cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Η Μινωική θρησκεία κατα τη νεοανακτορική περίοδο (1700 π. Χ. -1450 π.Χ.):
Creators: name: Σφακιανάκη, Κωνσταντίνα Χρόνη
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Μινωική θρησκεία
Μινωικό πάνθεο
Ανανεωτική δύναμη της φύσς
Minoan religion
Minoan pantheon
Regeneration power of nature

description: Στην παρούσα μεταπτυχιακή εργασία επιχειρήθηκε μια προσπάθεια καταγραφής στοιχείων που σχετίζονται με την θρησκευτική ζωή των Μινωιτών κατά την Νεοανακτορική περίοδο. Πληροφορηθήκαμε ότι ο ακρογωνιαίος λίθος για τη δομή της Μινωικής θρησκείας ήταν η ανανεωτική δύναμη της φύσης, «ο κύκλος της βλάστησης». Κύριος εκφραστής της θεωρήθηκε η γυναικεία μορφή, η οποία απέκτησε θεϊκή και κυρίαρχη θέση μέσα στην Μινωική κοινωνία. Με βάση τις εικονιστικές αναπαραστάσεις που ανακαλύφθηκαν από τις αρχαιολογικές ανασκαφές, αρχαιολόγοι διέκριναν ένα μινωικό πάνθεο. Στην προσπάθεια ερμηνείας του μινωικού αυτού πάνθεου αναφέρθηκαν ουράνιες, επίγειες και χθόνιες θεότητες. Στην ερευνά μας καταγράψαμε τα ιερά σπήλαια, τα ιερά κορυφής, τα ανακτορικά ιερά και αλλά πολλά που αποτέλεσαν τόπους και χώρους τέλεσης λατρείας. Στους ιερούς αυτούς τόπους τελούνταν οι μυστηριακές τελετουργίες της μινωικής θρησκευτικής ζωής. Σε αυτές τις ιεροτελεστίες άνηκαν: το μυστήριο της επιφάνειας της θεότητας (θεοφάνειας), η προσφορά αναίμακτων και αιματηρών θυσιών, ο ιερός χορός κ.α. Ασχοληθήκαμε επιπλέον και με τα ιερά σύμβολα της μινωικής θρησκείας, τα αντικείμενα αυτά ήταν: το ζεύγος κεράτων, ο διπλός πέλεκυς, το βουκράνιο κ.α.. και αναγνωρίστηκαν ως ιερά σύμβολα της Μινωικής θρησκείας.
description: At the present thesis it was attempted a thorough study at the lost civilization of the prehistoric Crete. The purpose of this treatise was to compile evidences about the religious life of the Minoans. Albeit, the lack of written records about the religious beliefs impeded this research. However, every archaeological finding was taken into consideration with the focus being on the New Palace period. Consulting archaeological, religious and others sources, it was derived that the cornerstone of the structure of the Minoan religion was the regeneration power of nature,” the circle of nature”. Principal figure was the goddess who had predominant position. Furthermore, based on the representations found, a pantheon was proposed with celestial, terrestrial and chthonic deities. Grave importance was given to the sanctums which were found in palaces, caves and at mountains’ peeks. There, a variety of religious ceremonies, like the Epiphany of the deity, occurred with bloodless and blood sacrifices. Concluding, it must be noted that multiple symbols were characterized as religious such as the horns of cons, double-axe and the boucrania, sacral knots etc
Site percolation on square and simple cubic lattices with extended neighborhoods and their continuum limit
Creators: name: Xun, Zhipeng
name: Hao, Dapeng
name: Ziff, Robert M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: By means of Monte Carlo simulations, we study long-range site percolation on square and simple cubic lattices with various combinations of nearest neighbors, up to the eighth neighbors for the square lattice and the ninth neighbors for the simple cubic lattice. We find precise thresholds for 23 systems using a single-cluster growth algorithm. Site percolation on lattices with compact neighborhoods can be mapped to problems of lattice percolation of extended shapes, such as disks and spheres, and the thresholds can be related to the continuum thresholds $η_c$ for objects of those shapes. This mapping implies $zp_{c} \sim 4 η_c = 4.51235$ in 2D and $zp_{c} \sim 8 η_c = 2.73512$ in 3D for large $z$ for circular and spherical neighborhoods respectively, where $z$ is the coordination number. Fitting our data to the form $p_c = c/(z+b)$ we find good agreement with $c = 2^d η_c$; the constant $b$ represents a finite-$z$ correction term. We also study power-law fits of the thresholds.
Pulsational and evolutionary analysis of the double-mode RR Lyrae star BS Com
Creators: name: Dekany, I.
name: Kovacs, G.
name: Jurcsik, J.
name: Szabo, R.
name: Varadi, M.
name: Sodor, A.
name: Posztobanyi, K.
name: Hurta, Zs.
name: Vida, K.
name: Vityi, N.
name: Szing, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We derive the basic physical parameters of the field double-mode RR Lyrae star BS Com from its observed periods and the requirement of consistency between the pulsational and evolutionary constraints. By using the current solar-scaled horizontal branch evolutionary models of Pietrinferni et al. (2004) and our linear non-adiabatic purely radiative pulsational models, we get M/M(Sun) = 0.698 +/- 0.004, log(L/L(Sun)) = 1.712 +/- 0.005, T(eff) = 6840 +/- 14 K, [Fe/H] = -1.67 +/- 0.01, where the errors are standard deviations assuming uniform age distribution along the full range of uncertainty in age. The last two parameters are in a good agreement with the ones derived from the observed BVIc colours and the updated ATLAS9 stellar atmosphere models. We get T(eff) = 6842 +/- 10 K, [Fe/H] = -1.58 +/- 0.11, where the errors are purely statistical ones. It is remarkable that the derived parameters are nearly independent of stellar age at early evolutionary stages. Later stages, corresponding to the evolution toward the asymptotic giant branch are most probably excluded because the required high temperatures are less likely to satisfy the constraints posed by the colours. We also show that our conclusions are only weakly sensitive to nonlinear period shifts predicted by current hydrodynamical models.
description: Accepted for publication by MNRAS on 2008 February 01. The paper contains 4 figures and 8 tables
Real-time parameter inference in reduced-order flame models with heteroscedastic Bayesian neural network ensembles
Creators: name: Sengupta, Ushnish
name: Croci, Maximilian L.
name: Juniper, Matthew P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Fluid Dynamics (physics.flu-dyn)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: The estimation of model parameters with uncertainties from observed data is a ubiquitous inverse problem in science and engineering. In this paper, we suggest an inexpensive and easy to implement parameter estimation technique that uses a heteroscedastic Bayesian Neural Network trained using anchored ensembling. The heteroscedastic aleatoric error of the network models the irreducible uncertainty due to parameter degeneracies in our inverse problem, while the epistemic uncertainty of the Bayesian model captures uncertainties which may arise from an input observation's out-of-distribution nature. We use this tool to perform real-time parameter inference in a 6 parameter G-equation model of a ducted, premixed flame from observations of acoustically excited flames. We train our networks on a library of 2.1 million simulated flame videos. Results on the test dataset of simulated flames show that the network recovers flame model parameters, with the correlation coefficient between predicted and true parameters ranging from 0.97 to 0.99, and well-calibrated uncertainty estimates. The trained neural networks are then used to infer model parameters from real videos of a premixed Bunsen flame captured using a high-speed camera in our lab. Re-simulation using inferred parameters shows excellent agreement between the real and simulated flames. Compared to Ensemble Kalman Filter-based tools that have been proposed for this problem in the combustion literature, our neural network ensemble achieves better data-efficiency and our sub-millisecond inference times represent a savings on computational costs by several orders of magnitude. This allows us to calibrate our reduced-order flame model in real-time and predict the thermoacoustic instability behaviour of the flame more accurately.
From AdS3/CFT2 to Black Holes/Topological Strings
Creators: name: Gaiotto, Davide
name: Strominger, Andrew
name: Yin, Xi
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The elliptic genus Z_{BH} of a large class of 4D black holes can be expressed as an M-theory partition function on an AdS_3xS^2xCY_3 attractor. We approximate this partition function by summing over multiparticle chiral primary states of membranes which wrap curves in the CY_3 and tile Landau levels on the horizon S^2. Significantly, membranes and antimembranes can preserve the same supercharges if they occupy antipodal points on the horizon. It is shown the membrane contribution to Z_{BH} gives precisely the topological string partition function Z_{top} while the antimembranes give \bar Z_{top}, implying Z_{BH}=|Z_{top}|^2 in this approximation.
description: 11 pages
Shadows beneath the wind : Singapore, world city and open region
Creators: name: MacLeod, Scott Alexander
Publisher: name: University of British Columbia
Year: 2009

description: This study examines the production of a new regional space known as the Growth Triangle. The Growth Triangle represents a (re)integration of the economies of Singapore, the Riau Archipelago in Indonesia and Johor State in Malaysia. It is argued that the Growth Triangle should be seen as an ‘open region.’ The open region is affected by a wide range of ‘external’ influences and is open to shifting representations which are important to its unfolding. The study takes on the interpretation of the open region through a consideration of the unstable and amorphous realm of ‘middle space.’ Middle space is manifold. It includes: 1) the middle spaces between the global and the local; 2) the middle spaces between conceptual divisions (e.g., urban/rural and labour/capital); and 3) the middle spaces of circulation (i.e., connections between individuals, firms and places). The triangulation of these three arenas provides a heuristic device for the examination of the changes sweeping the Growth Triangle. The analysis moves from a time when the region’s global niche was based on the movement of goods to more recent developments where-in the movement of information and capital are crucial. The global flows of information and capital are the ‘winds’ of the title. The region, and various ways of conceptualizing it, are the ‘shadows.’ The main fmdings are that: 1) global change must be seen in terms of local roots and consequences; 2) local differentiation and the representation of difference are increasingly important, even in the frame of globalization; 3) analytic strength may be gained by dulling the edges of interpretive constructs (such as information or labour); 4) there are strong connections between the circulation of goods, people, money and information (spatial interaction) and the generation of new and distinct geographies (areal differentiation); and 5) there are strong linkages between Singapore’s shift towards advanced world city functions (‘intensive globalization’) and the mega-urbanization of the near-by international hinterlands (‘extensive globalization’). To understand each of the three corners of the Growth Triangle one must engage Singapore as a World City and as an Open Region.
L'Hospital-type rules for monotonicity and limits: Discrete case
Creators: name: Pinelis, Iosif
Publisher: name: arXiv
Year: 2006
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: General Mathematics (math.GM)
subject: FOS: Mathematics
subject: 26A48, 39A70, 11B99, 40A05

description: Assuming that a "derivative" ratio rho:=f'/g' of the ratio r:=f/g of differentiable functions f and g is monotonic (that is, rho is increasing or decreasing), it was shown in previous papers that then r can switch at most once, from decrease to increase or vice versa. In the present paper, "discrete" versions of such l'Hospital-type rules for monotonicity (as well as "discrete" versions of l'Hospital's rules for limits) are obtained, for functions f and g defined on an interval of integers.
description: 6 pages
Self-Polarization and Dynamical Cooling of Nuclear Spins in Double Quantum Dots
Creators: name: Rudner, M. S.
name: Levitov, L. S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Spontaneous nuclear polarization is predicted in double quantum dots in the spin-blocked electron transport regime. The polarization results from an instability of the zero-polarization state when singlet and triplet electron energy levels are brought into resonance by the effective hyperfine field of the nuclei on the electrons. The nuclear spins, once polarized, serve as a cold bath for cooling electrons below the lattice (phonon) temperature. We estimate the relevant time scales and discuss the conditions necessary to observe these phenomena.
description: 4 pages, 3 figures, updated journal version
A search for non-reciprocal magnons in MnPS$_3$
Creators: name: Wildes, A. R.
name: Okamoto, S.
name: Xiao, D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Recent articles have suggested that the quasi-two dimensional antiferromagnet MnPS$_3$ may have non-reciprocal magnons, whereby magnons in a Brillouin zone corner at +q have different energies than those at $-$q. The magnons along the Brillouin zone boundaries were measured using neutron three-axis spectrometry, paying careful attention to the resolution function, to determine whether such non-reciprocity was present. The data show that, within the resolution, there are no significant differences between the magnons in opposite Brillouin zone corners.
description: 5 pages, 3 figures
Silica-on-Silicon Waveguide Quantum Circuits
Creators: name: Politi, Alberto
name: Cryan, Martin J.
name: Rarity, John G.
name: Yu, Siyuan
name: O'Brien, Jeremy L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum technologies based on photons are anticipated in the areas of information processing, communication, metrology, and lithography. While there have been impressive proof-of-principle demonstrations in all of these areas, future technologies will likely require an integrated optics architecture for improved performance, miniaturization and scalability. We demonstrated high- fidelity silica-on-silicon integrated optical realizations of key quantum photonic circuits, including two-photon quantum interference with a visibility of 94.8(5)%; a controlled-NOT gate with logical basis fidelity of 94.3(2)%; and a path entangled state of two photons with fidelity >92%.
description: 4 pages, 4 figures, comments welcome
Three isotopologues CO survey of Molecular Clouds in the CMa OB1 complex
Creators: name: Lin, Ze-Hao
name: Sun, Yan
name: Xu, Ye
name: Yang, Ji
name: Li, Ying-Jie
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Using the Purple Mountain Observatory 13.7-m millimeter telescope at Delingha in China, we have conducted a large-scale simultaneous survey of $^{12}$CO, $^{13}$CO, and \xxco ($J$ = 1--0) toward the CMa OB1 complex with a sky coverage of 16.5 deg$^{\rm 2}$ ($221^{\circ}.5\leq l\leq227^{\circ}$, $-2^{\circ}.5\leq b\leq0^{\circ}.5$). Emission from the CMa OB1 complex is found in the range 7 km s$^{-1}\ \leq$ V$_\mathrm{LSR}\ \leq$ 25 km s$^{-1}$. The large-scale structure, physical properties and chemical abundances of the molecular clouds are presented. A total of 83 C$^{18}$O molecular clumps are identified with GaussClumps algorithm within the mapped region. We find that 94% of these C$^{18}$O molecular clumps are gravitationally bound. The relationship between their size and mass indicates that none of the C$^{18}$O clump has the potential to form high-mass stars. Using semi-automatic IDL algorithm, we newly discover 85 CO outflow candidates in the mapped area, including 23 bipolar outflows candidates. Additionally, a comparative study reveals evidence for significant variety of physical properties, evolutionary stages, and levels of star formation activity in different sub-regions of the CMa OB1 complex.
description: 31 pages, 20 figures, 10 tables, accepted for publication in ApJS
Unveiling the nature of the highly absorbed X-ray source SAXJ1748.2-2808 with XMM-Newton
Creators: name: Sidoli, L.
name: Mereghetti, S.
name: Favata, F.
name: Oosterbroek, T.
name: Parmar, A. N.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on the results of an EPIC XMM-Newton observation of the faint source SAXJ1748.2-2808 and the surrounding field. This source was discovered during the BeppoSAX Galactic center survey performed in 1997-1998. A spatial analysis resulted in the detection of 31 sources within the EPIC field of view. SAXJ1748.2-2808 is clearly resolved into 2 sources in EPIC images with the brighter contributing almost 80% of the 2-10keV flux. Spectral fits to this main source are consistent with an absorbed power-law with a photon index of 1.4+/-0.5 and absorption equivalent to 14E22cm-2 together with an iron line at 6.6+/-0.2 keV with an equivalent width of ~780eV. The significantly better statistics of the XMM-Newton observation, compared with BeppoSAX,allows to exclude a thermal nature for the X-ray emission. A comparison with other observations of SAXJ1748.2-2808 does not reveal any evidence for spectral or intensity long-term variability. Based on these properties we propose that the source is a low-luminosity high-mass X-ray binary located in the Galactic center region.
description: accepted for publication in A&A
Bianchi spacetimes in noncommutative phase-space
Creators: name: Vakili, B.
name: Khosravi, N.
name: Sepangi, H. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The effects of noncommutativity in the phase-space of the classical and quantum cosmology of Bianchi models are investigated. Exact solutions in both commutative and noncommutative cases are presented and compared. Further, the Noether symmetries of the Bianchi class A spacetimes are studied in both cases and similarities and differences are discussed.
description: 19 pages, 2 figures, to appear in Class. Quantum Grav
Multi-field inflation from single-field models
Creators: name: Bojowald, Martin
name: Brahma, Suddhasattwa
name: Crowe, Sean
name: Ding, Ding
name: McCracken, Joseph
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Quantization implies independent degrees of freedom that do not appear in the classical theory, given by fluctuations, correlations, and higher moments of a state. A systematic derivation of the resulting dynamical systems is presented here in a cosmological application for near-Gaussian states of a single-field inflation model. As a consequence, single-field Higgs inflation is made viable observationally by becoming a multi-field model with a specific potential for a fluctuation field interacting with the inflaton expectation value. Crucially, non-adiabatic methods of semiclassical quantum dynamics reveal important phases that can set suitable initial conditions for slow-roll inflation (in combination with the uncertainty relation), and then end inflation after the observationally preferred number of e-folds. New parameters in the interaction potential are derived from properties of the underlying background state, demonstrating how background non-Gaussianity can affect observational features of inflation or, conversely, how observations may be used to understand the quantum state of the inflaton.
description: 35 pages, 16 figures
Thermal and hard scales in transverse momentum distributions, fluctuations and entanglement
Creators: name: Feal, Xabier
name: Pajares, Carlos
name: Vazquez, Ricardo
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We analyze the transverse momentum distributions of pp, pPb, XeXe and PbPb collisions at different RHIC and LHC energies and centralities as well as the corresponding distributions for Higgs production decaying into $γγ$ and 4l. A simple linear relation is found between the effective thermal temperature and the hard scale, approximately valid for all processes and mainly determined by the hard scale fluctuations. In order to go further, it is shown that the whole spectrum of pp collisions can be described by a single function showing that the thermal temperature is determined solely by the hard scale and its fluctuations. The possible relation between the multiplicities of the soft and hard scales is explored.
Holography and the scale-invariance of density fluctuations
Creators: name: Magueijo, Joao
name: Smolin, Lee
name: Contaldi, Carlo R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study a scenario for the very early universe in which there is a fast phase transition from a non-geometric, high temperature phase to a low temperature, geometric phase described by a classical solution to the Einstein equations. In spite of the absence of a classical metric, the thermodynamics of the high temperature phase may be described by making use of the holographic principle. The thermal spectrum of fluctuations in the high temperature phase manifest themselves after the phase transition as a scale invariant spectrum of fluctuations. A simple model of the phase transition confirms that the near scale invariance of the fluctuations is natural; but the model also withstands detailed comparison with the data.
description: Extended discussion, with revisions
Local Extreme Learning Machines and Domain Decomposition for Solving Linear and Nonlinear Partial Differential Equations
Creators: name: Dong, Suchuan
name: Li, Zongwei
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: Machine Learning (cs.LG)
subject: Computational Physics (physics.comp-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: We present a neural network-based method for solving linear and nonlinear partial differential equations, by combining the ideas of extreme learning machines (ELM), domain decomposition and local neural networks. The field solution on each sub-domain is represented by a local feed-forward neural network, and $C^k$ continuity is imposed on the sub-domain boundaries. Each local neural network consists of a small number of hidden layers, while its last hidden layer can be wide. The weight/bias coefficients in all hidden layers of the local neural networks are pre-set to random values and are fixed, and only the weight coefficients in the output layers are training parameters. The overall neural network is trained by a linear or nonlinear least squares computation, not by the back-propagation type algorithms. We introduce a block time-marching scheme together with the presented method for long-time dynamic simulations. The current method exhibits a clear sense of convergence with respect to the degrees of freedom in the neural network. Its numerical errors typically decrease exponentially or nearly exponentially as the number of degrees of freedom increases. Extensive numerical experiments have been performed to demonstrate the computational performance of the presented method. We compare the current method with the deep Galerkin method (DGM) and the physics-informed neural network (PINN) in terms of the accuracy and computational cost. The current method exhibits a clear superiority, with its numerical errors and network training time considerably smaller (typically by orders of magnitude) than those of DGM and PINN. We also compare the current method with the classical finite element method (FEM). The computational performance of the current method is on par with, and oftentimes exceeds, the FEM performance.
description: 62 pages, 48 figures, 12 tables
Nonlinear Topological Valley Hall Edge States Arising from Type-II Dirac Cones
Creators: name: Zhong, Hua
name: Xia, Shiqi
name: Li, Yongdong
name: Zhang, Yiqi
name: Song, Daohong
name: Liu, Chunliang
name: Chen, Zhigang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Type-II Dirac/Weyl points, although impermissible in particle physics due to Lorentz covariance, were uncovered in condensed matter physics, driven by fundamental interest and intriguing applications of topological materials. Recently, there has been a surge of exploration of such generic points using various engineered platforms including photonic crystals, waveguide arrays, metasurfaces, magnetized plasma and polariton micropillars, aiming towards relativistic quantum emulation and understanding of exotic topological phenomena. Such endeavors, however, have focused mainly on linear topological states in real or synthetic Dirac/Weyl materials. Here, we demonstrate nonlinear valley Hall edge states (VHESs) in laser-writing anisotropic photonic lattices hosting type-II Dirac points. These self-trapped VHESs, manifested as topological gap quasi-solitons, are fundamentally distinct from their linear counterparts in type-I lattices and from all previously found topological solitons. Our finding may provide a route for understanding nonlinear phenomena in Lorentz-violating topological systems and for developing advanced light sources from topological insulator lasers.
description: 15 pages, 4 figures
Synchronization dynamics in non-normal networks: the trade-off for optimality
Creators: name: Muolo, Riccardo
name: Carletti, Timoteo
name: Gleeson, James P.
name: Asllani, Malbor
Publisher: name: arXiv
Year: 2020
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Synchronization is an important behavior that characterizes many natural and human made systems composed by several interacting units. It can be found in a broad spectrum of applications, ranging from neuroscience to power-grids, to mention a few. Such systems synchronize because of the complex set of coupling they exhibit, the latter being modeled by complex networks. The dynamical behavior of the system and the topology of the underlying network are strongly intertwined, raising the question of the optimal architecture that makes synchronization robust. The Master Stability Function (MSF) has been proposed and extensively studied as a generic framework to tackle synchronization problems. Using this method, it has been shown that for a class of models, synchronization in strongly directed networks is robust to external perturbations. In this paper, our approach is to transform the non-autonomous system of coupled oscillators into an autonomous one, showing that previous results are model-independent. Recent findings indicate that many real-world networks are strongly directed, being potential candidates for optimal synchronization. Inspired by the fact that highly directed networks are also strongly non-normal, in this work, we address the matter of non-normality by pointing out that standard techniques, such as the MSF, may fail in predicting the stability of synchronized behavior. These results lead to a trade-off between non-normality and directedness that should be properly considered when designing an optimal network, enhancing the robustness of synchronization.
Covering numbers and schlicht functions
Creators: name: Drouin, Philippe
name: Ransford, Thomas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Complex Variables (math.CV)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 30C45 (primary) 54E35 (secondary)

description: We determine upper and lower bounds for the minimal number of balls of a given radius needed to cover the space of schlicht functions.
Overdensities of Submillimetre-Bright Sources around Candidate Protocluster Cores Selected from the South Pole Telescope Survey
Creators: name: Wang, George
name: Hill, Ryley
name: Chapman, S. C.
name: Weiß, A.
name: Scott, Douglas
name: Aravena, Manuel
name: Archipley, Melanie Ann
name: Béthermin, Matthieu
name: De Breuck, Carlos
name: Canning, R. E. A.
name: Dong, Chenxing
name: Everett, W. B.
name: Gonzalez, Anthony
name: Greve, Thomas R.
name: Hayward, Christopher C.
name: Hezaveh, Yashar
name: Marrone, D. P.
name: Jarugula, Sreevani
name: Phadke, Kedar A.
name: Reuter, Cassie A.
name: Spilker, Justin S.
name: Vieira, Joaquin D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present APEX-LABOCA 870 micron observations of the fields surrounding the nine brightest, high-redshift, unlensed objects discovered in the South Pole Telescope's (SPT) 2500 square degrees survey. Initially seen as point sources by SPT's 1-arcmin beam, the 19-arcsec resolution of our new data enables us to deblend these objects and search for submillimetre (submm) sources in the surrounding fields. We find a total of 98 sources above a threshold of 3.7 sigma in the observed area of 1300 square arcminutes, where the bright central cores resolve into multiple components. After applying a radial cut to our LABOCA sources to achieve uniform sensitivity and angular size across each of the nine fields, we compute the cumulative and differential number counts and compare them to estimates of the background, finding a significant overdensity of approximately 10 at 14 mJy. The large overdensities of bright submm sources surrounding these fields suggest that they could be candidate protoclusters undergoing massive star-formation events. Photometric and spectroscopic redshifts of the unlensed central objects range from 3 to 7, implying a volume density of star-forming protoclusters of approximately 0.1 per giga-parsec cube. If the surrounding submm sources in these fields are at the same redshifts as the central objects, then the total star-formation rates of these candidate protoclusters reach 10,000 solar masses per year, making them much more active at these redshifts than what has been seen so far in both simulations and observations.
A positivity conjecture related to the Riemann zeta function
Creators: name: Bellemare, Hugues
name: Langlois, Yves
name: Ransford, Thomas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Number Theory (math.NT)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 11M06 (primary), 46E20 (secondary)

description: According to two remarkable theorems of Nyman and Báez-Duarte, the Riemann hypothesis is equivalent to a simply-stated criterion concerning least-squares approximation. In carrying out computations related to this criterion, we have observed a curious phenomenon: for no apparent reason, at least the first billion entries of a certain infinite triangular matrix associated to the Riemann zeta function are all positive. In this article we describe the background leading to this observation, and make a conjecture.
Σύμβαση ανταποδοτικής χορηγίας. Σύμβαση σπόνσορινγκ:
Creators: name: Κόκκινος, Σωτήριος Θωμά
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Χορηγία
Ανταποδοτική χορηγία
Sponsoring

description: Η σύμβαση ανταποδοτικής χορηγίας αποτελεί μία από τις σύγχρονες μορφές συμβάσεων στην ελληνική οικονομία και αγορά. Η έλλειψη, ωστόσο, νομοθετικής ρύθμισης καθιστά το έργο κάθε ερμηνευτή του δικαίου δύσκολο, αφού η εν λόγω sui generis σύμβαση πρέπει να αντιμετωπίζεται με αναγωγή σε γενικότερες διατάξεις και αρχές του εμπορικού και του αστικού δικαίου. Η μεγάλη οικονομική σημασία της χορηγίας, όπως η τελευταία χρησιμοποιείται παραπληρωματικά με τη διαφήμιση στην προώθηση μία επιχείρησης, γεννά επιπλέον ζητήματα. Γεγονός, πάντως, παραμένει ότι η χορηγία είναι περισσότερο αποδοτική στην πράξη, σε σύγκριση με τη διαφήμιση.
description: The Sponsoring is one of the most modern contracts in the greek economy and market. It is a fact that there is no law of sponsoring – contract, so that all problems concerning Sponsoring could be solved. This absence of the law means that in order to occupy with a sponsoring – contract, we have to use the general principles of the commercial and the civil law. This problem is much more important, if somebody considers the great importance of the Sponsoring – contract in the greek economy. Furthermore, we have to add that the Sponsoring is used in the same way as the Advertising, although Sponsporing is much more efficient as a contract.
Activity ageing in growing networks
Creators: name: Lambiotte, R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We present a model for growing information networks where the ageing of a node depends on the time at which it entered the network and on the last time it was cited. The model is shown to undergo a transition from a small-world to large-world network. The degree distribution may exhibit very different shapes depending on the model parameters, e.g. delta-peaked, exponential or power-law tailed distributions.
description: 9 pages, 2 figures
Fast and Secure Distributed Nonnegative Matrix Factorization
Creators: name: Qian, Yuqiu
name: Tan, Conghui
name: Ding, Danhao
name: Li, Hui
name: Mamoulis, Nikos
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Cryptography and Security (cs.CR)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Nonnegative matrix factorization (NMF) has been successfully applied in several data mining tasks. Recently, there is an increasing interest in the acceleration of NMF, due to its high cost on large matrices. On the other hand, the privacy issue of NMF over federated data is worthy of attention, since NMF is prevalently applied in image and text analysis which may involve leveraging privacy data (e.g, medical image and record) across several parties (e.g., hospitals). In this paper, we study the acceleration and security problems of distributed NMF. Firstly, we propose a distributed sketched alternating nonnegative least squares (DSANLS) framework for NMF, which utilizes a matrix sketching technique to reduce the size of nonnegative least squares subproblems with a convergence guarantee. For the second problem, we show that DSANLS with modification can be adapted to the security setting, but only for one or limited iterations. Consequently, we propose four efficient distributed NMF methods in both synchronous and asynchronous settings with a security guarantee. We conduct extensive experiments on several real datasets to show the superiority of our proposed methods. The implementation of our methods is available at https://github.com/qianyuqiu79/DSANLS.
description: Published in IEEE Transactions on Knowledge and Data Engineering (TKDE). This arXiv version includes the appendices with additional proofs
Lazy representation & comprehension of very large genomic data resources in R / Bioconductor
Creators: name: Liu, Qian
name: Pagès, Hervé
name: Morgan, Martin
Publisher: name: F1000 Research Limited
Year: 2019

description: Motivation: With the increasing challenges in understanding very large and complex genomic data, urgent demands are present for computational and bioinformatics tools to efficiently translate the data into clinically important insights. Methods: R / Bioconductor provides robust, scalable software infrastructures and interoperable statistical methods to help tackle these challenges. Previously, DelayedArray has been developed to represent very big genomic data sets (e.g., count data from scRNA-seq). DelayedArray allows users to perform common array operations without loading the data in memory. We and others have extended DelayedArray to different backends for scalable computation, such as Hierarchical Data Format (HDF) and Genomic Data Structure (GDS). DelayedDataFrame is developed for lazy representation of sample metadata (e.g., the clinical characteristics for samples). VariantExperiment is a lightweight container for lazy data structures representing both assay and annotation data for a complete experiment. Results: These data structures provide rich semantics for data operations with familiar paradigms such as “matrix” and “data.frame”, and present minimal requirements for memory use and for bioinformaticians to learn new techniques. Conclusion: These data structures considerably improve the acquisition, management, analysis and dissemination of big genomic datasets, and benefit the broad community of bioinformatic software developers and domain-specific cancer researchers.
Giant quantum oscillations in thermal transport in low-density metals via electron absorption of phonons
Creators: name: Bermond, B.
name: Wawrzynczak, R.
name: Zherlitsyn, S.
name: Kotte, T.
name: Helm, T.
name: Gorbunov, D.
name: Gu, G. D.
name: Li, Q.
name: Janasz, F.
name: Meng, T.
name: Menges, F.
name: Felser, C.
name: Wosnitza, J.
name: Grushin, Adolfo G.
name: Carpentier, David
name: Gooth, J.
name: Galeski, S.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Oscillations of conductance observed in strong magnetic fields are a striking manifestation of the quantum dynamics of charge carriers in solids. The large charge carrier density in typical metals sets the scale of oscillations in both electrical and thermal conductivity, which characterize the Fermi surface. In semimetals, thermal transport at low-charge carrier density is expected to be phonon dominated, yet several experiments observe giant quantum oscillations in thermal transport. This raises the question of whether there is an overarching mechanism leading to sizable oscillations that survives in phonon-dominated semimetals. In this work, we show that such a mechanism exists. It relies on the peculiar phase-space allowed for phonon scattering by electrons when only a few Landau levels are filled. Our measurements on the Dirac semimetal ZrTe5 support this counter-intuitive mechanism through observation of pronounced thermal quantum oscillations, since they occur in similar magnitude and phase in directions parallel and transverse to the magnetic field. Our phase-space argument applies to all low-density semimetals, topological or not, including graphene and bismuth. Our work illustrates that phonon absorption can be leveraged to reveal degrees of freedom through their imprint on longitudinal thermal transport.
Spoken word recognition as a function of lexical knowledge and language proficiency level in adult ESL learners
Creators: name: Barbour, Ross Patrick
Publisher: name: University of British Columbia
Year: 2009

description: This study assesses the usefulness of Marsien-Wilson’s (1989, 1987; Marsien Wilson & Welsh, 1978) cohort model of spoken (first language) word recognition as a method of explaining the high-speed, on-line processes involved in recognizing spoken words while listening to a second language. Two important assumptions of the model are: 1) syntactic and semantic properties of mental lexical entries can function to-facilitate spoken word recognition and 2) spoken word recognition is a function of the frequency of exposure to words in the general language environment. These assumptions were tested in three functionally defined levels of language proficiency: Native Speakers of English, Fluent Users of ESL, and Advanced learners of ESL. Their performance was compared on a reading cloze test and a spoken-word recognition task in which there were five different levels of contextual richness prior to a target word, and two levels of word frequency. The cloze results indicated that the three groups differed in their general English proficiency. Congruent with the cohort model, there was a significant overall effect of sentence context and word frequency on recognition latency. Despite the difference in cloze scores and immersion experience between the two ESL groups, there were no reliable differences in their recognition latencies or latency profiles across sentence contexts or across word frequency. There was an interaction of ESL group, word frequency, and sentence context. This may be due to a reorganization of rules used during processing or a restructuring of lexical knowledge. There was also an interesting non-linear relationship between recognition latency and language immersion time. Spoken word recognition speed decreased in the early immersion experience, and then increased with further exposure. There was a significant difference in overall mean recognition latency between the Native and the ESL speakers, with the ESL subjects responding on average 98 msec slower than the Native Speakers. However, there were no significant differences in the way Native Speakers and the ESL subjects used sentence context. In contrast with the comparison across the sentential contexts, there was a significant difference in the recognition profiles of the Native English speakers and the ESL subjects across word frequency.
Towards Refining the Topological Strings on Compact Calabi-Yau 3-folds
Creators: name: Huang, Min-xin
name: Katz, Sheldon
name: Klemm, Albrecht
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Algebraic Geometry (math.AG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We make a proposal for calculating refined Gopakumar-Vafa numbers (GVN) on elliptically fibered Calabi-Yau 3-folds based on refined holomorphic anomaly equations. The key examples are smooth elliptic fibrations over (almost) Fano surfaces. We include a detailed review of existing mathematical methods towards defining and calculating the (unrefined) Gopakumar-Vafa invariants (GVI) and the GVNs on compact Calabi-Yau 3-folds using moduli of stable sheaves, in a language that should be accessible to physicists. In particular, we discuss the dependence of the GVNs on the complex structure moduli and on the choice of an orientation. We calculate the GVNs in many instances and compare the B-model predictions with the geometric calculations. We also derive the modular anomaly equations from the holomorphic anomaly equations by analyzing the quasi-modular properties of the propagators. We speculate about the physical relevance of the mathematical choices that can be made for the orientation.
description: 92 pages, 2 pdf figures
Lindblad rate equations
Creators: name: Budini, Adrian A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper we derive an extra class of non-Markovian master equations where the system state is written as a sum of auxiliary matrixes whose evolution involve Lindblad contributions with local coupling between all of them, resembling the structure of a classical rate equation. The system dynamics may develops strong non-local effects such as the dependence of the stationary properties with the system initialization. These equations are derived from alternative microscopic interactions, such as complex environments described in a generalized Born-Markov approximation and tripartite system-environment interactions, where extra unobserved degrees of freedom mediates the entanglement between the system and a Markovian reservoir. Conditions that guarantees the completely positive condition of the solution map are found. Quantum stochastic processes that recover the system dynamics in average are formulated. We exemplify our results by analyzing the dynamical action of non-trivial structured dephasing and depolarizing reservoirs over a single qubit.
description: 12 pages, 2 figures
Φωτοκαταλυτική επεξεργασία φωτογραφικών αποβλήτων:
Creators: name: Αντωνιάδης, Απόστολος Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Φωτοκαταλυτική Οξείδωση
Φωτογραφικά Απόβλητα
Αναγωγή Ιόντων Αργύρου
Photocatalytic Oxidation
Photo- processing wastewater
Reduction of silver ions

description: Σκοπός της διατριβής ήταν η μελέτη της φωτοκαταλυτικής επεξεργασίας φωτογραφικών αποβλήτων. Πιο συγκεκριμένα, μελετήθηκε η απόδοση της ετερογενούς φωτοκαταλυτικής οξείδωσης ως προς την απόδοση της οξείδωσης των φωτογραφικών αποβλήτων. Ταυτόχρονα, μελετήθηκε η απόδοση της παραπάνω μεθόδου ως προς την αναγωγή των περιεχόμενων σε αυτά ιόντων αργύρου. Μελετήθηκε η επίδραση της συγκέντρωσης του ημιαγωγού και του υπεροξειδίου του υδρογόνου. Συμπερασματικά, η ετερογενής φωτοκαταλυτική οξείδωση μπορεί να αποτελέσει μία ιδιαίτερα αποτελεσματική επεξεργασία, μόνη της η σε συνδυασμό με άλλες μεθόδους, για την μείωση του οργανικού φορτίου και την αναγωγή και ανάκτηση των ιόντων αργύρου των φωτογραφικών αποβλήτων. Ωστόσο απαιτείται περαιτέρω έρευνα για την εφαρμογή της εν λόγω μεθόδου σε πιλοτική και πραγματική κλίμακα, με τελικό στόχο την αξιοποίηση της ηλιακής ενέργειας στην επεξεργασία των φωτογραφικών αποβλήτων.
description: The aim of the present thesis was the study of the photocatalytic oxidation of photo – processing wastewater.More specifically, the efficiency of the heterogeneous photocatalytic oxidation concerning the result of the oxidation of the photo – processing wastewater was studied.Moreover, the efficiency of the above used method concerning the efficiency of the reduction of silver ions, which are present at the above wastewater, was studied. The studied parameters concerning the efficiency of the heterogeneous photocatalytic oxidation are the concentration of the semiconductor as well as the concentration of the hydrogen peroxide.As a main conclusion, heterogeneous photocatalytic oxidation may be considered as an effective method, in combination with other treatment methods or alone itself, for the oxidation of the organic content, as well as the reduction of the silver ions of the photo – processing wastewater. Although, further research is needed for the implication of the mentioned method at pilot and large scale implementations, with final goal the application of solar energy at the treatment of photo – processing wastewater.
Influence of optical feedback on harmonic pulsating solutions of long-cavity mode-locked VECSELs
Creators: name: Bartolo, A.
name: Seidel, T.
name: Vigne, N.
name: Garnache, A.
name: Beaudoin, G.
name: Sagnes, I.
name: Huyet, G.
name: Giudici, M.
name: Javaloyes, J.
name: Gurevich, S.
name: Marconi, M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We analyse the effect of optical feedback on the dynamics of external-cavity mode-locked semiconductor lasers operated in the long cavity regime. Depending on the ratio between the cavity round-trip time and the feedback delay, we show experimentally that feedback acts as a solution discriminator that either reinforces or hinders the appearance of one of the multiple coexisting mode-locked harmonic solutions. Our theoretical analysis reproduces well the experiment. We identify asymmetrical resonance tongues due to the temporal symmetry breaking induced by gain depletion.
description: 4 pages, 5 pictures, submitted to Optics Letters