cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Parity-Violating Observables of Two-Nucleon Systems in Effective Field Theory
Creators: name: Liu, C. -P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: A newly-proposed parity-violating nucleon-nucleon interaction based on effective field theory is studied in this work. It is found that at low energy, i.e., E_lab less than 90 MeV for 1S0-3P0 transitions and E_lab less than 40 MeV for 3S1-1P1 and 3S1-3P1 transitions, the parity-violating observables can be completely specified by a minimal set of six parameters. It contains five low-energy constants, which are equivalent to the Danilov parameters, and an additional parameter that characterizes the long-range one-pion exchange and is proportional to the parity-violating pion-nucleon coupling constant. Selected observables in two-nucleons systems are analyzed in this framework with their dependence on these parameters being expressed in a nearly model-independent way.
description: 31 pages, 5 figures (22 panels), and 6 tables
NAS-FAS: Static-Dynamic Central Difference Network Search for Face Anti-Spoofing
Creators: name: Yu, Zitong
name: Wan, Jun
name: Qin, Yunxiao
name: Li, Xiaobai
name: Li, Stan Z.
name: Zhao, Guoying
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Face anti-spoofing (FAS) plays a vital role in securing face recognition systems. Existing methods heavily rely on the expert-designed networks, which may lead to a sub-optimal solution for FAS task. Here we propose the first FAS method based on neural architecture search (NAS), called NAS-FAS, to discover the well-suited task-aware networks. Unlike previous NAS works mainly focus on developing efficient search strategies in generic object classification, we pay more attention to study the search spaces for FAS task. The challenges of utilizing NAS for FAS are in two folds: the networks searched on 1) a specific acquisition condition might perform poorly in unseen conditions, and 2) particular spoofing attacks might generalize badly for unseen attacks. To overcome these two issues, we develop a novel search space consisting of central difference convolution and pooling operators. Moreover, an efficient static-dynamic representation is exploited for fully mining the FAS-aware spatio-temporal discrepancy. Besides, we propose Domain/Type-aware Meta-NAS, which leverages cross-domain/type knowledge for robust searching. Finally, in order to evaluate the NAS transferability for cross datasets and unknown attack types, we release a large-scale 3D mask dataset, namely CASIA-SURF 3DMask, for supporting the new 'cross-dataset cross-type' testing protocol. Experiments demonstrate that the proposed NAS-FAS achieves state-of-the-art performance on nine FAS benchmark datasets with four testing protocols.
description: Accepted by IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI); the CASIA-SURF 3DMask dataset is available at http://www.cbsr.ia.ac.cn/users/jwan/database/3DMask.pdf
Οθωμανική Κρήτη: ο αιώνας μετά την κατάκτηση: η εφαρμογή του οθωμανικού δικαίου- οι μάρτυρες επί της διαδικασίας
Creators: name: Καλογεράκης, Αντώνιος Κυριάκου
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Οθωμανική Αυτοκρατορία- Κρήτη
Ισλαμικό δίκαιο- Σαρία
Χάνδακας- 17ος – 18ος αιώνας
Ottoman Empire- ottoman Crete
Islamic law- Sharia
Candia- 17th – 18th century

description: Η κατάκτηση της Κρήτης σηματοδότησε το τέλος της οθωμανικής επέκτασης στην Νοτιοανατολική Ευρώπη. Η εκπόρθηση του Χάνδακα και η επιβολή της οθωμανικής κυριαρχίας, μέσα από την διαμόρφωση νέων θεσμών, αποτελούν το θέμα αυτής της εργασίας. Ειδικότερα εξετάζεται η εφαρμογή του οθωμανικού δικαίου στο νησί και η περίπτωση των μαρτύρων επί της διαδικασίας (şuhud ul- hal). Μέσα από δύο κώδικες του ιεροδικείου Ηρακλείου, επιχειρείται μία προσωπογραφική προσέγγιση των μαρτύρων επί της διαδικασίας ενώ τέλος παρατίθενται και τα επί μέρους συμπεράσματα, τα οποία προέκυψαν από την έρευνα και αφορούν την κοινωνική προέλευση των μαρτύρων, την συσχέτισή τους με τους διαδίκους και άλλες υποθέσεις εργασίας που μας απασχόλησαν.
description: The conquest of Crete in 1669 signaled the end of Ottoman expansion in South Eastern Europe. The capture of Candia and the imposition of Ottoman rule through the formation of new institutions, constitute the subject of this paper. A particular point of concern is the implementation of Ottoman law on the island and the witnesses to the procedure (şuhud ul-hal). A prosopographic approach of the witnesses on the procedure is being attempted through two registers of the islamic court of Heraklion, while other conclusions , which emerged from the research, concerning the social background of the witnesses, the existence or not of a relationship with the litigants and other assumptions that we considered, are also being presented.
Factorization of Seiberg-Witten Curves with Fundamental Matter
Creators: name: Janik, Romuald A.
name: Obers, Niels A.
name: Ronne, Peter B.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present an explicit construction of the factorization of Seiberg-Witten curves for N=2 theory with fundamental flavors. We first rederive the exact results for the case of complete factorization, and subsequently derive new results for the case with breaking of gauge symmetry U(Nc) to U(N1)xU(N2). We also show that integrality of periods is necessary and sufficient for factorization in the case of general gauge symmetry breaking. Finally, we briefly comment on the relevance of these results for the structure of N=1 vacua.
description: 24 pages, 2 figures
Optimisation of study laboratory methods: The researcher’s real game changer
Creators: name: Mayito, Jonathan
name: I Andia
name: M Belay
name: DA Jolliffe
name: DP Kateete
name: ST Reece
name: AR Martineau
Publisher: name: AAS Open Research
Year: 2019

description: Objectives
Good quality study results largely depend on robustness of study methods used. This PhD project will investigate detection of tuberculosis (TB) genetic material in stem cells as a diagnostic and preventive therapy monitoring target. As part of the laboratory methods, we set out to optimise; magnetic based cell sorting and TB genetic material extraction, using peripheral blood white cells and BCG bacteria.

Methods
These optimisation experiments were performed during a 3 month attachment to Queen Mary University of London and University of Cambridge. Nine experiments were performed to optimise separation of white cells, sorting of stem cells, and extraction of genetic materials. Blood dilution was initially in 1:1 ratio and subsequently in 1:2 ratio.
Results
Results showed that UltraPure magnetic micro-bead kit and MS separation column were superior. Double-dilution of blood using a special buffer, and filtering white cells before adding magnetic-beads, greatly improved UltraPure-MS column performance. BCG genetic material was detected only with organic salt based extraction but not heating or commercial kit.
Conclusion
The nine experiments helped to identify procedures for use in the main study to ensure optimum results.

This work was supported by THRiVE-2 support, a DELTAS Africa grant # DEL-15-011 from Welcome Trust grant # 107742/Z/15/Z and the UK government.
Path integral renormalisation in loop quantum cosmology
Creators: name: Bodendorfer, Norbert
name: Han, Muxin
name: Haneder, Fabian
name: Liu, Hongguang
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A coarse graining technique akin to block spin transformations that groups together fiducial cells in a homogeneous and isotropic universe has been recently developed in the context of loop quantum cosmology. The key technical ingredient was an SU(1, 1) group and Lie algebra structure of the physical observables as well as the use of Perelomov coherent states for SU(1, 1). It was shown that the coarse graining operation is completely captured by changing group representations. Based on this result, it was subsequently shown that one can extract an explicit renormalisation group flow of the loop quantum cosmology Hamiltonian operator in a simple model with dust-clock. In this paper, we continue this line of investigation and derive a coherent state path integral formulation of this quantum theory and extract an explicit expression for the renormalisation-scale dependent classical Hamiltonian entering the path integral for a coarse grained description at that scale. We find corrections to the non-renormalised Hamiltonian that are qualitatively similar to those previously investigated via canonical quantisation. In particular, they are again most sensitive to small quantum numbers, showing that the large quantum number (spin) description captured by so called "effective equations" in loop quantum cosmology does not reproduce the physics of many small quantum numbers (spins). Our results have direct impact on path integral quantisation in loop quantum gravity, showing that the usually taken large spin limit should be expected not to capture (without renormalisation, as mostly done) the physics of many small spins that is usually assumed to be present in physically reasonable quantum states.
description: 25 pages, 1 figure
Positive and negative magnetocapacitance in magnetic nanoparticle systems
Creators: name: Lawes, G.
name: Tackett, R.
name: Masala, O.
name: Adhikary, B.
name: Naik, R.
name: Seshadri, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The dielectric properties of MnFe$_2$O$_4$ and $γ$-Fe$_2$O$_3$ magnetic nanoparticles embedded in insulating matrices were investigated. The samples showed frequency dependent dielectric anomalies coincident with the magnetic blocking temperature and significant magnetocapacitance above this blocking temperature, as large as 0.4% at H = 10kOe. For both samples the magnetic field induced change in dielectric constant was proportional to the square of the sample magnetization. These measurements suggest that the dielectric properties of magnetic nanoparticles are closely related to the disposition of magnetic moments in the system. As neither bulk gamma-Fe2O3 nor MnFe2O3 are magnetoelectric materials, this magnetodielectric coupling is believed to arise from extrinsic effects which are discussed in light of recent work relating magnetoresistive and magnetocapacitive behavior.
description: 3 pages, 3 figures
Nonequilibrium field-induced phase separation in single-file diffusion
Creators: name: Tabatabaei, Fatemeh
name: Schütz, Gunter M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Using an analytically tractable lattice model for reaction-diffusion processes of hard-core particles we demonstrate that under nonequilibrium conditions phase coexistence may arise even if the system is effectively one-dimensional as e.g. in the channel system of some zeolites or in artificial optical lattices. In our model involving two species of particles a steady-state particle current is maintained by a density gradient between the channel boundaries and by the influence of an external driving force. This leads to the development of a fluctuating but always microscopically sharp interface between two domains of different densities which are fixed by the boundary chemical potentials. The internal structure of the interface becomes very simple for strong driving force. We calculate the drift velocity and diffusion coefficient of the interface in terms of the microscopic model parameters.
description: 38 pages, 2 figures
Τεχνικές υπολογιστικής νοημοσύνης σε παιχνίδια μάχης πρώτου προσώπου:
Creators: name: Πετράκης, Στυλιανός Παναγιώτη
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Υπολογιστική νοημοσύνη
Νευρωνικά δίκτυα
Παιχνίδια μάχης πρώτου προσώπου
Computational intelligence
Neural networks
First person shooter games

description: σε αυτή την εργασία προτείνουμε την χρήση τεχνικών υπολογιστικής νοημοσύνης σε παιχνίδια μάχης πρώτου προσώπου. στο πρώτο μέρος θα παρουσιάσουμε τις τεχνικές υπολογιστικής νοημοσύνης που έχουν προταθεί σε αυτή την κατηγορία παιχνιδιών, χωρίζοντάς τες σε τρείς βασικές κατηγορίες: νευρωνικά δίκτυα, εξελικτικές μεθόδους, που περιλαμβάνουν τους γενετικούς και μιμητικούς αλγορίθμους καθώς και τις υβριδικές μεθόδους, όπως επίσης και τις τεχνικές ασαφούς λογικής. στην συνέχεια θα παρουσιάσουμε συνοπτικά τις αντίστοιχες τεχνικές τεχνητής νοημοσύνης που έχουν προταθεί για τον τομέα των παιχνιδιών μάχης πρώτου προσώπου. στο δεύτερο μέρος θα περιγράψουμε την ανάπτυξη δύο τεχνικών υπολογιστικής νοημοσύνης χρησιμοποιώντας το εμπορικό ηλεκτρονικό παιχνίδι unreal tournament με σκοπό να βελτιώσουμε την απόδοση των χαρακτήρων που ελέγχει ο υπολογιστής (bots), με την χρήση νευρωνικών δικτύων. οι τεχνικές αυτές θα ασχολούνται με δύο κύριες λειτουργίες ενός παίκτη μέσα στο παιχνίδι: την επιλογή όπλου ανάλογα με την περίσταση και την αξιολόγηση της επικινδυνότητας μιας μάχης. τέλος θα προτείνουμε μελλοντικές προεκτάσεις των τεχνικών που παρουσιάστηκαν και θα προσφέρουμε έναν οδηγό για οποιονδήποτε ενδιαφέρεται να ασχοληθεί με την ανάπτυξη bots σε αυτή την πλατφόρμα.
description: in this thesis, we will focus on the usage of computational intelligence techniques in first person shooter games. in the first part, we will describe the proposed computational intelligence techniques for this game genre, after dividing them into three basic categories: neural networks, evolutionary methods, which include genetic and memetic algorithms, as well as hybrid methods, and fuzzy logic techniques. we will also briefly present the artificial intelligence techniques in first person shooter games. in the second part we will describe and implement two computational intelligence techniques using the unreal tournament game, in order to improve the performance of non player characters (bots) inside the game, using neural networks. those techniques will deal with the choice of the right weapon depending on the situation the bot will be in and the evaluation of the danger in a battle. finally, we will propose some future applications and plans for the described algorithms and we will offer a tutorial to anyone interested in bot development using this platform.
Topological magnetic order and superconductivity in EuRbFe$_4$As$_4$
Creators: name: Hemmida, M.
name: Winterhalter-Stocker, N.
name: Ehlers, D.
name: von Nidda, H. -A. Krug
name: Yao, M.
name: Bannies, J.
name: Rienks, E. D. L.
name: Kurleto, R.
name: Felser, C.
name: Büchner, B.
name: Fink, J.
name: Gorol, S.
name: Förster, T.
name: Arsenijevic, S.
name: Fritsch, V.
name: Gegenwart, P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study single crystals of the magnetic superconductor EuRbFe$_4$As$_4$ by magnetization, electron spin resonance (ESR), angle-resolved photoemission spectroscopy (ARPES) and electrical resistance in pulsed magnetic fields up to 630 kOe. The superconducting state below 36.5 K is almost isotropic and only weakly affected by the development of Eu$^{2+}$ magnetic order at 15 K. On the other hand, for the external magnetic field applied along the c-axis the temperature dependence of the ESR linewidth reveals a Berezinskii-Kosterlitz-Thouless topological transition below 15 K. This indicates that Eu$^{2+}$-planes are a good realization of a two-dimensional XY-magnet, which reflects the decoupling of the Eu$^{2+}$ magnetic moments from superconducting FeAs-layers.
Dynamics and control of the expansion of finite-size plasmas produced in ultraintense laser-matter interactions
Creators: name: Peano, F.
name: Martins, J. L.
name: Fonseca, R. A.
name: Silva, L. O.
name: Coppa, G.
name: Peinetti, F.
name: Mulas, R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The strong influence of the electron dynamics provides the possibility of controlling the expansion of laser-produced plasmas by appropriately shaping the laser pulse. A simple irradiation scheme is proposed to tailor the explosion of large deuterium clusters, inducing the formation of shock structures, capable of driving nuclear fusion reactions. Such a scenario has been thoroughly investigated, resorting to two- and three-dimensional particle-in-cell simulations. Furthermore, the intricate dynamics of ions and electrons during the collisionless expansion of spherical nanoplasmas has been analyzed in detail using a self-consistent ergodic-kinetic model. This study clarifies the transition from hydrodynamic-like to Coulomb-explosion regimes.
On inner Kan complexes in the category of dendroidal sets
Creators: name: Moerdijk, Ieke
name: Weiss, Ittay
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Topology (math.AT)
subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 55P48, 55U10, 55U40 (Primary) 18D50, 18D10, 18G30 (Secondary)

description: The category of dendroidal sets is an extension of that of simplicial sets, suitable for defining nerves of operads rather than just of categories. In this paper, we prove some basic properties of inner Kan complexes in the category of dendroidal sets. In particular, we extend fundamental results of Boardman and Vogt, of Cordier and Porter, and of Joyal to dendroidal sets.
description: 41 pages. Minor corrections to Sections 4 and 9
How Stands Collapse II
Creators: name: Pearle, Philip
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: I review ten problems associated with the dynamical wave function collapse program, which were described in the first of these two papers. Five of these, the \textit{interaction, preferred basis, trigger, symmetry} and \textit{superluminal} problems, were discussed as resolved there. In this volume in honor of Abner Shimony, I discuss the five remaining problems, \textit{tails, conservation law, experimental, relativity, legitimization}. Particular emphasis is given to the tails problem, first raised by Abner. The discussion of legitimization contains a new argument, that the energy density of the fluctuating field which causes collapse should exert a gravitational force. This force can be repulsive, since this energy density can be negative. Speculative illustrations of cosmological implications are offered.
description: 37 pages
Dyadic Green's Functions and Guided Surface Waves for a Surface Conductivity Model of Graphene
Creators: name: Hanson, George W.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: An exact solution is obtained for the electromagnetic field due to an electric current in the presence of a surface conductivity model of graphene. The graphene is represented by an infinitesimally-thin, local and isotropic two-sided conductivity surface. The field is obtained in terms of dyadic Green's functions represented as Sommerfeld integrals. The solution of plane-wave reflection and transmission is presented, and surface wave propagation along graphene is studied via the poles of the Sommerfeld integrals. For isolated graphene characterized by complex surface conductivity, a proper transverse-electric (TE) surface wave exists if and only if the imaginary part of conductivity is positive (associated with interband conductivity), and a proper transverse-magnetic (TM) surface wave exists when the imaginary part of conductivity is negative (associated with intraband conductivity). By tuning the chemical potential at infrared frequencies, the sign of the imaginary part of conductivity can be varied, allowing for some control over surface wave properties.
description: 9 figures
Gaia Early Data Release 3: Modelling and calibration of Gaia's point and line spread functions
Creators: name: Rowell, N.
name: Davidson, M.
name: Lindegren, L.
name: van Leeuwen, F.
name: Castañeda, J.
name: Fabricius, C.
name: Bastian, U.
name: Hambly, N. C.
name: Hernández, J.
name: Bombrun, A.
name: Evans, D. W.
name: De Angeli, F.
name: Riello, M.
name: Busonero, D.
name: Crowley, C.
name: Mora, A.
name: Lammers, U.
name: Gracia, G.
name: Portell, J.
name: Biermann, M.
name: Brown, A. G. A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Context: The unprecedented astrometric precision of the Gaia mission relies on accurate estimates of the locations of sources in the Gaia data stream. This is ultimately performed by point spread function (PSF) fitting, which in turn requires an accurate reconstruction of the PSF. Gaia Early Data Release 3 (EDR3) will, for the first time, use a PSF calibration that models several of the strongest dependences, leading to signficantly reduced systematic errors. Aims: We describe the PSF model and calibration pipeline implemented for Gaia EDR3, including an analysis of the calibration results over the 34 months of data. We include a discussion of the limitations of the current pipeline and directions for future releases. This will be of use both to users of Gaia data and as a reference for other precision astrometry missions. Methods: We develop models of the 1D line spread function (LSF) and 2D PSF profiles based on a linear combination of basis components. We fit the models to selected primary sources in independent time ranges, using simple parameterisations for the colour and other dependences. Variation in time is smoothed by merging the independent calibrations in a square root information filter, with resets at certain mission events that induce a discontinuous change in the PSF. Results: The PSF calibration shows strong time and colour dependences that accurately reproduce the varying state of the Gaia astrometric instrument. Analysis of the residuals reveals both the performance and the limitations of the current models and calibration pipeline, and indicates the directions for future development. Conclusions: The PSF modelling and calibration carried out for Gaia EDR3 represents a major step forwards in the data processing and will lead to reduced systematic errors in the core mission data products. Further significant improvements are expected in the future data releases.
description: Accepted by A&A for inclusion in Gaia EDR3 special issue
D-branes in Nongeometric Backgrounds
Creators: name: Lawrence, Albion
name: Schulz, Michael B.
name: Wecht, Brian
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: "T-fold" backgrounds are generically-nongeometric compactifications of string theory, described by T^n fibrations over a base N with transition functions in the perturbative T-duality group. We review Hull's doubled torus formalism, which geometrizes these backgrounds, and use the formalism to constrain the D-brane spectrum (to leading order in g_s and alpha') on T^n fibrations over S^1 with O(n,n;Z) monodromy. We also discuss the (approximate) moduli space of such branes and argue that it is always geometric. For a D-brane located at a point on the base N, the classical ``D-geometry'' is a T^n fibration over a multiple cover of N.
description: 29 pages; uses harvmac.tex; v2: substantial revision throughout
PowerDynamics.jl -- An experimentally validated open-source package for the dynamical analysis of power grids
Creators: name: Plietzsch, Anton
name: Kogler, Raphael
name: Auer, Sabine
name: Merino, Julia
name: Gil-de-Muro, Asier
name: Liße, Jan
name: Vogel, Christina
name: Hellmann, Frank
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: PowerDynamics.jl is a Julia package for time-domain modeling of power grids that is specifically designed for the stability analysis of systems with high shares of renewable energies. It makes use of Julia's state-of-the-art differential equation solvers and is highly performant even for systems with a large number of components. Further, it is compatible with Julia's machine learning libraries and allows for the utilization of these methods for dynamical optimization and parameter fitting. The package comes with a number of predefined models for synchronous machines, transmission lines and inverter systems. However, the strict open-source approach and a macro-based user-interface also allows for an easy implementation of custom-built models which makes it especially interesting for the design and testing of new control strategies for distributed generation units. This paper presents how the modeling concept, implemented component models and fault scenarios have been experimentally tested against measurements in the microgrid lab of TECNALIA.
Ramification of Quaternion Algebras over Stable Elliptic Surfaces
Creators: name: Perego, Arvid
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14G99

description: We give a geometrical criterion to determine when a quaternion algebra over the function field of a stable elliptic surface X is an Azumaya algebra over X.
description: 12 pages
Neutrino Majorana Masses from String Theory Instanton Effects
Creators: name: Ibanez, L. E.
name: Uranga, A. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Finding a plausible origin for right-handed neutrino Majorana masses in semirealistic compactifications of string theory remains one of the most difficult problems in string phenomenology. We argue that right-handed neutrino Majorana masses are induced by non-perturbative instanton effects in certain classes of string compactifications in which the $U(1)_{B-L}$ gauge boson has a Stückelberg mass. The induced operators are of the form $e^{-U}ν_Rν_R$ where $U$ is a closed string modulus whose imaginary part transforms appropriately under $B-L$. This mass term may be quite large since this is not a gauge instanton and $Re U$ is not directly related to SM gauge couplings. Thus the size of the induced right-handed neutrino masses could be a few orders of magnitude below the string scale, as phenomenologically required. It is also argued that this origin for neutrino masses would predict the existence of R-parity in SUSY versions of the SM. Finally we comment on other phenomenological applications of similar instanton effects, like the generation of a $μ$-term, or of Yukawa couplings forbidden in perturbation theory.
description: 40 pages, 4 figures (v2: added references, small corrections)(v3: minor corrections)
Coherent Quasiclassical Dynamics of a Persistent Current Qubit
Creators: name: Berns, D. M.
name: Oliver, W. D.
name: Valenzuela, S. O.
name: Shytov, A. V.
name: Berggren, K. K.
name: Levitov, L. S.
name: Orlando, T. P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: A new regime of coherent quantum dynamics of a qubit is realized at low driving frequencies in the strong driving limit. Coherent transitions between qubit states occur via the Landau-Zener process when the system is swept through an energy-level avoided crossing. The quantum interference mediated by repeated transitions gives rise to an oscillatory dependence of the qubit population on the driving field amplitude and flux detuning. These interference fringes, which at high frequencies consist of individual multiphoton resonances, persist even for driving frequencies smaller than the decoherence rate, where individual resonances are no longer distinguishable. A theoretical model that incorporates dephasing agrees well with the observations.
description: 4 pages, 5 figures
Longest increasing subsequence as expectation of a simple nonlinear stochastic PDE with a low noise intensity
Creators: name: Katzav, E.
name: Nechaev, S.
name: Vasilyev, O.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We report some new observation concerning the statistics of Longest Increasing Subsequences (LIS). We show that the expectation of LIS, its variance, and apparently the full distribution function appears in statistical analysis of some simple nonlinear stochastic partial differential equation (SPDE) in the limit of very low noise intensity.
description: 6 pages, 4 figures, reference added
Non-gaussianity in fluctuations from warm inflation
Creators: name: Moss, Ian G
name: Xiong, Chun
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The scalar mode density perturbations in a the warm inflationary scenario are analysed with a view to predicting the amount of non-gaussianity produced by this scenario. The analysis assumes that the inflaton evolution is strongly damped by the radiation, with damping terms that are temperature independent. Entropy fluctuations during warm inflation play a crucial role in generating non-gaussianity and result in a distinctive signal which should be observable by the Planck satellite.
description: 14 pages, 2 figures, v2 terminology corrected
Balancing selection and genetic variation of Plasmodium falciparum vaccine candidate genes in sub-Saharan Africa populations
Creators: name: Mouhamadou  Fadel Diop
name: A Worwui
name: K Mane
name: E Kamau
name: A Djimde
name: U D’Alessandro
name: A.A Ngwa
Publisher: name: AAS Open Research
Year: 2019

description: Objective: The next generation vaccine design must take into considerations the variations in vaccine candidate antigens. These can be captured through an analysis of diversity and balancing selection, which can identify more candidate loci and gene domains. The aim is to identify and characterize regions of the genome and candidate vaccine antigens that are under balancing selection across Plasmodium falciparum populations in sub-Saharan Africa.
Method: Genome-wide SNPs were extracted from 2375 samples across 16 countries in Africa. Genome scan for balancing selection was determined from Tajima’s D and ß indices per locus. 10 candidate vaccine genes were selected and further characterized for diversity in African populations using population genetic parameters. The haplotype structure across these candidates were visualized with t-SNE.
Results: 365 SNPs at maf 1% were informative across vaccine candidate genes. Except for PfSEA, they all had a positive overall Tajima’s D. The domains under balancing selection within each gene was similar across all populations. Except for a highly differentiated Ethiopian population, heterozygosity was low for all genes across all populations.
Conclusion: Balancing selection target a wide variety of similar gene loci in the genome of Plasmodium populations from Africa. New targets of balancing selection and allelic variation should be considered to refine multivalent vaccine design.
Διαχείριση Εμπιστοσύνης στις Συναλλαγές Ευφυών Πρακτόρων στο Σημασιολογικό Ιστό:
Creators: name: Μαλλιαράκης, Χρήστος Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Μοντέλο Εμπιστοσύνης
Ευφυείς Πράκτορες
Σημασιολογικός Ιστός
Trust Model
Intelligent Agents
Semantic Web

description: Η σημαντική ανάπτυξη πολύ-πρακτορικών συστημάτων (MAS) στο Σημασιολογικό Ιστό έχει καταστήσει αναγκαία την ανάπτυξη μηχανισμών εμπιστοσύνης που θα διέπουν τις συναλλαγές μεταξύ των ευφυών πρακτόρων. Στόχος της διπλωματικής εργασίας είναι η γενικότερη μελέτη των μετρικών εμπιστοσύνης που έχουν προταθεί μέχρι σήμερα και, ειδικότερα, η ανάπτυξη ενός νέου μοντέλου εμπιστοσύνης. Ειδικότερο πεδίο εφαρμογής είναι η διαπραγμάτευση μεταξύ ευφυών πρακτόρων στο Σημασιολογικό Ιστό.
description: The important development of multi-agent systems (MAS) in the Semantic Web has rendered necessary the development of trust mechanisms that will supervise the transactions between the intelligent agents. The objective of the thesis is the study of the trust metrics that have been proposed up to today and, more specifically, the development of a new trust model. In particular, the domain of application is the negotiation between intelligent agents in the Semantic Web.
The Hagedorn temperature in a decoupled sector of AdS/CFT
Creators: name: Harmark, Troels
name: Kristjansson, Kristjan R.
name: Orselli, Marta
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We match the Hagedorn/deconfinement temperature of planar N=4 super Yang-Mills (SYM) on R x S^3 to the Hagedorn temperature of string theory on AdS_5 x S^5. The match is done in a near-critical region where both gauge theory and string theory are weakly coupled. On the gauge theory side we are taking a decoupling limit found in hep-th/0605234 in which the physics of planar N=4 SYM is given exactly by the ferromagnetic XXX_{1/2} Heisenberg spin chain. We find moreover a general relation between the Hagedorn/deconfinement temperature and the thermodynamics of the Heisenberg spin chain. On the string theory side, we identify the dual limit which is taken of string theory on a maximally symmetric pp-wave background with a flat direction, obtained from a Penrose limit of AdS_5 x S^5. We compute the Hagedorn temperature of the string theory and find agreement with the Hagedorn/deconfinement temperature computed on the gauge theory side. Finally, we discuss a modified decoupling limit in which planar N=4 SYM reduces to the XXX_{1/2} Heisenberg spin chain with an external magnetic field.
description: 7 pages. Talk presented by MO at the RTN workshop, Napoli, Oct. 9-13, 2007
Confronting X-ray Emission Models with the Highest-Redshift Kiloparsec-scale Jets: the z=3.89 Jet in Quasar 1745+624
Creators: name: Cheung, C. C.
name: Stawarz, L.
name: Siemiginowska, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A newly identified kiloparsec-scale X-ray jet in the high-redshift z=3.89 quasar 1745+624 is studied with multi-frequency Very Large Array, Hubble Space Telescope, and Chandra X-ray imaging data. This is only the third large-scale X-ray jet beyond z>3 known and is further distinguished as being the most luminous relativistic jet observed at any redshift, exceeding 10^45 erg/s in both the radio and X-ray bands. Apart from the jet's extreme redshift, luminosity, and high inferred equipartition magnetic field (in comparison to local analogues), its basic properties such as X-ray/radio morphology and radio polarization are similar to lower-redshift examples. Its resolved linear structure and the convex broad-band spectral energy distributions of three distinct knots are also a common feature among known powerful X-ray jets at lower-redshift. Relativistically beamed inverse Compton and `non-standard' synchrotron models have been considered to account for such excess X-ray emission in other jets; both models are applicable to this high-redshift example but with differing requirements for the underlying jet physical properties, such as velocity, energetics, and electron acceleration processes. One potentially very important distinguishing characteristic between the two models is their strongly diverging predictions for the X-ray/radio emission with increasing redshift. This is considered, though with the limited sample of three z>3 jets it is apparent that future studies targeted at very high-redshift jets are required for further elucidation of this issue. Finally, from the broad-band jet emission we estimate the jet kinetic power to be no less than 10^46 erg/s, which is about 10% of the Eddington luminosity corresponding to this galaxy's central [abridged]
description: ApJ, accepted. No changes from version 1. 17 pages emulateapj style, 7 figures
The Effects of Atmospheric Dispersion on High-Resolution Solar Spectroscopy
Creators: name: Reardon, Kevin P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the effects of atmospheric dispersion on observations of the Sun at the ever-higher spatial resolutions afforded by increased apertures and improved techniques. The problems induced by atmospheric refraction are particularly significant for solar physics because the Sun is often best observed at low elevations, and the effect of the image displacement is not merely a loss of efficiency, but the mixing of information originating from different points on the solar surface. We calculate the magnitude of the atmospheric dispersion for the Sun during the year and examine the problems produced by this dispersion in both spectrographic and filter observations. We describe an observing technique for scanning spectrograph observations that minimizes the effects of the atmospheric dispersion while maintaining a regular scanning geometry. Such an approach could be useful for the new class of high-resolution solar spectrographs, such as SPINOR, POLIS, TRIPPEL, and ViSP.
Vacuum Birefringence in a Rotating Magnetic Field
Creators: name: Adler, Stephen L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We calculate the vacuum polarization-induced ellipticity acquired by a linearly polarized laser beam of angular frequency $\bar ω$ on traversing a region containing a transverse magnetic field rotating with a small angular velocity $Ω$ around the beam axis. The transmitted beam contains the fundamental frequency $\bar ω$ and weak sidebands of frequency $\bar ω\pm 2 Ω$, but no other sidebands. To first order in small quantities, the ellipticity acquired by the transmitted beam is independent of $Ω$, and is the same as would be calculated in the approximation of regarding the magnetic field as fixed at its instantaneous angular orientation, using the standard vacuum birefringence formulas for a static magnetic field. Also to first order, there is no rotation of the polarization plane of the transmitted beam. Analogous statements hold when the magnetic field strength is slowly varying in time.
description: 20 pages; v2 has simplification of results of Eqs. (9a,b), and new Sec. 5 giving a perturbation theory derivation of results; v3 has minor revisions suggested by referee--this is final published version; v4, typos corrected
Untangling planar graphs from a specified vertex position - Hard cases
Creators: name: Kang, Mihyun
name: Pikhurko, Oleg
name: Ravsky, Alexander
name: Schacht, Mathias
name: Verbitsky, Oleg
Publisher: name: arXiv
Year: 2008
Subjects: subject: Discrete Mathematics (cs.DM)
subject: Computational Geometry (cs.CG)
subject: FOS: Computer and information sciences

description: Given a planar graph $G$, we consider drawings of $G$ in the plane where edges are represented by straight line segments (which possibly intersect). Such a drawing is specified by an injective embedding $π$ of the vertex set of $G$ into the plane. We prove that a wheel graph $W_n$ admits a drawing $π$ such that, if one wants to eliminate edge crossings by shifting vertices to new positions in the plane, then at most $(2+o(1))\sqrt n$ of all $n$ vertices can stay fixed. Moreover, such a drawing $π$ exists even if it is presupposed that the vertices occupy any prescribed set of points in the plane. Similar questions are discussed for other families of planar graphs.
description: 18 pages, 4 figures. Lemma 3.3 is corrected, several amendments are made throughout the paper
Superposition of intra- and inter-layer excitons in twistronic MoSe$_2$/WSe$_2$ bilayers probed by resonant Raman scattering
Creators: name: McDonnell, Liam P.
name: Viner, Jacob J. S.
name: Ruiz-Tijerina, David A.
name: Rivera, Pasqual
name: Xu, Xiaodong
name: Fal'ko, Vladimir I.
name: Smith, David C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Hybridisation of electronic bands of two-dimensional materials, assembled into twistronic heterostructures, enables one to tune their optoelectronic properties by selecting conditions for resonant interlayer hybridisation. Resonant interlayer hybridisation qualitatively modifies the excitons in such heterostructures, transforming these optically active modes into superposition states of interlayer and intralayer excitons. For MoSe$_2$/WSe$_2$ heterostructures, strong hybridization occurs between the holes in the spin-split valence band of WSe$_2$ and in the top valence band of MoSe$_2$, especially when both are bound to the same electron in the lowest conduction band of WSe$_2$. Here we use resonance Raman scattering to provide direct evidence for the hybridisation of excitons in twistronic MoSe$_2$/WSe$_2$ structures, by observing scattering of specific excitons by phonons in both WSe$_2$ and MoSe$_2$. We also demonstrate that resonance Raman scattering spectroscopy opens up a wide range of possibilities for quantifying the layer composition of the superposition states of the exciton and the interlayer hybridisation parameters in heterostructures of two-dimensional materials.
description: 32 pages, 5 figures, 8 supplementary figures, 8 supplementary tables. 2D Mater. (2021)
Universal Reconnection of Non-Abelian Cosmic Strings
Creators: name: Eto, Minoru
name: Hashimoto, Koji
name: Marmorini, Giacomo
name: Nitta, Muneto
name: Ohashi, Keisuke
name: Vinci, Walter
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show that local/semilocal strings in Abelian/non-Abelian gauge theories with critical couplings always reconnect classically in collision, by using moduli space approximation. The moduli matrix formalism explicitly identifies a well-defined set of the vortex moduli parameters. Our analysis of generic geodesic motion in terms of those shows right-angle scattering in head-on collision of two vortices, which is known to give the reconnection of the strings.
description: 5 pages; v2 references added; v3 the final version
On the Possibility of Faster-Than-Light Motion of the Compton Electron
Creators: name: Kotel'nikov, G. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: The kinematics of Compton-effect with violated invariance of the velocity of light has been considered. It has been shown that in this case faster-than-light motion of the Compton electron is possible. The motion (if it exists really) begins with the energy of the incident gamma-quantum above 360 keV.
description: 21 pages
Analysis of the unconcentrated background of the EPIC-pn camera on board XMM-Newton
Creators: name: Marelli, Martino
name: Molendi, Silvano
name: Rossetti, Mariachiara
name: Gastaldello, Fabio
name: Salvetti, David
name: De Luca, Andrea
name: Bartalucci, Iacopo
name: Kühl, Patrick
name: Esposito, Paolo
name: Ghizzardi, Simona
name: Tiengo, Andrea
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Our understanding of the background of the EPIC/pn camera onboard XMM-Newton is incomplete. This affects the study of extended sources and can influence the predictions of the background of future X-ray missions. We provide new results based on the analysis of the largest data set ever used. We focus on the unconcentrated component of the EPIC/pn background - supposedly related to cosmic rays interacting with the telescope. We find that the out-field of view region of the pn detector is actually exposed to the sky. After cleaning from the sky contamination, the unconcentrated background does not show significant spatial variations and its time behaviour is anti-correlated with the solar cycle. We find a very tight, linear correlation between unconcentrated backgrounds detected in the EPIC/pn and MOS2 cameras: this permits the correct evaluation of the pn unconcentrated background of each exposure on the basis of MOS2 data, avoiding the use (as usual) of the contaminated pn regions. We find a tight, linear correlation between the pn unconcentrated background and the proton flux in the 630-970 MeV energy band measured by SOHO/EPHIN. Through this relationship we quantify the contribution of cosmic ray interactions to the pn unconcentrated background and we find a second source which contributes to the pn unconcentrated background for a significant fraction (30%-70%), that does not vary with time and is roughly isotropic. Hard X-ray photons of the CXB satisfy all the known properties of this new component. Our findings provide an important observational confirmation of simulation results on ATHENA.
description: 21 pages, 14 figures, 2 tables; accepted by the Astrophysical Journal
VVVX-Gaia Discovery of a Low Luminosity Globular Cluster in the Milky Way Disk
Creators: name: Garro, E. R.
name: Minniti, D.
name: Gómez, M.
name: Alonso-García, J.
name: Barbá, R. H.
name: Barbuy, B.
name: Clariá, J. J.
name: Chené, A. N.
name: Dias, B.
name: Hempel, M.
name: Ivanov, V. D.
name: Lucas, P. W.
name: Majaess, D.
name: Mauro, F.
name: Bidin, C. Moni
name: Palma, T.
name: Pullen, J. B.
name: Saito, R. K.
name: Smith, L.
name: Surot, F.
name: Alegría, S. Ramírez
name: Rejkuba, M.
name: Ripepi, V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Milky Way globular clusters (MW GCs) are difficult to identify at low Galactic latitudes because of high differential extinction and heavy star crowding. The new deep near-IR images and photometry from the VISTA Variables in the Via Láctea Extended Survey (VVVX) allow us to chart previously unexplored regions. Our long term aim is to complete the census of MW GCs. The immediate goals are to estimate the astrophysical parameters, measuring their reddenings, extinctions, distances, total luminosities, proper motions, sizes, metallicities and ages. We use the near-IR VVVX survey database, in combination with Gaia DR2 optical photometry, and with the Two Micron All Sky Survey (2MASS) photometry. We report the detection of a heretofore unknown Galactic Globular Cluster at $RA =$ 14:09:00.0; $DEC=-$65:37:12 (J2000). We calculate a reddening of $E(J-K_s)=(0.3\pm 0.03)$ mag and an extinction of $A_{K_s}=(0.15\pm 0.01)$ mag for this new GC. Its distance modulus and corresponding distance were measured as $(m-M)=(15.93\pm0.03)$ mag and $D=(15.5\pm1.0)$ kpc, respectively. We estimate the metallicity and age by comparison with known GCs and by fitting PARSEC and Dartmouth isochrones, finding $[Fe/H]=(-0.70\pm0.2)$ dex and $t=(11.0\pm1.0)$ Gyr. The mean GC PMs from Gaia are $μ_{α^\ast}=(-4.68 \pm 0.47 )$ mas $yr^{-1}$ and $μ_δ=(-1.34 \pm 0.45)$ mas $yr^{-1}$. The total luminosity of our cluster is estimated to be $M_{Ks}=(-7.76\pm 0.5)$ mag. We have found a new low-luminosity, old and metal-rich globular cluster, situated in the far side of the Galactic disk, at $R_{G}=11.2$ kpc from the Galactic centre, and at $z=1.0$ kpc below the plane. Interestingly, the location, metallicity and age of this globular cluster are coincident with the Monoceros Ring (MRi) structure.