cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Braking PSR J1734-3333 with a possible fall-back disk
Creators: name: Liu, X. W.
name: Xu, R. X.
name: Qiao, G. J.
name: Han, J. L.
name: Tong, H.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The very small braking index of PSR J1734-3333, $n=0.9\pm0.2$, challenges the current theories of braking mechanisms in pulsars. We present a possible interpretation that this pulsar is surrounded by a fall-back disk and braked by it. A modified braking torque is proposed based on the competition between the magnetic energy density of a pulsar and the kinetic energy density of a fall-back disk. With this torque, a self-similar disk can fit all the observed parameters of PSR J1734-3333 with natural initial parameters. In this regime, the star will evolve to the region having anomalous X-ray pulsars and soft gamma repeaters in the $P-\dot{P}$ diagram in about 20000 years and stay there for a very long time. The mass of the disk around PSR J1734-3333 in our model is about $10M_{\oplus}$, similar to the observed mass of the disk around AXP 4U 0142+61.
description: 8 pages, 3 figures, 1 table
A quantum Mermin--Wagner theorem for a generalized Hubbard model on a 2D graph
Creators: name: Kelbert, Mark
name: Suhov, Yurii
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 82B10, 60B15, 82B26

description: This paper is the second in a series of papers considering symmetry properties of a bosonic quantum system over an 2D graph, with continuous spins, in the spirit of the Mermin--Wagner theorem. Here we consider bosonic systems on bi-dimensional graphs where particles can jump from a vertex to another (a generalized Hubbard model). The Feynman--Kac representation is used for proving that if the local Hamiltonians are invariant under a continuous group of transformations ${\tt G}$ (a Euclidean space or a torus of dimension $d'$ acting on a torus of dimension $d\geq d'$) then any infinite-volume Gibbs state from a certain class (introduced in the paper) is also ${\tt G}$-invariant.
description: 48 pages
Tuning the Self Assembly of Bio-inspired Catalysts and Materials
Creators: name: Aitken, Heather
Publisher: name: The Australian National University
Year: 2022

description: With a view to designing selective bio-inspired catalysts, the following thesis seeks to understand and tune the self-assembly of bio-inspired and biological materials and catalysts. The first chapter introduces the concept of self-assembly and its importance in bio-inspired chemistry. In chapter 2, to highlight the role of self-assembly in biology, DNA G-quadruplex formation is simulated using molecular dynamics to determine the structural deformities caused by specific mutations of the human telomerase reverse transcriptase gene which are over-expressed in most cancers. In chapter 3, self-assembly of a model bio-inspired amphiphilic polymer is studied using experimental and computational chemistry techniques. The hydrophobicity and mechanical properties of this dynamic non- covalent material is tuned by altering the monomer ratio and swelling conditions. In chapter 4, the importance of weak non-covalent interactions in catalysing small molecule reactions and determining their selectivity is highlighted using quantum mechanics calculations. Finally in chapter 5, using what we have learned in chapters 2-4, we build a self-assembled enzyme mimic using amphiphilic macromolecules, for selective ester hydrolysis.
Optical measurement and modeling of interactions between two hole or two electron spins in coupled InAs quantum dots
Creators: name: Greilich, Alex
name: Bădescu, Ştefan C.
name: Kim, Danny
name: Bracker, Allan S.
name: Gammon, Daniel
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Two electron spins in quantum dots coupled through coherent tunneling are generally acknowledged to approximately obey Heisenberg isotropic exchange. This has not been established for two holes. Here we measure the spectra of two holes and of two electrons in two vertically stacked self-assembled InAs quantum dots using optical spectroscopy as a function of electric and magnetic fields. We find that the exchange is approximately isotropic for both systems, but that significant asymmetric contributions, arising from spin-orbit and Zeeman interactions combined with spatial asymmetries, are required to explain large anticrossings and fine-structure energy splittings in the spectra. Asymmetric contributions to the isotropic Hamiltonian for electrons are of the order of a few percent while those for holes are an order of magnitude larger.
description: 5 pages, 3 figures
Causality constraints for charged particles
Creators: name: König, Sebastian
name: Lee, Dean
name: Hammer, H. -W.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In quantum systems with short-range interactions, causality imposes nontrivial constraints on low-energy scattering parameters. We investigate these causality constraints for systems where a long-range Coulomb potential is present in addition to a short-range interaction. The main result is an upper bound for the Coulomb-modified effective range parameter. We discuss the implications of this bound to the effective field theory for nuclear halo systems. In particular, we consider several examples of proton--nucleus and nucleus--nucleus scattering. For the bound-state regime, we find relations for the asymptotic normalization coefficients (ANCs) of nuclear halo states. As an application of these relations, we extract the ANCs of the excited 2+ and 1- states in O-16 from alpha--C-12 scattering data.
description: 34 pages, 6 figures, published version
Sorcery Accusation-Related Violence in PNG - Part 8: Responses to Prevent Sorcery Accusation Turning to Violence - Reporting from the SARV Incident Database
Creators: name: Forsyth, Miranda
name: Losoncz, Ibolya
name: Gibbs, Philip
name: Hukula, Fiona
name: Kipongi, William
Publisher: name: Canberra, ACT: Dept. of Pacific Affairs, Research School of Pacific and Asian Studies, The Australian National University
Year: 2021

description: This In Brief is the final part in a series presenting findings from a multi-year study of sorcery accusation-related violence (SARV) in PNG in four hotspot provinces — Enga, The Autonomous Region of Bougainville (Bougainville), Jiwaka and the National Capital District (NCD) — over a four-and-a-half-year period (January 20161–June 2020). It summarises what we have learnt about who tries to intervene in incidents of SARV, and the respective efficacy of responses aimed at preventing sorcery accusations turning into physical or property violence.
Das Deutsche Archäologische Institut. Geschichte und Dokumente
Creators: name: Narr, Karl J.
Publisher: name: Bonner Jahrbücher
Year: 2019

description: Rezension zu: Anita Rieche, Die Satzungen des Deutschen Archäologischen Instituts 1828-1972. Das Deutsche Archäologische Institut. Geschichte und Dokumente 1. Verlag Philipp von Zabern, Mainz 1979. 235 Seiten, 8 Tafeln Lothar Wickert, Beiträge zur Geschichte des Deutschen Archäologischen Instituts 1879-1929. Das Deutsche Archäologische Institut. Geschichte und Dokumente 2. Verlag Philipp von Zabern, Mainz 1979. 203 Seiten, 16 Tafeln K. Bittel, F. W. Deichmann, W. Grünhagen, W. Kaiser, Th. Kraus und H. Kyrieleis, Beiträge zur Geschichte des Deutschen Archäologischen Instituts 1929-1979. Teil 1. Das Deutsche Archäologische Institut. Geschichte und Dokumente 3. Verlag Philipp von Zabern, Mainz 1979. 167 Seiten, 16 Tafeln Hellmut Sichtermann, Vier Briefe August von Platens an Eduard Gerhard. Das Deutsche Archäologische Institut. Geschichte und Dokumente 4. Verlag Philipp von Zabern, Mainz 1979. 62 Seiten, 11 Tafeln Wolfram Hoepfner und Fritz Neumeyer, Das Haus Wiegand von Peter Behrens in Berlin-Dahlem. Baugeschichte und Kunstgegenstände eines herrschaftlichen Wohnhauses. Das Deutsche Archäologische Institut. Geschichte und Dokumente 6. Verlag Philipp von Zabern, Mainz 1979. 211 Seiten, 101 Abbildungen, 25 Tafeln Horst Blank, Die Bibliothek des Deutschen Archäologischen Instituts in Rom. Das Deutsche Archäologische Institut. Geschichte und Dokumente 7. Verlag Philipp von Zabern, Mainz 1979. 49 Seiten, 8 Tafeln
description: Bonner Jahrbücher, Bd. 186.1986: Bonner Jahrbücher
Maria R.-Alföldi (Hrsg.), Studien zu den Fundmünzen der Antike 2
Creators: name: Chantraine, Heinrich
Publisher: name: Bonner Jahrbücher
Year: 2019

description: Rezension zu: Maria R.-Alföldi (Hrsg.), Studien zu den Fundmünzen der Antike 2. Gebr. Mann Verlag, Berlin 1984. 268 Seiten, 14 Textabbildungen, 96 Tabellen, 23 Diagramme
description: Bonner Jahrbücher, Bd. 186.1986: Bonner Jahrbücher
Implications of purely classical gravity for inflationary tensor modes
Creators: name: Ashoorioon, Amjad
name: Dev, P. S. Bhupal
name: Mazumdar, Anupam
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss the implications of purely classical, instead of quantum, theory of gravity for the gravitational wave spectrum generated during inflation. We show that a positive detection of primordial gravitational waves will no longer suffice to determine the scale of inflation in this case -- even a high-scale model of inflation can bypass the observational constraints due to large uncertainties in the initial classical amplitude of the tensor modes.
description: v1: 4 pages; v2:6 pages. This is the first paper to argue that a positive detection of B-modes would signify that initial conditions for primordial gravity waves is set by quantum initial conditions and not by classical ones
The Parameterized Post-Friedmann Framework for Theories of Modified Gravity: Concepts, Formalism and Examples
Creators: name: Baker, Tessa
name: Ferreira, Pedro G.
name: Skordis, Constantinos
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A unified framework for theories of modified gravity will be an essential tool for interpreting the forthcoming deluge of cosmological data. We present such a formalism, the Parameterized Post-Friedmann framework (PPF), which parameterizes the cosmological perturbation theory of a wide variety of modified gravity models. PPF is able to handle spin-0 degrees of freedom from new scalar, vector and tensor fields, meaning that it is not restricted to simple models based solely on cosmological scalar fields. A direct correspondence is maintained between the parameterization and the underlying space of theories, which allows us to build up a `dictionary' of modified gravity theories and their PPF correspondences. In this paper we describe the construction of the parameterization and demonstrate its use through a number of worked examples relevant to the current literature. We indicate how the formalism will be implemented numerically, so that the dictionary of modified gravity can be pitted against forthcoming observations.
description: 24 pages, updated to match version published in PRD. Discussion of section 4 extended. Suggestions for the busy reader are given at the end of section 1
Universal anisotropic finite-size critical behavior of the two-dimensional Ising model on a strip and of d-dimensional models on films
Creators: name: Kastening, Boris
Publisher: name: arXiv
Year: 2012
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Anisotropy effects on the finite-size critical behavior of a two-dimensional Ising model on a general triangular lattice in an infinite-strip geometry with periodic, antiperiodic, and free boundary conditions (bc) in the finite direction are investigated. Exact results are obtained for the scaling functions of the finite-size contributions to the free energy density. With xi_> the largest and xi_< the smallest bulk correlation length at a given temperature near criticality, we find that the dependence of these functions on the ratio xi_< / xi_> and on the angle parameterizing the orientation of the correlation volume is of geometric rather than dynamic origin. Since the scaling functions are independent of the particular microscopic realization of the anisotropy within the two-dimensional Ising model, our results provide a limited verification of universality. We explain our observations by considering finite-size scaling of free energy densities of general weakly anisotropic models on a d-dimensional film, i.e., in an L x infinity^(d-1) geometry, with bc in the finite direction that are invariant under a shear transformation relating the anisotropic and isotropic cases. This allows us to relate free energy scaling functions in the presence of an anisotropy to those of the corresponding isotropic system. We interpret our results as a simple and transparent case of anisotropic universality, where, compared to the isotropic case, scaling functions depend additionally on the shape and orientation of the correlation volume. We conjecture that this universality extends to cases where the geometry and/or the bc are not invariant under the shear transformation and argue in favor of validity of two-scale factor universality for anisotropic systems.
description: 16 pages, 4 figures; ref. [14] corrected
Chaotic Brane Inflation
Creators: name: Shlaer, Benjamin
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We illustrate a framework for constructing models of chaotic inflation where the inflaton is the position of a D3 brane along the universal cover of a string compactification. In our scenario, a brane rolls many times around a non-trivial one-cycle, thereby unwinding a Ramond-Ramond flux. These "flux monodromies" are similar in spirit to the monodromies of Silverstein, Westphal, and McAllister, and their four-dimensional description is that of Kaloper and Sorbo. Assuming moduli stabilization is rigid enough, the large-field inflationary potential is protected from radiative corrections by a discrete shift symmetry.
description: Journal version, includes kinetic steepening possibility
Liquid crystal spatial-mode converters for the orbital angular momentum of light
Creators: name: Slussarenko, Sergei
name: Piccirillo, Bruno
name: Chigrinov, Vladimir
name: Marrucci, Lorenzo
name: Santamato, Enrico
Publisher: name: arXiv
Year: 2012
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present a tunable liquid crystal device that converts pure orbital angular momentum eigenmodes of a light beam into equal-weight superpositions of opposite-handed eigenmodes and vice versa. For specific input states, the device may thus simulate the behavior of a π/2 phase retarder in a given two-dimensional orbital angular momentum subspace, analogous to a quarter-wave plate for optical polarization. A variant of the same device generates the same final modes starting from a Gaussian input.
description: 6 pages, 6 figures
Nonlocal extension of relativistic non-equilibrium thermostatics
Creators: name: Ilin, Alexei S.
name: Balakin, Alexander B.
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Based on the formalism of nonlocal extension of the Israel-Stewart causal thermodynamics on the one hand, and on the formalism of the extended thermostatics on the other hand, we propose the new model of nonlocal relativistic non-equilibrium thermostatics for description of the static spherically symmetric stellar systems. This nonlocal formalism operates with the pair of orthogonal four-vectors: one of them is the standard unit timelike medium velocity four-vector, the second one is the unit spacelike director. We derived the extended equation describing the profile of the non-equilibrium pressure, which can be indicated as the static analog of the Burgers constitutive equation known in classical rheology.
description: 3 pages, 0 Figures, Short communication based on the talk presented on the Fifth International Winter School-Seminar on Gravitation, Astrophysics and Cosmology Petrov Readings -2022, Kazan, Russia
Probing Pre-galactic Metal Enrichment with High-Redshift Gamma-Ray Bursts
Creators: name: Wang, F. Y.
name: Bromm, Volker
name: Greif, Thomas H.
name: Stacy, Athena
name: Dai, Z. G.
name: Loeb, Abraham
name: Cheng, K. S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We explore high-redshift gamma-ray bursts (GRBs) as promising tools to probe pre-galactic metal enrichment. We utilize the bright afterglow of a Pop III GRB exploding in a primordial dwarf galaxy as a luminous background source, and calculate the strength of metal absorption lines that are imprinted by the first heavy elements in the intergalactic medium (IGM). To derive the GRB absorption line diagnostics, we use an existing highly-resolved simulation of the formation of a first galaxy which is characterized by the onset of atomic hydrogen cooling in a halo with virial temperature >10^4 K. We explore the unusual circumburst environment inside the systems that hosted Pop III stars, modeling the density evolution with the self-similar solution for a champagne flow. For minihalos close to the cooling threshold, the circumburst density is roughly proportional to (1+z) with values of about a few cm^{-3}. In more massive halos, corresponding to the first galaxies, the density may be larger, n>100 cm^{-3}. The resulting afterglow fluxes may be detectable with the JWST and VLA in the near-IR and radio wavebands, respectively, out to redshift z>20. We predict that the maximum of the afterglow emission shifts from near-IR to millimeter bands with peak fluxes from mJy to Jy at different observed times. GRBs are ideal tools for probing the metal enrichment in the early IGM, due to their high luminosities and featureless power-law spectra. The metals in the first galaxies produced by the first supernova (SN) explosions are likely to reside in low-ionization stages. We show that if the afterglow can be observed sufficiently early, analysis of the metal lines can distinguish whether the first heavy elements were produced in a PISN, or a core-collapse (Type II) SN, thus constraining the initial mass function of the first stars.
description: 13 pages (emulateapj), 13 figures, 2 tables, accepted for publication in ApJ
The interacting resonant level model in nonequilibrium: finite temperature effects
Creators: name: Kennes, D. M.
name: Meden, V.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the steady-state properties as well as the relaxation dynamics of the nonequilibrium interacting resonant level model at finite temperatures. It constitutes the prototype model of a correlated charge fluctuating quantum dot. The two reservoirs are held at different chemical potentials---the difference being the bias voltage---and different temperatures; we discuss the transport through as well as the occupancy of the single level dot. First, we show analytically that in the steady state the reservoir temperatures in competition with the other energy scales act as infrared cutoffs. This is rather intuitive but, depending on the parameter regime under consideration, leads to a surprisingly rich variety of power laws in the current as a function of the temperatures and the bias voltage with different interaction dependent exponents. Next we clarify how finite reservoir temperatures affect the dynamics. They allow to tune the interplay of the two frequencies characterizing the oscillatory part of the time evolution of the model at zero temperature. For the exponentially decaying part we disentangle the contributions of the level-lead hybridization and the temperatures to the decay rates. We identify a coherent-to-incoherent transition in the long time dynamics as the temperature is raised. It occurs at an interaction dependent critical temperature. Finally, taking different temperatures in the reservoirs we discuss the relaxation dynamics of a temperature gradient driven current.
description: 12 pages, 6 figures, 1 table
African Migration: Exploring The Role Of Development And States
Creators: name: Flahaux, Marie-Laurence
name: de Haas, Hein
Publisher: name: Zenodo
Year: 2014
Subjects: Africa
Migration
Development
Migration Policies

description: Abstract

Africa is often seen as a continent of mass migration and displacement caused by poverty, violent conflict and environmental stress. Yet such perceptions are based on stereotypes rather than theoretically informed empirical research. Drawing on the migration and visa databases from the Determinants of International Migration – DEMIG project and the Global Bilateral Migration Database (GBMD), this paper explores the evolution and drivers of migration within, towards and from Africa in the post-colonial period. Contradicting common ideas of Africa as a ‘continent on the move’, the analysis shows that intra-African migration intensities have gone down. This may be related to state formation and the related imposition of barriers towards free movement in the wake of decolonisation as well as the concomitant rise of nationalism and inter-state tensions. While African migration remains overwhelmingly intra-continental, since the late 1980s there has been an acceleration and spatial diversification (beyond colonial patterns) of emigration out of Africa to Europe, North America, the Gulf and Asia. This diversification of African emigration seems partly driven by the introduction of visa and other immigration restrictions by European states. Contradicting conventional interpretations of African migration being essentially driven by poverty, violence and underdevelopment, increasing migration out of Africa seems rather to be driven by processes of development and social transformation which have increased Africans’ capabilities and aspirations to migrate, a trend which is likely to continue in the future.
Subgeometric rates of convergence of Markov processes in the Wasserstein metric
Creators: name: Butkovsky, Oleg
Publisher: name: arXiv
Year: 2012
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: We establish subgeometric bounds on convergence rate of general Markov processes in the Wasserstein metric. In the discrete time setting we prove that the Lyapunov drift condition and the existence of a "good" $d$-small set imply subgeometric convergence to the invariant measure. In the continuous time setting we obtain the same convergence rate provided that there exists a "good" $d$-small set and the Douc-Fort-Guillin supermartingale condition holds. As an application of our results, we prove that the Veretennikov-Khasminskii condition is sufficient for subexponential convergence of strong solutions of stochastic delay differential equations.
description: Published in at http://dx.doi.org/10.1214/13-AAP922 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Some New Identities of Genocchi Numbers and Polynomials involving Bernoulli and Euler polynomials
Creators: name: Araci, Serkan
name: Acikgoz, Mehmet
name: Şen, Erdoğan
Publisher: name: arXiv
Year: 2012
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: In this paper, we will deal with some new formulae for two product Genocchi polynomials together with both Euler polynomials and Bernoulli polynomials. We get some applications for Genocchi polynomials. Our applications possess a number of interesting properties to study in Theory of Analytic numbers which we express in the present paper.
description: 10 pages, submitted
Chelodina rugosa
Creators: name: Georges, Arthur
name: Adams, Mark
name: McCORD, William
Publisher: name: Zenodo
Year: 2002
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Testudines
Chelidae
Chelodina
Chelodina rugosa

description: Chelodina rugosa X Chelodina burrungandjii
hybrids: Daly River, NT [14°15'S 132°38'E, N = 1].
description: Published as part of Georges, Arthur, Adams, Mark & McCORD, William, 2002, Electrophoretic delineation of species boundaries within the genus Chelodina (Testudines: Chelidae) of Australia, New Guinea and Indonesia, pp. 401-421 in Zoological Journal of the Linnean Society 134 (4) on page 407, DOI: 10.1046/j.1096-3642.2002.00007.x, http://zenodo.org/record/5434026
Mean Field Theory of Dynamical Systems Driven by External Signals
Creators: name: Massar, Marc
name: Massar, Serge
Publisher: name: arXiv
Year: 2012
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Dynamical systems driven by strong external signals are ubiquituous in nature and engineering. Here we study "echo state networks", networks of a large number of randomly connected nodes, which represent a simple model of a neural network, and have important applications in machine learning. We develop a mean field theory of echo state networks. The dynamics of the network is captured by the evolution law, similar to a logistic map, for a single collective variable. When the network is driven by many independent external signals, this collective variable reaches a steady state. But when the network is driven by a single external signal, the collective variable is nonstationnary but can be characterised by its time averaged distribution. The predictions of the mean field theory, including the value of the largest Lyaponuov exponent, are compared with the numerical integration of the equations of motion.
description: 7 pages, 6 figures
Neue Untersuchungen auf den Rentierjägerstationen von Deimern, Kr. Soltau
Creators: name: Nowothnig, Walter
Publisher: name: Nachrichten aus Niedersachsens Urgeschichte
Year: 2019

description: Nachrichten aus Niedersachsens Urgeschichte, Bd. 32 (1963): Nachrichten aus Niedersachsens Urgeschichte
Observing The Early Stages Of Cme Development In The Low Corona.  Characterizing The Link Between Coronal Mass Ejections (Cmes) And Coronal Waves Stereo A/
Creators: name: Leja, Joel
Publisher: name: Zenodo
Year: 2014
Subjects: Solar physics
Coronal mass ejections
Coronal waves

description: Final presentations of the Center for Astrophysics HEA/SSP Solar Summer Intern Program.
XXI Международная научно-практическая конференция «Актуальные проблемы науки и образования в условиях современных вызовов» Ч.2.
Creators: name: ООО "Институт развития образования и консалтинга"
Publisher: name: ООО "Институт развития образования и консалтинга"
Year: 2023

description: XXI Международная научно-практическая конференция «Актуальные проблемы науки и образования в условиях современных вызовов» Ч.2.
Pool Inference Attacks on Local Differential Privacy: Quantifying the Privacy Guarantees of Apple's Count Mean Sketch in Practice
Creators: name: Gadotti, Andrea
name: Houssiau, Florimond
name: Annamalai, Meenatchi Sundaram Muthu Selva
name: de Montjoye, Yves-Alexandre
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: Behavioral data generated by users' devices, ranging from emoji use to pages visited, are collected at scale to improve apps and services. These data, however, contain fine-grained records and can reveal sensitive information about individual users. Local differential privacy has been used by companies as a solution to collect data from users while preserving privacy. We here first introduce pool inference attacks, where an adversary has access to a user's obfuscated data, defines pools of objects, and exploits the user's polarized behavior in multiple data collections to infer the user's preferred pool. Second, we instantiate this attack against Count Mean Sketch, a local differential privacy mechanism proposed by Apple and deployed in iOS and Mac OS devices, using a Bayesian model. Using Apple's parameters for the privacy loss $\varepsilon$, we then consider two specific attacks: one in the emojis setting -- where an adversary aims at inferring a user's preferred skin tone for emojis -- and one against visited websites -- where an adversary wants to learn the political orientation of a user from the news websites they visit. In both cases, we show the attack to be much more effective than a random guess when the adversary collects enough data. We find that users with high polarization and relevant interest are significantly more vulnerable, and we show that our attack is well-calibrated, allowing the adversary to target such vulnerable users. We finally validate our results for the emojis setting using user data from Twitter. Taken together, our results show that pool inference attacks are a concern for data protected by local differential privacy mechanisms with a large $\varepsilon$, emphasizing the need for additional technical safeguards and the need for more research on how to apply local differential privacy for multiple collections.
description: Published at USENIX Security 2022. This is the full version, please cite the USENIX version (see journal reference field)
Extended Simulations Of A Flux Rope Model For Cme Initiation
Creators: name: Constable, Jonathan
Publisher: name: Zenodo
Year: 2014
Subjects: Solar physics
Coronal mass ejections

description: Final presentations of the Center for Astrophysics HEA/SSP Solar Summer Intern Program.
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Implementation of a spatial two-dimensional quantum random walk with tunable decoherence
Creators: name: Svozilík, Jiří
name: León-Montiel, Roberto de Jesús
name: Torres, Juan P.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We put forward a new, versatile and highly-scalable experimental setup for the realization of discrete two-dimensional quantum random walks with a single-qubit coin and tunable degree of decoherence. The proposed scheme makes use of a small number of simple optical components arranged in a multi-path Mach-Zehnder-like configuration, where a weak coherent state with average photon number of 1 is injected. Environmental effects (decoherence) are generated by a spatial light modulator, which introduces pure dephasing in the transverse spatial plane, perpendicular to the direction of propagation of the light beam. By controlling the characteristics of this dephasing, one can explore a great variety of scenarios of quantum random walks: pure quantum evolution (ballistic spread), fast fluctuating environment leading to a diffusive classical random walk, and static disorder resulting in the observation of Anderson localization.
An efficient multigrid calculation of the far field map for Helmholtz and Schrödinger equations
Creators: name: Cools, Siegfried
name: Reps, Bram
name: Vanroose, Wim
Publisher: name: arXiv
Year: 2012
Subjects: subject: Numerical Analysis (math.NA)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper we present a new highly efficient calculation method for the far field amplitude pattern that arises from scattering problems governed by the d-dimensional Helmholtz equation and, by extension, Schrödinger's equation. The new technique is based upon a reformulation of the classical real-valued Green's function integral for the far field amplitude to an equivalent integral over a complex domain. It is shown that the scattered wave, which is essential for the calculation of the far field integral, can be computed very efficiently along this complex contour (or manifold, in multiple dimensions). Using the iterative multigrid method as a solver for the discretized damped scattered wave system, the proposed approach results in a fast and scalable calculation method for the far field map. The complex contour method is successfully validated on Helmholtz and Schrödinger model problems in two and three spatial dimensions, and multigrid convergence results are provided to substantiate the wavenumber scalability and overall performance of the method.
description: SIAM Journal on Scientific Computing, 29 pages, 10 figures, 5 tables
Flare Luminosity And The Relation To The Solar Wind And The Current Solar Minimum Conditions
Creators: name: Gray, Roderick
Publisher: name: Zenodo
Year: 2014
Subjects: Solar physics
Solar flares

description: Final presentations of the Center for Astrophysics HEA/SSP Solar Summer Intern Program.
description: Abstract:
The Sun is an active and energetic star. From time to time, based on favorable magnetic structures, the Sun gives off bursts of energy in the form of particles and light. The light is commonly referred to as a solar flare, which is of great interest both scientifically as well as due to its relation to space weather. This project examined the luminosity in flares between Hinode's XRT, GOES and STEREO data to gain an understanding as to the energy budget of the flare as well as to the flare class that has already been used as a standard in space weather prediction. This is an important step to understanding the energy of the flare as well as the future of space weather prediction. It will be applicable to the soon to be launched SDO- AIA instrument which will observe the whole Sun full time.
LHC Coverage of RPV MSSM with Light Stops
Creators: name: Evans, Jared A.
name: Kats, Yevgeny
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We examine the sensitivity of recent LHC searches to signatures of supersymmetry with R-parity violation (RPV). Motivated by naturalness of the Higgs potential, which would favor light third-generation squarks, and the stringent LHC bounds on spectra in which the gluino or first and second generation squarks are light, we focus on scenarios dominated by the pair production of light stops. We consider the various possible direct and cascade decays of the stop that involve the trilinear RPV operators. We find that in many cases, the existing searches exclude stops in the natural mass range and beyond. However, typically there is little or no sensitivity to cases dominated by UDD operators or LQD operators involving taus. We propose several ideas for searches which could address the existing gaps in experimental coverage of these signals.
description: 41 pages, 12 figures; v2: included new searches (see footnote 10), minor corrections and improvements
Search for pair production of third-generation leptoquarks and top squarks in pp collisions at sqrt(s) = 7 TeV
Creators: name: CMS Collaboration
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Results are presented from a search for the pair production of third-generation scalar and vector leptoquarks, as well as for top squarks in R-parity-violating supersymmetric models. In either scenario, the new, heavy particle decays into a tau lepton and a b quark. The search is based on a data sample of pp collisions at sqrt(s) = 7 TeV, which is collected by the CMS detector at the LHC and corresponds to an integrated luminosity of 4.8 inverse femtobarns. The number of observed events is found to be in agreement with the standard model prediction, and exclusion limits on mass parameters are obtained at the 95% confidence level. Vector leptoquarks with masses below 760 GeV are excluded and, if the branching fraction of the scalar leptoquark decay to a tau lepton and a b quark is assumed to be unity, third-generation scalar leptoquarks with masses below 525 GeV are ruled out. Top squarks with masses below 453 GeV are excluded for a typical benchmark scenario, and limits on the coupling between the top squark, tau lepton, and b quark, lambda'[333] are obtained. These results are the most stringent for these scenarios to date.
description: Replaced with published version. Added journal reference and DOI
Efficiency vs. multi-photon contribution test for quantum dots
Creators: name: Predojevic, Ana
name: Jezek, Miroslav
name: Huber, Tobias
name: Jayakumar, Harishankar
name: Kauten, Thomas
name: Solomon, Glenn S.
name: Filip, Radim
name: Weihs, Gregor
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The development of linear quantum computing within integrated circuits demands high quality semiconductor single photon sources. In particular, for a reliable single photon source it is not sufficient to have a low multi-photon component, but also to possess high efficiency. We investigate the photon statistics of the emission from a single quantum dot with a method that is able to sensitively detect the trade-off between the efficiency and the multi-photon contribution. Our measurements show, that the light emitted from the quantum dot when it is resonantly excited possess a very low multi-photon content. Additionally, we demonstrated, for the first time, the non-Gaussian nature of the quantum state emitted from a single quantum dot.
description: This paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the bellow given URL on the OSA website. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law
TUM-FAÇADE: Reviewing and enriching point cloud benchmarks for façade segmentation
Creators: name: Wysocki, Olaf
name: Hoegner, Ludwig
name: Stilla, Uwe
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Point clouds are widely regarded as one of the best dataset types for urban mapping purposes. Hence, point cloud datasets are commonly investigated as benchmark types for various urban interpretation methods. Yet, few researchers have addressed the use of point cloud benchmarks for façade segmentation. Robust façade segmentation is becoming a key factor in various applications ranging from simulating autonomous driving functions to preserving cultural heritage. In this work, we present a method of enriching existing point cloud datasets with façade-related classes that have been designed to facilitate façade segmentation testing. We propose how to efficiently extend existing datasets and comprehensively assess their potential for façade segmentation. We use the method to create the TUM-FAÇADE dataset, which extends the capabilities of TUM-MLS-2016. Not only can TUM-FAÇADE facilitate the development of point-cloud-based façade segmentation tasks, but our procedure can also be applied to enrich further datasets.
description: 3D-ARCH 2022, Mantova, Italy, 2022, ISPRS conference
New solid forms of griseofulvin: a solvate and a relict polymorph related to reported solvates
Creators: name: Diniz, Mariana
name: Spoletti, Enrico
name: Ghosh, Peuli
name: Svärd, Michael
name: RASMUSON, AKE
name: HUDSON, SARAH
Publisher: name: University of Limerick
Year: 2023
Subjects: classificationCode: 34
subject: Chemical sciences
subject: FOS: Chemical sciences

description: This work presents two new solid forms, a polymorph and a solvate, of the antifungal active pharmaceutical ingredient griseofulvin (GSF). The novel forms were characterized by powder X-ray diffraction, differential scanning calorimetry, and thermogravi-metric analysis, and their crystal structures were determined by single-crystal X-ray diffraction. The new polymorphic form (GSF Form VI) was obtained upon drying at room temperature the GSF-acetonitrile solvate. GSF Form VI is a relict structure related to reported solvates of GSF. Thermal stability studies show that Form VI is metastable and monotropically related to the stable GSF Form I. The new GSF-n-butyl acetate solvate was obtained by crystallization from an n-butyl acetate solution. The stoichiometry of the n-butyl acetate solvate is 1:0.5. The solvate loses the solvent from the crystal lattice at a temperature between 363.15 and 374.15 K
Nonextremal black holes in gauged supergravity and the real formulation of special geometry
Creators: name: Klemm, Dietmar
name: Vaughan, Owen
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We give a rather general recipe for constructing nonextremal black hole solutions to N=2, D=4 gauged supergravity coupled to abelian vector multiplets. This problem simplifies considerably if one uses the formalism developed in arXiv:1112.2876, based on dimensional reduction and the real formulation of special geometry. We use this to find new nonextremal black holes for several choices of the prepotential, that generalize the BPS solutions found in arXiv:0911.4926. Some physical properties of these black holes are also discussed.
description: 26 pages, uses JHEP3.cls. v2: Minor corrections, 1 ref. added
Iterative unfolding with the Richardson-Lucy algorithm
Creators: name: Zech, Guenter
Publisher: name: arXiv
Year: 2012
Subjects: subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: The Richardson-Lucy unfolding approach is simple and excellently performing. It efficiently suppresses artificial high frequency contributions and permits to introduce known features of the true distribution. An algorithm to fix the number of iterations to an optimal value has been developed and tested with five different types of distributions, with different event numbers and with different binnings. The influence of the starting distribution has been studied. A simple way to document the unfolding result such that it can be compared to theoretical predictions is proposed.
description: revised, Table 1 extended, references improved + minor modifications
Cross Attention Transformers for Multi-modal Unsupervised Whole-Body PET Anomaly Detection
Creators: name: Patel, Ashay
name: Tudiosu, Petru-Danial
name: Pinaya, Walter H. L.
name: Cook, Gary
name: Goh, Vicky
name: Ourselin, Sebastien
name: Cardoso, M. Jorge
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Cancer is a highly heterogeneous condition that can occur almost anywhere in the human body. 18F-fluorodeoxyglucose is an imaging modality commonly used to detect cancer due to its high sensitivity and clear visualisation of the pattern of metabolic activity. Nonetheless, as cancer is highly heterogeneous, it is challenging to train general-purpose discriminative cancer detection models, with data availability and disease complexity often cited as a limiting factor. Unsupervised anomaly detection models have been suggested as a putative solution. These models learn a healthy representation of tissue and detect cancer by predicting deviations from the healthy norm, which requires models capable of accurately learning long-range interactions between organs and their imaging patterns with high levels of expressivity. Such characteristics are suitably satisfied by transformers, which have been shown to generate state-of-the-art results in unsupervised anomaly detection by training on normal data. This work expands upon such approaches by introducing multi-modal conditioning of the transformer via cross-attention i.e. supplying anatomical reference from paired CT. Using 294 whole-body PET/CT samples, we show that our anomaly detection method is robust and capable of achieving accurate cancer localization results even in cases where normal training data is unavailable. In addition, we show the efficacy of this approach on out-of-sample data showcasing the generalizability of this approach with limited training data. Lastly, we propose to combine model uncertainty with a new kernel density estimation approach, and show that it provides clinically and statistically significant improvements when compared to the classic residual-based anomaly maps. Overall, a superior performance is demonstrated against leading state-of-the-art alternatives, drawing attention to the potential of these approaches.
description: Accepted for publication at the Journal of Machine Learning for Biomedical Imaging (MELBA) https://melba-journal.org/2023:006
Phase transitions with infinitely many absorbing states in complex networks
Creators: name: Sander, Renan S.
name: Ferreira, Silvio C.
name: Pastor-Satorras, Romualdo
Publisher: name: arXiv
Year: 2012
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We instigate the properties of the threshold contact process (TCP), a process showing an absorbing-state phase transition with infinitely many absorbing states, on random complex networks. The finite size scaling exponents characterizing the transition are obtained in a heterogeneous mean field (HMF) approximation and compared with extensive simulations, particularly in the case of heterogeneous scale-free networks. We observe that the TCP exhibits the same critical properties as the contact process (CP), which undergoes an absorbing-state phase transition to a single absorbing state. The accordance among the critical exponents of different models and networks leads to conjecture that the critical behavior of the contact process in a HMF theory is a universal feature of absorbing state phase transitions in complex networks, depending only on the locality of the interactions and independent of the number of absorbing states. The conditions for the applicability of the conjecture are discussed considering a parallel with the susceptible-infected-susceptible epidemic spreading model, which in fact belongs to a different universality class in complex networks.
description: 9 pages, 6 figures to appear in Phys Rev E
Coronal Heating Of An Active Region Observed By Xrt On May 5, 2010: A Look At Quasi-Static Vs Alfven Wave Heating Of Coronal Loops
Creators: name: Persichetti, Amanda
Publisher: name: Zenodo
Year: 2014
Subjects: Solar physics
Alfven waves
Coronal loops

description: Final presentations of the Center for Astrophysics HEA/SSP Solar Summer Intern Program.