cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Dissipation in graphene and nanotube resonators
Creators: name: Seoanez, C.
name: Guinea, F.
name: Neto, A. H. Castro
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Different damping mechanisms in graphene nanoresonators are studied: charges in the substrate, ohmic losses in the substrate and the graphene sheet, breaking and healing of surface bonds (Velcro effect), two level systems, attachment losses, and thermoelastic losses. We find that, for realistic structures and contrary to semiconductor resonators, dissipation is dominated by ohmic losses in the graphene layer and metallic gate. An extension of this study to carbon nanotube-based resonators is presented.
description: Published version with updated references
Magnetodipolar interlayer interaction effect on the magnetization dynamics of a trilayer square element with the Landau domain structure
Creators: name: Berkov, D. V.
name: Gorn, N. L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a detailed numerical simulation study of the effects caused by the magnetodipolar interaction between ferromagnetic (FM) layers of a trilayer magnetic nanoelement on its magnetization dynamics. As an example we use a Co/Cu/Ni80Fe20 element with a square lateral shape where the magnetization of FM layers forms a closed Landau-like domain pattern. First we show that when the thickness of the non-magnetic (NM) spacer is in the technology relevant region h ~ 10 nm, magnetodipolar interaction between 90o Neel domain walls in FM layers qualitatively changes the equilibrium magnetization state of these layers. In the main of the paper we compare the magnetization dynamics induced by a sub-nsec field pulse in a single-layer Ni80Fe20 (Py) element and in the Co/Cu/Py trilayer element. Here we show that (i) due to the spontaneous symmetry breaking of the Landau state in the FM/NM/FM trilayer its domains and domain walls oscillate with different frequencies and have different spatial oscillation patterns; (ii) magnetization oscillations of the trilayer domains are strongly suppressed due to different oscillation frequencies of domains in Co and Py; (iii) magnetization dynamics qualitatively depends on the relative rotation sense of magnetization states in Co and Py layers and on the magnetocrystalline anisotropy kind of Co crystallites. Finally we discuss the relation of our findings with experimental observations of magnetization dynamics in magnetic trilayers, performed using the element-specific time-resolved X-ray microscopy.
description: Submitted to PRB, 31 pages, including 14 figures; any constructive comments are mostly welcome, please sent it to D. Berkov, e-mail db@innovent-jena.de
The Luminosity Distribution of Globular Clusters in Dwarf Galaxies
Creators: name: Bergh, Sidney van den
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The majority of the globular clusters associated with the Sagittarius dwarf galaxy are faint. In this respect it differs significantly from the globular cluster systems surrounding typical giant galaxies. The observation that most of globular clusters in the outer halo of the Galaxy are also sub-luminous may be understood by assuming that these clusters once also belonged to faint cluster-rich dwarf systems that were subsequently captured and destroyed by the Milky Way System.
description: Astronomical Journal, in press
Particularly Efficient Star Formation in M33
Creators: name: Gardan, E.
name: Braine, J.
name: Schuster, K. F.
name: Brouillet, N.
name: Sievers, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The Star Formation (SF) rate in galaxies is an important parameter at all redshifts and evolutionary stages of galaxies. In order to understand the increased SF rates in intermediate redshift galaxies one possibility is to study star formation in local galaxies with properties frequently found at this earlier epoch like low metallicity and small size. We present sensitive observations of the molecular gas in M 33, a small Local Group spiral at a distance of 840 kpc which shares many of the characteristics of the intermediate redshift galaxies. The observations were carried out in the CO(2--1) line with the HERA heterodyne array on the IRAM 30 m telescope. A 11\arcmin$\times$22\arcmin region in the northern part of M 33 was observed, reaching a detection threshold of a few 10$^{3}$ \msol. The correlation in this field between the CO emission and tracers of SF (8\mum, 24\mum, \Ha, FUV) is excellent and CO is detected very far North, showing that molecular gas forms far out in the disk even in a small spiral with a subsolar metallicity. One major molecular cloud was discovered in an interarm region with no HI peak and little if any signs of SF -- without a complete survey this cloud would never have been found. The radial dependence of the CO emission has a scale length similar to the dust emission, less extended than the \Ha or FUV. If, however, the $\ratioo$ ratio varies inversely with metallicity, then the scale length of the H$_2$ becomes similar to that of the \Ha or FUV. Comparing the SF rate to the H$_2$ mass shows that M 33, like the intermediate redshift galaxies it resembles, has a significantly higher SF efficiency than large local universe spirals.
description: 16 pages, 15 figures
Front propagation into unstable metal nanowires
Creators: name: Bürki, J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Long, cylindrical metal nanowires have recently been observed to form and be stable for seconds at a time at room temperature. Their stability and structural dynamics is well described by a continuum model, the nanoscale free-electron model, which predicts cylinders in certain intervals of radius to be linearly unstable. In this paper, I study how a small, localized perturbation of such an unstable wire grows exponentially and propagates along the wire with a well-defined front. The front is found to be pulled, and forms a coherent pattern behind it. It is well described by a linear marginal stability analysis of front propagation into an unstable state. In some cases, nonlinearities of the wire dynamics are found to trigger an invasive mode that pushes the front. Experimental procedures that could lead to the observation of this phenomenon are suggested.
description: 6 pages, 4 figures
Anisotropic quantum Hall states in the presence of interactions with fourfold rotational symmetry
Creators: name: Kumar, Prashant
name: Bhatt, R. N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the effects of anisotropic interactions in the quantum Hall effect in the presence of a fourfold discrete rotational ($C_4$) symmetry. Employing the density matrix renormalization group technique on an infinite cylinder geometry (iDMRG), we calculate the anisotropy response of the Laughlin state at $ν=1/3$ and the composite-Fermi liquid (CFL) state at $ν=1/2$. We find that the anisotropy transferred from the interaction potential to the $ν=1/3$ state is stronger when compared to the complementary case of an anisotropic band. Further, the strength of anisotropy reduces as the interaction is made shorter ranged. Quite surprisingly, at $ν=1/2$, we find that the deformation in the CF Fermi-surface changes sign as the interaction range is reduced. Our results imply that the short-distance and long-distance parts of the interaction potential have opposite effects on the CFL state in the presence of $C_4$-symmetric anisotropy.
description: 7 pages, 7 figures
Security Research Advances in 2009
Creators: name: Beznosov, Konstantin
Publisher: name: Zenodo
Year: 2009
Subjects: computer security

description: This presentation reviews latest scientific conference reports on the cutting edge research in computer security. It presents and explains 2009 highlights from such top world annual research conferences as IEEE Symposium in Security and Privacy, ACM Conference in Computer and Communications Security (CCS), Symposium on Network and Distributed Systems Security (NDSS), Symposium on Usable Privacy and Security (SOUPS), ACM Symposium on Access Control Models and Technologies (SACMAT), New Security Paradigms Workshop (NSPW). For those who missed any of these venues in 2009, it provides an opportunity to catch up with the developments in the computer security technologies. The attendees will gain an understanding in the intuition behind latest technological advancements.
NLO effects for $Ω_{QQQ}$ Baryons in QCD Sum Rules
Creators: name: Wu, Ren-Hua
name: Zuo, Yu-Sheng
name: Meng, Ce
name: Ma, Yan-Qing
name: Chao, Kuang-Ta
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the triply heavy baryons $Ω_{QQQ}$ $(Q=c, b)$ in the QCD sum rules by performing the first calculation of the next-to-leading order (NLO) contribution to the perturbative QCD part of the correlation functions. Compared with the leading order (LO) result, the NLO contribution is found to be very important to the $Ω_{QQQ}$. This is because the NLO not only results in a large correction, but also reduces the parameter dependence, making the Borel platform more distinct, especially for the $Ω_{bbb}$ in the $\overline{\rm{MS}}$ scheme, where the platform appears only at NLO but not at LO. Particularly, owing to the inclusion of the NLO contribution, the renormalization schemes ($\bar {MS}$ and On-Shell) dependence and the scale dependence are significantly reduced. Consequently, after including the NLO contribution to the perturbative part in the QCD sum rules, the masses are estimated to be $4.53^{+0.26}_{-0.11}$ GeV for $Ω_{ccc}$ and $14.27^{+0.33}_{-0.32}$ GeV for $Ω_{bbb}$, where the results are obtained at $μ=M_B$ with errors including those from the variation of the renormalization scale $μ$ in the range $(0.8-1.2) M_B$. A careful study of the $μ$ dependence in a wide range is further performed, which shows that the LO results are very sensitive to the choice of $μ$ whereas the NLO results are considerably better. In addition to the $μ=M_B$ result, a more stable value, (4.75-4.80) GeV, for the $Ω_{ccc}$ mass is found in the range of $μ=(1.2-2.0) M_B$, which should be viewed as a more relevant prediction in our NLO approach because of $μ$ dependence.
description: An auxiliary file added showing calculations of NLO amplitudes; More discussions added on renormalization scale dependence. 12 pages, 6 figures, 5 tables. to be published in Chinese Physics C
Hardy's theorem for the q-Bessel Fourier transform
Creators: name: Dhaouadi, Lazhar
Publisher: name: arXiv
Year: 2007
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics

description: In this paper we give a q-analogue of the Hardy's theorem for the $q$-Bessel Fourier transform. The celebrated theorem asserts that if a function $f$ and its Fourier transform $\hat{f}$ satisfying $|f(x)|\leq c.e^{-{1/2} x^2}$ and $|\hat{f}(x)|\leq c.e^{-{1/2} x^2}$ for all $x\in\mathbb{% R}$ then $f(x)=\text{const}.e^{-{1/2} x^2}$.
Προτάσεις για τη διατύπωση ενός ενιαίου ηθικού και νομικού υποβάθρου για τη διεξαγωγή της ιατρικής έρευνας με βάση το ελληνικό και αγγλοσαξονικό μοντέλο:
Creators: name: Αθανασάκη, Ροζαλή Β.
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: subject: Ιατρική Ηθική
subject: Βιοηθική
subject: Ιατρική Έρευνα
subject: Ελλάδα
subject: Medical Ethics
subject: FOS: Health sciences
subject: Bioethics
subject: Clinical Research
subject: Greece

description: Η πρόοδος στην τεχνολογία έχει επηρεάσει την κλινική έρευνα δημιουργώντας νέα ηθικά διλήμματα τα οποία δεν εχουν αντιμετωπισθεί από πολλά νομικά συστήματα συμπεριλαμβανομένου και του ελληνικού. Οι στόχοι αυτής της διατριβής είναι αφενός να εντοπίσει και να αξιολογήσει αυτά τα ηθικά ζητήματα και να κρίνει την αντιμετώπιση τους από την αγγλοσαξονική (Ηνωμένο Βασίλειο, την Αυστραλία, τον Καναδά, κλπ..) και την ελληνική πλευρά και αφ’ετέρου να εξετάσει αν νομικές λύσεις για την ιατρική έρευνα που βασίζονται σε αγγλοσαξονικές ηθικές μπορούν να εφαρμοστούν στο ελληνικό δίκαιο. Το αποτέλεσμα είναι ένα σύνολο από δέκα προτάσεις που εφαρμόζονται ήδη στην Ευρώπη και προσαρμόστηκαν με την ελληνική έννοια της ιατρικής ηθικής.
description: The advances in technology have transformed clinical research and generated new ethical dilemmas which are not addressed by many legal systems including the Greek one. The objectives of this thesis are to identify these dilemmas and evaluate how these are judged both by the Anglo-Saxon (United Kingdom, Australia, Canada etc.) and the Mediterranean ethical perspectives and second to examine how legal solutions for medical research based on ethical foundations can be applied into Greek law. The result is a set of ten proposals that are already implemented in Europe and are found to be compatible with the Greek notion of medical ethics.
Modeling the Galactic Neutron Star Population for Use in Continuous Gravitational Wave Searches
Creators: name: Reed, Brendan T.
name: Deibel, Alex
name: Horowitz, C. J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Searches for continuous gravitational waves from \textit{unknown} Galactic neutron stars provide limits on the shapes of neutron stars. A rotating neutron star will produce gravitational waves if asymmetric deformations exist in its structure that are characterized by the star's ellipticity. In this study, we use a simple model of the spatial and spin distribution of Galactic neutron stars to estimate the total number of neutron stars probed, using gravitational waves, to a given upper limit on the ellipticity. This may help optimize future searches with improved sensitivity. The improved sensitivity of third-generation gravitational wave detectors may increase the number of neutron stars probed, to a given ellipticity, by factors of 100 to 1000.
description: Accepted by ApJ
title: Frauen*hausarbeit heute - Eine Untersuchung von Konzepten zur Qualitätssicherung der Praxis Sozialer Arbeit in Frauen*häusern und Erarbeitung von Möglichkeiten ihrer Erweiterung
Creators: name: Opitz, Linda
Publisher: name: Hochschule Hannover
Year: 2022
Subjects: subject: 360 Soziale Probleme, Sozialdienste, Versicherungen

description: Die Gewaltschutzarbeit mit Betroffenen, die auf das Asylsystem angewiesen sind, birgt regelmäßig widersprüchliche Logiken: Feministische Systemkritik an patriarchalen gesellschaftlichen Strukturen stößt auf die primär funktionale Logik institutionalisierter Sozialer Arbeit. Diese mehrheitlich von einer weißen# Dominanzgesellschaft bestimmten unterstützungsgebenden Strukturen, reproduzieren strukturelle sowie institutionelle Alltagsrassismen und vervielfältigen somit soziale Ungleichheit. Feministische Arbeit zeichnet sich jedoch durch den Abbau eben dieser aus. Entsprechend ist das Thematisieren von intersektionalen Unterdrückungsstrukturen, die sich gegenseitig verstärken für eine feministisch orientierte Frauen*hausarbeit obligatorisch. Es geht in der Frauen*hausarbeit nicht mehr nur um das Schaffen eines Schutzraumes, sondern um viele weitere Aspekte die z. T. auf den ersten Blick diffus wirken. Umso wichtiger scheint es, sich mit aktuellem sozialarbeiterischem Fachwissen auseinanderzusetzen, damit die kritisch feministische Arbeit den erwünschten Effekt erzielt. Was genau dieser Effekt sein soll und kann, könnte durch ein adäquates Konzept zur Qualitätssicherung gemeinsam mit den beteiligten Akteur*innen bestimmt werden. In dieser Untersuchung wird der Frage nachgegangen mit welchen Mitteln eine Qualitätssicherung aus der Perspektive eines rassismuskritisch systemischen Professionsverständnisses in Autonomen Frauenhäusern dauerhaft unter Berücksichtigung der Souveränität gelingen kann.
Spitzer spectral line mapping of supernova remnants: I. Basic data and principal component analysis
Creators: name: Neufeld, David A.
name: Hollenbach, David J.
name: Kaufman, Michael J.
name: Snell, Ronald L.
name: Melnick, Gary J.
name: Bergin, Edwin A.
name: Sonnentrucker, Paule
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the results of spectroscopic mapping observations carried out toward small (1 x 1 arcmin) regions within the supernova remnants W44, W28, IC443, and 3C391 using the Infrared Spectrograph of the Spitzer Space Telescope. These observations, covering the 5.2 - 37 micron spectral region, have led to the detection of a total of 15 fine structure transitions of Ne+, Ne++, Si+, P+, S, S++, Cl+, Fe+, and Fe++; the S(0) - S(7) pure rotational lines of molecular hydrogen; and the R(3) and R(4) transitions of hydrogen deuteride. In addition to these 25 spectral lines, the 6.2, 7.7, 8.6, 11.3 and 12.6 micron PAH emission bands were also observed. Most of the detected line transitions have proven strong enough to map in several sources, providing a comprehensive picture of the relative distribution of the various line emissions observable in the Spitzer/IRS bandpass. A principal component analysis of the spectral line maps reveals that the observed emission lines fall into five distinct groups, each of which may exhibit a distinct spatial distribution: (1) lines of S and H2 (J > 2); (2) the H2 S(0) line; (3) lines of ions with appearance potentials less than 13.6 eV; (4) lines of ions with appearance potentials greater than 13.6 eV, not including S++; (5) lines of S++. Lines of group (1) likely originate in molecular material subject to a slow, nondissociative shock that is driven by the overpressure within the supernova remnant, and lines in groups (3) - (5) are associated primarily with dissociative shock fronts with a range of (larger) shock velocities. The H2 S(0) line shows a low-density diffuse emission component, and - in some sources - a shock-excited component.
description: 43 pages, including 21 figures. Accepted for publication in ApJ
Systematics and Consequences of Comet Nucleus Outgassing Torques
Creators: name: Jewitt, David
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Anisotropic outgassing from comets exerts a torque sufficient to rapidly change the angular momentum of the nucleus, potentially leading to rotational instability. Here, we use empirical measures of spin changes in a sample of comets to characterize the torques and to compare them with expectations from a simple model. Both the data and the model show that the characteristic spin-up timescale, $τ_s$, is a strong function of nucleus radius, $r_n$. Empirically, we find that the timescale for comets (most with perihelion 1 to 2 AU and eccentricity $\sim$0.5) varies as $τ_s \sim 100 r_n^{2}$, where $r_n$ is expressed in kilometers and $τ_s$ is in years. The fraction of the nucleus surface that is active varies as $f_A \sim 0.1 r_n^{-2}$. We find that the median value of the dimensionless moment arm of the torque is $k_T$ = 0.007 (i.e. $\sim$0.7\% of the escaping momentum torques the nucleus), with weak ($
description: 36 Pages, 6 Figures, AJ in press
Memory efficient scheduling of Strassen-Winograd's matrix multiplication algorithm
Creators: name: Boyer, Brice
name: Dumas, Jean-Guillaume
name: Pernet, Clément
name: Zhou, Wei
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mathematical Software (cs.MS)
subject: FOS: Computer and information sciences

description: We propose several new schedules for Strassen-Winograd's matrix multiplication algorithm, they reduce the extra memory allocation requirements by three different means: by introducing a few pre-additions, by overwriting the input matrices, or by using a first recursive level of classical multiplication. In particular, we show two fully in-place schedules: one having the same number of operations, if the input matrices can be overwritten; the other one, slightly increasing the constant of the leading term of the complexity, if the input matrices are read-only. Many of these schedules have been found by an implementation of an exhaustive search algorithm based on a pebble game.
On the moduli space of semilocal strings and lumps
Creators: name: Eto, Minoru
name: Evslin, Jarah
name: Konishi, Kenichi
name: Marmorini, Giacomo
name: Nitta, Muneto
name: Ohashi, Keisuke
name: Vinci, Walter
name: Yokoi, Naoto
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study BPS non-abelian semilocal vortices in U(Nc) gauge theory with Nf flavors, Nf > Nc, in the Higgs phase. The moduli space for arbitrary winding number is described using the moduli matrix formalism. We find a relation between the moduli spaces of the semilocal vortices in a Seiberg-like dual pairs of theories, U(Nc) and U(Nf-Nc). They are two alternative regularizations of a "parent" non-Hausdorff space, which tend to the same moduli space of sigma-model lumps in the infinite gauge coupling limits. We examine the normalizability of the zero-modes and find the somewhat surprising phenomenon that the number of normalizable zero-modes, dynamical fields in the effective action, depends on the point of the moduli space we are considering. We find, in the lump limit, an effective action on the vortex worldsheet, which we compare to that found by Shifman and Yung.
description: 1+48 pages, 5 fig. v2 several changes to secton 6.3, sections 6.4 and 6.5 added
Surface polaritons on left-handed spheres
Creators: name: Ancey, Stéphane
name: Décanini, Yves
name: Folacci, Antoine
name: Gabrielli, Paul
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We consider the interaction of an electromagnetic field with a left-handed sphere, i.e., with a sphere fabricated from a left-handed material, in the framework of complex angular momentum techniques. We emphasize more particularly, from a semiclassical point of view, the resonant aspects of the problem linked to the existence of surface polaritons. We prove that the long-lived resonant modes can be classified into distinct families, each family being generated by one surface polariton propagating close to the sphere surface and we physically describe all the surface polaritons by providing, for each one, its dispersion relation and its damping. This can be achieved by noting that each surface polariton corresponds to a particular Regge pole of the electric part (TM) or the magnetic part (TE) of the $S$ matrix of the sphere. Moreover, for both polarizations, we find that there exists a particular surface polariton which corresponds, in the large radius limit, to that supported by the plane interface. There also exists, for both polarizations, an infinite family of surface polaritons of whispering gallery type having no analogs in the plane interface case and specific to left-handed materials. They present a "left-handed behavior" (phase and group velocities are opposite) as well as a very weak damping. They could be very useful in the context of plasmonics or cavity quantum electrodynamics.
description: v3: Typos corrected
Photonic molecules made of matched and mismatched microcavities: new functionalities of microlasers and optoelectronic components
Creators: name: Boriskina, Svetlana V.
name: Benson, Trevor M.
name: Sewell, Phillip
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Photonic molecules, named by analogy with chemical molecules, are clusters of closely located electromagnetically interacting microcavities or "photonic atoms". As two or several microcavities are brought close together, their optical modes interact, and a rich spectrum of photonic molecule supermodes emerges, which depends both on geometrical and material properties of individual cavities and on their mutual interactions. Here, we discuss ways of controllable manipulation of photonic molecule supermodes, which improve or add new functionalities to microcavity-based optical components. We present several optimally-tuned photonic molecule designs for lowering thresholds of semiconductor microlasers, producing directional light emission, enhancing sensitivity of microcavity-based bio(chemical)sensors, and optimizing electromagnetic energy transfer around bends of coupled-cavity waveguides. Photonic molecules composed of identical microcavities as well as of microcavities with various degrees of size or material detuning are discussed. Microwave experiments on scaled photonic molecule structures are currently under way to confirm our theoretical predictions.
description: 10 pages with 12 figures
A remarkable DG-module model for configuration spaces
Creators: name: Lambrechts, Pascal
name: Stanley, Don
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 55R80 ; 55P62

description: Let M be a simply-connected closed manifold and consider the (ordered) configuration space of $k$ points in M, F(M,k). In this paper we construct a commutative differential graded algebra which is a potential candidate for a model of the rational homotopy type of F(M,k). We prove that our model it is at least a Sigma_k-equivariant differential graded model. We also study Lefschetz duality at the level of cochains and describe equivariant models of the complement of a union of polyhedra in a closed manifold.
description: Minor revision
Poster: OpenIDemail Enabled Browser
Creators: name: Sun, San-Tsai
name: Beznosov, Konstantin
Publisher: name: Zenodo
Year: 2009

description: Today's Web is site-centric. Web users have to maintain a separate copy of user ID and password for each website, which leads to weaker passwords and password re-use across accounts. Currently, single-domain SSO is not scalable to the Web and federated SSO requires pre-built agreements and trust relationships between identity and service providers. OpenID is promising, but it has usability issues of URI-based identifier scheme and is vulnerable to phishing attacks. In this poster, we describe the architecture, design, and implementation of a proposed system for usable and secure Web single sign-on. Our approach builds OpenID support into web browsers, hides OpenID identifiers from users with their existing email accounts, extends the OpenID protocol to perform authentication directly by browsers, and introduces an OpenIDAuth HTTP access authentication scheme to convey authenticated identities automatically into websites that support OpenID for authentication.
Atom-in-jellium predictions of the shear modulus at high pressure
Creators: name: Swift, Damian C.
name: Lockard, Thomas
name: Hamel, Sebastien
name: Wu, Christine J.
name: Benedict, Lorin X.
name: Sterne, Philip A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Atom-in-jellium calculations of the Einstein frequency in condensed matter and of the equation of state were used to predict the variation of shear modulus from zero pressure to ~$10^7$ g/cm$^3$, for several elements relevant to white dwarf (WD) stars and other self-gravitating systems. This is by far the widest range reported electronic structure calculation of shear modulus, spanning from ambient through the one-component plasma to extreme relativistic conditions. The predictions were based on a relationship between Debye temperature and shear modulus which we assess to be accurate at the o(10%) level, and is the first known use of atom-in-jellium theory to calculate a shear modulus. We assessed the overall accuracy of the method by comparing with experimental measurements and more detailed electronic structure calculations at lower pressures.
Strings on AdS_2 and the High-Energy Limit of Noncritical M-Theory
Creators: name: Horava, Petr
name: Keeler, Cynthia A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Noncritical M-theory in 2+1 dimensions has been defined as a double-scaling limit of a nonrelativistic Fermi liquid on a flat two-dimensional plane. Here we study this noncritical M-theory in the limit of high energies, analogous to the α'\to\infty limit of string theory. In the related case of two-dimensional Type 0A strings, it has been argued that the conformal α'\to\infty limit leads to AdS_2 with a propagating fermion whose mass is set by the value of the RR flux. Here we provide evidence that in the high-energy limit, the natural ground state of noncritical M-theory similarly describes the AdS_2\times S^1 spacetime, with a massless propagating fermion. We argue that the spacetime effective theory in this background is captured by a topological higher-spin extension of conformal Chern-Simons gravity in 2+1 dimensions, consistently coupled to a massless Dirac field. Intriguingly, the two-dimensional plane populated by the original nonrelativistic fermions is essentially the twistor space associated with the symmetry group of the AdS_2\times S^1 spacetime; thus, at least in the high-energy limit, noncritical M-theory can be nonperturbatively described as a "Fermi liquid on twistor space."
description: 31 pages; references added
title: Struktur und Fließkinetik von Polymeren in ionenspurgeätzten Nanoporen
Creators: name: Grefe, Ann-Kathrin
Publisher: name: UNSPECIFIED
Year: 2021

description: Das Ziel dieser Arbeit ist die Untersuchung der Struktur und der Fließkinetik von Polymeren unter räumlicher Einschränkung in ionenspurgeätzten Nanoporen. Röntgenkleinwinkelstreuung und Rasterkraftmikroskopie zeigen, dass sich durch Ionenspurätzung wohldefinierte zylindrische Nanoporen mit Radien im Bereich einiger 10 nm bis einiger 100 nm herstellen lassen. Insbesondere wird nachgewiesen, dass eine Atomlagenabscheidung von SiO2 in einer äußerst homogenen Beschichtung der Nanoporen resultiert, welche die Porenform nicht beeinflusst. Zur Untersuchung der Fließkinetik kommt als Modellsystem das bei Raumtemperatur als amorphe Schmelze vorliegende Homopolymer Polydimethylsiloxan zum Einsatz. Durch zeitaufgelöste Röntgenkleinwinkelstreuung und eigens entwickelte Modellfunktionen wird gezeigt, dass dessen Fließkinetik innerhalb der Nanoporen zwar qualitativ mit der klassischen Kapillarströmung übereinstimmt, jedoch quantitativ eine Verlangsamung der Füllgeschwindigkeit auftritt. Diese kann durch den Effekt einer adsorbierten Randschicht, welche den effektiven Porenradius verkleinert, erklärt werden. Die Struktur von Polymeren innerhalb der Nanoporen wird anhand des Modellsystems eines teilkristallinen Polyethylenglycol-Homopolymers untersucht. Röntgenkleinwinkel- und Röntgenweitwinkelstreuung, Rasterkraftmikroskopie sowie Dynamische Differenzkalorimetrie zeigen, dass sich innerhalb großer Nanoporen konzentrische Lamellen ausbilden. Hierbei wird im Rahmen der Röntgenkleinwinkelstreuung ein Modell zur Beschreibung der kombinierten Streuung von Nanoporen und eingeschlossenem Polymer entwickelt. Bei einer Verkleinerung des Porenradius findet man einen Übergang der lamellaren Konfiguration zu ungebogenen Lamellen. Dieser spiegelt sich im Schmelzverhalten der Kristallite wieder. Bezüglich der Kristallitorientierung ergibt sich, dass für beide Lamellenkonfigurationen die PEG-Kettenachse jeweils senkrecht auf der Porenachse steht und das Kristallitwachstum entlang der Poren erfolgt.
Public Rental Housing Governance in Urban China
Creators: name: Yan, Juan
Publisher: name: A+BE | Architecture and the Built Environment
Year: 2021

description: Recently, Chinese Public Rental Housing (PRH) provision has witnessed a shift from ‘government’ to ‘governance’: policy making shifted from government steering to mixed forms involving government, market and civic actors to pursue effective and fair policies. In the meantime, this new-era PRH governance is credited with mixed results. However, the existing studies fail to describe the mechanisms underlying this new-era governance of PRH with the rising involvement of market actors and those in civil society and whether the new-era governance is considered to be effective, achieving the objective of stability. Therefore, this PhD research aims to fill the two research gaps through building a better understanding of the PRH governance in the current Chinese context and evaluating PRH governance. To fulfil this aim, this dissertation is underpinned by a theoretical foundation from the governance perspective and adopts a mixedmethod approach with quantitative and qualitative data in the study of Chinese PRH provision. The dissertation reveals the essence of the current Chinese PRH governance by bringing forth a governance model and shows the structures and mechanisms for non-governmental actors to play a role in the governance of PRH. The dissertation also shows the perceived governance outcomes from tenants’ perspective and demonstrates two main governance challenges of Inclusionary Housing, a newly introduced instrument adopted in the Chinese PRH governance. Based on the results, this PhD research theoretically and empirically contributes to the housing governance literature.
description: A+BE | Architecture and the Built Environment, No. 02 (2021): Public Rental Housing Governance in Urban China
Holographic BCFTs and Communicating Black Holes
Creators: name: Geng, Hao
name: Lüst, Severin
name: Mishra, Rashmish K.
name: Wakeham, David
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the AdS/BCFT duality between two-dimensional conformal field theories with two boundaries and three-dimensional anti-de Sitter space with two Karch-Randall branes. We compute the entanglement entropy of a bipartition of the BCFT, on both the gravity side and the field theory side. At finite temperature this entanglement entropy characterizes the communication between two braneworld black holes, coupled to each other through a common bath. We find a Page curve consistent with unitarity. The gravitational result, computed using double-holographically realized quantum extremal surfaces, matches the conformal field theory calculation. At zero temperature, we obtain an interesting extension of the AdS$_3$/BCFT$_2$ correspondence. For a central charge $c$, we find a gap $(\frac{c}{16},\frac{c}{12})$ in the spectrum of the scaling dimension $Δ_{\text{bcc}}$ of the boundary condition changing operator (which interpolates mismatched boundary conditions on the two boundaries of the BCFT). Depending on the value of $Δ_{\text{bcc}}$, the gravitational dual is either a defect global AdS$_3$ geometry or a single sided black hole, and in both cases there are two Karch-Randall branes.
description: 43 pages, 9 figures, published version in JHEP
Μελέτη οδοντογναθικών χαρακτηριστικών παιδιών με μειωμένη σωματική ανάπτυξη λόγω ανεπάρκειας αυξητικής ορμόνης και των μεταβολών τους μετά την χορήγησή της:
Creators: name: Μανουκάκης, Ιωάννης Α.
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Μειωμένη σωματική ανάπτυξη
Ανεπάρκεια αυξητικής ορμόνης
Οδοντογναθικά χαρακτηριστικά
Χορήγηση αυξητικής ορμόνης
Reduced physical development
Growth hormone deficiency
Dentofacial characteristics
Growth hormone administration

description: Ο σκοπός αυτής της προοπτικής μακρόχρονης έρευνας είναι να μελετήσει και να διερευνήσει για πρώτη φορά στην βιβλιογραφία α) τα οδοντογναθικά χαρακτηριστικά παιδιών με μειωμένη σωματική ανάπτυξη και κοντό ανάστημα λόγω μεμονωμένης ιδιοπαθούς ανεπάρκειας αυξητικής ορμόνης και β) την επίδραση της χορήγησης αυξητικής ορμόνης στο κρανιοπροσωπικό σύμπλεγμα κατά την θεραπεία του κοντού αναστήματος σε συνδυασμό με την μειωμένη σωματική ανάπτυξη. Τα ευρήματα αυτής της προοπτικής μακρόχρονης έρευνας αναδεικνύουν την σοβαρή επίδραση της ανεπάρκειας της αυξητικής ορμόνης στα οδοντογναθικά χαρακτηριστικά όπως και την έντονη επίδραση του φύλου τόσο στην ανεπάρκεια της αυξητικής ορμόνης όσο και στην θεραπευτική χορήγηση της. Η θεραπευτική χορήγηση της αυξητικής ορμόνης σε συνδυασμό με την μειωμένη σωματική ανάπτυξη επέφερε σημαντικές μεταβολές , στο συγκεκριμένο ηλικιακό εύρος ασθενών στην πρώτη διετία, που οδήγησαν κύρια σε βελτιώσεις και ομαλοποιήσεις των χαρακτηριστικών που η ανεπάρκεια αυξητικής ορμόνης είχε επηρεάσει. Η ηλικία του ασθενούς κατά την έναρξη της θεραπείας έδειξε σημαντικές συσχετίσεις με μεταβολές συγκεκριμένων οδοντογναθικών χαρακτηριστικών.
description: The aim of this longitudinal comparative research is to study and investigate for the first time in the literature a) the dentofacial characteristics of children with reduced physical growth and short stature due to isolated idiopathic growth hormone deficiency, and b) the effect of the administration of growth hormone on the craniofacial complex during the treatment of short stature.The findings of this longitudinal comparative research highlight the significant effects of growth hormone deficiency on dentofacial characteristics, as well as the strong influence of gender on both the effects of growth hormone deficiency and the consequences of therapeutic hormone administration.Τhe administration of the growth hormone combined with the reduced physical growth brought about significant changes, ιn the first two years of treatment and in this age range of patients, that were mainly beneficial in terms of improvements and normalization of characteristics affected by growth hormone deficiency. The age of the patient at the start of therapy showed significant correlations with changes in specific dentofacial characteristics.
Convection and AGN Feedback in Clusters of Galaxies
Creators: name: Chandran, Benjamin D. G.
name: Rasera, Yann
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A number of studies have shown that the convective stability criterion for the intracluster medium (ICM) is very different from the Schwarzchild criterion due to the effects of anisotropic thermal conduction and cosmic rays. Building on these studies, we develop a model of the ICM in which a central active galactic nucleus (AGN) accretes hot intracluster plasma at the Bondi rate and produces cosmic rays that cause the ICM to become convectively unstable. The resulting convection heats the intracluster plasma and regulates its temperature and density profiles. By adjusting a single parameter in the model (the size of the cosmic-ray acceleration region), we are able to achieve a good match to the observed density and temperature profiles in a sample of eight clusters. Our results suggest that convection is an important process in cluster cores. An interesting feature of our solutions is that the cooling rate is more sharply peaked about the cluster center than is the convective heating rate. As a result, in several of the clusters in our sample, a compact cooling flow arises in the central region with a size R that is typically a few kpc. The cooling flow matches onto a Bondi flow at smaller radii. The mass accretion rate in the Bondi flow is equal to, and controlled by, the rate at which mass flows in through the cooling flow. Our solutions suggest that the AGN regulates the mass accretion rate in these clusters by controlling R: if the AGN power rises above the equilibrium level, R decreases, the mass accretion rate drops, and the AGN power drops back down to the equilibrium level.
description: 41 pages, 7 figures, accepted for publication in ApJ. Changes in this version: extended discussion of Bondi accretion in clusters, better mass model, new numerical solutions
Pomeranchuk instability: symmetry breaking and experimental signatures
Creators: name: Quintanilla, J.
name: Hooley, C.
name: Powell, B. J.
name: Schofield, A. J.
name: Haque, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We discuss the emergence of symmetry-breaking {\it via} the Pomeranchuk instability from interactions that respect the underlying point-group symmetry. We use a variational mean-field theory to consider a 2D continuum and a square lattice. We describe two experimental signatures: a symmetry-breaking pattern of Friedel oscillations around an impurity; and a structural transition.
description: corrected typos, added and updated references, better-resolution figures
Rheology of immiscible two-phase flow in mixed wet porous media: Dynamic pore network model and capillary fiber bundle model results
Creators: name: Fyhn, Hursanay
name: Sinha, Santanu
name: Roy, Subhadeep
name: Hansen, Alex
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Immiscible two-phase flow in porous media with mixed wet conditions was examined using a capillary fiber bundle model, which is analytically solvable, and a dynamic pore network model. The mixed wettability was implemented in the models by allowing each tube or link to have a different wetting angle chosen randomly from a given distribution. Both models showed that mixed wettability can have significant influence on the rheology in terms of the dependence of the global volumetric flow rate on the global pressure drop. In the capillary fiber bundle model, for small pressure drops when only a small fraction of the tubes were open, it was found that the volumetric flow rate depended on the excess pressure drop as a power law with an exponent equal to 3/2 or 2 depending on the minimum pressure drop necessary for flow. When all the tubes were open due to a high pressure drop, the volumetric flow rate depended linearly on the pressure drop, independent of the wettability. In the transition region in between where most of the tubes opened, the volumetric flow depended more sensitively on the wetting angle distribution function and was in general not a simple power law. The dynamic pore network model results also showed a linear dependence of the flow rate on the pressure drop when the pressure drop is large. However, out of this limit the dynamic pore network model demonstrated a more complicated behaviour that depended on the mixed wettability condition and the saturation. In particular, the exponent relating volumetric flow rate to the excess pressure drop could take on values anywhere between 1.0 and 1.8. The values of the exponent were highest for saturations approaching 0.5, also, the exponent generally increased when the difference in wettability of the two fluids were larger and when this difference was present for a larger fraction of the porous network.
description: 23 pages, 9 figures
Signatures of Hierarchical Mergers in Black Hole Spin and Mass distribution
Creators: name: Tagawa, Hiromichi
name: Haiman, Zoltán
name: Bartos, Imre
name: Kocsis, Bence
name: Omukai, Kazuyuki
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recent gravitational wave (GW) observations by LIGO/Virgo show evidence for hierarchical mergers, where the merging BHs are the remnants of previous BH merger events. These events may carry important clues about the astrophysical host environments of the GW sources. In this paper, we present the distributions of the effective spin parameter ($χ_\mathrm{eff}$), the precession spin parameter ($χ_\mathrm{p}$), and the chirp mass ($m_\mathrm{chirp}$) expected in hierarchical mergers. Under a wide range of assumptions, hierarchical mergers produce (i) a monotonic increase of the average of the typical total spin for merging binaries, which we characterize with ${\bar χ}_\mathrm{typ}\equiv \overline{(χ_\mathrm{eff}^2+χ_\mathrm{p}^2)^{1/2}}$, up to roughly the maximum $m_\mathrm{chirp}$ among first-generation (1g) BHs, and (ii) a plateau at ${\bar χ}_\mathrm{typ}\sim 0.6$ at higher $m_\mathrm{chirp}$. We suggest that the maximum mass and typical spin magnitudes for 1g BHs can be estimated from ${\bar χ}_\mathrm{typ}$ as a function of $m_\mathrm{chirp}$. The GW data observed in LIGO/Virgo O1--O3a prefers an increase in ${\bar χ}_\mathrm{typ}$ at low $m_\mathrm{chirp}$, which is consistent with the growth of the BH spin magnitude by hierarchical mergers, at $\sim 2 σ$ confidence. A Bayesian analysis suggests that 1g BHs have the maximum mass of $\sim 15$--$30\,M_\odot$ if the majority of mergers are of high-generation BHs (not among 1g-1g BHs), which is consistent with mergers in active galactic nucleus disks and/or nuclear star clusters, while if mergers mainly originate from globular clusters, 1g BHs are favored to have non-zero spin magnitudes of $\sim 0.3$. We also forecast that signatures for hierarchical mergers in the ${\bar χ}_\mathrm{typ}$ distribution can be confidently recovered once the number of GW events increases to $\gtrsim O(100)$.
description: 20 pages, 10 figures, accepted in MNRAS
COREnext 6th Newsletter
Creators: name: AUSTRALO
Publisher: name: Zenodo
Year: 2025

description: Welcome to the summary of COREnext recent progress!

As the COREnext project reaches key milestones, this newsletter highlights our Mid-term Review, recent achievements in architectural design (WP3), advancements in communication components (WP4), and reliable, energy-efficient solutions for next-generation systems (WP5). These updates showcase our commitment to driving innovation and preparingfor the challenges of tomorrow.
Polarized Image of Equatorial Emission in the Kerr Geometry
Creators: name: Gelles, Zachary
name: Himwich, Elizabeth
name: Palumbo, Daniel C. M.
name: Johnson, Michael D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We develop a simple toy model for polarized images of synchrotron emission from an equatorial source around a Kerr black hole by using a semi-analytic solution of the null geodesic equation and conservation of the Penrose-Walker constant. Our model is an extension of Narayan et al. (2021), which presented results for a Schwarzschild black hole, including a fully analytic approximation. Our model includes an arbitrary observer inclination, black hole spin, local boost, and local magnetic field configuration. We study the geometric effects of black hole spin on photon parallel transport and isolate these effects from the complicated combination of relativistic, gravitational, and electromagnetic processes in the emission region. We find an analytic approximation, consistent with previous work, for the subleading geometric effect of spin on observed face-on polarization rotation in the direct image: $Δ{\rm EVPA} \sim -2a/r_{\rm s}^2$, where $a$ is the black hole spin and $r_{\rm s}$ is the emission radius. We further show that spin introduces an order unity effect on face-on subimages: $Δ{\rm EVPA} \sim \pm a/\sqrt{27}$. We also use our toy model to analyze polarization "loops" observed during flares of orbiting hotspots. Our model provides insight into polarimetric simulations and observations of black holes such as those made by the EHT and GRAVITY.
description: 25 pages, 12 figures. Published in PRD on August 24, 2021