cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Variational principles of nonlinear magnetoelastostatics and their correspondences
Creators: name: Sharma, Basant Lal
name: Saxena, Prashant
Publisher: name: arXiv
Year: 2020
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: We derive the equations of nonlinear magnetoelastostatics using several variational formulations involving the mechanical deformation and an independent field representing the magnetic component. An equivalence is also discussed, modulo certain boundary integrals or constant integrals, between these formulations using the Legendre transform and properties of Maxwell's equations. The second variation based bifurcation equations are stated for the incremental fields as well for all five variational principles. When the total potential energy is defined over the infinite space surrounding the body, we find that the inclusion of certain term in the energy principle, associated with the externally applied magnetic field, leads to slight changes in the Maxwell stress tensor and associated boundary conditions. On the other hand, when the energy contained in the magnetic field is restricted to finite volumes, we find that there is a correspondence between the discussed formulations and associated expressions of physical entities. In view of a diverse set of boundary data and nature of externally applied controls in the problems studied in the literature, along with a equally diverse list of variational principles employed in modeling, our analysis emphasizes care in the choice of variational principle and unknown fields so that consistency with other choices is also satisfied.
description: arXiv admin note: text overlap with arXiv:1911.07090
The archaeological record of the Galatians in Anatolia, 278-63 B.C.
Creators: name: Nixon, Lucia Frances
Publisher: name: University of British Columbia
Year: 2010

description: The Galatians were a group of Celts who arrived in Anatolia from the west in 278 B.C. According to the historical sources, they earned their livelihood by plundering and by serving as mercenaries in the eastern Mediterranean. Ancient authors state that the Galatians constituted a definite threat to the cities of western Asia Minor before they were settled in central Anatolia. Galatia became a Roman province in 25 B.C.; by that time, the Galatians had been thoroughly absorbed by the local population. The purpose of this paper is to see what archaeological evidence exists for the presence of the Galatians in Anatolia during the pre-provincial period, and how that evidence can be obtained. Three types of evidence are examined: pottery, burials and grave goods, and forts and settlements. Galatian pottery is still a controversial subject requiring more study and excavation. Only one burial site, Karalar, can definitely be identified by an inscription in Greek. The evidence from this site suggests that the Galatians adopted various types of Hellenistic tomb architecture and that they placed a fundamentally Hellenistic selection of grave goods within their tombs and graves. Galatian burials are therefore hard to distinguish from ordinary Hellenistic burials in Anatolia. Three tores and three fibulae from burials at Karalar, Bolu, and Bogazk5y are probably Celtic; that there are so few of them suggests that they had been imported from Europe, and that the Galatians were not themselves metalworkers in the Celtic tradition. Such objects cannot be used as the sole means of identifying Galatian burials. The situation is little better for forts and settlements. Some have been identified because they were inhabited by literate people before or after the arrival of the Galatians; others have been suggested because of the likelihood of their location. Settlement seems to be more dense west of the Halys but more surveys and excavation are necessary to test this emerging pattern. So far, the pre-provincial period has yielded little in the way of archaeological evidence for the presence of the Galatians in Anatolia, despite the solid background provided by the historical sources. The Galatians had little connection with the European Celts and adapted easily to local customs. This capacity for adaptation makes it difficult to say what is Galatian and what is Anatolian Hellenistic. Only further work in the field can remedy this state of affairs.
Photoemission kinks and phonons in cuprates
Creators: name: Reznik, D.
name: Sangiovanni, G.
name: Gunnarssonii, O.
name: Devereaux, T. P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: One of the possible mechanisms of high Tc superconductivity is Cooper pairing with the help of bosons, which change the slope of the electronic dispersion as observed by photoemission. Giustino et al. calculated that in the high temperature superconductor La1.85Sr0.15CuO4 crystal lattice vibrations (phonons) should have a negligible effect on photoemission spectra and concluded that phonons do not play an important role. We show that the calculations employed by Giustino et al. fail to reproduce huge influence of electron-phonon coupling on important phonons observed in experiments. Thus one would expect these calculations to similarly fail in explaining the role of electron-phonon coupling for the electronic dispersion.
description: To appear in Nature as a Brief Communiction Arising
Protected Long-Distance Guiding of Hypersound Underneath a Nano-Corrugated Surface
Creators: name: Yaremkevich, Dmytro D.
name: Scherbakov, Alexey V.
name: Kukhtaruk, Serhii M.
name: Linnik, Tetiana L.
name: Khokhlov, Nikolay E.
name: Godejohann, Felix
name: Dyatlova, Olga A.
name: Nadzeyka, Achim
name: Pattnaik, Debi P.
name: Wang, Mu
name: Roy, Syamashree
name: Campion, Richard P.
name: Rushforth, Andrew W.
name: Gusev, Vitalyi E.
name: Akimov, Andrey V.
name: Bayer, Manfred
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Within a new paradigm for communications on the nanoscale, high-frequency surface acoustic waves are becoming effective data carrier and encoder. On-chip communications require acoustic wave propagation along nano-corrugated surfaces which strongly scatter traditional Rayleigh waves. Here we propose the delivery of information using subsurface acoustic waves with hypersound frequencies ~20 GHz, which is a nanoscale analogue of subsurface sound waves in the ocean. A bunch of subsurface hypersound modes is generated by pulsed optical excitation in a multilayer semiconductor structure with a metallic nanograting on top. The guided hypersound modes propagate coherently beneath the nanograting, retaining the surface imprinted information, on a distance of more than 50 μm which essentially exceeds the propagation length of Rayleigh waves. The concept is suitable for interfacing single photon emitters, such as buried quantum dots, carrying coherent spin excitations in magnonic devices, and encoding the signals for optical communications at the nanoscale.
description: 18 pages (inc. references), 5 figures
Magnon transport in $\mathrm{\mathbf{Y_3Fe_5O_{12}}}$/Pt nanostructures with reduced effective magnetization
Creators: name: Gückelhorn, Janine
name: Wimmer, Tobias
name: Müller, Manuel
name: Geprägs, Stephan
name: Hübl, Hans
name: Gross, Rudolf
name: Althammer, Matthias
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: For applications making use of magnonic spin currents damping effects, which decrease the spin conductivity, have to be minimized. We here investigate the magnon transport in an yttrium iron garnet thin film with strongly reduced effective magnetization. We show that in a three-terminal device the effective magnon conductivity can be increased by a factor of up to six by a current applied to a modulator electrode, which generates damping compensation above a threshold current. Moreover, we find a linear dependence of this threshold current on the applied magnetic field. We can explain this behavior by the reduced effective magnetization and the associated nearly circular magnetization precession.
Explaining Deep Reinforcement Learning Agents In The Atari Domain through a Surrogate Model
Creators: name: Sieusahai, Alexander
name: Guzdial, Matthew
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: One major barrier to applications of deep Reinforcement Learning (RL) both inside and outside of games is the lack of explainability. In this paper, we describe a lightweight and effective method to derive explanations for deep RL agents, which we evaluate in the Atari domain. Our method relies on a transformation of the pixel-based input of the RL agent to an interpretable, percept-like input representation. We then train a surrogate model, which is itself interpretable, to replicate the behavior of the target, deep RL agent. Our experiments demonstrate that we can learn an effective surrogate that accurately approximates the underlying decision making of a target agent on a suite of Atari games.
description: 9 pages, 3 figures, AIIDE 2021
PSR J1410-6132: A young, energetic pulsar associated with EGRET source 3EG J1410-6147
Creators: name: O'Brien, J. T.
name: Johnston, S.
name: Kramer, M.
name: Lyne, A. G.
name: Bailes, M.
name: Possenti, A.
name: Burgay, M.
name: Lorimer, D. R.
name: McLaughlin, M. A.
name: Hobbs, G.
name: Parent, D.
name: Guillemot, L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the discovery of PSR J1410-6132, a 50-ms pulsar found during a high-frequency survey of the Galactic plane, using a 7-beam 6.3-GHz receiver on the 64-m Parkes radio telescope. The pulsar lies within the error box of the unidentified EGRET source 3EG J1410-6147, has a characteristic age of 26 kyr and a spin-down energy of 10^37 erg s^-1. It has a very high dispersion measure of 960+/-10 cm^-3 pc and the largest rotation measure of any pulsar, RM=+2400 +/- 30 rad m^-2. The pulsar is very scatter-broadened at frequencies of 1.4 GHz and below, making pulsed emission almost impossible to detect. Assuming a distance of 15 kpc, the pulsar's spin-down energy and a gamma-ray efficiency factor of ~10 per cent is sufficient to power the gamma-ray source. We therefore believe we have identified the nature of 3EG J1410-6147. This new discovery suggests that deep targeted high-frequency surveys of inner-galaxy EGRET sources could uncover further young, energetic pulsars.
description: Accepted for publication in MNRAS
Antiracist Work in Mathematics Classrooms
Creators: name: Battey, Dan
name: Coleman, Monique A.
Publisher: name: Journal of Urban Mathematics Education
Year: 2021

description: Uprisings against police violence have placed the institution of policing front and center in conversations about societal change. In our work with activists, we have engaged in collecting and analyzing public records data to inform community organizing for change. In this editorial we discuss how to obtain, interpret, and analyze public records on policing as a way to support educators and youth to investigate policing in their own communities. Specifically, we discuss how to embed this work in Youth Participatory Action Research as a way to respond to youth concerns about their community in a way that leads to action. Briefly, we illustrate how this occurred in one classroom in an urban school where students made meaningful connections between their analyses of local police data and their personal experiences with racially disparate policing, which led some students to become change agents in their communities. This work demonstrates the simultaneous cultivation of youth engagement with mathematics and activism.
description: Journal of Urban Mathematics Education, Vol. 14 No. 1B (2021): Special Issue – Mathematics for Social Justice
A quantum metric on the Cantor Space
Creators: name: Aguilar, Konrad
name: López, Alejandra
Publisher: name: arXiv
Year: 2019
Subjects: subject: Operator Algebras (math.OA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 46L89, 46L30, 58B34

description: The first author and Latrémolière had introduced a quantum metric (in the sense of Rieffel) on the algebra of complex-valued continuous functions on the Cantor space. We show that this quantum metric is distinct from the quantum metric induced by a classical metric on the Cantor space. We accomplish this by showing that the seminorms induced by each quantum metric (Lip-norms) are distinct on a dense subalgebra of the algebra of complex-valued continuous functions on the Cantor space. In the process, we develop formulas for each Lip-norm on this dense subalgebra and show these Lip-norms agree on a Hamel basis of this subalgebra. Then, we use these formulas to find families of elements for which these Lip-norms disagree.
description: 22 pages
Multiple Parton Scattering in Nuclei: Modified DGLAP Evolution for Fragmentation Functions
Creators: name: Deng, Wei-tian
name: Wang, Xin-Nian
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Within the framework of generalized factorization of higher-twist contributions to semi-inclusive cross section of deeply inelastic scattering off a large nucleus, multiple parton scattering leads to an effective medium-modified fragmentation function and the corresponding medium-modified DGLAP evolution equations. We extend the study to include gluon multiple scattering and induced quark-antiquark production via gluon fusion . We numerically solve these medium-modified DGLAP (mDGLAP) evolution equations and study the scale ($Q^2$), energy ($E$), length ($L$) and jet transport parameter ($\hat q$) dependence of the modified fragmentation functions for a jet propagating in a uniform medium with finite length (a "brick" problem). We also discuss the concept of parton energy loss within such mDGLAP evolution equations and its connection to the modified fragmentation functions. With a realistic Wood-Saxon nuclear geometry, we calculate the modified fragmentation functions and compare to experimental data of DIS off large nuclei. The extracted jet transport parameter at the center of a large nucleus is found to be $\hat q_{0}=0.024\pm0.008$ GeV$^{2}$/fm.
description: 21 pages in RevTex with 19 figures (some contents are added in this version)
Maximality of Laplacian Algebras, with Applications to Invariant Theory
Creators: name: Mendes, Ricardo A. E.
name: Radeschi, Marco
Publisher: name: arXiv
Year: 2020
Subjects: subject: Representation Theory (math.RT)
subject: Commutative Algebra (math.AC)
subject: Differential Geometry (math.DG)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 13A50, 53C12

description: We show Laplacian algebras are maximal, and give applications to the Classical Invariant Theory of real orthogonal representations of compact groups, including: The solution of the Inverse Invariant Theory problem for finite groups. An if-and-only-if criterion for when a separating set is a generating set. And the introduction of a class of generalized polarizations which, in a certain class of representations (including all representations of finite groups), always generates the algebra of invariants of their diagonal representations.
description: 19 pages; Title, abstract, and order of results in the Introduction changed in order to emphasize the main result (maximality of Laplacian algebras); other small changes in exposition in various places; no changes in the actual results. Version accepted for publication by AMPA
Ideal-theoretic Explanation of Capacity-achieving Decoding
Creators: name: Bhandari, Siddharth
name: Harsha, Prahladh
name: Kumar, Mrinal
name: Sudan, Madhu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In this work, we present an abstract framework for some algebraic error-correcting codes with the aim of capturing codes that are list-decodable to capacity, along with their decoding algorithm. In the polynomial ideal framework, a code is specified by some ideals in a polynomial ring, messages are polynomials and their encoding is the residue modulo the ideals. We present an alternate way of viewing this class of codes in terms of linear operators, and show that this alternate view makes their algorithmic list-decodability amenable to analysis. Our framework leads to a new class of codes that we call affine Folded Reed-Solomon codes (which are themselves a special case of the broader class we explore). These codes are common generalizations of the well-studied Folded Reed-Solomon codes and Multiplicity codes, while also capturing the less-studied Additive Folded Reed-Solomon codes as well as a large family of codes that were not previously known/studied.
 More significantly our framework also captures the algorithmic list-decodability of the constituent codes. Specifically, we present a unified view of the decoding algorithm for ideal theoretic codes and show that the decodability reduces to the analysis of the distance of some related codes. We show that good bounds on this distance lead to capacity-achieving performance of the underlying code, providing a unifying explanation of known capacity-achieving results. In the specific case of affine Folded Reed-Solomon codes, our framework shows that they are list-decodable up to capacity (for appropriate setting of the parameters), thereby unifying the previous results for Folded Reed-Solomon, Multiplicity and Additive Folded Reed-Solomon codes.
description: 36 pages
Anti-plane surface waves in media with surface structure: discrete vs. continuum model
Creators: name: Eremeyev, Victor A.
name: Sharma, Basant Lal
Publisher: name: arXiv
Year: 2019
Subjects: subject: Classical Physics (physics.class-ph)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: We present a comparison of the dispersion relations derived for anti-plane surface waves using the two distinct approaches of the surface elasticity vis-a-vis the lattice dynamics. We consider an elastic half-space with surface stresses described within the Gurtin-Murdoch model, and present a formulation of its discrete counterpart that is a square lattice half-plane with surface row of particles having mass and elastic bonds different from the ones in the bulk. As both models possess anti-plane surface waves we discuss similarities between the continuum and discrete viewpoint. In particular, in the context of the behaviour of phase velocity, we discuss the possible characterization of the surface shear modulus through the parameters involved in lattice formulation.
On $(t,r)$ broadcast domination of certain grid graphs
Creators: name: Crepeau, Natasha
name: Harris, Pamela E.
name: Hays, Sean
name: Loving, Marissa
name: Rennie, Joseph
name: Kirby, Gordon Rojas
name: Vasquez, Alexandro
Publisher: name: arXiv
Year: 2019
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C69

description: Let $G=( V(G), E(G) )$ be a connected graph with vertex set $V(G)$ and edge set $E(G)$. We say a subset $D$ of $V(G)$ dominates $G$ if every vertex in $V \setminus D$ is adjacent to a vertex in $D$. A generalization of this concept is $(t,r)$ broadcast domination. We designate certain vertices to be towers of signal strength $t$, which send out signal to neighboring vertices with signal strength decaying linearly as the signal traverses the edges of the graph. We let $\mathbb{T}$ be the set of all towers, and we define the signal received by a vertex $v\in V(G)$ from a tower $w \in \mathbb T$ to be $f(v)=\sum_{w\in \mathbb{T}}max(0,t-d(v,w))$. Blessing, Insko, Johnson, Mauretour (2014) defined a $(t,r)$ broadcast dominating set, or a $(t,r) $ broadcast, on $G$ as a set $\mathbb{T} \subseteq V(G) $ such that $f(v)\geq r$ for all $v\in V(G)$. The minimal cardinality of a $(t, r)$ broadcast on $G$ is called the $(t, r)$ broadcast domination number of $G$. In this paper, we present our research on the $(t,r)$ broadcast domination number for certain graphs including paths, grid graphs, the slant lattice, and the king's lattice.
description: 17 pages, 16 figures, edited to incorporate referee's comments, to appear in Involve
Goto Numbers of a Numerical Semigroup Ring and the Gorensteiness of Associated Graded Rings
Creators: name: Bryant, Lance
Publisher: name: arXiv
Year: 2008
Subjects: subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 13A15 (Primary), 13H10, 13A30, 13B22 (Secondary)

description: The Goto number of a parameter ideal Q in a Noetherian local ring (R,m) is the largest integer q such that Q : m^q is integral over Q. The Goto numbers of the monomial parameter ideals of R = k[[x^{a_1}, x^{a_2},..., x_{a_ν}]] are characterized using the semigroup of R. This helps in computing them for classes of numerical semigroup rings, as well as on a case-by-case basis. The minimal Goto number of R and its connection to other invariants is explored. Necessary and sufficient conditions for the associated graded rings of R and R/x^{a_1}R to be Gorenstein are also given, again using the semigroup of R.
description: 36 pages, corrected typos and improved exposition throughout. To appear in Communications in Algebra
The number of representations of $n$ as a growing number of squares
Creators: name: Holley-Reid, John
name: Rouse, Jeremy
Publisher: name: arXiv
Year: 2019
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: Primary 11E25, Secondary 41A60

description: Let $r_{k}(n)$ denote the number of representations of the integer $n$ as a sum of $k$ squares. In this paper, we give an asymptotic for $r_{k}(n)$ when $n$ grows linearly with $k$. As a special case, we find that \[ r_{n}(n) \sim \frac{B \cdot A^{n}}{\sqrt{n}}, \] with $B \approx 0.2821$ and $A \approx 4.133$.
description: 8 pages
A dislocation-dipole in one dimensional lattice model
Creators: name: Sharma, Basant Lal
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A family of equilibria corresponding to dislocation-dipole, with variable separation between the two dislocations of opposite sign, is constructed in a one dimensional lattice model. A suitable path connecting certain members of this family is found which exhibits the familiar Peierls relief. A landscape for the variation of energy has been presented to highlight certain sequential transition between these equilibria that allows an interpretation in terms of quasi-statically separating pair of dislocations of opposite sign from the viewpoint of closely related Frenkel-Kontorova model. Closed form expressions are provided for the case of a piecewise-quadratic potential wherein an analysis of the effect of an intermediate spinodal region is included.
คลี่คลายด้วยลายพิมพ์ดีเอ็นเอ...ปริศนาแห่งโรมานอฟ
Creators: name: สุภาพร สุกสีเหลือง
Publisher: name: Genetics Society of Thailand
Year: 2008
Subjects: ดีเอ็นเอ, โรมานอฟ, ฮีโมฟิเลีย

description: 2, 1, Thai Journal of Genetics
Higher rank quantum-classical correspondence
Creators: name: Hilgert, Joachim
name: Weich, Tobias
name: Wolf, Lasse L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: For a compact Riemannian locally symmetric space $Γ\backslash G/K$ of arbitrary rank we determine the location of certain Ruelle-Taylor resonances for the Weyl chamber action. We provide a Weyl-lower bound on an appropriate counting function for the Ruelle-Taylor resonances and establish a spectral gap which is uniform in $Γ$ if $G/K$ is irreducible of higher rank. This is achieved by proving a quantum-classical correspondence, i.e. a 1:1-correspondence between horocyclically invariant Ruelle-Taylor resonant states and joint eigenfunctions of the algebra of invariant differential operators on $G/K$.
description: 23 pages, 6 figures
The Isaac Newton Telescope monitoring survey of Local Group dwarf galaxies. II. The star formation history of Andromeda I derived from long period variables
Creators: name: Saremi, Elham
name: Javadi, Atefeh
name: Navabi, Mahdieh
name: van Loon, Jacco Th.
name: Khosroshahi, Habib G.
name: Arbab, Behzad Bojnordi
name: McDonald, Iain
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: An optical monitoring survey in the nearby dwarf galaxies was carried out with the 2.5-m Isaac Newton Telescope (INT). 55 dwarf galaxies and four isolated globular clusters in the Local Group (LG) were observed with the Wide Field Camera (WFC). The main aims of this survey are to identify the most evolved asymptotic giant branch (AGB) stars and red supergiants at the end-point of their evolution based on their pulsational instability, use their distribution over luminosity to reconstruct the star formation history (SFH), quantify the dust production and mass loss from modelling the multi-wavelength spectral energy distributions, and relate this to luminosity and radius variations. In this second of a series of papers, we present the methodology used to estimate SFH based on long-period variable (LPV) stars and then derive it for Andromeda\,I (And\,I) dwarf galaxy as an example of the survey. Using our identified 59 LPV candidates within two half-light radii of And\,I and Padova stellar evolution models, we estimated the SFH of this galaxy. A major epoch of star formation occurred in And\,I peaking around 6.6 Gyr ago, reaching $0.0035\pm0.0016$ M$_\odot$ yr$^{-1}$ and only slowly declining until 1--2 Gyr ago. The presence of some dusty LPVs in this galaxy corresponds to a slight increase in recent star formation peaking around 800 Myr ago. We evaluate a quenching time around 4 Gyr ago ($z<0.5$), which makes And\,I a late-quenching dSph. A total stellar mass $(16\pm7)\times10^6$ M$_\odot$ is calculated within two half-light radii of And\,I for a constant metallicity $Z=0.0007$.
description: Accepted for publication in ApJ
A Theoretical Approach for Computing Magnetic Anisotropy in Single Molecule Magnets
Creators: name: Raghunathan, Rajamani
name: Ramasesha, S.
name: Sen, Diptiman
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a theoretical approach to calculate the molecular magnetic anisotropy parameters, $D_M$ and $E_M$ for single molecule magnets in any eigenstate of the exchange Hamiltonian, treating the anisotropy Hamiltonian as a perturbation. Neglecting inter-site dipolar interactions, we calculate molecular magnetic anisotropy in a given total spin state from the known single-ion anisotropies of the transition metal centers. The method is applied to $Mn_{12}Ac$ and $Fe_8$ in their ground and first few excited eigenstates, as an illustration. We have also studied the effect of orientation of local anisotropies on the molecular anisotropy in various eigenstates of the exchange Hamiltonian. We find that, in case of $Mn_{12}Ac$, the molecular anisotropy depends strongly on the orientation of the local anisotropies and the spin of the state. The $D_M$ value of $Mn_{12}Ac$ is almost independent of the orientation of the local anisotropy of the core $Mn(IV)$ ions. In the case of $Fe_8$, the dependence of molecular anisotropy on the spin of the state in question is weaker.
description: 8 pages, 12 figures, 2 tables
Contour dynamics model for electric discharges
Creators: name: Arrayás, M.
name: Fontelos, M. A.
name: Jiménez, C.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: A contour dynamics model for electrical discharges is obtained and analyzed. The model is deduced as the asymptotic limit of the minimal streamer model for the propagation of electric discharges, in the limit of small electron diffusion. The dispersion relation for a non planar 2-D discharge is calculated. The development and propagation of finger-like patterns are studied and their main features quantified.
description: 4 pages, 2 fig
Decoupling inequalities for short generalized Dirichlet sequences
Creators: name: Fu, Yuqiu
name: Guth, Larry
name: Maldague, Dominique
Publisher: name: arXiv
Year: 2021
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: We study decoupling theory for functions on $\mathbb{R}$ with Fourier transform supported in a neighborhood of short Dirichlet sequences $\{\log n\}_{n=N+1}^{N+N^{1/2}}$, as well as sequences with similar convexity properties. We utilize the wave packet structure of functions with frequency support near an arithmetic progression.
description: 54 pages; added small-cap type decoupling; included a transference argument, which we learned from James Maynard, that implies corollaries on $L^p$ estimates for short generalized Dirichlet sequences from parabola decoupling
Spectroscopic binaries among AGB stars: The star V Hydrae, a binary eclipsed by its jet ?
Creators: name: Planquart, Léa
name: Jorissen, Alain
name: Van Winckel, Hans
name: Van Eck, Sophie
name: Ortiz, Roberto
Publisher: name: Zenodo
Year: 2021
Subjects: AGB stars, binaries

description: Radial velocity (RV) monitoring is one of the methods to identify stars belonging to a binary system. However, asymptotic giant branch (AGB) stars in binary systems are more difficult to detect because their orbital signature is polluted by the regular envelope pulsation. The RV of a sample of suspected binary AGB stars has been monitored in order to detect their possible orbital motion. This RV monitoring has been performed using the high-resolution HERMES spectrograph installed on the Mercator telescope. Here we focus on the binary properties of the carbon star V Hydrae. The star is known to emit collimated bullets every 8.5 years, which is a common phenomenon during the transition from AGB to PN. It is known as well to emit a rapid jet (200 km/s), detected in the submm CO lines. Our RV monitoring has shown that the orbital period is 17 years, which is just twice the recurrence time-scale of the bullet ejections, whereas the orbital period exactly matches the long-term modulation seen in the AAVSO light curve. The comparison of the RV and light curves reveals that the photometric obscuration (by several mags!) occurs at the time when the companion is in front of the AGB star, so that it is likely that these obscurations are caused by the jet emitted by (the accretion disc around?) the companion. This situation is reminiscent of the one frequently occurring among post-AGB binary systems, so that V Hya thus appears to share properties of AGB and post-AGB systems.
Not All Requirements Prioritization Criteria Are Equal at All Times: A Quantitative Analysis
Creators: name: Svensson, Richard Berntsson
name: Torkar, Richard
Publisher: name: arXiv
Year: 2021
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Requirement prioritization is recognized as an important decision-making activity in requirements engineering and software development. Requirement prioritization is applied to determine which requirements should be implemented and released. In order to prioritize requirements, there are several approaches/techniques/tools that use different requirements prioritization criteria, which are often identified by gut feeling instead of an in-depth analysis of which criteria are most important to use. Therefore, in this study we investigate which requirements prioritization criteria are most important to use in industry when determining which requirements are implemented and released, and if the importance of the criteria change depending on how far a requirement has reached in the development process. We conducted a quantitative study of one completed project from one software developing company by extracting 32,139 requirements prioritization decisions based on eight requirements prioritization criteria for 11,110 requirements. The results show that not all requirements prioritization criteria are equally important, and this change depending on how far a requirement has reached in the development process.
Series and Product Relations Made from Primes
Creators: name: Hicks, Ken
name: Ward, Kevin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: It is known that the sum of the reciprocal of integers, $\sum_n (1/n)$, and the sum of the reciprocal of primes, $\sum_n (1/p_n)$, both diverge. Here, we study a series made from primes that sums exactly to 1. We also show this sum is simply related to an infinite product over primes. We then generalize the form of the series (and its related product), extending this idea to other number theoretic sets such as twin primes. Evaluating a product made from twin primes gives a new mathematical constant.
description: 9 pages, no figures
Jucys-Murphy elements, orthogonal matrix integrals, and Jack measures
Creators: name: Matsumoto, Sho
Publisher: name: arXiv
Year: 2010
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05E15, 20C08, 05E05

description: We study symmetric polynomials whose variables are odd-numbered Jucys-Murphy elements. They define elements of the Hecke algebra associated to the Gelfand pair of the symmetric group with the hyperoctahedral group. We evaluate their expansions in zonal spherical functions and in double coset sums. These evaluations are related to integrals of polynomial functions over orthogonal groups. Furthermore, we give an extension of them, based on Jack polynomials.
description: 36 pages. v2: minor correction
Divisors of Fourier coefficients of two newforms
Creators: name: Kumar, Arvind
name: Kumari, Moni
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: For a pair of distinct non-CM newforms of weights at least 2, having rational integral Fourier coefficients $a_{1}(n)$ and $a_{2}(n)$, under GRH, we obtain an estimate for the set of primes $p$ such that $$ ω(a_1(p)-a_2(p)) \le [ 7k+{1}/{2}+k^{1/5}],$$ where $ω(n)$ denotes the number of distinct prime divisors of an integer $n$ and $k$ is the maximum of their weights. As an application, under GRH, we show that the number of primes giving congruences between two such newforms is bounded by $[7k+{1}/{2}+k^{1/5} ]$. We also obtain a multiplicity one result for newforms via congruences.
description: Comments are welcome
A critical edition of George Whetstone’s An Heptameron of Civill Discourses (1582)
Creators: name: Shklanka, Diana
Publisher: name: University of British Columbia
Year: 2010

description: This dissertation provides a critical old-spelling edition of George whetstone's An Heptameron of Civill Discourses (1582). The text follows the principles formulated by McKerrow, Greg, and Bowers. Ten known extant copies of the Heptameron have been collated: the Folger Shakespeare Library STC 25337, copy 3, has been used as the control text. The textual apparatus includes a textual introduction, a bibliographical description of the Heptameron, and lists of substantive emendations, emendations of accidentals, press variants, and variants in the 1593 edition, entitled Aurelia, The Paragon of Pleasure and Princely Delights. The critical introduction summarizes Whetstone's life and works; relates the Heptameron to the Renaissance interest in Italy, to the ideal of civility, to courtesy literature, to dialogue literature, to marriage literature, and to Renaissance prose fiction; discusses Whetstone's sources; and examines the book's structure. The notes explain mythological, historical, literary, and contemporary allusions; identify proverbs; suggest sources; and illustrate the accuracy of Whetstone's observations on Italy. A bibliography, a glossary, and indices of proper nouns, stories, and first lines of poems complete the critical apparatus. The dissertation shows that Whetstone, drawing both on his own experience of Italy and on a variety of literary traditions and sources, fuses fact and fancy into a carefully constructed literary work, in which discussions, dramatic entertainments, poems, and tales are thematically integrated, progressing towards a definite resolution in the Seventh Day's Exercise.
Symmetries of spin systems and Birman-Wenzl-Murakami algebra
Creators: name: Kulish, P. P.
name: Manojlovic, N.
name: Nagy, Z.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We consider integrable open spin chains related to the quantum affine algebras U_q(o(3)) and U_q(A_2^{(2)}). We discuss the symmetry algebras of these chains with the local C^3 space related to the Birman-Wenzl-Murakami algebra. The symmetry algebra and the Birman-Wenzl-Murakami algebra centralize each other in the representation space, and this defines the structure of the spin system spectra. Consequently, the corresponding multiplet structure of the energy spectra is obtained.
description: 22 pages; typos corrected
Two-loop leading-colour QCD helicity amplitudes for two-photon plus jet production at the LHC
Creators: name: Chawdhry, Herschel A.
name: Czakon, Michal
name: Mitov, Alexander
name: Poncelet, Rene
Publisher: name: RWTH Aachen University
Year: 2021
Subjects: subject: 530

description: 1-13 (2021). doi:10.18154/RWTH-2021-10469
Information-theoretical Limits of Recursive Estimation and Closed-loop Control in High-contrast Imaging
Creators: name: Pogorelyuk, Leonid
name: Pueyo, Laurent
name: Males, Jared R.
name: Cahoy, Kerri
name: Kasdin, N. Jeremy
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: 85-10

description: A lower bound on unbiased estimates of wavefront errors (WFE) is presented for the linear regime of small perturbation and active control of a high-contrast region (dark hole). Analytical approximations and algorithms for computing the closed-loop covariance of the WFE modes are provided for discrete- and continuous-time linear WFE dynamics. Our analysis applies to both image-plane and non-common-path wavefront sensing (WFS) with Poisson-distributed measurements and noise sources (i.e., photon-counting mode). Under this assumption, we show that recursive estimation benefits from infinitesimally short exposure times, is more accurate than batch estimation and, for high-order WFE drift dynamical processes, scales better than batch estimation with amplitude and star brightness. These newly-derived contrast scaling laws are a generalization of previously known theoretical and numerical results for turbulence-driven Adaptive Optics. For space-based coronagraphs, we propose a scheme for combining models of WFE drift, low-order non-common-path WFS (LOWFS) and high-order image-plane WFS (HOWFS) into closed-loop contrast estimates. We also analyze the impact of residual low-order WFE, sensor noise, and other sources incoherent with the star, on closed-loop dark-hole maintenance and the resulting contrast. As an application example, our model suggests that the Roman Space Telescope might operate in a regime that is dominated by incoherent sources rather than WFE drift, where the WFE drift can be actively rejected throughout the observations with residuals significantly dimmer than the incoherent sources. The models proposed in this paper make possible the assessment of the closed-loop contrast of coronagraphs with combined LOWFS and HOWFS capabilities, and thus help estimate WFE stability requirements of future instruments.
description: 33 pages, 9 figures, 2 tables
Nonlinear Propagation of Crossing Electromagnetic Waves in Vacuum due to Photon-Photon Scattering
Creators: name: Tommasini, Daniele
name: Ferrando, Albert
name: Michinel, Humberto
name: Seco, Marcos
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: We review the theory for photon-photon scattering in vacuum, and some of the proposals for its experimental search, including the results of our recent works on the subject. We then describe a very simple and sensitive proposal of an experiment and discuss how it can be used at the present (HERCULES) and the future (ELI) ultrahigh power laser facilities either to find the first evidence of photon-photon scattering in vacuum, or to significantly improve the current experimental limits.
description: Talk delivered (by D.T.) at the International Workshop on the Frontiers of Modern Plasma Physics, Trieste, 2008. To appear in the proceedings
Exact correlations in topological quantum chains
Creators: name: Jones, Nick G.
name: Verresen, Ruben
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Although free-fermion systems are considered exactly solvable, they generically do not admit closed expressions for nonlocal quantities such as topological string correlations or entanglement measures. We derive closed expressions for such quantities for a dense subclass of certain classes of topological fermionic wires (classes BDI and AIII). Our results also apply to spin chains called generalised cluster models. While there is a bijection between general models in these classes and Laurent polynomials, restricting to polynomials with degenerate zeros leads to a plethora of exact results: (1) we derive closed expressions for the string correlation functions - the order parameters for the topological phases in these classes; (2) we obtain an exact formula for the characteristic polynomial of the correlation matrix, giving insight into ground state entanglement; (3) the latter implies that the ground state can be described by a matrix product state (MPS) with a finite bond dimension in the thermodynamic limit - an independent and explicit construction for the BDI class is given in a concurrent work [Phys. Rev. Res. 3 (2021), 033265, 26 pages, arXiv:2105.12143]; (4) for BDI models with even integer topological invariant, all non-zero eigenvalues of the transfer matrix are identified as products of zeros and inverse zeros of the aforementioned polynomial. General models in these classes can be obtained by taking limits of the models we analyse, giving a further application of our results. To the best of our knowledge, these results constitute the first application of Day's formula and Gorodetsky's formula for Toeplitz determinants to many-body quantum physics.
Epoch of Reionization Power Spectrum Limits from Murchison Widefield Array Data Targeted at EoR1 Field
Creators: name: Rahimi, M.
name: Pindor, B.
name: Line, J. L. B.
name: Barry, N.
name: Trott, C. M.
name: Webster, R. L.
name: Jordan, C. H.
name: Wilensky, M.
name: Yoshiura, S.
name: Beardsley, A.
name: Bowman, J.
name: Byrne, R.
name: Chokshi, A.
name: Hazelton, B. J.
name: Hasegawa, K.
name: Howard, E.
name: Greig, B.
name: Jacobs, D.
name: Joseph, R.
name: Kolopanis, M.
name: Lynch, C.
name: McKinley, B.
name: Mitchell, D. A.
name: Murray, S.
name: Morales, M. F.
name: Pober, J. C.
name: Takahashi, K.
name: Tingay, S. J.
name: Wayth, R. B.
name: Wyithe, J. S. B.
name: Zheng, Q.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Current attempts to measure the 21cm Power Spectrum of neutral hydrogen during the Epoch of Reionization are limited by systematics which produce measured upper limits above both the thermal noise and the expected cosmological signal. These systematics arise from a combination of observational, instrumental, and analysis effects. In order to further understand and mitigate these effects, it is instructive to explore different aspects of existing datasets. One such aspect is the choice of observing field. To date, MWA EoR observations have largely focused on the EoR0 field. In this work, we present a new detailed analysis of the EoR1 field. The EoR1 field is one of the coldest regions of the Southern radio sky, but contains the very bright radio galaxy Fornax-A. The presence of this bright extended source in the primary beam of the interferometer makes the calibration and analysis of EoR1 particularly challenging. We demonstrate the effectiveness of a recently developed shapelet model of Fornax-A in improving the results from this field. We also describe and apply a series of data quality metrics which identify and remove systematically contaminated data. With substantially improved source models, upgraded analysis algorithms and enhanced data quality metrics, we determine EoR power spectrum upper limits based on analysis of the best $\sim$14-hours data observed during 2015 and 2014 at redshifts 6.5, 6.8 and 7.1, with the lowest $2σ$ upper limit at z=6.5 of $Δ^2 \leq (73.78 ~\mathrm{mK)^2}$ at $k=0.13~\mathrm{h~ Mpc^{-1}}$, improving on previous EoR1 measurement results.
description: 18 pages, 17 figures, Accepted for publication in MNRAS
The BCS Critical Temperature at High Density
Creators: name: Henheik, Joscha
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We investigate the BCS critical temperature $T_c$ in the high-density limit and derive an asymptotic formula, which strongly depends on the behavior of the interaction potential $V$ on the Fermi-surface. Our results include a rigorous confirmation for the behavior of $T_c$ at high densities proposed by Langmann, Triola, and Balatsky (Phys. Rev. Lett. 122, 2019) and identify precise conditions under which superconducting domes arise in BCS theory.
description: 24 pages; final version
Double point surgery and configurations of surfaces
Creators: name: Kim, Hee Jung
name: Ruberman, Daniel
Publisher: name: arXiv
Year: 2010
Subjects: subject: Geometric Topology (math.GT)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: 57Q45 (primary), 57M60 (secondary)

description: We introduce a new operation, double point surgery, on immersed surfaces in a 4-manifold, and use it to construct knotted configurations of surfaces in many 4-manifolds. Taking branched covers, we produce smoothly exotic actions of Z/m x Z/n on simply connected 4-manifolds with complicated fixed-point sets.
description: Final version; to appear in Journal of Topology. Removed assertion about the restriction of the Z/m x Z/n action to the Z/m and Z/n subgroups