cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Thermal conductivity in the vortex state of the superconductor UPd_2Al_3
Creators: name: Tewordt, L.
name: Fay, D.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The magneto-thermal conductivity kappa is calculated for the vortex state of UPd_2Al_3 by assuming horizontal gap nodes. The Green's function method we employed takes into account the effects of supercurrent flow and Andreev scattering on the quasiparticles due to Abrikosov's vortex lattice order parameter. The calculated angular dependence of kappa_{yy} for field rotation theta_0 in the ac-plane depends strongly on field strength H, impurity scattering, anisotropy of the Fermi velocity, and temperature. For finite temperatures and the clean unitary scattering limit we get qualitative agreement with recent experiments for all four proposed gap functions having horizontal line nodes at ck_z = 0, pi/4, and pi/2.
description: 12 pages, 3 figures with several parts
Phase and Amplitude Responses of Narrow-Band Optical Filter Measured by Microwave Network Analyzer
Creators: name: Wang, Hsi-Cheng
name: Ho, Keang-Po
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: The phase and amplitude responses of a narrow-band optical filter are measured simultaneously using a microwave network analyzer. The measurement is based on an interferometric arrangement to split light into two paths and then combine them. In one of the two paths, a Mach-Zehnder modulator generates two tones without carrier and the narrow-band optical filter just passes through one of the tones. The temperature and environmental variations are removed by separated phase and amplitude averaging. The amplitude and phase responses of the optical filter are measured to the resolution and accuracy of the network analyzer.
Consentimento informado no contexto da Ciência Aberta: convergências, divergências e possíveis pontos de integração
Creators: name: Ferrigolo Melo, Jonas
name: Rockembach, Moisés
Publisher: name: Zenodo
Year: 2024

description: Apresentação realizada na sessão Comunicação III, da 15ª Conferência Lusófona de Ciência Aberta, na Escola Superior de Enfermagem do Porto (ESEP), de 01 a 04 de outubro de 2024.
Helical magnetic order and Fermi surface nesting in non-centrosymmetric ScFeGe
Creators: name: Karna, Sunil K.
name: Tristant, D.
name: Hebert, J. K.
name: Cao, G.
name: Chapai, R.
name: Phelan, W. A.
name: Zhang, Q.
name: Wu, Y.
name: Dhital, C.
name: Li, Y.
name: Cao, H. B.
name: Tian, W.
name: Cruz, C. R. Dela
name: Aczel, A. A.
name: Zaharko, O.
name: Khasanov, A.
name: McGuire, M. A.
name: Roy, A.
name: Xie, W.
name: Browne, D. A.
name: Vekhter, I.
name: Meunier, V.
name: Shelton, W. A.
name: Adams, P. W.
name: Sprunger, P. T.
name: Young, D. P.
name: Jin, R.
name: DiTusa, J. F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: An investigation of the structural, magnetic, thermodynamic, and charge transport properties of non-centrosymmetric hexagonal ScFeGe reveals it to be an anisotropic metal with a transition to a weak itinerant incommensurate helimagnetic state below $T_N = 36$ K. Neutron diffraction measurements discovered a temperature and field independent helical wavevector \textbf{\textit{k}} = (0 0 0.193) with magnetic moments of 0.53 $μ_{B}$ per formula unit confined to the {\it ab}-plane. Density functional theory calculations are consistent with these measurements and find several bands that cross the Fermi level along the {\it c}-axis with a nearly degenerate set of flat bands just above the Fermi energy. The anisotropy found in the electrical transport is reflected in the calculated Fermi surface, which consists of several warped flat sheets along the $c$-axis with two regions of significant nesting, one of which has a wavevector that closely matches that found in the neutron diffraction. The electronic structure calculations, along with a strong anomaly in the {\it c}-axis conductivity at $T_N$, signal a Fermi surface driven magnetic transition, similar to that found in spin density wave materials. Magnetic fields applied in the {\it ab}-plane result in a metamagnetic transition with a threshold field of $\approx$ 6.7 T along with a sharp, strongly temperature dependent, discontinuity and a change in sign of the magnetoresistance for in-plane currents. Thus, ScFeGe is an ideal system to investigate the effect of in-plane magnetic fields on an easy-plane magnetic system, where the relative strength of the magnetic interactions and anisotropies determine the topology and magnetic structure.
description: 15 pages, 13 figures
Traveling waves and geometric scaling at non-zero momentum transfer
Creators: name: Marquet, C.
name: Peschanski, R.
name: Soyez, G.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We extend the search for traveling-wave asymptotic solutions of the non-linear Balitsky-Kovchegov (BK) saturation equation to non-forward dipole-target amplitudes. Making use of conformal invariant properties of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) kernel, we exhibit traveling-wave solutions in momentum space in the region where the momentum transfer q is smaller than the characteristic scale Q of the projectile. We prove geometric scaling in the variable Q/(q Omega_s(Y)) where Omega_s(Y) has the same energy dependence as in the forward analysis.
description: 14 pages, 2 figures, minor changes and misprints corrected, version to be published
Reemergence of superconductivity in pressurized quasi-one-dimensional superconductor K2Mo3As3
Creators: name: Huang, Cheng
name: Guo, Jing
name: Zhao, Kang
name: Cui, Fan
name: Qin, Shengshan
name: Mu, Qingge
name: Zhou, Yazhou
name: Cai, Shu
name: Yang, Chongli
name: Long, Sijin
name: Yang, Ke
name: Li, Aiguo
name: Wu, Qi
name: Ren, Zhian
name: Hu, Jiangping
name: Sun, Liling
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Here we report a pressure-induced reemergence of superconductivity in recently discovered superconductor K2Mo3As3, which is the first experimental case observed in quasi-one-dimensional superconductors. We find that, after full suppression of the ambient-pressure superconducting (SC-I) state at 8.7 GPa, an intermediary non-superconducting state sets in and prevails to the pressure up to 18.2 GPa, however, above this pressure a new superconducting (SC-II) state appears unexpectedly. High pressure x-ray diffraction measurements demonstrate that the pressure-induced dramatic change of the lattice parameter c contributes mainly to the emergence of the SC-II state. Combined with the theioretical calculations on band strcture, our results suggest that the reemergemce of superconductivity is associated with the change of the complicated interplay among different orbital electrons, driven by the pressure-induced unisotropic change of the lattice.
description: 17 pages and 4 figures
Weak approximation on del Pezzo surfaces of degree 1
Creators: name: Várilly-Alvarado, Anthony
Publisher: name: arXiv
Year: 2008
Subjects: subject: Number Theory (math.NT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14G05; 12G05

description: We study del Pezzo surfaces of degree 1 of the form w^2 = z^3 + Ax^6 + By^6 in the weighted projective space P_k(1,1,2,3), where k is a perfect field of characteristic not 2 or 3 and A,B \in k^*. Over a number field, we exhibit an infinite family of (minimal) counterexamples to weak approximation amongst these surfaces, via a Brauer-Manin obstruction.
description: 20 pages, no figures, Latex. Introduction revised to highlight Theorem 3.3; typos corrected. Magma scripts included at end of sourcefile
Von Hentig, Hartmut: ...der werfe den ersten Stein
Creators: name: Schroer, Jürgen
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 42 Nr. 2 (1993): Ökumenische Rundschau, Band 42, Heft 2
The Time Delays of Gravitational Lens HE0435-1223: An Early-Type Galaxy With a Rising Rotation Curve
Creators: name: Kochanek, C. S.
name: Morgan, N. D.
name: Falco, E. E.
name: McLeod, B. A.
name: Winn, J. N.
name: Dembicky, J.
name: Ketzeback, B.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present Hubble Space Telescope images and 2 years of optical photometry of the quadruple quasar HE0435-1223. The time delays between the intrinsic quasar variations are 14.4+/-0.8 (A-D), 8.0+/-0.8 (A-B) and 2.1+/-0.8 (A-C) days. We also observed non-intrinsic variations of ~0.1 mag/yr that we attribute to microlensing. Instead of the traditional approach of assuming a rotation curve for the lens galaxy and then deriving the Hubble constant (H_0), we assume H_0=(72+/-7) km/s/Mpc and derive constraints on the rotation curve. On the scale over which the lensed images occur (1.2"=5kpc/h=1.5R_e), the lens galaxy must have a rising rotation curve, and it cannot have a constant mass-to-light ratio. These results add to the evidence that the structures of early-type galaxies are heterogeneous.
description: 36 pages, 10 figures, submitted to ApJ
Correlation Functions: Getting into Shape
Creators: name: Pratt, Scott
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The ability to measure characteristics of source shapes using non-identical particle correlations is discussed. Both strong-interaction induced and Coulomb induced correlations are shown to provide sensitivity to source shapes. By decomposing correlation functions with spherical or Cartesian harmonics, details of the shapes can be especially well isolated.
description: Conf. Proc. for 21st Workshop on Nucl. Dynamics, Breckenridge, CO, Feb. 2005
Electron transfer properties of flavin-modified and axial ligand variants of cytochrome c
Creators: name: Twitchett, Mark Bradley
Publisher: name: University of British Columbia
Year: 2009

description: Electron transfer (ET) reactions of metalloproteins are central to many biological processes. This fact combined with the simplicity of the chemistry involved makes this type of reaction amenable to detailed experimental and theoretical analysis. The current work employs two novel forms of mitochondrial cytochrome c to investigate critical structural factors that dictate the efficiency of intermolecular and intramolecular ET reactions of this protein and that have implications for metalloproteins in general. The first of these approaches involved the use of a new technique to study intramolecular ET reactions in which a combination of site-directed mutagenesis and chemical modification was used to construct a family of synthetic flavocytochromes c. Previous studies by Tollin and Cusanovich have used flavins extensively to investigate intermolecular ET reactions of electron transfer proteins, but flavins have not been used previously as donors in the study of intramolecular ET reactions. In the present work, flash photolysis was used to study the intramolecular ET kinetics of four cytochrome variants bearing a flavin group at position 8, 39, 62, or 85. To complement this work, the theoretical models of Beratan, Betts and Onuchic and of Siddarth and Marcus were used to identify the theoretically optimal ET pathways and donor-acceptor electronic coupling for each of these derivatives. A major finding derived from the kinetic studies of these synthetic flavocytochromes is that the reorganization energy for electron transfer, λ, of the flavin center is 0.7(2) eV. In addition, the theoretical models for these reactions demonstrate that the correlation of the rate constants for intramoleculer ET observed can be understood in terms of the nature and length of the ET pathway between the donor and acceptor centers. The second approach described in this thesis involved the study of three cytochrome c variants in which the Met80 ligand to the heme iron was replaced with an alanyl residue. Analysis of the intermolecular reduction of these variants by Fe(EDTA)²⁻ was undertaken to gain insight into the role of the Met80 ligand and two other active site residues in regulating the electron transfer reactivity of the cytochrome. These variants exhibited a remarkable range in reactivity with this reductant as represented by the apparent electrostatics-corrected self-exchange rate constants, k₁₁ [sup corr], exhibited in this reaction (pH 7, μ= 0.1 M, 25 °C): Met80Ala, k₁₁[sup corr] = 1.1 M⁻¹ s⁻¹; Met80Ala/Tyr67Phe, k₁₁[sup corr] = 3.4 x 102; and Met80Ala/Phe82Ser, k₁₁ [sup corr]= 4.3 x lO⁻² M ⁻¹s⁻¹. Possible explanations of these results are discussed.
Restricting Majorana phases in the Tri-Bi-Maximal limit
Creators: name: Rivera-Agudelo, Diana C.
name: Tostado, S. L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Tri-Bi-Maximal pattern has been long investigated as the symmetric scenario that lies behind the neutrino mixing matrix. It predicts a null reactor angle and hence forbids $CP$ violation in the lepton sector, which is in contrast to the current experimental determinations. We explore different deviations from this pattern to restore the compatibility with the latest fits of neutrino mixing parameters. We consider two unitary matrices to correct the symmetric pattern, each of them is written in terms of one single angle and one complex phase, which will be constrained by the experimental mixings and from symmetry restrictions in the mass matrix. We note that these correction parameters would allow us to obtain simultaneous information about the Dirac and Majorana $CP$ phases in some specific scenarios. We show that the predicted values lead to sharped regions for the neutrinoless double beta decay amplitude, in the selected cases, that could be tested with forthcoming results.
description: 24 pages, 19 figures
Differentiable sampling of molecular geometries with uncertainty-based adversarial attacks
Creators: name: Schwalbe-Koda, Daniel
name: Tan, Aik Rui
name: Gómez-Bombarelli, Rafael
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Neural network (NN) interatomic potentials provide fast prediction of potential energy surfaces, closely matching the accuracy of the electronic structure methods used to produce the training data. However, NN predictions are only reliable within well-learned training domains, and show volatile behavior when extrapolating. Uncertainty quantification approaches can flag atomic configurations for which prediction confidence is low, but arriving at such uncertain regions requires expensive sampling of the NN phase space, often using atomistic simulations. Here, we exploit automatic differentiation to drive atomistic systems towards high-likelihood, high-uncertainty configurations without the need for molecular dynamics simulations. By performing adversarial attacks on an uncertainty metric, informative geometries that expand the training domain of NNs are sampled. When combined to an active learning loop, this approach bootstraps and improves NN potentials while decreasing the number of calls to the ground truth method. This efficiency is demonstrated on sampling of kinetic barriers and collective variables in molecules, and can be extended to any NN potential architecture and materials system.
description: 12 pages, 4 figures, supporting information
Neutron stars in globular clusters: formation and observational manifestations
Creators: name: Kuranov, A. G.
name: Postnov, K. A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Population synthesis is used to model the number of neutron stars in globular clusters that are observed as LMXBs and millisecond PSRs. The dynamical interaction between binary and single stars in a GC are assumed to take place with a permanently replenished "background" of single stars whose density distribution keeps track with the cluster evolution as a whole and evolution of single stars. We use the hypothesis (Podsiadlowski et al) that NS forming in binary systems from components with initial masses \sim 8-12 M_\odot during the electron-capture collapse of the degenerate O-Ne-Mg core do not acquire a high space velocities (kicks). The remaining NSs (i.e. from single stars with M>8 M_\odot or binary comonents with M>12 M_\odot) are assumed to be born with high kicks, as found from obsrevations of single pulsars (Hobbs et al. 2005). Under this assumption, a sizeable fraction of NSs remain in GCs (about 1000 NSs in a GC with a mass of 5\times 10^5 M_\odot). The number of ms PSRs formed in the cluster via accretion spin-up in binaries is then about 10, which is consistent with observations. Our modelling reproduces the observed shape of the X-ray luminosity function for accreting NSs in binaries with normal and degenerate components and the distribution of spin periods of ms PSRs in GCs under the assumption of accretion-driven magnetic field decay of NSs up to a bottom value of 10^8 G. The number of LMXBs and ms PSRs dynamically expelling from GCs is also calculated.
description: LATEX, 21 pages, 8 gif figures, Astronomy Letters, in press
Existence of solutions for a quasilinear elliptic system with local nonlinearity on $\mathbb R^N$
Creators: name: Zhang, Xingyong
name: Liu, Cuiling
Publisher: name: arXiv
Year: 2020
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper, we investigate the existence of solutions for a class of quasilinear elliptic system \begin{eqnarray*} \begin{cases}{ccc} -\mbox{div}(ϕ_1(|\nabla u|)\nabla u)+V_1(x)ϕ_1(|u|)u=λF_u(x, u,v), \ \ x\in \mathbb R^N, -\mbox{div}(ϕ_2(|\nabla v|)\nabla v)+V_2(x)ϕ_2(|v|)v=λF_v(x, u,v), \ \ x\in \mathbb R^N, u\in W^{1,Φ_1}(\mathbb R^N), v\in W^{1,Φ_2}(\mathbb R^N), \end{cases} \end{eqnarray*} where $N\ge 2$, $\inf_{\mathbb R^N}V_i(x)>0,i=1,2$, and $λ>0$. We obtain that when the nonlinear term $F$ satisfies some growth conditions only in a circle with center $0$ and radius $4$, system has a nontrivial solution $(u_λ,v_λ)$ with $\|(u_λ,v_λ)\|_{\infty}\le 2$ for every $λ$ large enough, and the families of solutions $\{(u_λ,v_λ)\}$ satisfy that $\|(u_λ,v_λ)\|\to 0$ as $λ\to \infty$. Moreover, a corresponding result for a quasilinear elliptic equation is also obtained, which is better than the result for the elliptic system.
Few-Mode Fiber Coupling Efficiency for Free-Space Optical Communication
Creators: name: Fan, Xingjie
name: Wang, Dawei
name: Cheng, Julian
name: Yang, Jingkai
name: Ma, Jing
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Signal Processing (eess.SP)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Few-mode fiber is a significant component of free-space optical communication at the receiver to obtain achievable high coupling efficiency. A theoretical coupling model from the free-space optical communication link to a few-mode fiber is proposed based on a scale-adapted set of Laguerre-Gaussian modes. It is found that the coupling efficiency of various modes behaves differently in the presence of atmospheric turbulence or random jitter. Based on this model, the optimal coupling geometry parameter is obtained to maximize the coupling efficiency of the selected mode of few-mode fiber. The communication performance with random jitter is investigated. It is shown that the few-mode fiber has better bit-error rate performance than single-mode fiber, especially in high signal-to-noise ratio regimes.
description: 8 pages, 8 figures
Bose-Einstein Condensation of Magnons in Cs2CuCl4
Creators: name: Radu, T.
name: Wilhelm, H.
name: Yushankhai, V.
name: Kovrizhin, D.
name: Coldea, R.
name: Tylczynski, Z.
name: Luehmann, T.
name: Steglich, F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report on results of specific heat measurements on single crystals of the frustrated quasi-2D spin-1/2 antiferromagnet Cs_2CuCl_4 (T_N=0.595 K) in external magnetic fields B<12 T and for temperatures T>30 mK. Decreasing B from high fields leads to the closure of the field-induced gap in the magnon spectrum at a critical field B_c = 8.51 T and a magnetic phase transition is clearly seen below B_c. In the vicinity to B_c, the phase transition boundary is well described by the power-law T_c(B)\propto (B_c-B)^{1/ϕ} with the measured critical exponent ϕ\simeq 1.5. These findings are interpreted as a Bose-Einstein condensation of magnons.
description: 5 pages, 4 figures, experiment and theory
Distinguishing Modified Gravity from Dark Energy
Creators: name: Bertschinger, Edmund
name: Zukin, Phillip
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The acceleration of the universe can be explained either through dark energy or through the modification of gravity on large scales. In this paper we investigate modified gravity models and compare their observable predictions with dark energy models. Modifications of general relativity are expected to be scale-independent on super-horizon scales and scale-dependent on sub-horizon scales. For scale-independent modifications, utilizing the conservation of the curvature scalar and a parameterized post-Newtonian formulation of cosmological perturbations, we derive results for large scale structure growth, weak gravitational lensing, and cosmic microwave background anisotropy. For scale-dependent modifications, inspired by recent $f(R)$ theories we introduce a parameterization for the gravitational coupling $G$ and the post-Newtonian parameter $γ$. These parameterizations provide a convenient formalism for testing general relativity. However, we find that if dark energy is generalized to include both entropy and shear stress perturbations, and the dynamics of dark energy is unknown a priori, then modified gravity cannot in general be distinguished from dark energy using cosmological linear perturbations.
description: Accepted by PRD
The pentaquark $Θ^+(1540)$ in the string model
Creators: name: Krivoruchenko, M. I.
name: Martemyanov, B. V.
name: Faessler, Amand
name: Fuchs, C.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We consider the $Θ^+(1540)$ pentaquark in the string model that correctly reproduces the linear Regge trajectories for the case of orbital excitations of light $q\bar q$ mesons and $qqq$ baryons. Assuming (and arguing in favour of) the diquark-antiquark-diquark ($[ud]\bar s [ud]$) clustering of this orbitally excited object we found its mass about $290 \rm {MeV}$ above the experimental value $1540 \rm {MeV}$. In the model considered this discrepancy could be attributed to the change of the constituent mass of $\bar s$ antiquark as compared to that of $s$ quark localized at the string end.
description: 4 pages, 5 figures
EXPRES. II. Searching for Planets Around Active Stars: A Case Study of HD 101501
Creators: name: Cabot, Samuel H. C.
name: Roettenbacher, Rachael M.
name: Henry, Gregory W.
name: Zhao, Lily
name: Harmon, Robert O.
name: Fischer, Debra A.
name: Brewer, John M.
name: Llama, Joe
name: Petersburg, Ryan R.
name: Szymkowiak, Andrew E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: By controlling instrumental errors to below 10 cm/s, the EXtreme PREcision Spectrograph (EXPRES) allows for a more insightful study of photospheric velocities that can mask weak Keplerian signals. Gaussian Processes (GP) have become a standard tool for modeling correlated noise in radial velocity datasets. While GPs are constrained and motivated by physical properties of the star, in some cases they are still flexible enough to absorb unresolved Keplerian signals. We apply GP regression to EXPRES radial velocity measurements of the 3.5 Gyr old chromospherically active Sun-like star, HD 101501. We obtain tight constraints on the stellar rotation period and the evolution of spot distributions using 28 seasons of ground-based photometry, as well as recent $TESS$ data. Light curve inversion was carried out on both photometry datasets to reveal the spot distribution and spot evolution timescales on the star. We find that the $> 5$ m/s rms radial velocity variations in HD 101501 are well-modeled with a GP stellar activity model without planets, yielding a residual rms scatter of 45 cm/s. We carry out simulations, injecting and recovering signals with the GP framework, to demonstrate that high-cadence observations are required to use GPs most efficiently to detect low-mass planets around active stars like HD 101501. Sparse sampling prevents GPs from learning the correlated noise structure and can allow it to absorb prospective Keplerian signals. We quantify the moderate to high-cadence monitoring that provides the necessary information to disentangle photospheric features using GPs and to detect planets around active stars.
description: 25 pages, 16 figures, accepted to AJ
Feasibility of space-based measurement-device-independent quantum key distribution
Creators: name: Wang, Xingyu
name: Dong, Chen
name: Zhao, Shanghong
name: Liu, Yong
name: Liu, Xiaowen
name: Zhu, Haonan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The measurement-device-independent (MDI) QKD is considered to be an alternative to overcome the currently trusted satellite paradigm. However, the feasibility of the space-based MDI-QKD remains unclear in terms of the factors: the high-loss uplink between a ground station and a satellite, the limited duration when two ground stations are simultaneously visible, as well as the rigorous requirements for the two-photon interference when performing the Bell-state Measurement (BSM). In this paper, we present a feasibility assessment of space-based MDI-QKD based on the Micius satellite. Integrated with the orbital dynamics model and atmosphere channel model, a framework is presented to explore the whole parameters space including orbit height, elevation angle, apertures of transceiver and atmospheric turbulence intensity to give the considerations for improving key rates and subsequently provide a relevant parameter tradeoff for the implementation of space-based MDI-QKD. We further investigate the heart of MDI-QKD, the two-photon interference considerations such as the frequency calibration and time synchronization technology against Doppler shift, and the way of performing the intensity optimization method in the dynamic and asymmetric channels. Our work can be used as a pathfinder to support decisions involving as the selection of the future quantum communication satellite missions.
description: 13 pages;10 figures
Effective Field Theory of Distorted-Photonic Crystal: Exact Solutions of the Geodesics Equation
Creators: name: Kitagawa, Hitoshi
name: Nanjyo, Kanji
name: Kitamura, Kyoko
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Photonic crystals are periodic structure of dielectric materials that can control light propagations in the media because of their photonic-dispersion led by the well-ordered lattice-points arrangements. We here study the behavior of light propagation in distorted-photonic crystals (D-PCs), which possess the gradual spatial distortion of lattice-points positions, as the effective field theory in terms of the differential geometry. In order to investigate the trajectory of light ray in the D-PC, we derive the geodesics equation that is given from the principle of least action, with defining the metric tensor in terms of the lattice-positions distortion. The geodesics equation indicates that the trajectory can be bent by just introducing lattice-positions distortion. We show some exact solutions of the trajectory in the case of simple distortion and that those results well agree with the results of the Finite Difference Time Domain (FDTD) simulations.
A Rotating Kaluza-Klein Black Hole with Squashed Horizons
Creators: name: Wang, Tower
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We find a rotating Kaluza-Klein black hole solution with a squashed $S^3$ horizon in five dimensions. This is a Kerr counterpart of the charged one found by Ishihara and Matsuno (hep-th/0510094) recently. The space-time is geodesic complete and free of naked singularity. Its asymptotic structure is a twisted $S^1$ fiber bundle over a four dimensional Minkowski space-time. We also study the mass and thermodynamics of this black hole.
description: LaTeX file, 18 pages, minor corrections, accepted by Nuclear Physics B
Probing electroweak phase transition with multi-TeV muon colliders and gravitational waves
Creators: name: Liu, Wei
name: Xie, Ke-Pan
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the complementarity of the proposed multi-TeV muon colliders and the near-future gravitational wave (GW) detectors to the first order electroweak phase transition (FOEWPT), taking the real scalar extended Standard Model as the representative model. A detailed collider simulation shows the FOEWPT parameter space can be greatly probed via the the vector boson fusion production of the singlet, and its subsequent decay to the di-Higgs or di-boson channels. Especially, almost all the parameter space yielding detectable GW signals can be probed by the muon colliders. Therefore, if we could detect stochastic GWs in the future, a muon collider could provide a hopeful crosscheck to identify their origin. On the other hand, there is considerable parameter space that escapes GW detections but is within the reach of the muon colliders. The precision measurements of Higgs couplings could also probe the FOEWPT parameter space efficiently.
description: 15 pages + references, 5 figures. Accepted by JHEP
Formal Lagrangian Operad
Creators: name: Cattaneo, Alberto S.
name: Dherin, Benoit
name: Felder, Giovanni
Publisher: name: arXiv
Year: 2005
Subjects: subject: Symplectic Geometry (math.SG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Given a symplectic manifold $M$, we may define an operad structure on the the spaces $\op^k$ of the Lagrangian submanifolds of $(\bar{M})^k\times M$ via symplectic reduction. If $M$ is also a symplectic groupoid, then its multiplication space is an associative product in this operad. Following this idea, we provide a deformation theory for symplectic groupoids analog to the deformation theory of algebras. It turns out that the semi-classical part of Kontsevich's deformation of $C^\infty(\R^d)$ is a deformation of the trivial symplectic groupoid structure of $T^*\R^d$.
description: 29 pages, 3 figures
Werbick, Jürgen: Vom entscheidend und unterscheidend Christlichen
Creators: name: Müller, Wolfgang
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 42 Nr. 2 (1993): Ökumenische Rundschau, Band 42, Heft 2
An empirical analysis of the corporate call decision
Creators: name: Carlson, Murray
Publisher: name: University of British Columbia
Year: 2009

description: In this thesis we provide insights into the behavior of financial managers of utility companies by studying their decisions to redeem callable preferred shares. In particular, we investigate whether or not an option pricing based model of the call decision, with managers who maximize shareholder value, does a better job of explaining callable preferred share prices and call decisions than do other models of the decision. In order to perform these tests, we extend an empirical technique introduced by Rust (1987) to include the use of information from preferred share prices in addition to the call decisions. The model we develop to value the option embedded in a callable preferred share differs from standard models in two ways. First, as suggested in Kraus (1983), we explicitly account for transaction costs associated with a redemption. Second, we account for state variables that are observed by the decision makers but not by the preferred shareholders. We interpret these unobservable state variables as the benefits and costs associated with a change in capital structure that can accompany a call decision. When we add this variable, our empirical model changes from one which predicts exactly when a share should be called to one which predicts the probability of a call as the function of the observable state. These two modifications of the standard model result in predictions of calls, and therefore of callable preferred share prices, that are consistent with several previously unexplained features of the data; we show that the predictive power of the model is improved in a statistical sense by adding these features to the model. The pricing and call probability functions from our model do a good job of describing call decisions and preferred share prices for several utilities. Using data from shares of the Pacific Gas and Electric Co. (PGE) we obtain reasonable estimates for the transaction costs associated with a call. Using a formal empirical test, we are able to conclude that the managers of the Pacific Gas and Electric Company clearly take into account the value of the option to delay the call when making their call decisions. Overall, the model seems to be robust to tests of its specification and does a better job of describing the data than do simpler models of the decision making process. Limitations in the data do not allow us to perform the same tests in a larger cross-section of utility companies. However, we are able to estimate transaction cost parameters for many firms and these do not seem to vary significantly from those of PGE. This evidence does not cause us to reject our hypothesis that managerial behavior is consistent with a model in which managers maximize shareholder value.
Spectral Properties of Prompt Emission of Four Short Gamma-Ray Bursts Observed by the Suzaku-WAM and the Konus-Wind
Creators: name: Ohno, Masanori
name: Fukazawa, Yasushi
name: Takahashi, Takuya
name: Yamaoka, Kazutaka
name: Sugita, Satoshi
name: Pal'shin, Valentin
name: Sakamoto, Takanori
name: Sato, Goro
name: Hurley, Kevin
name: Frederiks, Dmitry
name: Oleynik, Philipp
name: Ulanov, Mikhail
name: Tashiro, Makoto
name: Urata, Yuji
name: Onda, Kaori
name: Tamagawa, Toru
name: Terada, Yukikatsu
name: Suzuki, Motoko
name: Soojing, Hong
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have performed a joint analysis of prompt emission from four bright short gamma-ray bursts (GRBs) with the Suzaku-WAM and the Konus-Wind experiments. This joint analysis allows us to investigate the spectral properties of short-duration bursts over a wider energy band with a higher accuracy. We find that these bursts have a high E$_{\rm peak}$, around 1 MeV and have a harder power-law component than that of long GRBs. However, we can not determine whether these spectra follow the cut-off power-law model or the Band model. We also investigated the spectral lag, hardness ratio, inferred isotropic radiation energy and existence of a soft emission hump, in order to classify them into short or long GRBs using several criteria, in addition to the burst duration. We find that all criteria, except for the existence of the soft hump, support the fact that our four GRB samples are correctly classified as belonging to the short class. In addition, our broad-band analysis revealed that there is no evidence of GRBs with a very large hardness ratio, as seen in the BATSE short GRB sample, and that the spectral lag of our four short GRBs is consistent with zero, even in the MeV energy band, unlike long GRBs. Although our short GRB samples are still limited, these results suggest that the spectral hardness of short GRBs might not differ significantly from that of long GRBs, and also that the spectral lag at high energies could be a strong criterion for burst classification.
description: 23 pages, 6 figures, accepted for Publications of the Astronomical Society of Japan
Warneck, Wilfried: Friedenskirchliche Existenz im Konziliaren Prozess
Creators: name: Assmann, Reinhard
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 42 Nr. 2 (1993): Ökumenische Rundschau, Band 42, Heft 2
Statistical Mechanics of Dislocation Pileups in Two Dimensions
Creators: name: Zhang, Grace H.
name: Nelson, David R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Dislocation pileups directly impact the material properties of crystalline solids through the arrangement and collective motion of interacting dislocations. We study the statistical mechanics of these ordered defect structures embedded in two dimensional crystals, where the dislocations themselves form one-dimensional lattices. In particular, pileups exemplify a new class of inhomogeneous crystals characterized by spatially varying lattice spacings. By analytically formulating key statistical quantities and comparing our theory to numerical experiments using an intriguing mapping of dislocation positions onto the eigenvalues of recently studied random matrix ensembles, we uncover two types of one-dimensional phase transitions in dislocation pileups: a thermal depinning transition out of long-range translational order from the pinned-defect phase, due to a periodic Peierls potential, to a floating-defect state, and finally the melting out of a quasi-long range ordered floating defect-solid phase to a defect-liquid. We also find the set of transition temperatures at which these transitions can be directly observed through the one-dimensional structure factor, where the delta function Bragg peaks, at the pinned-defect to floating-defect transition, broaden into algebraically diverging Bragg peaks, which then sequentially disappear as one approaches the two-dimensional melting transition of the host crystal. We calculate a set of temperature-dependent critical exponents for the structure factor and radial distribution function, and obtain their exact forms for both uniform and inhomogeneous pileups using random matrix theory.
description: 24 pages, 8 figures
On Petersson's partition limit formula
Creators: name: Castaño-Bernard, Carlos
name: Luca, Florian
Publisher: name: arXiv
Year: 2020
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11F30, 11R29, 11P82

description: For each prime $p\equiv 1\pmod{4}$ consider the Legendre character $χ=(\frac{\cdot}{p})$. Let $p_\pm(n)$ be the number of partitions of $n$ into parts $λ>0$ such that $χ(λ)=\pm 1$. Petersson proved a beautiful limit formula for the ratio of $p_+(n)$ to $p_-(n)$ as $n\to\infty$ expressed in terms of important invariants of the real quadratic field $\mathbb{Q}(\sqrt{p})$. But his proof is not illuminating and Grosswald conjectured a more natural proof using a Tauberian converse of the Stolz-Cesàro theorem. In this paper we suggest an approach to address Grosswald's conjecture. We discuss a monotonicity conjecture which looks quite natural in the context of the monotonicity theorems of Bateman-Erdős.
description: Online Ready - International Journal of Number Theory
Conjugacy of 2-spherical subgroups of Coxeter groups and parallel walls
Creators: name: Caprace, Pierre-Emmanuel
Publisher: name: arXiv
Year: 2005
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 20F5, 20F65, 20F67, 51F15

description: Let (W,S) be a Coxeter system of finite rank (ie |S| is finite) and let A be the associated Coxeter (or Davis) complex. We study chains of pairwise parallel walls in A using Tits' bilinear form associated to the standard root system of (W,S). As an application, we prove the strong parallel wall conjecture of G Niblo and L Reeves [J Group Theory 6 (2003) 399--413]. This allows to prove finiteness of the number of conjugacy classes of certain one-ended subgroups of W, which yields in turn the determination of all co-Hopfian Coxeter groups of 2--spherical type.
description: This is the version published by Algebraic & Geometric Topology on 14 November 2006
Floquet Cavity Electromagnonics
Creators: name: Xu, Jing
name: Zhong, Changchun
name: Han, Xu
name: Jin, Dafei
name: Jiang, Liang
name: Zhang, Xufeng
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Hybrid magnonics has recently attracted intensive attentions as a promising platform for coherent information processing. In spite of its rapid development, on-demand control over the interaction of magnons with other information carriers, in particular microwave photons in electromagnonic systems, has been long missing, significantly limiting the broad applications of hybrid magnonics. Here, we show that by introducing Floquet engineering into cavity electromagnonics, coherent control on the magnon-microwave photon coupling can be realized. Leveraging the periodic temporal modulation from a Floquet drive, our first-of-its-kind Floquet cavity electromagnonic system can manipulate the interaction between hybridized cavity electromagnonic modes on demand. Moreover, we demonstrate a new coupling regime in such systems: the Floquet ultrastrong coupling, where the Floquet splitting is comparable with or even larger than the level spacing of the two interacting modes, resulting in the breakdown of the rotating wave approximation. Our findings open up new directions for magnon-based coherent signal processing.
description: 9 pages, 6 figures
Kartenbasierte Verhaltensentscheidung und Manöverplanung für automatische Fahrzeuge
Creators: name: Bender, Philipp
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2021
Subjects: Trajektorienplanung
Verhaltensgenerierung
Karten zum automatischen Fahren
Kombinatorische Aspekte der Bewegungsplanung

description: Assistenzsysteme erschließen sich immer größere Teile des öffentlichen Verkehrsraumes und die aktuelle Entwicklung steuert in Richtung automatischer Fahrzeuge. Diese Systeme nehmen die Position des Fahrers ein, müssen Entscheidungen treffen und Aktionen auslösen. Hierfür ist es notwendig, die Situation zu verstehen, Entscheidungsmöglichkeiten zu identifizieren und für eine getroffene Entscheidung Steuersignale zu generieren. In dieser Arbeit wird eine Kartenrepräsentation (Lanelet-Karten) und eine deterministische Verhaltensgenerierung vorgestellt. Die Verhaltensgenerierung bezieht die für das Verhalten relevante Information aus der Karte und setzt sie mit Beobachtungen aus der Sensorik in Beziehung. Das gewünschte Verhalten wird in Form von Nebenbedingungen an einen dem Stand der Technik entliehenen Trajektorienplaner übergeben. Die Verhaltensentscheidung wird anhand einer vollautomatisierten Fahrt im realen Straßenverkehr erprobt. Basierend auf den Ergebnissen wird untersucht, wie ein lokales Lösungsverfahren zur Trajektorienplanung so erweitert werden kann, dass auch Situationen beherrschbar sind, in denen sich mehrere – aber nicht ineinander überführbare – Optionen eröffnen. Es werden zwei Problemformulierungen und -lösungen vorgestellt und simulativ evaluiert.
The intrinsic and oscillated astrophysical neutrino flavor ratios
Creators: name: Athar, H.
name: Kim, C. S.
name: Lee, Jake
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The pp interactions taking place in the cosmos around us are a source of the astrophysical neutrinos of all the three flavors. In these interactions, the electron and the muon neutrinos mainly come from the production and the decay of the π^{\pm} mesons, whereas the tau neutrinos mainly come from the production and the decay of the D^{\pm}_{S} mesons. We estimate the three intrinsic neutrino flavor ratios for 1 GeV < E < 10^{12} GeV in the pp interactions and found them to be 1 : 2 : 3\times 10^{-5}. We study the effects of neutrino oscillations on these intrinsic ratios. We point out that the three ratios become 1 : 1 : 1 if L(pc)/E(GeV)> 10^{-10} in the presence of neutrino oscillations, where L is the distance to the astrophysical neutrino source in units of parsecs.
description: 23 pages, 5 figures, typos corrected, appeared in Mod. Phys. Lett. A
Neutrino non-standard interactions meet precision measurements of $N_{\rm eff}$
Creators: name: Du, Yong
name: Yu, Jiang-Hao
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The number of relativistic species, $N_{\rm eff}$, has been precisely calculated in the standard model, and would be measured to the percent level by CMB-S4 in future. Neutral-current non-standard interactions would affect neutrino decoupling in the early Universe, thus modifying $N_{\rm eff}$. We parameterize those operators up to dimension-7 in the effective field theory framework, and then provide a complete, generic and analytical dictionary for the collision term integrals. From precision measurements of $N_{\rm eff}$, the most stringent constraint is obtained for the dimension-6 vector-type neutrino-electron operator, whose scale is constrained to be above about 195 (331) GeV from Planck (CMB-S4). We find our results complementary to other experiments like neutrino coherent scattering, neutrino oscillation, collider, and neutrino deep inelastic scattering experiments.
description: Minor changes. Match the published version. To appear in JHEP
Strictly incoherent operations for one-qubit systems
Creators: name: Du, Shuanping
name: Bai, Zhaofang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Strictly incoherent operations (SIO) proposed in [Phys. Rev. Lett. 116, 120404 (2016)] are promising to be a good candidate of free operations in the resource theory of quantum coherence, setting against the central role of local operations and classical communication in the resource theory of quantum entanglement. An important open problem is an efficient description for strictly incoherent operations in physical region. Such a description plays key role for axiomatic study of resource theory of quantum coherence. We are aimed to give a structural characterization of bistochastic SIOs in terms of Pauli operators and the Phase operator for one-qubit systems. Some applications of our results are also sketched in reconstructing quantum thermal averages via a quantum computer and in coherence manipulation.
description: 5 pages,46 references