cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Emergence of Loop Quantum Cosmology from Loop Quantum Gravity: Lowest Order in h
Creators: name: Lin, Chun-Yen
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: To derive loop quantum cosmology from loop quantum gravity, I apply the model given in \cite{lin1} to a system with coupled gravitational and matter fields. The matter sector consists of a scalar field $phi$ serving as a cosmological clock, and other fields ${psi}$ providing physical spatial coordinates and frames. The physical Hilbert space of the model is constructed from the kinematical Hilbert space of loop quantum gravity, and the local observables in the physical Hilbert space are constructed using the matter coordinates and frames. A specific coherent physical state is then chosen, whose expectation values of the local observables give rise to homogeneous, isotropic and spatially flat gravitational and $phi$ fields at a late clock time. The equations governing these fields may be derived using the symmetry of the physical Hilbert space. When the matter back reactions from ${psi}$ are negligible, the result gives a specific loop quantum cosmological model in the $O(hbar^0)$ approximation, with calculable higher order corrections.
description: 31 pages MikteX file with 1 pdf figure
Simulation of metallic nanostructures for emission of THz radiation using the lateral photo-Dember effect
Creators: name: McBryde, Duncan
name: Barnes, Mark E.
name: Daniell, Geoff J.
name: Chung, Aaron L.
name: Mihoubi, Zakaria
name: Quarterman, Adrian H.
name: Wilcox, Keith G.
name: Tropper, Anne C.
name: Apostolopoulos, Vasilis
Publisher: name: arXiv
Year: 2012
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: A 2D simulation for the lateral photo-Dember effect is used to calculate the THz emission of metallic nanostructures due to ultrafast diffusion of carriers in order to realize a series of THz emitters.
description: Corrected version of a paper given at 2011 36th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)
The chemical history of molecules in circumstellar disks. II. Gas-phase species
Creators: name: Visser, R.
name: Doty, S. D.
name: van Dishoeck, E. F.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Context: The chemical composition of a molecular cloud changes dramatically as it collapses to form a low-mass protostar and circumstellar disk. Two-dimensional (2D) chemodynamical models are required to properly study this process. Aims: The goal of this work is to follow, for the first time, the chemical evolution in two dimensions all the way from a pre-stellar core into a circumstellar disk. Of special interest is the question whether the chemical composition of the disk is a result of chemical processing during the collapse phase, or whether it is determined by in situ processing after the disk has formed. Methods: Our model combines a semi-analytical method to get 2D axisymmetric density and velocity structures with detailed radiative transfer calculations to get temperature profiles and UV fluxes. Material is followed in from the core to the disk and a full gas-phase chemistry network -- including freeze-out onto and evaporation from cold dust grains -- is evolved along these trajectories. The abundances thus obtained are compared to the results from a static disk model and to observations of comets. Results: The chemistry during the collapse phase is dominated by a few key processes, such as the evaporation of CO or the photodissociation of H2O. At the end of the collapse phase, the disk can be divided into zones with different chemical histories. The disk is not in chemical equilibrium at the end of the collapse, so care must be taken when choosing the initial abundances for stand-alone disk chemistry models. Our model results imply that comets must be formed from material with different chemical histories: some of it is strongly processed, some of it remains pristine. Variations between individual comets are possible if they formed at different positions or different times in the solar nebula.
description: 18 pages, 12 figures, accepted by A&A
Homogeneous bilayer graphene film based flexible transparent conductor
Creators: name: Lee, Seunghyun
name: Lee, Kyunghoon
name: Liu, Chang-Hua
name: Zhong, Zhaohui
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Graphene is considered a promising candidate to replace conventional transparent conductors due to its low opacity, high carrier mobility and flexible structure. Multi-layer graphene or stacked single layer graphenes have been investigated in the past but both have their drawbacks. The uniformity of multi-layer graphene is still questionable, and single layer graphene stacks require many transfer processes to achieve sufficiently low sheet resistance. In this work, bilayer graphene film grown with low pressure chemical vapor deposition was used as a transparent conductor for the first time. The technique was demonstrated to be highly efficient in fabricating a conductive and uniform transparent conductor compared to multi-layer or single layer graphene. Four transfers of bilayer graphene yielded a transparent conducting film with a sheet resistance of 180 Ω_{\square} at a transmittance of 83%. In addition, bilayer graphene films transferred onto plastic substrate showed remarkable robustness against bending, with sheet resistance change less than 15% at 2.14% strain, a 20-fold improvement over commercial indium oxide films.
description: Published in Nanoscale, Nov. 2011 : http://www.rsc.org/nanoscale
New precision mass measurements of neutron-rich calcium and potassium isotopes and three-nucleon forces
Creators: name: Gallant, A. T.
name: Bale, J. C.
name: Brunner, T.
name: Chowdhury, U.
name: Ettenauer, S.
name: Lennarz, A.
name: Robertson, D.
name: Simon, V. V.
name: Chaudhuri, A.
name: Holt, J. D.
name: Kwiatkowski, A. A.
name: Mané, E.
name: Menéndez, J.
name: Schultz, B. E.
name: Simon, M. C.
name: Andreoiu, C.
name: Delheij, P.
name: Pearson, M. R.
name: Savajols, H.
name: Schwenk, A.
name: Dilling, J.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present precision Penning-trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity of neutron number N=32. Using the TITAN system the mass of $^{51}$K was measured for the first time, and the precision of the $^{51,52}$Ca mass values were improved significantly. The new mass values show a dramatic increase of the binding energy compared to those reported in the atomic mass evaluation. In particular, $^{52}$Ca is more bound by 1.74 MeV, and the behavior with neutron number deviates substantially from the tabulated values. An increased binding was predicted recently based on calculations that include three-nucleon (3N) forces. We present a comparison to improved calculations, which agree remarkably with the evolution of masses with neutron number, making neutron-rich calcium isotopes an exciting region to probe 3N forces at neutron-rich extremes.
description: 5 pages, 3 figures, submitted to PRL
Bursty communication patterns facilitate spreading in a threshold-based epidemic dynamics
Creators: name: Takaguchi, Taro
name: Masuda, Naoki
name: Holme, Petter
Publisher: name: arXiv
Year: 2012
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Records of social interactions provide us with new sources of data for understanding how interaction patterns affect collective dynamics. Such human activity patterns are often bursty, i.e., they consist of short periods of intense activity followed by long periods of silence. This burstiness has been shown to affect spreading phenomena; it accelerates epidemic spreading in some cases and slows it down in other cases. We investigate a model of history-dependent contagion. In our model, repeated interactions between susceptible and infected individuals in a short period of time is needed for a susceptible individual to contract infection. We carry out numerical simulations on real temporal network data to find that bursty activity patterns facilitate epidemic spreading in our model.
description: 15 pages, 4 figures, 1 table
Non-Detection of the Putative Substellar Companion to HD 149382
Creators: name: Norris, Jackson M.
name: Wright, Jason T.
name: Wade, Richard A.
name: Mahadevan, Suvrath
name: Gettel, Sara
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: It has been argued that a substellar companion may significantly influence the evolution of the progenitors of sdB stars. Recently, the bright sdB star HD 149382 has been claimed to host a substellar (possibly planetary) companion with a period of 2.391 days. This has important implications for the evolution of the progenitors of sdB stars as well as the source of the UV-excess seen in elliptical galaxies. In order to verify this putative planet, we made 10 radial velocity measurements of HD 149382 over 17 days with the High Resolution Spectrograph at the Hobby-Eberly Telescope. Our data conclusively demonstrate that the putative substellar companion does not exist, and they exclude the presence of almost any substellar companion with P < 28 days and Msin i >~ 1 Mjup.
description: 5 figures, 6 pages, 2 tables
Phosphorus fractionation of dairy processing waste recycled fertilizers reveals inadequacy of the standards, measurement and testing (SMT) protocol
Creators: name: Velasco-Sánchez, Á.
name: Khalaf, Nidal
name: Leahy, James J
name: Bennegadi-Laurent, N.
name: Trinsoutrot-Gattin, I.
name: Van Groenigen, J.W.
name: Moinet, G. Y. K.
Publisher: name: University of Limerick
Year: 2025
Subjects: classificationCode: 34
subject: Chemical sciences
subject: FOS: Chemical sciences

description: The Standards, Measurements and Testing (SMT) protocol is widely used to fractionate phosphorus (P); however, it lacks the focus on defining the solubility of P-fractions, which is usually performed independently. In this paper, the addition of a separate pre-wash step with H2O as a first step prior to the SMT protocol was tested to account for the solubility of P. Results were compared to a control unmodified SMT experiment. The differences in P-fractions were analyzed to determine the origin of the readily available P (soluble P). Six different dairy processing waste treatment products were investigated in the form of sludge, hydrochar, and ash. Water-soluble P (WSP) was correlated with weakly bound calcium (Ca), aluminum (Al) and iron (Fe). However, the SMT protocol failed to correctly identify the different pools of P as unexpected correlations were found between P and Ca, Al and Fe. Moreover, large concentrations of organic P were present in ashes (>10 mg P g−1). The organic P fraction included substantial amounts of Fe that correlated highly with P (R2 = 0.84). No association between WSP and any of the pools of P defined by SMT was detected, with the exception of total P and inorganic P. The paper concludes that SMT erroneously classifies P into different discrete fractions across various recycled P-products with fertilizer potential. A critical reevaluation of the SMT protocol is recommended, by abandoning the categorization of P into discrete pools and switching to solvent-based categories referring to the chemicals used in each extraction. Highlights ● SMT fractionation protocol was modified to assess water soluble phosphorus ● The modified SMT protocol was performed on 6 different P-recycled products (fertilizers) ● SMT protocol fails to identify correctly different fractions of phosphorus ● A critical reevaluation of SMT protocol is recommended
Performances and ageing study of resistive-anodes Micromegas detectors for HL-LHC environment
Creators: name: Jeanneau, F.
name: Alexopoulos, T.
name: Attié, D.
name: Boyer, M.
name: Derré, J.
name: Fanourakis, G.
name: Ferrer-Ribas, E.
name: Galán, J.
name: Gazis, E.
name: Geralis, T.
name: Giganon, A.
name: Giomataris, I.
name: Herlant, S.
name: Manjarrés, J.
name: Ntomari, E.
name: Schune, Ph.
name: Titov, M.
name: Tsipolitis, G.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: With the tenfold luminosity increase envisaged at the HL-LHC, the background (photons, neutrons, ...) and the event pile-up probability are expected to increase in proportion in the different experiments, especially in the forward regions like, for instance, the muons chambers of the ATLAS detector. Detectors based on the Micromegas principle should be good alternatives for the detector upgrade in the HL-LHC framework because of a good spatial (<100 \mum) and time (few ns) resolutions, high-rate capability, radiation hardness, good robustness and the possibility to build large areas. The aim of this study is to demonstrate that it is possible to reduce the discharge probability and protect the electronics by using a resistive anode plane in a high flux hadrons environment. Several prototypes of 10x10 cm2, with different pitches (0.5 to 2 mm) and different resistive layers have been tested at CERN (pi+@SPS). Several tests have been performed with a telescope at different voltages to assess the performances of the detectors in terms of position resolution and efficiency. The spark behaviour in these conditions has also been evaluated. Resistive coating has been shown to be a successful method to reduce the effect of sparks on the efficiency of micromegas. A good spatial resolution (~80 \mum) can be reached with a resistive strip coating detector of 1mm pitch and a high efficiency (> 98%) can be achieved with resistive-anode micromegas detector. An X-rays irradiation has been also performed, showing no ageing effect after more than 21 days exposure and an integrated charge of almost 1C.
Observation of bias-dependent position flipping of the electric field maximum in neutron irradiated SiC diodes
Creators: name: Quintana San Emeterio, Cristian
name: Duarte-Campderrós, Jordi
name: Montero, Raul
name: Navarrete Ramos, Efren
name: Rosich, Diego
name: Vila, Ivan
Publisher: name: Zenodo
Year: 2025

description: This study presents an investigation of the internal electric field distribution in neutron-irradiated silicon carbide (SiC) p-in-n diodes using the Two-Photon Absorption Transient Current Technique (TPA-TCT). By analyzing the transient signal characteristics with both Weighted Prompt Current (WPC) and Time-over-Threshold (ToT) estimators, the spatial evolution of the electric field was reconstructed under varying bias conditions. After irradiation, the diodes show significant carrier trapping and a non-uniform electric field profile. A key finding is the bias-dependent flipping of the electric field maximum: under reverse bias, the field is concentrated near the front side, while under forward bias, a prominent field peak emerges at the back side. The results also indicate that the ToT-based estimator provides more robust measurements in irradiated devices, being less sensitive to signal amplitude variations and SPA contamination. These observations support the hypothesis that forward biasing enhances charge collection by repositioning the active high-field region, and they underscore the importance of field engineering in radiation-hard detector design.
Tripartite Entanglement in Qudit Stabilizer States and Application in Quantum Error Correction
Creators: name: Looi, Shiang Yong
name: Griffiths, Robert B.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Consider a stabilizer state on $n$ qudits, each of dimension $D$ with $D$ being a prime or a squarefree integer, divided into three mutually disjoint sets or parts. Generalizing a result of Bravyi et al. [J. Math. Phys. \textbf{47}, 062106 (2006)] for qubits (D=2), we show that up to local unitaries on the three parts the state can be written as a tensor product of unentangled single-qudit states, maximally entangled EPR pairs, and tripartite GHZ states. We employ this result to obtain a complete characterization of the properties of a class of channels associated with stabilizer error-correcting codes, along with their complementary channels.
description: 15 pages, 2 figures
Relativistische Ionisationsdynamik von atomaren Systemen
Creators: name: Lenz, Ernst
Publisher: name: Technische Universität Berlin
Year: 2002
Subjects: subject: 530 Physik
subject: Dirac-Gleichung
subject: Intensive Laserfelder
subject: Ionisationsdynamik
subject: Numerik
subject: Relativistik
subject: Rückstreu-Modell
subject: Dirac-Equation
subject: Intense laser-fields
subject: Ionization-dynamics
subject: Numeric
subject: Relativistic
subject: Rescattering-model

description: Die vorliegende Arbeit befasst sich mit der relativistischen Ionisationsdynamik von atomaren Systemen in intensiven Laserfeldern, bei denen die relativistischen Effekte aufgrund der hohen Geschwindigkeiten der Elektronen nicht mehr zu vernachlässigen sind. Somit ist nun neben der relativistischen Massenzunahme auch das magnetische Feld B zu berücksichtigen, sowie die Frage nach Teilchenerzeugungsprozessen zu klären. Aufgrund der relativistischen Intensität des Laserfeldes ist eine Vernachlässigung des Kernpotenzials gerechtfertigt und die nachfolgende Propagation der Elektronen Wellenpakete darf als frei angenommen werden. Im ersten Teil dieser Arbeit werden die numerischen Verfahren zur Propagation der eindimensionalen relativistisch-quantenmechanischen Gleichungen vorgestellt und dabei die Propagation unter Benutzung der relativistischen Schrödinger-Gleichung und der Dirac-Gleichung verglichen. In diesem Zusammenhang wird die Umsetzung des Hamiltonoperators für die jeweils verwendeten Gleichungen auf ein Raum-Zeit-Gitter beschrieben. Die zeitliche Propagation wird in dieser Arbeit durch das Crank-Nicolson Verfahren beschrieben. Bei der Diskretisierung des Hamiltonoperators im Fall der relativistischen Schrödinger-Gleichung kommt das Verfahren der Fourier-Transformation zum Einsatz und im Fall der Dirac-Gleichung wird die Methode der finiten Differenzen realisiert. Als Besonderheit bei der Behandlung der Dirac-Gleichung ist unter anderem die Fermionen-Verdopplung sowie das Auftreten der Zitterbewegung zu berücksichtigen. Desweiteren beschäftigt sich diese Arbeit mit der möglichen Wechselwirkung von frei propagierenden Elektronen Wellenpaketen mit dem jeweiligen Mutterion bei zusätzlicher Berücksichtigung des magnetischen Feldes. Es wird außerdem eine Konstruktion aus gekreuzten Laserfeldern vorgestellt, die es den Elektronen prinzipiell ermöglicht wieder mit dem Mutterion in Wechselwirkung zu treten. In dem konstruierten Laserfeld werden die Auswirkungen des magnetischen Feldes teilweise kompensiert und somit können einige Elektronen wieder mit dem Mutterion in Wechselwirkung treten. Anhand von klassisch relativistischen Trajektorien wird gezeigt, wieviel Prozent der jeweils betrachteten Elektronen das Potenzial zu einer derartigen Wechselwirkung besitzen und damit zur Erzeugung von hohen Harmonischen genutzt werden könnten. In diesem Zusammenhang wird zusätzlich gezeigt, dass eine weitgehende Übereinstimmung zwischen den klassischen relativistischen Trajektorien und den korrekten quantenmechanischen Rechnungen besteht.
Architecture and Design of Medical Processor Units for Medical Networks
Creators: name: Ahamed, Syed V.
name: Rahman, Syed Shawon M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Other Computer Science (cs.OH)
subject: FOS: Computer and information sciences

description: This paper introduces analogical and deductive methodologies for the design medical processor units (MPUs). From the study of evolution of numerous earlier processors, we derive the basis for the architecture of MPUs. These specialized processors perform unique medical functions encoded as medical operational codes (mopcs). From a pragmatic perspective, MPUs function very close to CPUs. Both processors have unique operation codes that command the hardware to perform a distinct chain of subprocesses upon operands and generate a specific result unique to the opcode and the operand(s). In medical environments, MPU decodes the mopcs and executes a series of medical sub-processes and sends out secondary commands to the medical machine. Whereas operands in a typical computer system are numerical and logical entities, the operands in medical machine are objects such as such as patients, blood samples, tissues, operating rooms, medical staff, medical bills, patient payments, etc. We follow the functional overlap between the two processes and evolve the design of medical computer systems and networks.
description: 17 pages
title: Story of the round head
title: Conte de la tête ronde
Creators: name: Colombel, Véronique De
Publisher: name: Pangloss
Year: 2011
Subjects: subject: Linguistique
subject: Ouldeme

description: À la naissance d'un enfant qui arrive au monde avec une grosse tête ronde, un seul bras et une seule jambe, les parents décident de quitter pour toujours leur maison en y abandonnant l'enfant monstrueux. Mais la soeur aînée, qui n'est encore qu'une fillette, tient à l'emmener. Voyant cela, les parents abandonnent les deux enfants en chemin. Plus tard, après avoir demandé à sa soeur de le cogner contre un tamarinier, puis contre un arbre à grêlons, le garçon retrouve ses membres, puis un corps complet de jeune homme. Ensuite, il construit une maison tôlée et prend huit épouses. Pendant ce temps, sans enfant pour les aider, les vieux parents errent en brousse où ils tentent de survivre en se nourrissant de souchets sauvages. C'est alors que le garçon leur fait parvenir de la nourriture par magie. Il va ensuite à cheval à leur rencontre. Les parents, qui le prennent pour un Mandara, ont tout d'abord peur de lui. Puis ils finissent par reconnaître leur enfant et celui-ci leur offre alors le gîte et le couvert.
Spin-wave analysis of the transverse-field Ising model on the checkerboard lattice
Creators: name: Henry, Louis-Paul
name: Holdsworth, Peter C. W.
name: Mila, Frédéric
name: Roscilde, Tommaso
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The ground state properties of the S=1/2 transverse-field Ising model on the checkerboard lattice are studied using linear spin wave theory. We consider the general case of different couplings between nearest neighbors (J1) and next-to-nearest neighbors (J2). In zero field the system displays a large degeneracy of the ground state, which is exponential in the system size (for J1=J2) or in the system's linear dimensions (for J2>J1). Quantum fluctuations induced by a transverse field are found to be unable to lift this degeneracy in favor of a classically ordered state at the harmonic level. This remarkable fact suggests that a quantum-disordered ground state can be instead promoted when non-linear fluctuations are accounted for, in agreement with existing results for the isotropic case J1=J2. Moreover spin-wave theory shows sizable regions of instability which are further candidates for quantum-disordered behavior.
description: 12 pages, 13 figures
Efficient Algorithms to Enhance Recovery Schema in Link State Protocols
Creators: name: Abujassar, Radwan
name: Ghanbari, Mohammed
Publisher: name: arXiv
Year: 2011
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: With the increasing demands for real-time applications traffic in net- works such as video and voice a high convergence time for the existing routing protocols when failure occurred is required. These applications can be very sensitive to packet loss when link/node goes down. In this paper, we propose two algorithms schemas for the link state protocol to reroute the traffic in two states; first, pre-calculated an alternative and disjoint path with the primary one from the source to the destination by re-routing traffic through it, regardless of the locations of failure and the number of failed links. Second, rerouting the traffic via an alternative path from a node whose local link is down without the need to wait until the source node knows about the failure. This is achieved by creating a new backup routing table based on the original routing table which is computed by the dijkstra algorithm. The goal of these algorithms is to reduce loss of packets, end-to-end delay time, improve throughput and avoiding local loop when nodes re-converge the topology in case of failure.
description: 15 pages
Effect of uniaxial strain on plasmon excitations in graphene
Creators: name: Pellegrino, F. M. D.
name: Angilella, G. G. N.
name: Pucci, R.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Uniaxial strain is known to modify significantly the electronic properties of graphene, a carbon single layer of atomic width. Here, we study the effect of applied strain on the composite excitations arising from the coupling of charge carriers and plasmons in graphene, i.e. the plasmarons. Specifically, we predict that the plasmaron energy dispersion, which has been recently observed experimentally in unstrained graphene, is shifted and broadened by applied uniaxial strain. Thus, strain constitutes an additional parameter which may be useful to tune graphene properties in plasmaronic devices.
description: Invited oral lecture at the 23rd AIRAPT International Conference on "High Pressure Science and Technology", Mumbai (India), September 25-30, 2011. To be published in J. Phys.: Conf. Series (2012)
The 2XMMi/SDSS Galaxy Cluster Survey I. The first cluster sample and X-ray luminosity-temperature relation
Creators: name: Takey, A.
name: Schwope, A.
name: Lamer, G.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a catalogue of X-ray selected galaxy clusters and groups as a first release of the 2XMMi/SDSS Galaxy Cluster Survey. The survey is a search for galaxy clusters detected serendipitously in observations with XMM-Newton in the footprint of the Sloan Digital Sky Survey (SDSS). The main aims of the survey are to identify new X-ray galaxy clusters, investigate their X-ray scaling relations, identify distant cluster candidates and study the correlation of the X-ray and optical properties. In this paper we describe the basic strategy to identify and characterize the X-ray cluster candidates that currently comprise 1180 objects selected from the second XMM-Newton serendipitous source catalogue (2XMMi-DR3). Cross-correlation of the initial catalogue with recently published optically selected SDSS galaxy cluster catalogues yields photometric redshifts for 275 objects. Of these, 182 clusters have at least one member with a spectroscopic redshift from existing public data (SDSS-DR8). Here we present the X-ray properties of the first cluster sample which comprises 175 clusters, among which 139 objects are new X-ray discoveries while the others were previously known as X-ray sources. The first cluster sample from the survey covers a wide range of redshifts from 0.09 to 0.61, bolometric luminosities L_500 = 1.9 x 10^42 - 1.2 x 10^45 erg/s, and masses M_500 = 2.3 x 10^13 - 4.9 x 10^14 Msun. We extend the relation between the X-ray bolometric luminosity L_500 and the X-ray temperature towards significantly lower T and L and still find that the slope of the linear L-T relation is consistent with values published for high luminosities.
description: A&A accepted, 14 pages, 17 figures, 2 tables. The first cluster catalogue with the X-ray-optical overlay and fitted spectra for each cluster is publicly available from http://www.aip.de/groups/xray/XMM_SDSS_CLUSTERS
Estimating stellar mean density through seismic inversions
Creators: name: Reese, D. R.
name: Marques, J. P.
name: Goupil, M. J.
name: Thompson, M. J.
name: Deheuvels, S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Determining the mass of stars is crucial both to improving stellar evolution theory and to characterising exoplanetary systems. Asteroseismology offers a promising way to estimate stellar mean density. When combined with accurate radii determinations, such as is expected from GAIA, this yields accurate stellar masses. The main difficulty is finding the best way to extract the mean density from a set of observed frequencies. We seek to establish a new method for estimating stellar mean density, which combines the simplicity of a scaling law while providing the accuracy of an inversion technique. We provide a framework in which to construct and evaluate kernel-based linear inversions which yield directly the mean density of a star. We then describe three different inversion techniques (SOLA and two scaling laws) and apply them to the sun, several test cases and three stars. The SOLA approach and the scaling law based on the surface correcting technique described by Kjeldsen et al. (2008) yield comparable results which can reach an accuracy of 0.5 % and are better than scaling the large frequency separation. The reason for this is that the averaging kernels from the two first methods are comparable in quality and are better than what is obtained with the large frequency separation. It is also shown that scaling the large frequency separation is more sensitive to near-surface effects, but is much less affected by an incorrect mode identification. As a result, one can identify pulsation modes by looking for an l and n assignment which provides the best agreement between the results from the large frequency separation and those from one of the two other methods. Non-linear effects are also discussed as is the effects of mixed modes. In particular, it is shown that mixed modes bring little improvement as a result of their poorly adapted kernels.
description: Accepted for publication in A&A, 20 pages, 19 figures
Classification of double flag varieties of complexity 0 and 1
Creators: name: Ponomareva, Elizaveta
Publisher: name: arXiv
Year: 2012
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: A classification of double flag varieties of complexity 0 and 1 is obtained. An application of this problem to decomposing tensor products of irreducible representations of semisimple Lie groups is considered.
Incompressibility of polydisperse random close packed colloidal particles
Creators: name: Kurita, Rei
name: Weeks, Eric R.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We use confocal microscopy to study a random close packed sample of colloidal particles. We introduce an algorithm to estimate the size of each particle. Taking into account their sizes, we compute the compressibility of the sample as a function of wave vector $q$, and find that this compressibility vanishes linearly as $q \rightarrow 0$. The particle sizes must be considered to calculate the compressibility properly. These results also suggest that the experimental packing is hyperuniform.
description: 4 pages, 4 figures
Die Sehnsucht nach dem Süden
Creators: name: Hildebrandt, Siegfried
Publisher: name: Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege
Year: 2020

description: -
description: Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege, Bd. 45 Nr. 3 (2004): Burgen und Schlösser - Zeitschrift für Burgenforschung und Denkmalpflege
Proton-proton elastic scattering at the LHC energy of {\surd} = 7 TeV
Creators: name: The TOTEM Collaboration
name: Antchev, G.
name: Aspell, P.
name: Atanassov, I.
name: Avati, V.
name: Baechler, J.
name: Berardi, V.
name: Berretti, M.
name: Bozzo, M.
name: Brücken, E.
name: Buzzo, A.
name: Cafagna, F.
name: Calicchio, M.
name: Catanesi, M. G.
name: Covault, C.
name: Csanád, M.
name: Csörgö, T.
name: Deile, M.
name: Dimovasili, E.
name: Doubek, M.
name: Eggert, K.
name: Eremin, V.
name: Ferro, F.
name: Fiergolski, A.
name: Garcia, F.
name: Giani, S.
name: Greco, V.
name: Grzanka, L.
name: Heino, J.
name: Hilden, T.
name: Janda, M.
name: Kašpar, J.
name: Kopal, J.
name: Kundrát, V.
name: Kurvinen, K.
name: Lami, S.
name: Latino, G.
name: Lauhakangas, R.
name: Leszko, T.
name: Lippmaa, E.
name: Lokajíček, M.
name: Vetere, M. Lo
name: Rodríguez, F. Lucas
name: Macrí, M.
name: Magaletti, L.
name: Magazzú, G.
name: Mercadante, A.
name: Meucci, M.
name: Minutoli, S.
name: Nemes, F.
name: Niewiadomski, H.
name: Noschis, E.
name: Novak, T.
name: Oliveri, E.
name: Oljemark, F.
name: Orava, R.
name: Oriunno, M.
name: Österberg, K.
name: Perrot, A. -L.
name: Palazzi, P.
name: Pedreschi, E.
name: Petäjäjärvi, J.
name: Procházka, J.
name: Quinto, M.
name: Radermacher, E.
name: Radicioni, E.
name: Ravotti, F.
name: Robutti, E.
name: Ropelewski, L.
name: Ruggiero, G.
name: Saarikko, H.
name: Santroni, A.
name: Scribano, A.
name: Sette, G.
name: Snoeys, W.
name: Spinella, F.
name: Sziklai, J.
name: Taylor, C.
name: Turini, N.
name: Vacek, V.
name: Vítek, M.
name: Welti, J.
name: Whitmore, J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Proton-proton elastic scattering has been measured by the TOTEM experiment at the CERN Large Hadron Collider at {\surd}s = 7 TeV in dedicated runs with the Roman Pot detectors placed as close as seven times the transverse beam size (sbeam) from the outgoing beams. After careful study of the accelerator optics and the detector alignment, |t|, the square of four-momentum transferred in the elastic scattering process, has been determined with an uncertainty of d t = 0.1GeV p|t|. In this letter, first results of the differential cross section are presented covering a |t|-range from 0.36 to 2.5GeV2. The differential cross-section in the range 0.36 < |t| < 0.47 GeV2 is described by an exponential with a slope parameter B = (23.6{\pm}0.5stat {\pm}0.4syst)GeV-2, followed by a significant diffractive minimum at |t| = (0.53{\pm}0.01stat{\pm}0.01syst)GeV2. For |t|-values larger than ~ 1.5GeV2, the cross-section exhibits a power law behaviour with an exponent of -7.8_\pm} 0.3stat{\pm}0.1syst. When compared to predictions based on the different available models, the data show a strong discriminative power despite the small t-range covered.
description: 12pages, 5 figures, CERN preprint
IT Security Issues Within the Video Game Industry
Creators: name: Mohr, Stephen
name: Rahman, Syed Shawon
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cryptography and Security (cs.CR)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: IT security issues are an important aspect for each and every organization within the video game industry. Within the video game industry alone, you might not normally think of security risks being an issue. But as we can and have seen in recent news, no company is immune to security risks no matter how big or how small. While each of these organizations will never be exactly the same as the next, there are common security issues that can and do affect each and every video game company. In order to properly address those security issues, one of the current leading video game companies was selected in order to perform an initial security assessment. This security assessment provided a starting point upon which specific goals and procedures were determined to help mitigate those risks. The information contained within was initially completed on the case study but has been generalized to allow the information to be easily applied to any video game company.
description: 16 pages
Magnetic structure of CuCrO2: a single crystal neutron diffraction study
Creators: name: Frontzek, M.
name: Ehlers, G.
name: Podlesnyak, A.
name: Cao, H.
name: Matsuda, M.
name: Zaharko, O.
name: Aliouane, N.
name: Barilo, S.
name: Shiryaev, S. V.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: This paper presents results of a recent study of multiferroic \CCO\ by means of single crystal neutron diffraction. This system has two close magnetic phase transitions at $T\nsub{N1}=24.2$ K and $T\nsub{N2}=23.6$ K. The low temperature magnetic structure below $T\nsub{N2}$ is unambiguously determined to be a fully 3-dimensional proper screw. Between $T\nsub{N1}$ and $T\nsub{N2}$ antiferromagnetic order is found that is essentially 2-dimensional. In this narrow temperature range, magnetic near neighbor correlations are still long range in the ($H,K$) plane, whereas nearest neighbors along the $L$-direction are uncorrelated. Thus, the multiferroic state is realized only in the low-temperature 3-dimensional state and not in the 2-dimensional state.
Optimized optomechanical crystal cavity with acoustic radiation shield
Creators: name: Chan, Jasper
name: Safavi-Naeini, Amir H.
name: Hill, Jeff T.
name: Meenehan, Sean
name: Painter, Oskar
Publisher: name: arXiv
Year: 2012
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present the design of an optomechanical crystal nanobeam cavity that combines finite-element simulation with numerical optimization, and considers the optomechanical coupling arising from both moving dielectric boundaries and the photo-elastic effect. Applying this methodology results in a nanobeam with an experimentally realized intrinsic optical Q-factor of 1.2x10^6, a mechanical frequency of 5.1GHz, a mechanical Q-factor of 6.8x10^5 (at T=10K), and a zero-point-motion optomechanical coupling rate of g=1.1MHz.
description: 4 pages, 4 figures
On the Influence of Informed Agents on Learning and Adaptation over Networks
Creators: name: Tu, Sheng-Yuan
name: Sayed, Ali H.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Information Theory (cs.IT)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: Adaptive networks consist of a collection of agents with adaptation and learning abilities. The agents interact with each other on a local level and diffuse information across the network through their collaborations. In this work, we consider two types of agents: informed agents and uninformed agents. The former receive new data regularly and perform consultation and in-network tasks, while the latter do not collect data and only participate in the consultation tasks. We examine the performance of adaptive networks as a function of the proportion of informed agents and their distribution in space. The results reveal some interesting and surprising trade-offs between convergence rate and mean-square performance. In particular, among other results, it is shown that the performance of adaptive networks does not necessarily improve with a larger proportion of informed agents. Instead, it is established that the larger the proportion of informed agents is, the faster the convergence rate of the network becomes albeit at the expense of some deterioration in mean-square performance. The results further establish that uninformed agents play an important role in determining the steady-state performance of the network, and that it is preferable to keep some of the highly connected agents uninformed. The arguments reveal an important interplay among three factors: the number and distribution of informed agents in the network, the convergence rate of the learning process, and the estimation accuracy in steady-state. Expressions that quantify these relations are derived, and simulations are included to support the theoretical findings. We further apply the results to two models that are widely used to represent behavior over complex networks, namely, the Erdos-Renyi and scale-free models.
description: 35 pages, 8 figures
Microwave Frequency Fiber Interferometry in Submarine Deployed Telecommunication Cables
Creators: name: Bogris, A.
name: Simos, C.
name: Simos, I.
name: Wang, Y.
name: Fichtner, A.
name: Deligiannidis, S.
name: Melis, N. S.
name: Mesaritakis, C.
Publisher: name: arXiv
Year: 2025
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We operated a microwave frequency fiber interferometer in a telecommunication cable in the Ionian Sea, Greece, for two months. The capability of detecting undersea micro earthquakes (magnitude~1.5), tides and ocean waves is reported
Tailoring THz radiation by controlling tunnel photoionization events in gases
Creators: name: Babushkin, I.
name: Skupin, S.
name: Husakou, A.
name: Köhler, C.
name: Cabrera-Granado, E.
name: Bergé, L.
name: Herrmann, J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Applications ranging from nonlinear terahertz spectroscopy to remote sensing require broadband and intense THz radiation which can be generated by focusing two-color laser pulses into a gas. In this setup, THz radiation originates from the buildup of the electron density in sharp steps of attosecond duration due to tunnel ionization, and subsequent acceleration of free electrons in the laser field. We show that the spectral shape of the THz pulses generated by this mechanism is determined by superposition of contributions from individual ionization events. This provides a straightforward analogy with linear diffraction theory, where the ionization events play the role of slits in a grating. This analogy offers simple explanations for recent experimental observations and opens new avenues for THz pulse shaping based on temporal control of the ionization events. We illustrate this novel technique by tailoring the spectral width and position of the resulting radiation using multi-color pump pulses.
description: 9 pages, 5 figures
IT Security Plan for Flight Simulation Program
Creators: name: Hood, David
name: Rahman, Syed Shawon
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cryptography and Security (cs.CR)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Information security is one of the most important aspects of technology, we cannot protect the best interests of our organizations' assets (be that personnel, data, or other resources), without ensuring that these assetsare protected to the best of their ability. Within the Defense Department, this is vital to the security of not just those assets but also the national security of the United States. Compromise insecurity could lead severe consequences. However, technology changes so rapidly that change has to be made to reflect these changes with security in mind. This article outlines a growing technological change (virtualization and cloud computing), and how to properly address IT security concerns within an operating environment. By leveraging a series of encrypted physical and virtual systems, andnetwork isolation measures, this paper delivered a secured high performance computing environment that efficiently utilized computing resources, reduced overall computer processing costs, and ensures confidentiality, integrity, and availability of systems within the operating environment.
description: 24 pages
Environmental Determinants of COVID-19 Spread and Severity: An Exploratory Cross-Regional Analysis
Creators: name: Tencl, Jakub
Publisher: name: Zenodo
Year: 2025
Subjects: subject: COVID-19/epidemiology

description: The provided dataset contains COVID-19 statistics alongside environmental conditions for 14 regions at multiple time points. It includes metrics such as confirmed infection counts, deaths, testing figures, and environmental factors like temperature, humidity, and air pollution (PM2.5 levels). This analysis examines the descriptive statistics of these variables and explores potential correlations between environmental conditions and trends related to COVID-19. We present key findings, accompanied by supporting figures and tables, and discuss possible interpretations of the observed relationships.
Search for radial velocity variations in eight M-dwarfs with NIRSPEC/Keck II
Creators: name: Rodler, Florian
name: Deshpande, Rohit
name: Osorio, Maria Rosa Zapatero
name: Martin, Eduardo L.
name: Montgomery, Michele M.
name: del Burgo, Carlos
name: Creevey, Orlagh L.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Radial velocity (RV) measurements from near-infrared spectra have become a potentially powerful tool to search for planets around cool stars and sub-stellar objects. As part of a large survey to characterize M-dwarfs using NIRSPEC at Keck II, we obtained spectra of eight late M-dwarfs (spectral types M5.0-M8.0) during two or more observing epochs per target. These spectra were taken with intermediate spectral resolving powers (R \sim 20,000) in the J-band. Aims. We search for relative radial velocity variability in these late M-dwarfs and test the NIRSPEC capability of detecting short period brown dwarf and massive planetary companions around low-mass stars in the J-band (\approx 1.25 micron). Additionally, we reanalyzed the data of the M8-type star vB10 (one of our targets) presented in Zapatero Osorio et al. (2009), which were obtained with the same instrumentation as our data. Methods. [...] Results. For the entire M-dwarf sample, we do not find any evidence of relative RV variations induced by a short period brown dwarf or massive planetary companion. The typical RV precision of the measurements is between 180 and 300 m/s, which is sufficient to detect hot Neptunes around M-dwarfs. Also, we find that the spurious RV shift in Zapatero et al. (2009) of the star VB10 was caused by asymmetries in the instrumental profile between different observing epochs, which were not taken into account in their analysis.
description: A&A, 7 pages, 5 figures
Probing biological light-harvesting phenomena by optical cavities
Creators: name: Caruso, Filippo
name: Saikin, Semion K.
name: Solano, Enrique
name: Huelga, Susana F.
name: Aspuru-Guzik, Alán
name: Plenio, Martin B.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Optics (physics.optics)
subject: Biomolecules (q-bio.BM)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: We propose a driven optical cavity quantum electrodynamics (QED) set up aimed at directly probing energy transport dynamics in photosynthetic biomolecules. We show that detailed information concerning energy transfer paths and delocalization of exciton states can be inferred (and exciton energies estimated) from the statistical properties of the emitted photons. This approach provides us with a novel spectroscopic tool for the interrogation of biological systems in terms of quantum optical phenomena which have been usually studied for atomic or solid-state systems, e.g. trapped atoms and semiconductor quantum dots.
description: 10 pages, 16 figures