cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Fidelity of Quantum Interferometers
Creators: name: Bahder, Thomas B.
name: Lopata, Paul A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: For a generic interferometer, the conditional probability density distribution, $p(ϕ|m)$, for the phase $ϕ$ given measurement outcome $m$, will generally have multiple peaks. Therefore, the phase sensitivity of an interferometer cannot be adequately characterized by the standard deviation, such as $Δϕ\sim 1/\sqrt{N}$ (the standard limit), or $Δϕ\sim 1/N$ (the Heisenberg limit). We propose an alternative measure of phase sensitivity--the fidelity of an interferometer--defined as the Shannon mutual information between the phase shift $ϕ$\ and the measurement outcomes $m$. As an example application of interferometer fidelity, we consider a generic optical Mach-Zehnder interferometer, used as a sensor of a classical field. We find the surprising result that an entangled {\it N00N} state input leads to a lower fidelity than a Fock state input, for the same photon number.
description: 4 pages, 3 figures
Differentiably simple rings and ring extensions defined by $p$-basis
Creators: name: de Andrés, Celia del Buey
name: Sulca, Diego
name: Villamayor, Orlando E.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Commutative Algebra (math.AC)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 13B05, 14M15, 14L17

description: We review the concept of differentiably simple ring and we give a new proof of Harper's Theorem on the characterization of Noetherian differentiably simple rings in positive characteristic. We then study flat families of differentiably simple rings, or equivalently, finite flat extensions of rings which locally admit $p$-basis. These extensions are called "Galois extensions of exponent one". For such an extension $A\subset C$, we introduce an $A$-scheme, called the "Yuan scheme", which parametrizes subextensions $A\subset B\subset C$ such that $B\subset C$ is Galois of a fixed rank. So, roughly, the Yuan scheme can be thought of as a kind of Grassmannian of Galois subextensions. We finally prove that the Yuan scheme is smooth and compute the dimension of the fibers.
description: Revised version
title: Vision in motion : the complexities of time, space and motion experienced in the artwork and practice of len lye and laszlo moholy-nagy
title: Art, science and visuality : an investigation into artistic responses to science and visual technologies since the 19th Century.
titleType: AlternativeTitle
Creators: name: Clunie, Lisa Ann
Publisher: name: The Australian National University
Year: 2018

description: Vision in Motion is a lasting theoretical proposal left by one of Modernism's great artists - Laszlo Moholy-Nagy. Operating as an account of the curriculum for The Institute of Design, which he founded in Chicago, Vision in Motion proposes a democratic vision of self-expression, one that emphasises the necessity of integrating art with life. His proposal that we learn to utilise all our sensory capacities and to see everything in relationship, emphasises simultaneity and motion through the interconnection of space and time. In doing so Moholy-Nagy proposes a theory of perception and of change, which is dynamic and fitting for the modern age. This thesis will propose that another artist operating in similar fields at the same time was intuitively exploring many of these ideas: Len Lye; a New Zealander whose art practice paralleled and intersected with Moholy-Nagy's as an experimental film maker and kinetic sculptor. Where Moholy-Nagy's life-long pursuit was of the expression of light, Lye's was of motion, but both artists shared similar complexities in their work in regards to the treatment of space and time, responding to the annihilation of time and space as a result of 19th century technological and scientific developments. Yann Beauvais' essay "Rapports entre Len Lye et Moholy-Nagy" is the departure point for this thesis, using the concept of 'Vision in Motion' to investigate further the conjectures and differences between these two artists. In doing so this thesis aims to demonstrate that Lye was the exemplary artist that Moholy-Nagy theorised about, adding further prominence to the recognition of Lye as one of the great visionaries of interdisciplinary practice and Modernism.
Robust Machine Learning Applied to Astronomical Datasets I: Star-Galaxy Classification of the SDSS DR3 Using Decision Trees
Creators: name: Ball, Nicholas M.
name: Brunner, Robert J.
name: Myers, Adam D.
name: Tcheng, David
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We provide classifications for all 143 million non-repeat photometric objects in the Third Data Release of the Sloan Digital Sky Survey (SDSS) using decision trees trained on 477,068 objects with SDSS spectroscopic data. We demonstrate that these star/galaxy classifications are expected to be reliable for approximately 22 million objects with r < ~20. The general machine learning environment Data-to-Knowledge and supercomputing resources enabled extensive investigation of the decision tree parameter space. This work presents the first public release of objects classified in this way for an entire SDSS data release. The objects are classified as either galaxy, star or nsng (neither star nor galaxy), with an associated probability for each class. To demonstrate how to effectively make use of these classifications, we perform several important tests. First, we detail selection criteria within the probability space defined by the three classes to extract samples of stars and galaxies to a given completeness and efficiency. Second, we investigate the efficacy of the classifications and the effect of extrapolating from the spectroscopic regime by performing blind tests on objects in the SDSS, 2dF Galaxy Redshift and 2dF QSO Redshift (2QZ) surveys. Given the photometric limits of our spectroscopic training data, we effectively begin to extrapolate past our star-galaxy training set at r ~ 18. By comparing the number counts of our training sample with the classified sources, however, we find that our efficiencies appear to remain robust to r ~ 20. As a result, we expect our classifications to be accurate for 900,000 galaxies and 6.7 million stars, and remain robust via extrapolation for a total of 8.0 million galaxies and 13.9 million stars. [Abridged]
description: 27 pages, 12 figures, to be published in ApJ, uses emulateapj.cls
Lexical elicitation: voice quality; vocabulary
Creators: name: Buasri, Wasana
name: Lau-Preechathammarach, Raksit Tyler
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2023
Subjects: subject: sss

description: Elicitation of words differing only in voice quality (modal, breathy) and many other words. Consultant is a 49-year-old female.
On a conjecture of Soundararajan
Creators: name: Banks, William
name: Shparlinski, Igor
Publisher: name: arXiv
Year: 2020
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: Primary: 11N25, 11N69, Secondary: 11M20

description: Building on recent work of A. Harper (2012), and using various results of M. C. Chang (2014) and H. Iwaniec (1974) on the zero-free regions of $L$-functions $L(s,χ)$ for characters $χ$ with a smooth modulus $q$, we establish a conjecture of K. Soundararajan (2008) on the distribution of smooth numbers over reduced residue classes for such moduli $q$. A crucial ingredient in our argument is that, for such $q$, there is at most one "problem character" for which $L(s,χ)$ has a smaller zero-free region. Similarly, using the "Deuring-Heilbronn" phenomenon on the repelling nature of zeros of $L$-functions close to one, we also show that Soundararajan's conjecture holds for a family of moduli having Siegel zeros.
description: 17 pages
Mechanics of compliant serial manipulator composed of dual-triangle segments
Creators: name: Chablat, Damien
name: Zhao, Wanda
name: Pashkevich, Anatol
name: Klimchik, Alexandr
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: The paper focuses on the mechanics of a compliant serial manipulator composed of new type of dual-triangle elastic segments. Both the analytical and numerical methods were used to find the manipulator stable and unstable equilibrium configurations, as well as to predict corresponding manipulator shapes. The stiffness analysis was carried on for both loaded and unloaded modes, the stiffness matrices were computed using the Virtual Joint Method (VJM). The results demonstrate that either buckling or quasi-buckling phenomenon may occur under the loading, if the manipulator corresponding initial configuration is straight or non-straight one. Relevant simulation results are presented that confirm the theoretical study.
New-Physics Search through gamma gamma -> t tbar -> lX/bX
Creators: name: Grzadkowski, Bohdan
name: Hioki, Zenro
name: Ohkuma, Kazumasa
name: Wudka, Jose
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We probe optimal beam polarizations for new-physics search in top-quark and Higgs-boson sectors at Photon Linear Colliders (PLC). Expressing possible non-standard effects generated by SU(2)xU(1) gauge-invariant dimension-6 effective operators as anomalous top and Higgs couplings, we estimate expected statistical sensitivities of these couplings in gamma gamma -> t tbar -> lX/bX, using the optimal-observable method.
description: LaTeX_2e, 10 pages, Talk presented by K. Ohkuma at the 7th International Symposium on Radiative Corrections (RADCOR2005), Shonan Village, Japan, October 2-7, 2005
Diffraction Patterns in Deeply Virtual Compton Scattering
Creators: name: Mukherjee, Asmita
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We report on a calculation to show that the Fourier transform of the Deeply Virtual Compton Scattering (DVCS) amplitude with respect to the skewness variable ζat fixed invariant momentum transfer squared t gives results that are analogous to the diffractive scattering of a wave in optics. As a specific example, we utilize the quantum fluctuations of a fermion state at one loop in QED to obtain the behavior of the DVCS amplitude for electron-photon scattering. We then simulate the wavefunctions for a hadron by differentiating the above LFWFs with respect to M^2 and study the corresponding DVCS amplitudes in light-front longitudinal space.
description: Presented at the 17 th International Spin Physics Symposium, Kyoto, Japan, October 2-7, 2006
Current distribution in magnetically confined 2DEG: semiclassical and quantum mechanical treatment
Creators: name: Németh, Róbert
name: Kaufmann, Zoltán
name: Cserti, József
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In the ballistic regime we study both semiclassically and quantum mechanically the electron's dynamics in two-dimensional electron gas (2DEG) in the presence of an inhomogeneous magnetic field applied perpendicular to the plane. The magnetic field is constant inside four separate circular regions which are located at the four corners of a square of side length larger than the diameter of the circles, while outside the circles the magnetic field is zero. We carry out the stability analysis of the periodic orbits and for given initial conditions numerically calculate the two-dimensional invariant torus embedded in the four-dimensional phase space. Applying the Bohr--Sommerfeld and the Einstein--Brillouin--Keller semiclassical quantization methods we obtain the energy levels for different magnetic field strengths. We also perform exact quantum calculations solving numerically the discretized version of the Schrödinger equation. In our calculations, we consider only those bound states that are localized to the neighborhood of the four magnetic disks. We show that the semiclassical results are in good agreement with those found from our quantum calculations. Moreover, the current distribution and the phase of the different wave functions enable us to deduce the two quantum numbers $n_1$ and $n_2$ characterizing the energy levels in the semiclassical methods. Finally, we present two examples in which the quantum state shows a similar structure to the previous states, but these are special in the following sense. One of them is a scar state localized to the neighborhood of the periodic orbit while this orbit is already unstable. In the case of the other state, the current density is circulating in two rings in opposite direction. Thus, it is not consistent with the classical motion in the neighborhood of the periodic orbit.
description: 21 pages, 18 figures
The Ly-49 family of natural killer cell receptors
Creators: name: Brennan, John A.
Publisher: name: University of British Columbia
Year: 2009

description: This thesis investigates the nature of receptors involved in target cell recognition by natural killer (NK) cells. N K cells are thought to scan for self class I major histocompatibility complex (MHC) antigens, receive negative signals from interactions with these molecules, and lyse those cells which are unable to deliver protective signals. This system ensures that cells which have extinguished expression of class I M H C and evade T cell immunity are detected by N K cells. Ly- 49A was the first N K cell receptor found to receive inhibitory signals from class I MHC on opposing cells. Because Ly-49A is expressed by a subset of N K cells and recognizes only a fraction of class I molecules, additional subsets of N K cells are thought to exist which express receptors for class I molecules not recognized by Ly- 49A. Ly-49A is a type II transmembrane protein belonging to a group of related molecules encoded by a murine multigene family. The expression patterns and functional activities of other members of the Ly-49 gene family was the topic of this thesis. Ly-49A and Ly-49C expression was shown to identify distinct single positive, double positive, and double negative subsets of N K cells. Both Ly-49A and Ly-49C were found to mediate adhesion to class I MHC on a variety of cell lines. The specificity of these receptors was shown to be distinct but overlapping, with Ly-49C having a much broader range of class I ligands. All members of the Ly-49 family have an extracellular region homologous to the carbohydrate recognition domain of C-type lectins. The functional relevance of this domain was demonstrated by the inhibition of Ly-49C-mediated cell adhesion by both exogenous polysaccharides as well as by the modification of target cell surface carbohydrates. This suggests that the glycosylation of class I MHC may be a critical element in Ly-49 recognition. These combined results support the hypothesis that Ly-49 is a family of N K cell receptors with related, but distinct functions. Ly-49A and Ly-49C are both expressed by NK cells, but not by the same NK cells, and they both bind to class I MHC molecules, but not the same class I molecules. These receptors may therefore be responsible for the generation of an NK cell repertoire capable of recognizing cells which lose expression of single class I molecules.
Fusion of lipid bilayers induced by synthetic lipids and peptides
Creators: name: Bailey, Austin Lou
Publisher: name: University of British Columbia
Year: 2009

description: The fusion-inducing properties of three different synthetic lipid derivatives were investigated in model membranes. The results are discussed in terms of membrane destabilization caused by the formation of non-bilayer lipid structures following charge neutralization of the fusogenic components. First, studies on the fusion of large unilamellar vesicles (LUVs) composed of equimolar 1,2-dioleoyl-OT-phosphatidylethanolamine (DOPE) and the synthetic cationic lipid N,Ndimethyl- A/,Af-di-9-octadecenylammonium chloride (DODAC) with target membranes of varying lipid composition are presented. Membrane fusion was promoted by increased negative surface charge and, for liquid-crystalline lipids, by increased acyl chain unsaturation in target liposomes. However, the presence of disaturated phospholipids promoted fusion below the gel-to-liquid-crystalline transition temperature, an effect which was eliminated by the addition of cholesterol. It was also shown that DOPE/DODAC (1:1) LUVs fused with erythrocyte membranes and that this fusion was blocked by the presence of serum. Next, fusion of model lipid bilayers containing synthetic aminolipids and regulation of this fusion by inducing transbilayer asymmetry of these aminolipids via imposed pH gradients is discussed. Liposomes consisting of 5 mol% ±-l,2-dioleoyl-3-N,N-dimethylaminopropane (AL1) in egg phosphatidylcholine/DOPE/cholesterol (EPC/DOPE/Chol, 35:20:45) did not fuse at pH 4.0 or upon increasing the external pH of these vesicles to 7.5, which resulted in rapid transport of AL1 to the inner monolayer. However, dissipation of the imposed pH gradient led to redistribution of AL1 to the outer monolayer at pH 7.5 and caused liposomal fusion. The effect of varying the hydrocarbon structure of AL1 on the rate of fusion was demonstrated with five synthetic analogues. Finally, fusion of lipid bilayers induced at low pH by a synthetic lipopeptide (Lipo- AcE4K) derived from the fusion peptide of influenza hemagglutinin is discussed. The secondary structure of Lipo-AcE4K was not affected by pH, but increased membrane penetration was indicated by tryptophan fluorescence. Lipo-AcE4K formed stable liposomes with l-palmitoyl-2-oleoyl-jn-phosphatidylcholine (POPC) and EPC/Chol (55:45) at pH 7.5 but induced fusion of these vesicles at mildly acidic pH. Membrane destabilization increased with increasing lipopeptide concentrations, decreasing pH, inclusion of cholesterol, and incorporation of lipopeptide into the liposomal inner monolayer. Fusion of liposomes bearing Lipo-AcE4K with erythrocyte membranes was also demonstrated.
Neumann problem on a torus
Creators: name: Ashtab, Z.
name: Morais, J.
name: Porter, R. M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 31B20 (Primary) 35J05 35J25 65N21 (Secondary)

description: We consider the Dirichlet-to-Neumann mapping and the Neumann problem for the Laplace operator on a torus, given in toroidal coordinates. The Dirichlet-to-Neumann mapping is expressed with respect to series expansions in toroidal harmonics and thereby reduced to algebraic manipulations on the coefficients. A method for computing the numerical solutions of the corresponding Neumann problem is presented, and numerical illustrations are provided. We combine the results for interior and exterior domains to solve the Neumann problem for a toroidal shell.
description: 21 pages, 3 figures, 3 tables
A new beamline for positron annihilation lifetime spectroscopy
Creators: name: Weed, Ryan Winslow
Publisher: name: The Australian National University
Year: 2018
Subjects: subject: QC793.5.P625 W44 2011
subject: Positron annihilation
subject: Electron spectroscopy

description: The major aspect of this research is the development of a variable-energy PALS beamline based on a Surko-type buffer gas positron trap, the first of its kind in the world. A significant amount of work has gone into optimization of the timing and intensity characteristics of positron pulse. Successful implantation of 'Mills ideal function' bunching method has led to positron pulses of 800ps, allowing depth selective studies across a range of defect sizes, from point defects with lifetimes as low as 200ps, to large voids (~10 nm) resulting in lifetimes >50 ns. In addition to experimental development aspects, the materials investigations presented here focus on defects in semiconductor materials produced by ion implantation and focused laser pulses. The PALS beamline was used to demonstrate the suppression of void formation due to the Si/Si0{u2082} interface in Helium ion implanted silicon-on-insulator (SOl). Vacancy clustering in self-ion-implanted Germanium has also been studied using both the PALS beamline and Rutherford Backscattering Spectroscopy (RBS). The evolution of the ion implantation induced damage during annealing was investigated with results indicating that vacancy cluster occurs in both crystalline and amorphous states. In gallium antimonide, positrons were used to probe void formation in swift heavy ion implantation at various fluences, leading to a better understanding of the transition between isolated channels and heavily porous states as the ion implantation fluence increases. Finally, the positron beamline was used to study the large voids produced by focused femtosecond laser pulses in fused silica, where lifetimes associated with o-Ps annihilation in 0{u2082} filled voids were observed. By combining the PALS measurements with TEM images, the residual 0{u2082} pressure inside the voids after isochronal annealing was estimated and compared with expected values from Monte-Carlo simulations.
NuSTAR Non-detection of a Faint Active Galactic Nucleus in an Ultraluminous IR Galaxy with Kpc-scale Fast Wind
Creators: name: Chen, Xiaoyang
name: Ichikawa, Kohei
name: Noda, Hirofumi
name: Kawamuro, Taiki
name: Kawaguchi, Toshihiro
name: Toba, Yoshiki
name: Akiyama, Masayuki
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Large-scale outflows are generally considered as a possible evidence that active galactic nuclei (AGNs) can severely affect their host galaxies. Recently an ultraluminous IR galaxy (ULIRG) at $z=0.49$, AKARI J0916248+073034, was found to have a galaxy-scale [OIII] $λ$5007 outflow with one of the highest energy-ejection rates at $z<1.6$. However, the central AGN activity estimated from its torus mid-IR (MIR) radiation is weak relative to the luminous [OIII] emission. In this work we report the first NuSTAR hard X-ray follow-up of this ULIRG to constrain its current AGN luminosity. The intrinsic 2-10 keV luminosity shows a 90% upper-limit of $3.0\times10^{43}$ erg s$^{-1}$ assuming Compton-thick obscuration ($N_{\rm H}=1.5\times10^{24}$ cm$^{-2}$), which is only 3.6% of the luminosity expected from the extinction corrected [OIII] luminosity. With the NuSTAR observation, we succeed to identify that this ULIRG has a most extreme case of X-ray deficit among local ULIRGs. A possible scenario to explain the drastic declining in both of the corona (X-ray) and torus (MIR) is that the primary radiation from the AGN accretion disk is currently in a fading status, as a consequence of a powerful nuclear wind suggested by its powerful ionized outflow in the galaxy scale.
description: 8 pages, 2 figures, accepted for publication in The Astrophysical Journal Letters
Field-Effect Josephson Diode via Asymmetric Spin-Momentum-Locking States
Creators: name: Fu, Pei-Hao
name: Xu, Yong
name: Yang, Shengyuan A.
name: Lee, Ching Hua
name: Ang, Yee Sin
name: Liu, Jun-Feng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Recent breakthroughs in Josephson diodes dangle the possibility of extending conventional non-reciprocal electronics into the realm of superconductivity. While a strong magnetic field is recognized for enhancing diode efficiency, it concurrently poses a risk of undermining the essential superconductivity required for non-dissipative devices. To circumvent the need for magnetic-based tuning, we propose a field-effect Josephson diode based on the electrostatic gate control of finite momentum Cooper pairs in asymmetric spin-momentum-locking states. We propose two possible implementations of our gate-controlled mechanism: (i) a topological field-effect Josephson diode in time-reversal-broken quantum spin Hall insulators; and (ii) semiconductor-based field-effect Josephson diodes attainable in current experimental setups involving a Zeeman field and spin-orbit coupling. Notably, the diode efficiency is highly enhanced in the topological field-effect Josephson diode because the current carried by the asymmetric helical edge states is topologically protected and can be tuned by local gates. In the proposed Josephson diode, the combination of gates and asymmetric spin-momentum-locking nature is equivalent to that of a magnetic field, thus providing an alternative electrical operation in designing nonreciprocal superconducting devices.
description: 24 pages, 14 figures
Supplementary document for Laser-cavity locking at the 10^{-7} instability scale utilizing beam ellipticity - 6762964.pdf
Creators: name: Hosten, Onur
name: Diorico, Fritz
name: Zhutov, Artem
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: Experimental details and additional discussion
Semisimple elements and the little Weyl group of real semisimple $Z_m$-graded Lie algebras
Creators: name: de Graaf, Willem
name: Lê, Hông Vân
Publisher: name: arXiv
Year: 2022
Subjects: subject: Representation Theory (math.RT)
subject: Differential Geometry (math.DG)
subject: Group Theory (math.GR)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 11E72, 20G05, 20G20

description: We consider the semisimple orbits of a Vinberg $θ$-representation. First we take the complex numbers as base field. By a case by case analysis we show a technical result stating the equality of two sets of hyperplanes, one corresponding to the restricted roots of a Cartan subspace, the other corresponding to the complex reflections in the (little) Weyl group. The semisimple orbits have representatives in a finite number of sets that correspond to reflection subgroups of the (little) Weyl group. One of the consequences of our technical result is that the elements in a fixed such set all have the same stabilizer in the acting group. Secondly we study what happens when the base field is the real numbers. We look at Cartan subspaces and show that the real Cartan subspaces can be classified by the first Galois cohomology set of the normalizer of a fixed real Cartan subspace. In the real case the orbits can be classified using Galois cohomology. However, in order for that to work we need to know which orbits have a real representative. We show a theorem that characterizes the orbits of homogeneous semisimple elements that do have such a real representative. This closely follows and generalizes a theorem from \cite{bgl}.
description: Revised version, 18 p
Electric charge renormalization to all orders
Creators: name: Dittmaier, Stefan
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The electric charge renormalization constant, as defined in the Thomson limit, is expressed in terms of self-energies of the photon-Z-boson system in an arbitrary R_ξ-gauge to all perturbative orders. The derivation as carried out in the Standard Model holds in all spontaneously broken gauge theories with the SU(2)_w \times U(1)_Y gauge group in the electroweak sector and is based on the application of charge universality to a fake fermion with infinitesimal weak hypercharge and vanishing weak isospin, which effectively decouples from all other particles. Charge universality, for instance, follows from the known universal form of the charge renormalization constant as derived within the background-field formalism. Finally, we have generalized the described procedure to gauge theories with gauge group U(1)_Y \times G with any Lie group G, only assuming that electromagnetic gauge symmetry is unbroken and mixes with U(1)_Y transformations in a non-trivial way.
description: 23 pages pdflatex, 2 figures, one reference added
Computational study of hypersonic shock wave turbulent boundary layer interaction on a porous wall
Creators: name: Patel, Raj
Publisher: name: No Publisher Supplied
Year: 2023

description: The shock wave turbulent boundary layer interaction (STBLI) phenomenon has been actively researched in the last five decades. These interactions usually occur in hypersonic vehicles, where the shock generated from control surfaces interacts with the attached boundary layer. Designing hypersonic vehicles requires a tool to predict the aerothermodynamic loads, which can be done by performing Computation Fluid Dynamics (CFD) simulations. Reynolds-Averaged Navier-Stokes (RANS) simulations have been extensively used to predict the turbulent flow behavior, which utilizes the turbulence model to solve the nonlinear RANS equations. This computational study comprises two-dimensional RANS simulations of the interaction of incident shock waves with a turbulent boundary layer at Mach 6 in the presence of surface blowing. A couple of cases were computed, one without the surface blowing and the other with the presence of surface blowing. The computed results of surface heat transfer and pressure are compared with the experimental study done at the Calspan University at Buffalo Research Center (CUBRC). For this thesis, the k − ω and k − ϵ turbulence models were utilized to predict the surface heat transfer and pressure. The results show that both models predict the peak pressure values with experimental uncertainty in both cases. The k − ϵ model predicts the peak heat transfer with reasonable error in both cases. The k − ω model underpredicted the peak heat transfer in the case without surface blowing and gave anomalous results in predicting surface heat transfer over a porous plate. However, both turbulence models have proven to be poor predictors in the STBLI region.
$Λ_c N$ interaction in leading order covariant chiral effective field theory
Creators: name: Song, Jing
name: Xiao, Yang
name: Liu, Zhi-Wei
name: Wang, Chun-Xuan
name: Li, Kai-Wen
name: Geng, Li-Sheng
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the $Λ_c N$ interaction in the covariant chiral effective field theory (ChEFT) at leading order. All the relevant low-energy constants are determined by fitting to the lattice QCD simulations from the HAL QCD Collaboration. Extrapolating the results to the physical point, we show that the $Λ_c N$ interaction is weakly attractive in the $^1S_0$ channel, but in the $^3S_1$ channel, it is only attractive at extremely low energies and soon turns repulsive for larger laboratory energy. Furthermore, we show that the neglect of the $^3S_1-{}^3D_1$ coupling provided by the leading order covariant ChEFT would result in an attractive interaction in the $^3S_1$ channel at the physical point, which coincides with the previous non-relatistic ChEFT study. As a byproduct, we predict the $^3D_1$ phase shifts and the mixing angel $\varepsilon_1$, which can be checked by future lattice QCD simulations. In addition, we compare the $Λ_c N$ interaction with the $ΛN$ and $NN$ interactions to study how the baryon-nucleon ($BN$) interactions evolve as a function of the baryon mass with the replacement of a light quark by a strange or charm quark in the baryon ($B$).
description: 10 pages, 7 figures
An XMM-Newton Observation of the Massive Edge-on Sb Galaxy NGC 2613
Creators: name: Li, Zhiyuan
name: Wang, Q. Daniel
name: Irwin, Judith A.
name: Chaves, Tara
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present an XMM-Newton observation of the massive edge-on Sb galaxy NGC 2613. We discover that this galaxy contains a deeply embedded active nucleus with a 0.3-10 keV luminosity of 3.3x10^40 erg/s and a line-of-sight absorption column of 1.2x10^23 cm^-2. Within the 25 mag/arcsec^2 optical B-band isophote of the galaxy, we detect an additional 4 sources with an accumulated luminosity of 4.3x10^39 erg/s. The bulk of the unresolved X-ray emission spatially follows the near-infrared (NIR) K-band surface brightness distribution; the luminosity ratio L_X/L_K ~ 8x10^-4 is consistent with that inferred from galactic discrete sources. This X-ray-NIR association and the compatibility of the X-ray spectral fit with the expected spectrum of a population of discrete sources suggest that low-mass X-ray binaries (LMXBs) are the most likely emitters of the unresolved emission in the disk region. The remaining unresolved emission is primarily due to extraplanar hot gas. The luminosity of this gas is at least a factor of 10 less than that predicted by recent simulations of intergalactic gas accretion by such a massive galaxy with a circular rotation speed V_c ~ 304 km/s^2 (Toft et al. 2002). Instead, we find that the extraplanar hot gas most likely represents discrete extensions away from the disk, including two ``bubble-like'' features on either side of the nucleus. These extensions appear to correlate with radio continuum emission and, energetically, can be easily explained by outflows from the galactic disk.
description: 17 pages, accepted by MNRAS
The Russian invasion of Ukraine selectively depolarized the Finnish NATO discussion
Creators: name: Xia, Yan
name: Gronow, Antti
name: Malkamäki, Arttu
name: Ylä-Anttila, Tuomas
name: Keller, Barbara
name: Kivelä, Mikko
Publisher: name: arXiv
Year: 2022
Subjects: subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: The Russian invasion of Ukraine in 2022 dramatically reshaped the European security landscape. In Finland, public opinion on NATO had long been polarized along the left-right partisan axis, but the invasion led to a rapid convergence of the opinion toward joining NATO. We investigate whether and how this depolarization took place among polarized actors on Finnish Twitter. By analyzing retweeting patterns, we find three separated user groups before the invasion: a pro-NATO, a left-wing anti-NATO, and a conspiracy-charged anti-NATO group. After the invasion, the left-wing anti-NATO group members broke out of their retweeting bubble and connected with the pro-NATO group despite their difference in partisanship, while the conspiracy-charged anti-NATO group mostly remained a separate cluster. Our content analysis reveals that the left-wing anti-NATO group and the pro-NATO group were bridged by a shared condemnation of Russia's actions and shared democratic norms, while the other anti-NATO group, mainly built around conspiracy theories and disinformation, consistently demonstrated a clear anti-NATO attitude. We show that an external threat can bridge partisan divides in issues linked to the threat, but bubbles upheld by conspiracy theories and disinformation may persist even under dramatic external threats.
High-resolution laser spectroscopy of $^{27-32}$Al
Creators: name: Heylen, H.
name: Devlin, C. S.
name: Gins, W.
name: Bissell, M. L.
name: Blaum, K.
name: Cheal, B.
name: Filippin, L.
name: Ruiz, R. F. Garcia
name: Godefroid, M.
name: Gorges, C.
name: Holt, J. D.
name: Kanellakopoulos, A.
name: Kaufmann, S.
name: Koszorús, Á.
name: König, K.
name: Malbrunot-Ettanauer, S.
name: Miyagi, T.
name: Neugart, R.
name: Neyens, G.
name: Nörtershäuser, W.
name: Sánchez, R.
name: Sommer, F.
name: Rodríguez, L. V.
name: Xie, L.
name: Xu, Z. Y.
name: Yang, X. F.
name: Yordanov, D. T.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Hyperfine spectra of $^\text{27-32}$Al ($Z=13$) have been measured at the ISOLDE-CERN facility via collinear laser spectroscopy using the $3s^23p\ ^2\text{P}^\text{o} _{3/2}\rightarrow 3s^24s\ ^2\text{S}_{1/2}$ atomic transition. For the first time, mean-square charge radii of radioactive aluminum isotopes have been determined alongside the previously unknown magnetic dipole moment of $^{29}$Al and electric quadrupole moments of $^{29,30}$Al. A potentially reduced charge radius at $N=19$ may suggest an effect of the $N=20$ shell closure, which is visible in the Al chain, contrary to other isotopic chains in the $sd$ shell. The experimental results are compared to theoretical calculations in the framework of the valence-space in-medium similarity renormalization group using multiple sets of two and three-nucleon forces from chiral effective field theory. While the trend of experimental magnetic dipole and electric quadrupole moments is well reproduced, the absolute values are underestimated by theory, consistent with earlier studies. Moreover, both the scale and trend of the charge radii appear to be very sensitive to the chosen interaction.
In-plane thermal conductivity of large single crystals of Sm-substituted (Y$_{1-x}$Sm$_{x}$)Ba$_{2}$Cu$_{3}$O$_{7-δ}$
Creators: name: Matsukawa, M.
name: Noto, H.
name: Furusawa, H.
name: Yao, X.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We have investigated the in-plane thermal conductivity $κ_{ab}(T,H)$ of large single crystals of optimally oxygen-doped (Y$_{1-x}$,Sm$_{x}$)Ba$_{2}$Cu$_{3}$O$_{7-δ}$ ($x$=0, 0.1, 0.2 and 1.0) and YBa$_{2}$(Cu$_{1-y}$Zn$_{y}$)$_{3}$O$_{7-δ}$($y$=0.0071) as functions of temperature and magnetic field (along the c axis). For comparison, the temperature dependence of $κ_{ab}$ for as-grown crystals with the corresponding compositions are presented. The nonlinear field dependence of $κ_{ab}$ for all crystals was observed at relatively low fields near a half of $T_{c}$. We make fits of the $κ(H)$ data to an electron contribution model, providing both the mean free path of quasiparticles $\ell_{0}$ and the electronic thermal conductivity $κ_{e}$, in the absence of field. The local lattice distortion due to the Sm substitution for Y suppresses both the phonon and electron contributions. On the other hand, the light Zn doping into the CuO $_{2}$ planes affects solely the electron component below $T_{c}$, resulting in a substantial decrease in $\ell_{0}$ .
description: 7 pages,4 figures,1 table
Torsion homology growth and cheap rebuilding of inner-amenable groups
Creators: name: Uschold, Matthias
Publisher: name: arXiv
Year: 2022
Subjects: subject: Group Theory (math.GR)
subject: Algebraic Topology (math.AT)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57M07, 20E26, 43A07

description: We prove that virtually torsion-free, residually finite groups that are inner-amenable and non-amenable have the cheap 1-rebuilding property, a notion recently introduced by Abért, Bergeron, Frączyk and Gaboriau. As a consequence, the first $\ell^2$-Betti number with arbitrary field coefficients and log-torsion in degree 1 vanish for these groups. This extends results previously known for amenable groups to inner-amenable groups. We use a structure theorem of Tucker-Drob for inner-amenable groups showing the existence of a chain of q-normal subgroups.
description: 17 pages; v2: added missing hypothesis in Cor. 6.8, added Lemma 2.2 and Examples 2.4, 2.5; v3: replaced 'torsion-free' by 'virtually torsion-free'; final version, to appear in Groups, Geometry and Dynamics
Parity Violation and Chiral Oscillation of Cosmological Relic Neutrinos
Creators: name: Ge, Shao-Feng
name: Pasquini, Pedro
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The conventional derivation of neutrino oscillation treats neutrino mass eigenstate as plane wave with an overall evolution phase. Nevertheless, due to the intrinsic parity-violating nature of weak interactions, only the left-chiral neutrino can be produced as initial condition. On the other hand, the neutrino mass term connects the left-chiral component to the right-chiral one and unavoidably leads to generation of the later through oscillation. This chiral oscillation has significant consequences on the detection of the cosmological relic neutrinos. The event rate is reduced by a factor of 2 than the conventional prediction.
description: 5 pages, 1 figure
Essays in Microeconomics
Creators: name: McCracken, Scott T
Publisher: name: The Australian National University
Year: 2018
Subjects: subject: HF5823.M33 2011
subject: Advertising Economic aspects.
subject: Microeconomics

description: The first paper considers a two-stage duopoly model of costless advertising: in the first stage each firm simultaneously chooses the accuracy of signals informing consumers about how much they value its product; in the second stage firms compete in prices. We find that when the distributions of consumers' valuations for each product are identical, independent and symmetric, and the market is covered for any combination of first-stage choices, the subgame-perfect equilibrium involves both firms perfectly informing consumers in order to increase ex post differentiation and reduce price competition. When the market is not covered for all first-stage choices, one firm may no longer choose perfectly accurate signals in equilibrium, as an increase in the informativeness of a signal further lowers the ex post valuation of those consumers indifferent between purchasing or not, causing them to drop out of the market. Numerical results indicate that if the symmetric distribution of valuations is sufficiently peaked, then both firms inform perfectly; otherwise one firm informs perfectly and the other chooses the highest level of informativeness such that the market is covered. The second paper analyses the choice of commodity tax base when countries set their taxes non-cooperatively in a two-country symmetric reciprocal dumping model of homogeneous goods trade with trade costs and horizontal FDI. We show that under our assumption of linear demand, the consumption base (destination principle) weakly dominates the production base (origin principle) for a large range of plant fixed costs. When integration is complete, the destination principle dominates the origin principle for all levels of plant fixed costs below which FDI occurs under the origin principle. The third paper considers a static Cournot duopoly game with incomplete information regarding firms' marginal costs. Each player knows her own unit cost (low or high), but is uncertain of her opponent's cost. Posterior beliefs are consistent if they admit a common prior. Action symmetry holds if total output does not depend on which player has low or high cost. A player has independent beliefs if her posteriors are the same regardless of her type. Beliefs are essentially the same if each player of each type has the same posteriors about the type of the other player, or if they would be the same after a relabelling of types with low switched with high. We prove that action symmetry and consistent beliefs hold simultaneously if and only if beliefs are essentially the same or both players have independent beliefs. A player has independent beliefs and beliefs are consistent if and only if her opponent has independent beliefs and actions are symmetric. Finally, we investigate the degree to which small departures from each of these properties affects these results.
Asteroseismology of the DAV star R808
Creators: name: Chen, Yanhui
name: Shu, Hong
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The DAV star R808 was observed by 13 different telescopes for more than 170 hours in April 2008 on the WET run XCOV26. 25 independent pulsation frequencies were identified by this data set. We assumed 19 $m$ = 0 modes and performed an asteroseismological study on those 19 modes. We evolve grids of DAV star models by \texttt{WDEC} adopting the element diffusion scheme with pure and screened Coulomb potential effect. The core compositions are from white dwarf models evolved by \texttt{MESA}, which are thermal nuclear burning results. Our best fitting model is from the screened Coulomb potential scenario, which has parameters of log($M_{\rm He}/M_{\rm *}$) = -2.4, log($M_{\rm H}/M_{\rm *}$) = -5.2, $T_{\rm eff}$ = 11100\,K, $M_{\rm *}$ = 0.710\,$M_{\odot}$, log$g$ = 8.194, and $σ_{RMS}$ = 2.86\,s. The value of $σ_{RMS}$ is the smallest among the four existing asteroseismological work. The average period spacing is 46.299\,s for $l$ = 1 modes and 25.647\,s for $l$ = 2 modes. The other 6 observed modes can be fitted by $m$ $\neq$ 0 components of some modes for our best fitting model. Fitting the 25 observed modes, we obtain a $σ_{RMS}$ value of 2.59\,s. Considering the period spacings, we also assume, that at least in one case, we detect an $l$ = 2 trapped mode.
description: 8 pages, 5 figures, 6 tables, accepted by MNRAS on November 13
Energy of the Taub Cosmological Solution
Creators: name: Halpern, Paul
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We calculate the total energy of Taub's 1951 exact solution for a Bianchi type IX geometry using several different energy-localization procedures, including the prescriptions of Einstein, Papapetrou, Landau-Lifshitz and Moller. We compare these results to those for other anisotropic geometries, and comment on their relationship to Rosen's conjecture about the total energy of the universe.
description: 10 pages; added references and corrected a typo
A magnetotelluric instrument for probing the interiors of Europa and other worlds
Creators: name: Grimm, Robert
name: Nguyen, Ton
name: Persyn, Steve
name: Phillips, Mark
name: Stillman, David
name: Taylor, Tim
name: Delory, Greg
name: Turin, Paul
name: Espley, Jared
name: Gruesbeck, Jacob
name: Sheppard, Dave
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: One objective of a lander mission to Jupiter's icy moon Europa is to detect liquid water within 30 km as well as characterizing the subsurface ocean. In order to satisfy this objective, water within the ice shell must also be identified. Inductive electromagnetic (EM) methods are optimal for water detection on Europa because even a small fraction of dissolved salts will make water orders of magnitude more electrically conductive than the ice shell. Compared to induction studies by the Galileo spacecraft, measurements of higher-frequency ambient EM fields are necessary to resolve the shallower depths of intrashell water. Although these fields have been mostly characterized by prior missions, their unknown source structures and plasma properties do not allow EM sounding using a single surface magnetometer or the orbit-to-surface magnetic transfer function, respectively. Instead, broadband EM sounding can be accomplished from a single surface station using the magnetotelluric (MT) method, which measures horizontal electric fields as well as the three-component magnetic field. We have developed a prototype Europa Magnetotelluric Sounder (EMS) to meet the measurement requirements in the relevant thermal, vacuum, and radiation environment. EMS comprises central electronics, a fluxgate magnetometer on a mast, and three ballistically deployed electrodes to measure differences in surface electric potential. In this paper, we describe EMS development and testing as well as providing supporting information on the concept of operations and calculations on water detectability. EMS can uniquely determine the occurrence of intrashell water on Europa, providing important constraints on habitability.