of orbital-free density functional theory. An important aspect of this problem is correctly reproducing the Pauli potential, the response of the Pauli kinetic energy to a change in density. We analyze the behavior of the Pauli potential of non-relativistic neutral atoms under Lieb–Simon scaling—the process of taking nuclear charge and particle number to infinity, in which the kinetic energy tends to the Thomas–Fermi limit. We do this by mathematical analysis of the near-nuclear region and by calculating the exact orbital-dependent Pauli potential using the approach of Levy and Ouyang for closed-shell atoms out to element Z = 976. In rough analogy to Lieb and Simon’s own findings for the charge density, we find that the potential does not converge smoothly to the Thomas–Fermi limit on a point-by-point basis but separates into several distinct regions of behavior. Near the nucleus, the potential approaches a constant given by the difference in energy between the lowest and highest occupied eigenvalues. We discover a transition region in the outer core where the potential deviates unexpectedly and predictably from both the Thomas–Fermi potential and the gradient expansion correction to it. These results may provide insight into the semi-classical description of Pauli statistics and new constraints to aid the improvement of orbital-free density functional theory functionals.
Scaling relations of exciton diffusion in linear aggregates with static and dynamic disorder
Authors: Kunsel T. , Jansen T. L. C. , Knoester J. 
Published: October 2021

Exciton diffusion plays an important role in many opto-electronic processes and phenomena. Understanding the interplay of intermolecular coupling, static energetic disorder, and dephasing caused by environmental fluctuations (dynamic disorder) is crucial to optimize exciton diffusion under various physical conditions. We report on a systematic analysis of the exciton diffusion constant in linear aggregates using the Haken–Strobl–Reineker model to describe this interplay. We numerically investigate the static-disorder scaling of (i) the diffusion constant in the limit of small dephasing rate, (ii) the dephasing rate at which the diffusion is optimized, and (iii) the value of the diffusion constant at the optimal dephasing rate. Three scaling regimes are found, associated with, respectively, fully delocalized exciton states (finite-size effects), weakly localized states, and strongly localized states. The scaling powers agree well with analytically estimated ones. In particular, in the weakly localized regime, the numerical results corroborate the so-called quantum Goldilocks principle to find the optimal dephasing rate and maximum diffusion constant as a function of static disorder, while in the strong-localization regime, these quantities can be derived fully analytically.
Concepts and the Physical Realms
Authors: Singh Anirudh 
Published: October 2021

Humans live in many different worlds, each of which has its own representation in mind space. The world of the scientist will be called the physical realms. The laws of physics are an integral part of the real world, and humans acquire a natural understanding of these laws without regard to any mathematical formulation.
While the experimental physicist studies the behavior of the real world, the theoretical physicist develops and studies its representation in the mathematical world (i.e., mind space). It is not necessary to know the mathematical equations to be able to carry out a physical investigation. This can be performed through observation and recording of the data numerically, and using the processes of interpolation and extrapolation.
Practicing physicists usually find that they must adopt the roles of both the theoretical as well as the experimental physicist to achieve the aims of an experiment.
Observers play a vital role in physics. They become important when their state of motion changes, or when their presence affects the results of the experiment. The observer can be either animate or inanimate. Unlike inanimate observers, animate observers have access to mind space, which allows them to make decisions from collected information.
Formation of negative-ion resonance and dissociative attachment in collisions of NO2 with electrons
Authors: Liu Hainan , Jiang Xianwu , Yuen Chi-Hong , Kokoouline Viatcheslav , Ayouz Mehdi 
Published: October 2021

Abstract
The process of electron attachment to the NO2 molecule is investigated theoretically using an approach based on a study by O’Malley (1966 Phys. Rev.
150 14). The approach combines the normal mode approximation for representation of vibrational dynamics of NO2 and one-dimensional treatment, along each normal mode, of the attachment process as in O’Malley’s theory, such that only a modest computational effort is required to compute the attachment cross section. Taking into account the survival probability of the formed resonant state of

N
O

2

−

, the cross section for dissociative electron attachment to NO2 is also estimated. To compare with available experimental data, the theoretical cross section is convoluted with energy distribution of NO2–e− collisions with uncertainties reported in experimental studies. Peak values of the convoluted theoretical cross section are found to be about a factor of 2–10 larger than the experimental results.
Effect of helium flux on near-surface helium accumulation in plasma-exposed tungsten
Authors: Nandipati Giridhar , Hammond Karl D , Maroudas Dimitrios , Roche Kenneth J , Kurtz Richard J , Wirth Brian D , Setyawan Wahyu 
Published: October 2021

Abstract
We report results of object kinetic Monte Carlo (OKMC) simulations to understand the effect of helium flux on the near-surface helium accumulation in plasma-facing tungsten, which is initially pristine, defect-free, and has a (100) surface orientation. These OKMC simulations are performed at 933 K for fluxes ranging from 1022 to 4 × 1025 He/m2 s with 100 eV helium atoms impinging on a (100) surface up to a maximum fluence of 4 × 1019 He/m2. In the near-surface region, helium clusters interact elastically with the free surface. The interaction is attractive and results in the drift of mobile helium clusters towards the surface as well as increased trap mutation rates. The associated kinetics and energetics of the above-mentioned processes obtained from molecular dynamics simulations are also considered. The OKMC simulations indicate that in pristine tungsten, as the flux decreases, the retention of implanted helium decreases, and its depth distribution shifts to deeper below the surface. Furthermore, the fraction of retained helium diffusing into the bulk increases as well, so much so that for the flux of 1022 He/m2 s, almost all of the retained helium diffused into the bulk with minimal/negligible near-surface helium accumulation. At a given flux, with increasing fluence, the fraction of retained helium initially decreases and then starts to increase after reaching a minimum. The occurrence of the retention minimum shifts to higher fluences as the flux decreases. Although the near-surface helium accumulation spreads deeper into the material with decreasing flux and increasing fluence, the spread appears to saturate at depths between 80 and 100 nm. We present a detailed analysis of the influence of helium flux on the size and depth distribution of total helium and helium bubbles.
High temperature W-band complex permittivity measurements of thermally cycled ceramic-metal composites: AlN:Mo with 0.25 to 4.0 vol% Mo from 25 °C to 1000 °C in air
Authors: Cohick Zane W , Schaub Samuel C , Hoff Brad W , Dynys Frederick W , Baros Anthony E , Telmer Maxwell , Orozco Haylie , Grudt Rachael O , Hayden Steven C , Rittersdorf Ian M , Savrun Ender 
Published: October 2021

Abstract
An apparatus for measuring the W-band (75–110 GHz) complex permittivity of dielectrics at 1000 °C was developed. This apparatus allows for measurements at approximately twice the temperature of previously published high temperature free-space measurement systems while maintaining similar precision. Challenges were addressed related to high temperature measurements, including temperature uniformity, the accuracy of temperature measurements, and preventing temperature related changes to mm-wave measurement systems. The details of complex permittivity extraction from the measured S-parameters are discussed. Sources of error related to permittivity measurement and mathematical models were identified and are discussed in detail herein. Thermally-cycled, mm-wave absorbing, aluminum nitride ceramic composites containing varying levels of molybdenum additives were measured over the range of 25 °C–1000 °C. These measurements were compared to the same composites before thermal cycling. It was found that ceramic composites are largely stable after thermal cycling in terms of dielectric properties despite the presence of visible surface modifications.
Plasma flux and energy enhancement in BP-HiPIMS discharge via auxiliary anode and solenoidal coil
Authors: Han Mingyue , Luo Yang , Tang Ling , Gu Jiabin , Li Hua , Xu Ye , Luo Sida , Li LiuHe 
Published: October 2021

Abstract
As an emerging and extraordinary plasma source, the bipolar-pulse high power impulse magnetron sputtering (BP-HiPIMS) has promising prospects and wide industrial applications. In this paper, an effort to optimize the plasma flux and energy in BP-HiPIMS via auxiliary anode and solenoidal coil was made. This novel plasma source contains two types of auxiliary anode voltage (direct current and pulse) and one type of solenoidal coil current (direct current) to synergistically enhance the plasma generation and diffusion by electric field and magnetic field together. Systematic evaluations of discharge characteristics demonstrate that applying auxiliary anode voltage and coil magnetic field effectively contribute to a reduction in delay time of target current onset and increase in peak amplitude of target current, which are beneficial for improving plasma generation and target sputtering. The complex plasma dynamics are diagnosed by Langmuir probe and optical emission spectroscopy, and simulated by particle-in-cell/Monte Carlo collision approach. These comprehensive investigations on plasma parameters demonstrate that the plasma density, emission intensity of the metal ions, substrate current density, and ionization fraction of sputtered target particles have been improved with the increase of coil current. The observations of the increase in excitation temperature T
exc of Ar atoms, and more extended high-energy tails in electron energy distribution function curves imply that the plasma can be significantly heated by the auxiliary anode. Combining the simulation results and theoretical model proposed in the last sub-content, the diffusion and transport mechanism of charged-particles in complex electric and magnetic fields are discussed. From the theoretical analysis, the qualitative relation between the plasma density and coil current is well consistent with the measurements of electron density obtained by Langmuir probe. These evidences all support the idea that the plasma flux and energy can be enhanced in BP-HiPIMS discharge via auxiliary anode and solenoidal coil together.
Analyses on the nonequilibrium transport processes in a free-burning argon arc plasma under different operating conditions
Authors: Fang Chuan , Chen Jian , Li Jing , Zhang Zi-Ming , Guo Heng , Li Zhi-Hui , Zeng Shi , Li He-Ping 
Published: October 2021

Abstract
During discharges of an arc plasma, complex mass, momentum and energy exchanges exist between the arc column and the surrounding cold gas, forming a nonequilibrium region deviating from both the local thermodynamic equilibrium and local chemical equilibrium states. The nonequilibrium synergistic transport plays a crucial role not only in controlling the characteristics of the arc plasmas theoretically, but also in optimizing the plasma material processing qualities in actual applications. In this paper, the nonequilibrium transport processes in free-burning argon arc plasmas under different operating pressures and arc currents are studied based on a complete nonequilibrium fluid model, and are also validated by comparing with measured data. The energy transfer processes under various operating conditions, especially Joule heating, elastic and inelastic collisions, conductive and convective heat transfer, and energy transfer related to the temperature ratio spatial gradient, are analyzed based on the concept of the ‘energy tree.’ The revealed major energy transfer channels in the high-pressure argon arc plasmas also provide some possibilities to control the characteristics of thermal plasmas in the future.
Local, expressive, quantum-number-preserving VQE ansätze for fermionic systems
Authors: Anselmetti Gian-Luca R , Wierichs David , Gogolin Christian , Parrish Robert M 
Published: October 2021

Abstract
We propose VQE circuit fabrics with advantageous properties for the simulation of strongly correlated ground and excited states of molecules and materials under the Jordan–Wigner mapping that can be implemented linearly locally and preserve all relevant quantum numbers: the number of spin up (α) and down (β) electrons and the total spin squared. We demonstrate that our entangler circuits are expressive already at low depth and parameter count, appear to become universal, and may be trainable without having to cross regions of vanishing gradient, when the number of parameters becomes sufficiently large and when these parameters are suitably initialized. One particularly appealing construction achieves this with just orbital rotations and pair exchange gates. We derive optimal four-term parameter shift rules for and provide explicit decompositions of our quantum number preserving gates and perform numerical demonstrations on highly correlated molecules on up to 20 qubits.
Light Dirac neutrino portal dark matter with observable ΔN
eff
Authors: Biswas Anirban , Borah Debasish , Nanda Dibyendu 
Published: October 2021

Abstract
We propose a Dirac neutrino portal dark matter scenario
by minimally extending the particle content of the Standard Model
(SM) with three right-handed neutrinos (ν
R
), a Dirac fermion
dark matter candidate (ψ) and a complex scalar (ϕ), all
of which are singlets under the SM gauge group. An additional ℤ4
symmetry has been introduced for the stability of dark matter
candidate ψ and also ensuring the Dirac nature of light
neutrinos at the same time. Both the right handed neutrinos and
the dark matter thermalise with the SM plasma due to a new Yukawa
interaction involving ν
R
, ψ and ϕ while the latter
maintains thermal contact via the Higgs portal interaction.
The decoupling of ν
R
occurs when ϕ
loses its kinetic equilibrium with the SM plasma and thereafter
all three ℤ4 charged particles form an equilibrium
among themselves with a temperature TνR

.
The dark matter candidate ψ finally freezes out within the dark
sector and preserves its relic abundance. We have found that in the
present scenario, some portion of low mass dark matter (M
ψ ≲ 10 GeV)
is already excluded by the Planck 2018 data for keeping ν
R
s
in the thermal bath below a temperature of 600 MeV and thereby
producing an excess contribution to N
eff. The next
generation experiments like CMB-S4, SPT-3G etc. will have the required sensitivities to probe the entire
model parameter space of this minimal scenario,
especially the low mass range of ψ where direct detection
experiments are still not capable enough for detection.
Testing no-hair theorem
by quasi-periodic oscillations:
the
quadrupole of GRO J1655–40
Authors: Allahyari Alireza , Shao Lijing 
Published: October 2021

Abstract
We perform an observational test of no-hair theorem using
quasi-periodic oscillations within the relativistic precession model. Two
well motivated metrics we apply are Kerr-Q and Hartle-Thorne metrics in
which the quadrupole is the parameter that possibly encodes deviations from
the Kerr black hole. The expressions for the quasi-periodic frequencies are
derived before comparing the models with the observation. We encounter a
degeneracy in constraining spin and quadrupole parameters that makes it
difficult to measure their values. In particular, we here propose a novel
test of no-hair theorem by adapting the Hartle-Thorne metric. We complement our study by doing a model comparison. We find
that there is strong evidence that Kerr black hole is the source of the central object in GRO
J1655–40 given the present observational precisions.
Poincaré polynomials of generic torus orbit closures in Schubert varieties
Authors: Lee Eunjeong , Masuda Mikiya , Park Seonjeong , Song Jongbaek 
Published: October 2021

The closure of a generic torus orbit in the flag variety

G

/

B

G/B

of type

A
A

is known to be a permutohedral variety, and its Poincaré polynomial agrees with the Eulerian polynomial. In this paper, we study the Poincaré polynomial of a generic torus orbit closure in a Schubert variety in

G

/

B

G/B

. When the generic torus orbit closure in a Schubert variety is smooth, its Poincaré polynomial is known to agree with a certain generalization of the Eulerian polynomial. We extend this result to an arbitrary generic torus orbit closure which is not necessarily smooth.
Group actions: Entropy, mixing, spectra, and generic properties
Authors: Stepin Anatoly , Tikhonov Sergey 
Published: October 2021

We talk about several directions of V. Rokhlin’s heritage in ergodic theory: ideas that influenced the further development of investigations (genericity, approximations), problems put forward by V. Rokhlin in his papers, problems that V. Rokhlin put forward verbally (in particular, the question about homogeneous spectrum of finite multiplicity). We touch upon the directions close to the authors of this text and their school. Many of the questions raised by Rokhlin have analogs for different classes of transformations, for group actions, and versions about the genericity of properties appearing in these formulations. We will consider the corresponding topics in such a generalized sense.
Maximally inflected real trigonal curves on Hirzebruch surfaces
Authors: Zvonilov V. 
Published: October 2021

In 2014 A. Degtyarev, I. Itenberg, and the author gave a description, up to fiberwise equivariant deformations, of maximally inflected real trigonal curves of type I (over a base

B
B

of an arbitrary genus) in terms of the combinatorics of sufficiently simple graphs and for

B
=

P

1

B=\mathbb {P}^1

obtained a complete classification of such curves. In this paper, the mentioned results are extended to maximally inflected real trigonal curves of type II over

B
=

P

1

B=\mathbb {P}^1

.
Genetic divergence ofDeschampsia antarctica(Poaceae) population groups in the maritime Antarctic
Authors: Andreev Igor O , Parnikoza Ivan Yu , Konvalyuk Iryna I , Metcheva Roumiana , Kozeretska Iryna A , Kunakh Viktor A 
Published: October 2021

AbstractWe used inter-simple sequence repeats and inter-retrotransposon amplified polymorphism markers to assess genetic variation in Deschampsia antarctica populations in the context of its uneven distribution in the northern and central maritime Antarctic. Genetic diversity and population structure and differentiation were assessed in nine populations from geographically isolated population groups of D. antarctica, including the South Shetland Islands, Anvers Island and the Argentine Islands regions. In total, 265 amplified DNA fragments were scored, of which 220 (83.0%) were polymorphic. The total sample showed low genetic diversity (unbiased expected heterozygosity = 0.081 and Shannon diversity index = 0.115) and high population differentiation (molecular variance among populations = 0.659). We also found a trend toward a decrease in genetic diversity and an increase in population differentiation toward the southern edge of the species range. Principal coordinates analysis of polymerase chain reaction data and Bayesian population structure analysis showed three main clusters, which included plants originating from three spatially isolated population groups. The unweighted pair group method with arithmetic mean clustering of populations based on Nei’s genetic distances was mainly in agreement with this pattern. Testing of isolation by distance using the Mantel test demonstrated a significant correlation between genetic and ln-transformed geographical distance (r = 0.703). The data obtained indicate that the geographically isolated D. antarctica populations in the maritime Antarctic might form genetic clusters within the total range.
Multitargeted interventions to reduce dialysis-induced systemic stress
Authors: Canaud Bernard , Stephens Melanie P , Nikam Milind , Etter Michael , Collins Allan 
Published: October 2021

ABSTRACTHemodialysis (HD) is a life-sustaining therapy as well as an intermittent and repetitive stress condition for the patient. In ridding the blood of unwanted substances and excess fluid from the blood, the extracorporeal procedure simultaneously induces persistent physiological changes that adversely affect several organs. Dialysis patients experience this systemic stress condition usually thrice weekly and sometimes more frequently depending on the treatment schedule. Dialysis-induced systemic stress results from multifactorial components that include treatment schedule (i.e. modality, treatment time), hemodynamic management (i.e. ultrafiltration, weight loss), intensity of solute fluxes, osmotic and electrolytic shifts and interaction of blood with components of the extracorporeal circuit. Intradialytic morbidity (i.e. hypovolemia, intradialytic hypotension, hypoxia) is the clinical expression of this systemic stress that may act as a disease modifier, resulting in multiorgan injury and long-term morbidity. Thus, while lifesaving, HD exposes the patient to several systemic stressors, both hemodynamic and non-hemodynamic in origin. In addition, a combination of cardiocirculatory stress, greatly conditioned by the switch from hypervolemia to hypovolemia, hypoxemia and electrolyte changes may create pro-arrhythmogenic conditions. Moreover, contact of blood with components of the extracorporeal circuit directly activate circulating cells (i.e. macrophages–monocytes or platelets) and protein systems (i.e. coagulation, complement, contact phase kallikrein–kinin system), leading to induction of pro-inflammatory cytokines and resulting in chronic low-grade inflammation, further contributing to poor outcomes. The multifactorial, repetitive HD-induced stress that globally reduces tissue perfusion and oxygenation could have deleterious long-term consequences on the functionality of vital organs such as heart, brain, liver and kidney. In this article, we summarize the multisystemic pathophysiological consequences of the main circulatory stress factors. Strategies to mitigate their effects to provide more cardioprotective and personalized dialytic therapies are proposed to reduce the systemic burden of HD.