cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Atiyah-Patodi-Singer index theorem from axial anomaly
Creators: name: Kobayashi, Shun K.
name: Yonekura, Kazuya
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We give a very simple derivation of the Atiyah-Patodi-Singer (APS) index theorem and its small generalization by using the path integral of massless Dirac fermions. It is based on the Fujikawa's argument for the relation between the axial anomaly and the Atiyah-Singer index theorem, and only a minor modification of that argument is sufficient to show the APS index theorem. The key ingredient is the identification of the APS boundary condition and its generalization as physical state vectors in the Hilbert space of the massless fermion theory. The APS $η$-invariant appears as the axial charge of the physical states.
description: 16 pages, 3 figures
Ridge Structure associated with the Near-Side Jet in the (Delta phi)-(Delta eta) Correlation
Creators: name: Wong, Cheuk-Yin
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the (Delta phi)-(Delta eta) correlation associated with a near-side jet observed by the STAR Collaboration in heavy-ion collisions at RHIC [Ref. 1-6], the ridge structure can be explained by the momentum kick model in which the ridge particles are identified as medium partons which suffer a collision with the jet and acquire a momentum kick along the jet direction. If this is indeed the correct mechanism, the ridge structure associated with the near-side jet may be used to probe the parton momentum distribution at the moment of the jet-parton collision, leading to the result that at that instant the parton temperature is slightly higher and the rapidity width substantially greater than corresponding quantities of their evolution product inclusive particles at the end point of the nucleus-nucleus collision.
description: 15 pages, 9 figures
Beyond Linear Subspace Clustering: A Comparative Study of Nonlinear Manifold Clustering Algorithms
Creators: name: Abdolali, Maryam
name: Gillis, Nicolas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Subspace clustering is an important unsupervised clustering approach. It is based on the assumption that the high-dimensional data points are approximately distributed around several low-dimensional linear subspaces. The majority of the prominent subspace clustering algorithms rely on the representation of the data points as linear combinations of other data points, which is known as a self-expressive representation. To overcome the restrictive linearity assumption, numerous nonlinear approaches were proposed to extend successful subspace clustering approaches to data on a union of nonlinear manifolds. In this comparative study, we provide a comprehensive overview of nonlinear subspace clustering approaches proposed in the last decade. We introduce a new taxonomy to classify the state-of-the-art approaches into three categories, namely locality preserving, kernel based, and neural network based. The major representative algorithms within each category are extensively compared on carefully designed synthetic and real-world data sets. The detailed analysis of these approaches unfolds potential research directions and unsolved challenges in this field.
description: 55 pages
UMA REFLEXÃO SOBRE O EQUILÍBRIO DOS PLANOS DE BENEFÍCIOS DE CARÁTER PREVIDENCIÁRIO A PARTIR DAS DEMONSTRAÇÕES CONTÁBEISDOS FUNDOS DE PENSÃO
Creators: name: Silva, Fabiana Lopes
name: Chan, Betty Lilian
name: Martins, Gilberto Andrade
Publisher: name: Revista de Informação Contábil
Year: 2007
Subjects: fundos de pensão; equilíbrio de planos de benefícios; meta atuarial; déficit atuarial

description: O presente artigo tem por objetivo promover uma reflexão acerca do equilíbrio atuarial dos planos de benefícios de caráter previdenciário e, consequentemente, da solvência destes, com base nos superávits ou déficits apresentados nas demonstrações contábeis dos fundos de pensão. Os planos objetos deste estudo são os denominados de Benefício Definido (BD) e Contribuição Variável (CV), também conhecido como Planos Mistos. Para tanto, simulou-se a evolução de um plano de benefícios hipotético, buscando retratar nas demonstrações contábeis o efeito de eventuais desvios na premissa de ganho real de investimentos (meta atuarial). A simulação efetuada mostra que a ocorrência de superávits ou déficits contábeis não necessariamente reflete adequadamente o equilíbrio atuarial do plano. Além disso, foi constatada que a utilização de uma taxa de desconto fixa, em detrimento a uma taxa de desconto variável, propicia distorções na análise da situação do plano ao longo do tempo. Porém, a grande dificuldade na prática em se adotar uma taxa de juros variável é estabelecer a estrutura temporal de taxa de juros que possa refletir a realidade do plano, além do aumento da complexidade operacional na determinação do passivo atuarial.
description: Revista de Informação Contábil, v. 1, n. 1 (2007): RIC/UFPE - Revista de Informação Contábil
Secure and practical multiparty quantum digital signatures
Creators: name: Weng, Chen-Xun
name: Lu, Yu-Shuo
name: Gao, Rui-Qi
name: Xie, Yuan-Mei
name: Gu, Jie
name: Li, Chen-Long
name: Li, Bing-Hong
name: Yin, Hua-Lei
name: Chen, Zeng-Bing
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum digital signatures (QDSs) promise information-theoretic security against repudiation and forgery of messages. Compared with currently existing three-party QDS protocols, multiparty protocols have unique advantages in the practical case of more than two receivers when sending a mass message. However, complex security analysis, numerous quantum channels and low data utilization efficiency make it intractable to expand three-party to multiparty scenario. Here, based on six-state non-orthogonal encoding protocol, we propose an effective multiparty QDS framework to overcome these difficulties. The number of quantum channels in our protocol only linearly depends on the number of users. The post-matching method is introduced to enhance data utilization efficiency and make it linearly scale with the probability of detection events even for five-party scenario. Our work compensates for the absence of practical multiparty protocols, which paves the way for future QDS networks.
description: 9 pages, 6 figures
A PESQUISA BRASILEIRA EM CONTABILIDADE DO SETOR PÚBLICO: UMA ANÁLISE APÓS A IMPLEMENTAÇÃO DA LEI DE RESPONSABILIDADE FISCAL
Creators: name: Dos Reis, Luciano Gomes
name: Slomski, Valmor
name: Pereira, Carlos Alberto
name: De Melo, Gilmar Ribeiro
Publisher: name: Revista de Informação Contábil
Year: 2007
Subjects: contabilidade do setor público; pesquisa em contabilidade; lei de responsabilidade fiscal

description: O processo de modernização do Estado brasileiro provocou várias mudanças na forma como os gestores públicos tomam suas decisões. As transformações sociais pelas quais o país passou nos últimos 30 anos suscitaram à própria sociedade desenvolver mecanismos de controle do Poder Público, que culminaram com a publicação da Lei Complementar nº 101/2000, popularmente conhecida como Lei de Responsabilidade Fiscal. O presente artigo analisa a distribuição geográfica, a temática e a evolução da produção dos pesquisadores nacionais, que abordassem assuntos relativos à Contabilidade do Setor Público. A metodologia utilizada foi a pesquisa bibliográfica, que incluiu a verificação de artigos publicados em três congressos com periodicidade anual, considerados relevantes no meio acadêmico nacional: o Encontro Nacional da Associação de Pós-Graduação em Administração (ENANPAD), o Congresso Brasileiro de Custos e o Congresso USP de Controladoria e Contabilidade. Foram apuradas seguintes conclusões: a participação da Contabilidade Pública em trabalhos apresentados em Congressos é relativamente baixa, com 2,7% do total; a Região Nordeste possui o maior número de trabalhos aplicados na área pública; a Contabilidade Gerencial constitui o tema dominante e a esfera governamental com maior número de trabalhos apresentados é a municipal.
description: Revista de Informação Contábil, v. 1, n. 1 (2007): RIC/UFPE - Revista de Informação Contábil
Ferromagnetism of an all-carbon composite composed of a carbon nanowire nside a single-walled carbon nanotube
Creators: name: Yang, Xiaoping
name: Dong, Jinming
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using the first-principles spin density functional approach, we have studied magnetism of a new type of all-carbon nanomaterials, i.e., the carbon nanowires inserted into the single-walled carbon nanotubes. It is found that if the 1D carbon nanowire density is not too higher, the ferromagnetic ground state will be more stable than the antiferromagnetic one, which is caused by weak coupling between the 1D carbon nanowire and the single-walled carbon nanotube. Also, both dimerization of the carbon nanowire and carbon vacancy on the tube-wall are found to enhance the magnetic moment of the composite.
description: 3 figures
Women choosing not to have children : implications for social work practice and policy on reproductive choice
Creators: name: McCarthy, Claire Louise
Publisher: name: University of British Columbia
Year: 2010

description: The purpose of this research study was to explore the relationship between women who have chosen not to have children and one specific area of social policy, that of reproductive choice. Attitudes toward and access to voluntary sterilization and abortion were emphasized. A feminist qualitative research approach was used in this study. Based on interviews with ten childfree women and five community agency representatives/professionals, this research explored the experiences and attitudes of childfree women and community representatives toward voluntary sterilization and abortion. A substantive and theoretical coding process was used for data analysis. The results of this research indicate a discrepancy between what these childfree women expected from the process of obtaining a tubal ligation or abortion versus what actually happened to many of them in their contact with the medical profession. In particular, access to more information and the right to make an autonomous decision became poignant concerns in the study. Balancing the rights of women to voluntarily access abortion and sterilization against the rights of other women to not be coerced to have an abortion or tubal ligation is a challenge for our society. Social workers have a significant role to play both in terms of clinical work in the health field and at the social policy level to ensure that all women have the opportunity to make autonomous reproductive choices.
OpenID Security Analysis and Evaluation
Creators: name: Sun, San-Tsai
name: Beznosov, Konstantin
Publisher: name: Zenodo
Year: 2010
Subjects: OpenID
Security Analysis
Security Evaluation

description: OpenID is a promising user-centric Web single sign-on protocol. According to the OpenID Foundation, there are currently more than one billion OpenID-enabled user accounts provided by major service providers such as Google, Yahoo and AOL. In this presentation, I will present OpenID security analysis and the evaluation results on 200 OpenID-enabled websites.  Our preliminary result shows that more than 50% of OpenID-enabled websites are vulnerable to cross-site request forgery attack (CSRF) that allow an attacker to modify the victim's account profile information directly; and  75% of evaluated websites allow an attacker to force the victim to login their websites as the attacker stealthily. With additional practical adversary capabilities (e.g., trick users to use a malicious wireless access point or install a malicious browser extension) that enable an attacker to intercept the authentication response from the identity provider, the attacker can impersonate the victim on 65% of OpenID-enabled websites and re-masquerade the victim on 6% of the websites by simply applying the intercepted authentication responses. To the end, I will demonstrate the attack vectors employed in the evaluation process and discuss our proposed countermeasure for the current OpenID-enabled websites and future OpenID specification.
Towards Improving the Performance of Enterprise Authorization Systems using Speculative Authorization
Creators: name: Kini, Pranab
Publisher: name: Zenodo
Year: 2010
Subjects: Access Control
Latency
Machine Learning
Prediction

description: With the emergence of tighter corporate policies and government regulations, access control has become an integral part of business requirements in enterprises. The authorization process in enterprise systems follow the request-response model, where a policy enforcement point intercepts application requests, obtains authorization decisions from a remote policy decision point, and enforces those decisions. The two advantages of this model are (1) the separation between the application and authorization logic (2) reduction of authorization policy administration. However, the authorization process adds to the already existing latency for accessing resources, affecting enterprises negatively in terms of responsiveness of their systems. This dissertation presents an approach to reduce latency introduced by the authorization process. We present Speculative Authorization (SPAN), a prediction technique to address the problem of latency in enterprise authorization systems. SPAN predicts the possible future requests that could be made by a client, based on the present and past behavior of the client. Authorization decisions to the predicted requests are fetched even before the requests are made by the client, thus reducing the latency. SPAN is designed using a clustering technique that combines information about requests made by different clients in order to make predictions for a particular client. We present our results in terms of hit rate and precision, and demonstrate that SPAN improves the performance of authorization infrastructures. We also calculate the additional load incurred by the system to compute responses to the predicted requests, and provide measures to reduce the unnecessary load. Caching is a simple and inexpensive technique, popularly used to improve the latency of enterprise authorization systems. On the other hand, we have not seen any implementation of techniques like SPAN to reduce latency. To demonstrate the effectiveness of such techniques, we implement caching and SPAN in the same system, and show that combining the two techniques can further improve the performance of access control systems.
Gamma Factory Searches for Extremely Weakly-Interacting Particles
Creators: name: Chakraborti, Sreemanti
name: Feng, Jonathan L.
name: Koga, James K.
name: Valli, Mauro
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The Gamma Factory is a proposal to back-scatter laser photons off a beam of partially-stripped ions at the LHC, producing a beam of $\sim 10$ MeV to $1$ GeV photons with intensities of $10^{16}$ to $10^{18}~\text{s}^{-1}$. This implies $\sim 10^{23}$ to $10^{25}$ photons on target per year, many orders of magnitude greater than existing accelerator light sources and also far greater than all current and planned electron and proton fixed target experiments. We determine the Gamma Factory's discovery potential through "dark Compton scattering," $γe \to e X$, where $X$ is a new, weakly-interacting particle. For dark photons and other new gauge bosons with masses in the 1~to~100 MeV range, the Gamma Factory has the potential to discover extremely weakly-interacting particles with just a few hours of data and will probe couplings as low as $\sim 10^{-9}$ with a year of running. The Gamma Factory therefore may probe couplings lower than all other terrestrial experiments and is highly complementary to astrophysical probes. We outline the requirements of an experiment to realize this potential and determine the sensitivity reach for various experimental configurations.
description: 20 pages, 9 captioned figures. Version accepted in PRD
Fermion loop simulation of the lattice Gross-Neveu model
Creators: name: Gattringer, Christof
name: Hermann, Verena
name: Limmer, Markus
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a numerical simulation of the Gross-Neveu model on the lattice using a new representation in terms of fermion loops. In the loop representation all signs due to Pauli statistics are eliminated completely and the partition function is a sum over closed loops with only positive weights. We demonstrate that the new formulation allows to simulate volumes which are two orders of magnitude larger than those accessible with standard methods.
Electrical conductivity in the Hubbard model: orbital effects of magnetic field
Creators: name: Vucicevic, Jaksa
name: Zitko, Rok
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Calculation of conductivity in the Hubbard model is a challenging task. Recent years have seen much progress in this respect and numerically exact solutions are now possible in certain regimes. In this paper we discuss the calculation of conductivity for the square lattice Hubbard model in the presence of a perpendicular magnetic field, focusing on orbital effects. We present the relevant formalism in all detail and in full generality, and then discuss the simplifications that arise at the level of the dynamical mean field theory (DMFT). We prove that the Kubo bubble preserves gauge and translational invariance, and that in the DMFT the vertex corrections cancel regardless of the magnetic field. We present the DMFT results for the spectral function and both the longitudinal and Hall conductivity in several regimes of parameters. We analyze thoroughly the quantum oscillations of the longitudinal conductivity and identify a high-frequency oscillation component, arising as a combined effect of scattering and temperature, in line with recent experimental observations in moiré systems.
description: 32 pages, 21 figures
Inference on Eigenvalues of Wishart Distribution Using Asymptotics with respect to the Dispersion of Population Eigenvalues
Creators: name: Sheena, Yo
name: Takemura, Akimichi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62H10

description: In this paper we derive some new and practical results on testing and interval estimation problems for the population eigenvalues of a Wishart matrix based on the asymptotic theory for block-wise infinite dispersion of the population eigenvalues. This new type of asymptotic theory has been developed by the present authors in Takemura and Sheena (2005) and Sheena and Takemura (2007a,b) and in these papers it was applied to point estimation problem of population covariance matrix in a decision theoretic framework. In this paper we apply it to some testing and interval estimation problems. We show that the approximation based on this type of asymptotics is generally much better than the traditional large-sample asymptotics for the problems.
Corrections to the singlet-length distribution and the entanglement entropy in random singlet phases
Creators: name: Juhász, Róbert
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider random singlet phases of spin-$\frac{1}{2}$, random, antiferromagnetic spin chains, in which the universal leading-order divergence $\frac{\ln 2}{3}\ln\ell$ of the average entanglement entropy of a block of $\ell$ spins, as well as the closely related leading term $\frac{2}{3}l^{-2}$ in the distribution of singlet lengths are well known by the strong-disorder renormalization group (SDRG) method. Here, we address the question of how large the subleading terms of the above quantities are. By an analytical calculation performed along a special SDRG trajectory of the random XX chain, we identify a series of integer powers of $1/l$ in the singlet-length distribution with the subleading term $\frac{4}{3}l^{-3}$. Our numerical SDRG analysis shows that, for the XX fixed point, the subleading term is generally $O(l^{-3})$ with a non-universal coefficient and also reveals terms with half-integer powers: $l^{-7/2}$ and $l^{-5/2}$ for the XX and XXX fixed points, respectively. We also present how the singlet lengths originating in the SDRG approach can be interpreted and calculated in the XX chain from the one-particle states of the equivalent free-fermion model. These results imply that the subleading term next to the logarithmic one in the entanglement entropy is $O(\ell^{-1})$ for the XX fixed point and $O(\ell^{-1/2})$ for the XXX fixed point with non-universal coefficients. For the XX model, where a comparison with exact diagonalization is possible, the order of the subleading term is confirmed but we find that the SDRG fails to provide the correct non-universal coefficient.
description: 9 pages, 7 figures
Critical temperature for kaon condensation in color-flavor locked quark matter
Creators: name: Alford, Mark G.
name: Braby, Matt
name: Schmitt, Andreas
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the behavior of Goldstone bosons in color-flavor-locked (CFL) quark matter at nonzero temperature. Chiral symmetry breaking in this phase of cold and dense matter gives rise to pseudo-Goldstone bosons, the lightest of these being the charged and neutral kaons K^+ and K^0. At zero temperature, Bose-Einstein condensation of the kaons occurs. Since all fermions are gapped, this kaon condensed CFL phase can, for energies below the fermionic energy gap, be described by an effective theory for the bosonic modes. We use this effective theory to investigate the melting of the condensate: we determine the temperature-dependent kaon masses self-consistently using the two-particle irreducible effective action, and we compute the transition temperature for Bose-Einstein condensation. Our results are important for studies of transport properties of the kaon condensed CFL phase, such as bulk viscosity.
description: 24 pages, 8 figures, v2: new section about effect of electric neutrality on critical temperature added; references added; version to appear in J.Phys.G
A study of the relationship between childhood incest and interpersonal relationships in adult life
Creators: name: Pierce, Kathleen Anne
Publisher: name: University of British Columbia
Year: 2010

description: The purpose of this study is to determine if it is possible to establish a relationship between childhood experiences of incestuous abuse and specific problems in functioning and in interpersonal relationships as an adult. Since incest occurs in families where other dysfunctional features are present, it is usually difficult to separate the different influences on the individual in their family of origin and how they are affected later in life. A single subject was studied using material from audiotaped counselling sessions over a five month period. The contents of the tapes were analysed to see if the client was dealing with difficulties in interpersonal relationships, and if so, how the incest experience might be related to these problems. The study was augmented by audiotaped interviews with five counsellors who work in the sexual abuse field to ascertain their views on the implications of incest abuse on development and its relationship to problems in adult functioning. The study was viewed from a developmental perspective and the stages of trust, identity formation and intimacy were identified as stages of development that were adversely affected by the incestuous abuse. The results of the interviews with the counsellors supported these findings. The findings from the study were also examined by reference to psychoanalytic, loss and feminist perspectives on the nature of the developmental problems the subject encountered. It was found that it was possible to identify specific areas where the incest experiences were seriously affecting the adult survivor, especially in the areas of sexual dysfunction and problems in forming intimate relationships. Other features of the family dynamic were also identified as significant especially the difficulty the subject had in resolving problems in her relationship to her father and stepfather as well as residual feelings of ambivalence in her relationship with her mother. Recommendations were made concerning the need for more research in the area of sexual abuse and the need for many more treatment resources to meet the needs of abuse survivors.
Universal magnetic oscillations of DC conductivity in the incoherent regime of correlated systems
Creators: name: Vucicevic, Jaksa
name: Zitko, Rok
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Using the dynamical mean field theory we investigate the magnetic field dependence of DC conductivity in the Hubbard model on the square lattice, fully taking into account the orbital effects of the field introduced via the Peierls substitution. In addition to the conventional Shubnikov-de Haas quantum oscillations, associated with the coherent cyclotron motion of quasiparticles and the presence of a well-defined Fermi surface, we find an additional oscillatory component with a higher frequency that corresponds to the total area of the Brillouin zone. These paradigm-breaking oscillations appear at elevated temperature. This finding is in excellent qualitative agreement with the recent experiments on graphene superlattices. We elucidate the key roles of the off-diagonal elements of the current vertex and the incoherence of electronic states, and explain the trends with respect to temperature and doping.
description: 6 pages, 3 figures
On the generalised Chaplygin gas: worse than a big rip or quieter than a sudden singularity?
Creators: name: Bouhmadi-Lopez, Mariam
name: Gonzalez-Diaz, Pedro F.
name: Martin-Moruno, Prado
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Although it has been believed that the models with generalised Chaplygin gas do not contain singularities, in a previous work we have studied how a big freeze could take place in some kinds of phantom generalised Chaplygin gas. In the present work, we study some types of generalised Chaplygin gas in order to show how different sorts of singularities could appears in such models, in the future or in the past. We point out that: (i) singularities may not be originated from the phantom nature of the fluid, and (ii) if initially the tension of the brane in a brane-world Chaplygin model is large enough then an infrared cut off appears in the past.
description: 19 pages, 6 figures. Discussion expanded and references added. Version to appear in the International Journal of Modern Physics D
Full-time dynamics of modulational instability in spinor Bose-Einstein condensates
Creators: name: Doktorov, Evgeny V.
name: Rothos, Vassilis M.
name: Kivshar, Yuri S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We describe the full-time dynamics of modulational instability in F=1 spinor Bose-Einstein condensates for the case of the integrable three-component model associated with the matrix nonlinear Schroedinger equation. We obtain an exact homoclinic solution of this model by employing the dressing method which we generalize to the case of the higher-rank projectors. This homoclinic solution describes the development of modulational instability beyond the linear regime, and we show that the modulational instability demonstrates the reversal property when the growth of the modulation amplitude is changed by its exponential decay.
description: 6 pages, 2 figures, text slightly extended, a reference added
The Orbit Problem for Parametric Linear Dynamical Systems
Creators: name: Baier, Christel
name: Funke, Florian
name: Jantsch, Simon
name: Karimov, Toghrul
name: Lefaucheux, Engel
name: Luca, Florian
name: Ouaknine, Joël
name: Purser, David
name: Whiteland, Markus A.
name: Worrell, James
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We study a parametric version of the Kannan-Lipton Orbit Problem for linear dynamical systems. We show decidability in the case of one parameter and Skolem-hardness with two or more parameters. More precisely, consider a $d$-dimensional square matrix $M$ whose entries are algebraic functions in one or more real variables. Given initial and target vectors $u,v\in \mathbb{Q}^d$, the parametric point-to-point orbit problem asks whether there exist values of the parameters giving rise to a concrete matrix $N \in \mathbb{R}^{d\times d}$, and a positive integer $n\in \mathbb{N}$, such that $N^nu = v$. We show decidability for the case in which $M$ depends only upon a single parameter, and we exhibit a reduction from the well-known Skolem Problem for linear recurrence sequences, suggesting intractability in the case of two or more parameters.
description: Full version of the paper appearing at CONCUR 2021
Recombination in the universal four-fermion system
Creators: name: Deltuva, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Nuclear Theory (nucl-th)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: In the systems of spin $\frac12$ fermions with resonant $S$-wave interactions supporting only weakly bound dimers the antisymmetry forbids recombination of three (or more) fermions at zero energy. However, the fermion-fermion-dimer recombination is only partially suppressed. It is studied in the framework of momentum-space integral equations for the four-particle transition operators. In the vicinity of the unitary limit the fermion-fermion-dimer recombination rate, rescaled to build dimensionless quantity, is found to be linear in the effective range parameter, enabling a simple and accurate parametrization as well as evaluation of finite-range effects for any potential model. This feature makes the present results very useful in benchmarking different methods for three-cluster breakup and recombination calculations in four-particle systems. The interplay of the three-fermion and fermion-fermion-dimer recombination processes and their consequences for ultracold mixtures of fermions and dimers is discussed.
description: modified definition of the recombination rate
On the width of collective excitations in chiral soliton models
Creators: name: Weigel, H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In chiral soliton models for baryons the computation of hadronic decay widths of baryon resonances is a long standing problem. For the three flavor Skyrme model I present a solution to this problem that satisfies large--$N_C$ consistency conditions. As an application I focus on the hadronic decay of the $Θ$ and $Θ^*$ pentaquarks.
description: 8 pages, contribution to the proceedings of YKIS "New frontiers in QCD", Kyoto, Dec. 2006
Surpassing the Energy Resolution Limit with ferromagnetic torque sensors
Creators: name: Vinante, Andrea
name: Timberlake, Chris
name: Budker, Dmitry
name: Kimball, Derek Jackson
name: Sushkov, Alexander O.
name: Ulbricht, Hendrik
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: We discuss the fundamental noise limitations of a ferromagnetic torque sensor based on a levitated magnet in the tipping regime. We evaluate the optimal magnetic field resolution taking into account the thermomechanical noise and the mechanical detection noise at the standard quantum limit (SQL). We find that the Energy Resolution Limit (ERL), pointed out in recent literature as a relevant benchmark for most classes of magnetometers, can be surpassed by many orders of magnitude. Moreover, similarly to the case of a ferromagnetic gyroscope, it is also possible to surpass the standard quantum limit for magnetometry with independent spins, arising from spin-projection noise. Our finding indicates that magnetomechanical systems optimized for magnetometry can achieve a magnetic field resolution per unit volume several orders of magnitude better than any conventional magnetometer. We discuss possible implications, focusing on fundamental physics problems such as the search for exotic interactions beyond the standard model.
description: 6 pages, 3 figures
Singular loci of Bruhat-Hibi toric varieties
Creators: name: Brown, Justin A.
name: Lakshmibai, V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: For the toric variety X associated to the Bruhat poset of Schubert varieties in a minuscule G/P, we describe the singular locus in terms of the faces of the associated polyhedral cone. We further show that the singular locus is pure of codimension 3 in X.
description: 24 pages
The Geometry of Genus-One Helicoids
Creators: name: Hoffman, David
name: White, Brian
Publisher: name: arXiv
Year: 2007
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53A10, 49Q05

description: We prove: a properly embedded, genus-one minimal surface that is asymptotic to a helicoid and that contains two straight lines must intersect that helicoid precisely in those two lines. In particular, the two lines divide the surface into two connected components that lie on either side of the helicoid. We prove an analogous result for periodic helicoid-like surfaces. We also give a simple condition guaranteeing that an immersed minimal surface with finite genus and bounded curvature is asymptotic to a helicoid at infinity.
description: 22 pages. This updated version (Apr 17, 2009) contains a much simplified statement and proof of Lemma 3.2. This version will appear in Comm. Math. Helv
The Einstein relation generalized to non-equilibrium
Creators: name: Blickle, V.
name: Speck, T.
name: Lutz, C.
name: Seifert, U.
name: Bechinger, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The Einstein relation connecting the diffusion constant and the mobility is violated beyond the linear response regime. For a colloidal particle driven along a periodic potential imposed by laser traps, we test the recent theoretical generalization of the Einstein relation to the non-equilibrium regime which involves an integral over measurable velocity correlation functions.
Laser Guide Star Adaptive Optics Integral Field Spectroscopy of a Tightly Collimated Bipolar Jet from the Herbig Ae star LkHa 233
Creators: name: Perrin, Marshall D.
name: Graham, James R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have used the integral field spectrograph OSIRIS and laser guide star adaptive optics at Keck Observatory to obtain high angular resolution (0.06"), moderate spectral resolution (R ~ 3800) images of the bipolar jet from the Herbig Ae star LkHa 233, seen in near-IR [Fe II] emission at 1.600 & 1.644 microns. This jet is narrow and tightly collimated, with an opening angle of only 9 degrees, and has an average radial velocity of ~ 100 km/s. The jet and counterjet are asymmetric, with the red-shifted jet much clumpier than its counterpart at the angular resolution of our observations. The observed properties are in general similar to jets seen around T Tauri stars, though it has a relatively large mass flux of (1.2e-7 +- 0.3e-7) M_sun/year, near the high end of the observed mass flux range around T Tauri stars. We also spatially resolve an inclined circumstellar disk around LkHa 233, which obscures the star from direct view. By comparison with numerical radiative transfer disk models, we estimate the disk midplane to be inclined i = 65 +- 5 degrees relative to the plane of the sky. Since the star is seen only in scattered light at near-infrared wavelengths, we detect only a small fraction of its intrinsic flux. Because previous estimates of its stellar properties did not account for this, either LkHa 233 must be located closer than the previously believed, or its true luminosity must be greater than previously supposed, consistent with its being a ~4 M_sun star near the stellar birthline.
description: Accepted for publication in the ApJ
Promoting A Physical Security Mental Model For Personal Firewall Warnings
Creators: name: Raja, Fahimeh
name: Hawkey, Kirstie
name: Hsu, Steven
name: Wang, Kai-Le Clement
name: Beznosov, Konstantin
Publisher: name: Zenodo
Year: 2011
Subjects: Usable security, firewall, warning, mental model

description: We used an iterative process to design personal firewall warnings in which the functionality of a firewall is visualized based on a physical security mental model. We performed a study to determine the degree to which our proposed warnings are understandable for our participants, and the degree to which they convey the risks and encourage safe behavior as compared to warnings based on those from a popular personal firewall. Initial results show that our warnings facilitate the comprehension of warning information, better communicate risk, and increase the likelihood of safe behavior. Moreover, they provided participants with a better understanding of both the functionality of a personal firewall and the consequences of their actions.
Boundary Effects in Local Inflation and Spectrum of Density Perturbations
Creators: name: Ertan, Erol
name: Kaya, Ali
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We observe that when a local patch in a radiation filled Robertson-Walker universe inflates by some reason, outside perturbations can enter into the inflating region. Generally, the physical wavelengths of these perturbations become larger than the Hubble radius as they cross into the inflating space and their amplitudes freeze out immediately. It turns out that the corresponding power spectrum is not scale invariant. Although these perturbations cannot reach out to a distance inner observer shielded by a de Sitter horizon, they still indicate a curious boundary effect in local inflationary scenarios.
description: 11 pages, 8 figures, revtex4, v4: minor typos corrected, twocolumn version
Quantum emission assisted by energy landscape modification in pentacene-decorated carbon nanotubes
Creators: name: Li, Zhen
name: Otsuka, Keigo
name: Yamashita, Daiki
name: Kozawa, Daichi
name: Kato, Yuichiro K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Photoluminescent carbon nanotubes are expected to become versatile room-temperature single-photon sources that have applications in quantum information processing. Quantum emission from carbon nanotubes is often induced by localization of excitons or exciton-exciton annihilation. Here, we modify the local energy landscape of excitons by decorating nanoscale pentacene particles onto air-suspended single-walled carbon nanotubes. Directional exciton diffusion from the undecorated region to the decorated site is demonstrated, suggesting exciton trapping induced by local dielectric screening from pentacene particles. Photoluminescence and photon correlation measurements on a representative carbon nanotube reveal enhanced exciton-exciton annihilation and single-photon emission at room temperature. Pentacene particles are shown to promote strong photon antibunching at the decorated site, indicating that noncovalent functionalization using molecules can be an effective approach for energy landscape modification and quantum emission in carbon nanotubes.
description: 9 pages, 4 figures
Transmission of electromagnetic waves through nonlinear optical layers
Creators: name: Hincapie-Zuluaga, L. M.
name: Mazo-Vásquez, J. D.
name: Betancur-Silvera, C. A.
name: Reyes-Gómez, E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The excitation of soliton states in optical layers exhibiting Kerr nonlinearities is theoretically investigated. The optical transmission coefficient is obtained as a function of the nonlinearity power of an incident monochromatic electromagnetic wave polarized in the transverse electric configuration. In materials exhibiting a defocusing nonlinearity, soliton excitations are not observed if the nonlinearity power associated with the incident electromagnetic wave is below a well-defined value. At such a limiting value of the nonlinearity power, a soliton excitation with an electric-field amplitude independent of the position is found within the nonlinear layer, regardless of the incident-wave frequency value.
Οι περί παιδείας αντιλήψεις του Αγίου Αθανασίου του Παρίου και η αποτίμησή τους από λογίους της εποχής του:
Creators: name: Chen, Yingxue
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Αθανάσιος Πάριος
Παιδεία
Διαφωτισμός
Κοραής
Athanasios Parios
Εducation
Enlightenment
Korais

description: Η παρούσα μελέτη έχει ως σκοπό τη συστηματική αποσαφήνιση των περί παιδείας αντιλήψεων του Αγίου Αθανασίου Παρίου και την κριτική προσέγγιση της πολύπλευρης στάσης του έναντι των ιδεών του Διαφωτισμού. Πρώτα, αποσαφηνίσαμε τις βασικές έννοιες άνωθεν και θύραθεν σοφία της γνωσιολογίας του. Στην συνέχεια εξετάσαμε τη στάση του έναντι της ελληνικής αρχαιότητας. Αναθεωρήσαμε τις απόλυτες αρνητικές αξιολογήσεις προγενέστερων μελετών για την στάση του Παρίου προς τα μαθηματικά και τις φυσικές επιστήμες. Επισημάναμε την ενίοτε θετική στάση του προς τις φυσικές επιστήμες, καθώς επίσης άγνωστες πτυχές της μόρφωσής του στα μαθηματικά και στις φυσικές επιστήμες. Εξετάσαμε κυρίως στο πλαίσιο της παιδείας, τις βασικές έννοιες της αθεΐας στα συγγράμματά του. Ένας άλλος στόχος της μελέτης μας είναι η περιγραφή και ανάλυση του τρόπου με τον οποίο αξιολογήθηκε η εκπαιδευτική θεωρία και πράξη του Αθανασίου Παρίου από λογίους διάφορων ιδεολογικών ρευμάτων της εποχής του. Διερευνήσαμε τα ποικίλα σχόλια και τις αντιδράσεις λογίων της εποχής του, που προκλήθηκαν με την έκδοση του επίμαχου φυλλαδίου Αντιφώνησις. Τέλος, μελετήσαμε και την αξιολόγηση των διδακτικών εγχειριδίων Γραμματικής και Ρητορικής του Παρίου από λογίους της εποχής του.
description: The aim of this dissertation is to study systematically the educational thoughts of St. Athanasios Parios and to make a critical approach to his multidimensional attitude towards the ideas of the Enlightenment. First of all, I clarified the concepts wisdom from Above and secular wisdom in his works. Then I examined his attitude towards the Greek antiquity and reconsidered the absolute negative opinions of some previous studies on Parios’ attitude towards mathematics and the natural sciences. I discovered also some positive elements in his works about the natural sciences and revealed some unknown aspects of his education in mathematics and physics. From the educational point of view, I examined also the basic concepts of atheism in his writings. Another purpose of my dissertation is to describe and analyze the way how the educational theory and practice of Athanasios Parios is estimated by scholars of his time. I investigated in detail the various comments of his contemporary scholars with different ideological backgrounds on the controversial booklet of Parios Antiphonisis. Finally, I examined extensively the positive and negative comments of his contemporary scholars on the textbooks Grammar and Rhetoric which Parios taught in Greek schools.
Additional file 1 of MarineMetagenomeDB: a public repository for curated and standardized metadata for marine metagenomes
Creators: name: Nata’ala, Muhammad Kabiru
name: Avila Santos, Anderson P.
name: Coelho Kasmanas, Jonas
name: Bartholomäus, Alexander
name: Saraiva, João Pedro
name: Godinho Silva, Sandra
name: Keller-Costa, Tina
name: Costa, Rodrigo
name: Gomes, Newton C. M.
name: Ponce de Leon Ferreira de Carvalho, André Carlos
name: Stadler, Peter F.
name: Sipoli Sanches, Danilo
name: Nunes da Rocha, Ulisses
Publisher: name: figshare
Year: 2022
Subjects: subject: Information Systems
subject: FOS: Computer and information sciences

description: Additional file 1. Table S1: Dictionary of terms used for filtering out non-marine samples.
Hall field induced magnetoresistance oscillations of a two-dimensional electron system
Creators: name: Kunold, A.
name: Torres, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We develop a model of the nonlinear response to a DC electrical current of a two dimensional electron system(2DES) placed on a magnetic field. Based on the exact solution of the Schroedinger equation in arbitrarily strong electric and magnetic fields, and separating the relative and guiding center coordinates, a Kubo-like formula for the current is worked out as a response to the impurity scattering. Self-consistent expressions determine the longitudinal and Hall components of the electric field in terms of the DC current. The differential resistivity displays strong Hall field-induced oscillations, in agreement with the main features of the phenomenon observed in recent experiments.
description: 11 pages, 5 figures