cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Dimensional Physics
Creators: name: Kosmak, Christian
Publisher: name: Zenodo
Year: 2023
Subjects: gravitation, GR, QFT, space-time, geometric, matter, energy, space-time density

description: Dimensional physics (DP) is a theory that unites general relativity (GR) with quantum field theory (QFT). The QFT results, via a common basis in spacetime, from the GR as a correspondence principle. This requires assumptions about the structure of spacetime. There are different spacetimes and each is continuous. The number of space dimensions separates them from each other. The "dimensional transition" creates the quantisation. Any form of energy or mass is a spacetime density directly in spacetime. Gravity is a spacetime strain directly in spacetime. A density creates a stretch. Therefore, all "objects and forces" are changes in spacetime itself. There are no separate objects using spacetime as a "stage". Different spacetimes are not only a dynamic stage, they are the only actors. The various manifestations of the elementary particles of the Standard Model, are a combination of low-dimensional spacetime densities. The proposed solution in the DP is thus a geometric approach.
Effects of pressure on the ferromagnetic state of the CDW compound SmNiC2
Creators: name: Woo, B.
name: Seo, S.
name: Park, E.
name: Kim, J. H.
name: Jang, D.
name: Park, T.
name: Lee, H.
name: Ronning, F.
name: Thompson, J. D.
name: Sidorov, V. A.
name: Kwon, Y. S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report the pressure response of charge-density-wave (CDW) and ferromagnetic (FM) phases of the rare-earth intermetallic SmNiC2 up to 5.5 GPa. The CDW transition temperature (T_{CDW}), which is reflected as a sharp inflection in the electrical resistivity, is almost independent of pressure up to 2.18 GPa but is strongly enhanced at higher pressures, increasing from 155.7 K at 2.2 GPa to 279.3 K at 5.5 GPa. Commensurate with the sharp increase in T_{CDW}, the first-order FM phase transition, which decreases with applied pressure, bifurcates into the upper (T_{M1}) and lower (T_c) phase transitions and the lower transition changes its nature to second order above 2.18 GPa. Enhancement both in the residual resistivity and the Fermi-liquid T^2 coefficient A near 3.8 GPa suggests abundant magnetic quantum fluctuations that arise from the possible presence of a FM quantum critical point.
description: 5 pages, 5 figures
BBC newscast/North Korea music
Creators: name: (:Unav)
Publisher: name: Columbia University
Year: 2021

description: Part 1 contains English language newscast; partially BBC. Part 2 is North Korea music. 1) Radio Pyongyang - concert of representative Red Chinese music in honor of Zhou En Lai ??? Arr. Folk song; chamber music violin +piano on Chinese theme, martial song - Chinese orchestra - suite based on folk material - good quality - NK patriot song / 2) Russian accordion music - Radio Pyongyang - nat'l anthem - fair quality - Russian arr. Russian service radio Pyongyang
Robust minimality of iterated function systems with two generators
Creators: name: Homburg, Ale Jan
name: Nassiri, Meysam
Publisher: name: arXiv
Year: 2013
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We prove that any compact manifold without boundary admits a pair of diffeomorphisms that generates $C^1$ robustly minimal dynamics. We apply the results to the construction of blenders and robustly transitive skew product diffeomorphisms.
description: 16 pages, 2 figures
4/19 student revolution actuality recordings
Creators: name: (:Unav)
Publisher: name: Columbia University
Year: 2021
Subjects: April Revolution (Korea : 1960)

description: Actuality recordings made in Seoul (from possibly AP office hotel) during student revolution by George Hoshino (AP correspondent) / April 23rd - student demonstration / April 25th tanks and students + faculty demonstrate; demonstration held in the evening in front of Nat'l Assembly building, Seoul / Sound effects of funeral services (Christian and Buddhist) held at Severence Hospital and other Seoul hospitals - women weeping in words etc. - services, women weeping - visit to hospital by VP Chang Myun, meeting in hospital between Chang and Schoefield April 25th evening
Aircheck - Japan, N. Korea
Creators: name: (:Unav)
Publisher: name: Columbia University
Year: 2021
Subjects: Politics and government

description: Track 1: 1) Pyongyang - mass demonstration (Wed) - April 20th, 1960 / 2) Radio Japan - ??? Afternoon - April 27th / 3) BBC Friday - ??? From the editor / 4) Radio Peking Fri afternoon - entire transmission / Track 2: 1) ??? India radio news - Tuesday April 26th 2) Aust. B'casting Co. news 3) VOA / 4) NHK news + editorials
Broken relationship between superconducting pairing interaction and electronic dispersion kinks in LSCO
Creators: name: Park, S. R.
name: Cao, Y.
name: Wang, Q.
name: Fujita, M.
name: Yamada, K.
name: Mo, S. -K.
name: Dessau, D. S.
name: Reznik, D.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Electronic band dispersions in copper oxide superconductors have kinks around 70 meV that are typically attributed to coupling of electrons to a bosonic mode. We performed angle resolved photoemission spectroscopy (ARPES) experiments on overdoped cuprate high temperature superconductors to test the relationship between the superconducting transition temperature and electron-bosonic mode coupling. Remarkably, the kinks remain strong in the heavily overdoped region of the doping phase diagram of LSCO, even when the superconductivity completely disappears. This unexpected observation is incompatible with the conventional picture of superconductivity mediated by the sharp bosonic modes that are responsible for the kink. Therefore, the pairing likely originates from something else, such as from interactions with a very broad electronic spectrum or from an unconventional mechanism without pairing glue.
description: 5 pages, 3 figures. For the Supp. Mat., please contact the authors
The importance of stepping up in the excursion set approach
Creators: name: Musso, Marcello
name: Sheth, Ravi K.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Recently, we provided a simple but accurate formula which closely approximates the first crossing distribution associated with random walks having correlated steps. The approximation is accurate for the wide range of barrier shapes of current interest and is based on the requirement that, in addition to having the right height, the walk must cross the barrier going upwards. Therefore, it only requires knowledge of the bivariate distribution of the walk height and slope, and is particularly useful for excursion set models of the massive end of the halo mass function. However, it diverges at lower masses. We show how to cure this divergence by using a formulation which requires knowledge of just one other variable. While our analysis is general, we use examples based on Gaussian initial conditions to illustrate our results. Our formulation, which is simple and fast, yields excellent agreement with the considerably more computationally expensive Monte-Carlo solution of the first crossing distribution, for a wide variety of moving barriers, even at very low masses.
description: 10 pages, 5 figures
Prospects for asteroseismology of rapidly rotating B-type stars
Creators: name: Saio, Hideyuki
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In rapidly rotating stars Coriolis forces and centrifugal deformations modify the properties of oscillations; the Coriolis force is important for low-frequency modes, while the centrifugal deformation affects mainly p-modes. Here, we discuss properties of g- and r-mode oscillations in rotating stars. Predicted frequency spectra of high-order g-modes (and r-modes) excited in rapidly rotating stars show frequency groupings associated with azimuthal order $m$. We compare such properties with observations in rapidly rotating Be stars, and discuss what is learnt from such comparisons.
description: 18 pages, 7 figurs, in "Studying stellar Rotation and Convection", Lecture Notes in Physics (Springer Verlag, Berlin), M.J. Goupil, K. Belkacem, C. Neiner, F. Ligni\`eres, and J. J. Green (eds)
Scientific Objectives for UV/Visible Astrophysics Investigations: A Summary of Responses by the Community (2012)
Creators: name: Scowen, Paul A.
name: Perez, Mario R.
name: Neff, Susan G.
name: Benford, Dominic J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Following several recommendations presented by the Astrophysics Decadal Survey 2010 centered around the need to define "a future ultraviolet-optical space capability," on 2012 May 25, NASA issued a Request for Information (RFI) seeking persuasive ultraviolet (UV) and visible wavelength astrophysics science investigations. The goal was to develop a cohesive and compelling set of science objectives that motivate and support the development of the next generation of ultraviolet/visible space astrophysics missions. Responses were due on 10 August 2012 when 34 submissions were received addressing a number of potential science drivers. A UV/visible Mission RFI Workshop was held on 2012 September 20 where each of these submissions was summarized and discussed in the context of each other. We present a scientific analysis of these submissions and presentations and the pursuant measurement capability needs, which could influence ultraviolet/visible technology development plans for the rest of this decade. We also describe the process and requirements leading to the inception of this community RFI, subsequent workshop and the expected evolution of these ideas and concepts for the remainder of this decade.
description: 22 pages, 1 figure, 3 tables
Transparent Data Encryption -- Solution for Security of Database Contents
Creators: name: Deshmukh, Dr. Anwar Pasha
name: Qureshi, Dr. Riyazuddin
Publisher: name: arXiv
Year: 2013
Subjects: subject: Databases (cs.DB)
subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: The present study deals with Transparent Data Encryption which is a technology used to solve the problems of security of data. Transparent Data Encryption means encrypting databases on hard disk and on any backup media. Present day global business environment presents numerous security threats and compliance challenges. To protect against data thefts and frauds we require security solutions that are transparent by design.
description: 4 Pages 2 figures
CARATTERI ED EFFETTI DELLA CITTADINANZA TRA DIRITTO INTERNAZIONALE E FENOMENI DI INTEGRAZIONE REGIONALE: UNIONE EUROPEA E MERCOSUL
Creators: name: BELTRAME DE MOURA, ALINE
Publisher: name: Universit� degli Studi di Milano
Year: 2014

description: La presente tesi ha come obiettivo principale un?analisi dei caratteri salienti dell?istituto della cittadinanza e gli effetti che questo potrebbe produrre alla luce del diritto internazionale e dei processi di integrazione regionale. Tenendo presente che la cittadinanza, in quanto istituto di diritto interno, irradia i suoi effetti e soffre altres� limitazioni anche dall?esterno, tale da renderla rilevante per l?ordinamento giuridico internazionale, osserveremo come e in quali misure i fenomeni di integrazione regionale, quale Unione europea e Mercosul, impattano sulla tematica della cittadinanza. In questo senso, l?istituzione di una cittadinanza comune, la quale presuppone la titolarit� di quella nazionale, � stata alla base delle iniziative dell?Unione in questo campo. Pi� di recente, tale interesse ha coinvolto anche il Mercosul in ragione della crescente attenzione verso la disciplina delle aree sociali oltre che quelle economiche, soprattutto per quanto riguarda la circolazione e il soggiorno delle persone e l?approvazione di un piano di azione che prevede l?istituzione della Cittadinanza del Mercosul, ispirata dal modello europeo, entro il 2021.
CHARACTERIZATION OF THE ROLE OF USP25 IN EGFR ENDOCYTOSIS
Creators: name: WOESSNER, NADINE CAROLINE
Publisher: name: Universit� degli Studi di Milano
Year: 2015

description: The epidermal growth factor receptor (EGFR) is involved in a broad range of cellular responses. Deregulated EGFR signalling is a significant feature in different stages of oncogenesis and it contributes to several cancer types. One important mechanism whereby cancer cells can obtain increased and uncontrolled EGFR signalling is to escape down-modulation of the receptor. Ubiquitination of EGFR and of members of the endocytic machinery has a key role in this process, regulating receptor internalization, trafficking and degradation. Deubiquitinating enzymes (DUBs) can reverse the ubiquitination process, antagonizing or even promoting receptor degradation. To identify DUBs altering EGFR degradation we undertook a genome-wide small interfering RNA screen targeting all known active DUBs. In addition to previously described AMSH, USP8, USP2 and OTUD7B enzymes, we identified twelve novel DUBs affecting EGFR degradation by using immunoblot-based approaches complemented by an ELISA-based assay. Among them USP25, a member of the ubiquitin-specific protease (USP) family, displayed one of the strongest effects. We found that the degradation rate of EGFR is enhanced upon USP25 knock-down. Quantitative internalization assays revealed that depletion of USP25 leads to a faster internalization rate of EGFR. Consistently, overexpression of wild-type USP25, but not its catalytic inactive mutant, partially blocked EGFR internalization. Pathway analyses suggest that upon knock-down of USP25 a dynamin-independent endocytic route is activated, accounting for the increased EGFR internalization. Furthermore, we scored an increase in the EGFR ubiquitination upon USP25 knock-down, in particular at early time points post EGF stimulation, suggesting that EGFR is a direct target of USP25. Details regarding the kind of ubiquitin chains attached to the EGFR in the absence of USP25 are still lacking and are currently under investigation. We also validated the E3 ligase component Cullin 3 (CUL3) as USP25 interactor and we found that USP25 preferentially binds the neddylated active form of CUL3. Initial analyses with CUL3 suggest that ablation of USP25 and CUL3 have opposite effects on EGFR internalization and that the observed phenotypes compensate each other in double knock-down. Our data suggest that USP25 and CUL3 may form a stable complex with opposing activity on EGFR internalization, and led us to hypothesize that they are involved in a novel ?quality control? mechanism working at the plasma membrane. Taken together our study identifies USP25 as a novel negative regulator of EGFR ubiquitination and endocytosis, involved in early internalization events. USP25 may represent a suitable ?druggable? target for pathological conditions where EGFR is deregulated and opens up a promising direction for future investigations.
Charge-Focusing Readout of Time Projection Chambers
Creators: name: Ross, S. J.
name: Hedges, M. T.
name: Jaegle, I.
name: Rosen, M. D.
name: Seong, I. S.
name: Thorpe, T. N.
name: Vahsen, S. E.
name: Yamaoka, J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Time projection chambers (TPCs) have found a wide range of applications in particle physics, nuclear physics, and homeland security. For TPCs with high-resolution readout, the readout electronics often dominate the price of the final detector. We have developed a novel method which could be used to build large-scale detectors while limiting the necessary readout area. By focusing the drift charge with static electric fields, we would allow a small area of electronics to be sensitive to particle detection for a much larger detector volume. The resulting cost reduction could be important in areas of research which demand large-scale detectors, including dark matter searches and detection of special nuclear material. We present simulations made using the software package Garfield of a focusing structure to be used with a prototype TPC with pixel readout. This design should enable significant focusing while retaining directional sensitivity to incoming particles. We also present first experimental results and compare them with simulation.
description: 5 pages, 17 figures, Presented at IEEE Nuclear Science Symposium 2012
Precision spectroscopy of high rotational states in H_2 investigated by Doppler-free two-photon laser spectroscopy in the EF^1Σ_g^+ - X^1Σ_g^+ system
Creators: name: Dickenson, G. D.
name: Salumbides, E. J.
name: Niu, M.
name: Jungen, Ch.
name: Ross, S. C.
name: Ubachs, W.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Recently a high precision spectroscopic investigation of the EF^1Σ_g^+ - X^1Σ_g^+ system of molecular hydrogen was reported yielding information on QED and relativistic effects in a sequence of rotational quantum states in the X^1Σ^+_g$ ground state of the H_2 molecule [E.J. Salumbides et al., Phys. Rev. Lett. 107, 043005 (2011)]. The present paper presents a more detailed description of the methods and results. Furthermore, the paper serves as a stepping stone towards a continuation of the previous study by extending the known level structure of the EF^1Σ^+_g state to highly excited rovibrational levels through Doppler-free two photon spectroscopy. Based on combination differences between vibrational levels in the ground state, and between three rotational branches (O, Q and S branches) assignments of excited EF^1Σ^+_g levels, involving high vibrational and rotational quantum numbers, can be unambiguously made. For the higher EF^1Σ^+_g levels, where no combination differences are available, calculations were performed using the multi-channel quantum defect method, for a broad class of vibrational and rotational levels up to J=19. These predictions were used for assigning high-J EF-levels and are found to be accurate within 5 cm^-1.
description: 11 pages, 10 figures, 3 tables in article, 3 tables in supplemental material
A model for the shapes of advected triangles
Creators: name: Pumir, Alain
name: Wilkinson, Michael
Publisher: name: arXiv
Year: 2013
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Three particles floating on a fluid surface define a triangle. The aim of this paper is to characterise the shape of the triangle, defined by two of its angles, as the three vertices are subject to a complex or turbulent motion. We consider a simple class of models for this process, involving a combination of a random strain of the fluid and Brownian motion of the particles. Following D. G. Kendall, we map the space of triangles to a sphere, whose equator corresponds to degenerate triangles with colinear vertices, with equilaterals at the poles. We map our model to a diffusion process on the surface of the sphere and find an exact solution for the shape distribution. Whereas the action of the random strain tends to make the shape of the triangles infinitely elongated, in the presence of a Brownian diffusion of the vertices, the model has an equilibrium distribution of shapes. We determine here exactly this shape distribution in the simple case where the increments of the strain are diffusive.
description: 16 pages, 1 figure
Complexity Theory for Operators in Analysis
Creators: name: Kawamura, Akitoshi
name: Cook, Stephen
Publisher: name: arXiv
Year: 2013
Subjects: subject: Computational Complexity (cs.CC)
subject: Numerical Analysis (math.NA)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: F.1.1; F.1.3
subject: 03D15, 65Y20, 68Q05, 68Q15

description: We propose an extension of the framework for discussing the computational complexity of problems involving uncountably many objects, such as real numbers, sets and functions, that can be represented only through approximation. The key idea is to use (a certain class of) string functions as names representing these objects. These are more expressive than infinite sequences, which served as names in prior work that formulated complexity in more restricted settings. An advantage of using string functions is that we can define their "size" in the way inspired by higher-type complexity theory. This enables us to talk about computation on string functions whose time or space is bounded polynomially in the input size, giving rise to more general analogues of the classes P, NP, and PSPACE. We also define NP- and PSPACE-completeness under suitable many-one reductions. Because our framework separates machine computation and semantics, it can be applied to problems on sets of interest in analysis once we specify a suitable representation (encoding). As prototype applications, we consider the complexity of functions (operators) on real numbers, real sets, and real functions. For example, the task of numerical algorithms for solving a certain class of differential equations is naturally viewed as an operator taking real functions to real functions. As there was no complexity theory for operators, previous results only stated how complex the solution can be. We now reformulate them and show that the operator itself is polynomial-space complete.
description: 22 pages, 9 figures; a few typos fixed after journal publication
Islam in the Columbia Curriculum, 1886-2012: From Oriental Languages to Area Studies and Religious Studies
Creators: name: Riedel, Dagmar A.
Publisher: name: Columbia University
Year: 2013

description: The one-day conference was held on Thursday, 31 January 2013, in the Faculty House of Columbia University, 400 West 117th Street, New York, N. Y. 10027. It explored the history of Islamic Studies in North America in general, and at Columbia University in particular. Its starting point was the observation that Islamic Studies slipped into the Columbia curriculum when in the late 1880s Oriental languages were first added to the fledgling university’s course offerings. The conference was open to the public, but registration was requested, as seating in the Faculty House was limited. The conference accompanied a brick-and-mortar exhibition in honor of the 150th anniversary of the birth of the Columbia professors Richard Gottheil (1862-1936) and A. V. Williams Jackson (1862-1937). The exhibition showcased books and ephemera in Arabic, Armenian, Avestan, Persian, Sanskrit, Sumerian, and Turkish, exploring the interdependence between the development of library resources and the establishment of Columbia’s first Middle Eastern and South Asian Studies programs. The exhibition was on view in the Chang Octagon in the Rare Book and Manuscript Library (RBML) from 19 December 2012 until 31 March 2013. Conference and exhibition are archived here as pdf-files: Files 1-3 document the origin of the project and provide historical context: a 2005 proposal for improving access to Columbia Libraries’ Near Eastern special collections; the 2010 proposal for a brick-and-mortar exhibition about the history of Columbia’s Islamic collections; and an outline of the history of Islamic studies at Columbia, 1886-1959. Files 4-6 provide detailed information about the brick-and-mortar exhibition, including all labels, some documentary photographs, and the exhibition poster. Files 7-11 include the conference program and conference poster, as well as Dr. Riedel’s official introduction and the slides of her presentation. Organizer: Dagmar A. Riedel (Center for Iranian Studies, Columbia University) Graduate Student Assistant for the conference: Hannah K. Barker (Department of History, Columbia University) Liaison for the brick-and-mortar exhibition: Jane R. Siegel (RBML, Columbia University) The conference was sponsored by the Columbia University Seminar on Religion and Writing (#751), the American Institute of Iranian Studies, and the Friends of the Columbia Libraries.
Diffractive Effects and General Boundary Conditions in Casimir Energy
Creators: name: Karabali, Dimitra
name: Nair, V. P.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The effect of edges and apertures on the Casimir energy of an arrangement of plates and boundaries can be calculated in terms of an effective nonlocal lower-dimensional field theory that lives on the boundary. This formalism has been developed in a number of previous papers and applied to specific examples with Dirichlet boundary conditions. Here we generalize the formalism to arbitrary boundary conditions. As a specific example, the geometry of a flat plate and a half-plate placed parallel to it is considered for a number of different boundary conditions and the area-dependent and edge dependent contributions to the Casimir energy are evaluated. While our results agree with known results for those special cases (such as the Dirichlet and Neumann limits) for which other methods of calculation have been used, our formalism is suitable for general boundary conditions, especially for the diffractive effects.
description: 31 pages, 8 figures
Catching the fish - Constraining stellar parameters for TX Psc using spectro-interferometric observations
Creators: name: Klotz, D.
name: Paladini, C.
name: Hron, J.
name: Aringer, B.
name: Sacuto, S.
name: Marigo, P.
name: Verhoelst, T.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Stellar parameter determination is a challenging task when dealing with galactic giant stars. The combination of different investigation techniques has proven to be a promising approach. We analyse archive spectra obtained with the Short-Wavelength-Spectrometer (SWS) onboard of ISO, and new interferometric observations from the Very Large Telescope MID-infrared Interferometric instrument (VLTI/MIDI) of a very well studied carbon-rich giant: TX Psc. The aim of this work is to determine stellar parameters using spectroscopy and interferometry. The observations are used to constrain the model atmosphere, and eventually the stellar evolutionary model in the region where the tracks map the beginning of the carbon star sequence. Two different approaches are used to determine stellar parameters: (i) the 'classic' interferometric approach where the effective temperature is fixed by using the angular diameter in the N-band (from interferometry) and the apparent bolometric magnitude; (ii) parameters are obtained by fitting a grid of state-of-the-art hydrostatic models to spectroscopic and interferometric observations. We find a good agreement between the parameters of the two methods. The effective temperature and luminosity clearly place TX Psc in the carbon-rich AGB star domain in the H-R-diagram. Current evolutionary tracks suggest that TX Psc became a C-star just recently, which means that the star is still in a 'quiet' phase compared to the subsequent strong-wind regime. This is in agreement with the C/O ratio being only slightly larger than 1.
description: 11 pages, 9 figures, 5 tables
Orbital clustering of Martian Trojans: An asteroid family in the inner solar system?
Creators: name: Christou, Apostolos A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We report on the discovery of new Martian Trojans within the Minor Planet Center list of asteroids. Their orbital evolution over 10^8 yr shows characteristic signatures of dynamical longevity (Scholl et al, 2005) while their average orbits resemble that of the largest known Martian Trojan, 5261 Eureka. The group forms a cluster within the region where the most stable Trojans should reside. Based on a combinatorial analysis and a comparison with the Jovian Trojan population, we argue that both this feature and the apparent paucity of km-sized Martian Trojans (Trilling et al, 2006) as compared to expectations from earlier work (Tabachnik and Evans, 1999) is not due to observational bias but instead a natural end result of the collisional comminution (Jutzi et al, 2010) or, alternatively, the rotational fission (Pravec et al, 2010) of a progenitor L5 Trojan of Mars. Under the collisional scenario in particular, the new Martian Trojans are dynamically young, in agreement with our age estimate of this "cluster" of < 2 Gyr based on the earlier work of Scholl et al. This work highlights the Trojan regions of the Terrestrial planets as natural laboratories to study processes important for small body evolution in the solar system and provides the first direct evidence for an orbital cluster of asteroids close to the Earth.
description: 2 tables, 5 figures, accepted for publication in Icarus
Classification of Lie point symmetries for quadratic Li$\acute{\textbf{e}}$nard type equation $\ddot{x}+f(x)\dot{x}^2+g(x)=0$
Creators: name: Tiwari, Ajey K.
name: Pandey, S. N.
name: Senthilvelan, M.
name: Lakshmanan, M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In this paper we carry out a complete classification of the Lie point symmetry groups associated with the quadratic Li$\acute{e}$nard type equation, $\ddot {x} + f(x){\dot {x}}^{2} + g(x)= 0$, where $f(x)$ and $g(x)$ are arbitrary functions of $x$. The symmetry analysis gets divided into two cases, $(i)$ the maximal (eight parameter) symmetry group and $(ii)$ non-maximal (three, two and one parameter) symmetry groups. We identify the most general form of the quadratic Li$\acute{e}$nard equation in each of these cases. In the case of eight parameter symmetry group, the identified general equation becomes linearizable as well as isochronic. We present specific examples of physical interest. For the nonmaximal cases, the identified equations are all integrable and include several physically interesting examples such as the Mathews-Lakshmanan oscillator, particle on a rotating parabolic well, etc. We also analyse the underlying equivalence transformations.
Poster: How to Raise a Robot - Beyond Access Control Constraints in Assistive Humanoid Robots
Creators: name: Hemken, Niklas
name: Jacob, Florian
name: Peller-Konrad, Fabian
name: Kartmann, Rainer
name: Asfour, Tamim
name: Hartenstein, Hannes
Publisher: name: Association for Computing Machinery (ACM)
Year: 2023

description: Humanoid robots will be able to assist humans in their daily life, in particular due to their versatile action capabilities. However, while these robots need a certain degree of autonomy to learn and explore, they also should respect various constraints, for access control and beyond. We explore incorporating privacy and security constraints (Activity-Centric Access Control and Deep Learning Based Access Control) with robot task planning approaches (classical symbolic planning and end-to-end learning-based planning). We report preliminary results on their respective trade-offs and conclude that a hybrid approach will most likely be the method of choice.
Did massive black holes in globular clusters initially satisfy galactic scaling relations?
Creators: name: Kruijssen, J. M. Diederik
name: Lützgendorf, Nora
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The masses of supermassive black holes (SMBHs, M_BH=10^6-10^11 Msun) in the centres of galaxies are related to the host stellar spheroid mass and velocity dispersion. A key question is how these relations originate, and over which range of black hole masses they hold. It has been speculated that intermediate-mass black holes (IMBHs, M_BH=10^2-10^5 Msun) could play a fundamental role in the growth of SMBHs. A handful of IMBHs has recently been detected in Galactic globular clusters (GCs), but their masses are inconsistent with the galactic scaling relations of SMBHs. In this Letter, we derive the initial properties of the GCs using a standard analytical evolutionary model, of which the free parameters are fixed by independent constraints. We find that the observed IMBH masses initially followed the galactic SMBH scaling relations, and subsequently moved off these relations due to the dynamical evolution of their host GCs. This work is concluded with a brief discussion of the uncertainties and the implications of our results for the possible universality of massive black hole growth.
description: 6 pages, 2 figures; accepted by MNRAS Letters (27 May 2013)
Spectra of Cosmic Ray Protons and Helium Produced in Supernova Remnants
Creators: name: Ptuskin, V. S.
name: Zirakashvili, V. N.
name: Seo, E. S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Data obtained in the ATIC-2 (Advanced Thin Ionization Calorimeter), CREAM (Cosmic Ray Energetics and Mass)) and PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) experiments suggest that elemental interstellar spectra of cosmic rays below the knee at a few times $10^{6}$ GeV are not simple power laws, but they experience hardening at magnetic rigidity above about 240 GV. Another essential feature is the difference between proton and Helium energy spectra, so that the He/p ratio increases by more than 50% in the energy range from $10^{2}$ to $10^{4}$ GV. We consider the concavity of particle spectrum resulting from the nonlinear nature of diffusive shock acceleration in supernova remnants (SNR) as a possible reason for the observed spectrum hardening. Helium-to-proton ratio increasing with energy can be interpreted as a consequence of cosmic ray acceleration by forward and reverse shocks in SNRs. The contribution of particles accelerated by reverse shocks makes the concavity of the produced overall cosmic ray spectrum more pronounced. The spectra of protons and helium nuclei accelerated in SNRs and released into the interstellar medium are calculated. The derived steady state interstellar spectra are in reasonably good agreement with observations.
description: 18 pages, 2 figures, accepted to ApJ
Nuclear-spin-dependent coherent population trapping of single nitrogen vacancy centers in diamond
Creators: name: Golter, D. Andrew
name: Dinyari, Khodadad N.
name: Wang, Hailin
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Coherent population trapping (CPT) provides a highly sensitive means for probing the energy level structure of an atomic system. For a nitrogen vacancy center in diamond, the CPT offers an alternative to the standard optically-detected magnetic resonance method for measuring the hyperfine structure of the electronic ground states. We show that the nuclear spin dependent CPT measures directly the hyperfine splitting of these states due to the 14N nuclear spin. The CPT spectral response obtained in the presence of a strong microwave field, resonant or nearly resonant with a ground state spin transition, maps out the dynamic Stark splitting induced by the coherent spin excitation.
Cu NQR and NMR Studies of Optimally Doped Ca2-xNaxCuO2Cl2
Creators: name: Itoh, Y.
name: Machi, T.
name: Yamada, I.
name: Azuma, M.
name: Takano, M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report on Cu nuclear quadrupole resonance (NQR) and NMR studies of an optimally hole-doped superconductor Ca2-xNaxCuO2Cl2 (Tc ~ 28 K for x ~ 0.2). In spite of robust oxygen composition, we observed a multiple broad NQR frequency spectrum and nonexponential Cu nuclear spin-lattice relaxation, being similar to those of La2-xSrxCuO4-d.
description: 2 pages, 3 figures; to appear in J. Phys. Soc. Jpn (short note)
Non-Baryonic Dark Matter in Cosmology
Creators: name: Del Popolo, A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: This paper is a broad-band review of the current status of non-baryonic dark matter research. I start with a historical overview of the evidences of dark matter existence, then I discuss how dark matter is distributed from small scale to large scale, and I then verge the attention to dark matter nature: dark matter candidates and their detection. I finally discuss some of the limits of the $Λ$CDM model, with particular emphasis on the small scale problems of the paradigm.
description: 62 pages; 58 figures
Systematic Uncertainties In Constraining Dark Matter Annihilation From The Cosmic Microwave Background
Creators: name: Galli, Silvia
name: Slatyer, Tracy R.
name: Valdes, Marcos
name: Iocco, Fabio
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Anisotropies of the cosmic microwave background (CMB) have proven to be a very powerful tool to constrain dark matter annihilation at the epoch of recombination. However, CMB constraints are currently derived using a number of reasonable but yet un-tested assumptions that could potentially lead to a misestimation of the true bounds. In this paper we examine the potential impact of these systematic effects. In particular, we separately study the propagation of the secondary particles produced by annihilation in two energy regimes; first following the shower from the initial particle energy to the keV scale, and then tracking the resulting secondary particles from this scale to the absorption of their energy as heat, ionization, or excitation of the medium. We improve both the high and low energy parts of the calculation, in particular finding that our more accurate treatment of losses to sub-10.2 eV photons produced by scattering of high-energy electrons weakens the constraints on particular DM annihilation models by up to a factor of two. On the other hand, we find that the uncertainties we examine for the low energy propagation do not significantly affect the results for current and upcoming CMB data. We include the evaluation of the precise amount of excitation energy, in the form of Lyman-alpha photons, produced by the propagation of the shower, and examine the effects of varying the Helium fraction and Helium ionization fraction. In the recent literature, simple approximations for the fraction of energy absorbed in different channels have often been used to derive CMB constraints: we assess the impact of using accurate versus approximate energy fractions. Finally we check that the choice of recombination code (between RECFAST v1.5 and COSMOREC), to calculate the evolution of the free electron fraction in the presence of dark matter annihilation, introduces negligible differences.
description: 29 pages, 21 figures
title: Analysis of Ab Initio Protein Structure Prediction Methods
Creators: name: Alshammari, Maytha
name: He, Jing
Publisher: name: Old Dominion University Libraries
Year: 2023

description: Protein structure prediction produces atomic models of three-dimensional structure of a protein from its amino acid sequence. Understanding the function mechanism of proteins requires knowledge of three-dimensional structures. When developing new enzymes and drugs, it's essential to understand the structure of the target protein. In this study, we analyze models predicted using two ab initio protein structure prediction methods, trRosetta and Quark. A set of thirty protein chains was used to evaluate the effectiveness of the methods. The thirty chains were collected from Protein Data Bank (June – November, 2020). The length and the relative position of the predicted secondary structures were examined. We found that the accuracy of models obtained from trRosetta and Quark is good (TM score 0.358 - 0.969). However, in some cases, the methods were not able to accurately predict the relative location of the secondary structures which might affect the overall folding relationship among secondary structures.
Survey of Exciton-Phonon Sidebands by Magneto-optical Spectroscopy Using Highly Purified (6,5) Single-walled Carbon Nanotubes
Creators: name: Zhou, Weihang
name: Sasaki, Tatsuya
name: Nakamura, Daisuke
name: Saito, Hiroaki
name: Liu, Huaping
name: Kataura, Hiromichi
name: Takeyama, Shojiro
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report the first high-field magneto-optical study on the exciton-phonon sideband of single-walled carbon nanotubes (SWNTs) consisting only of (6,5) species. Both energy and intensity of the observed phonon sideband were found to be independent of the external magnetic field. Comparing with theoretical calculations, we confirmed that these sidebands originate from the optically forbidden K-momentum singlet excitons. Energy of these K-momentum dark excitons was extracted to be ~ 21.5 meV above the bright zero-momentum singlet excitons, in close agreement with recent theoretical predictions and experimentally determined values.
description: 14 pages, 4 figures
Invariant measure of the stochastic Allen-Cahn equation: the regime of small noise and large system size
Creators: name: Otto, Felix
name: Weber, Hendrik
name: Westdickenberg, Maria
Publisher: name: arXiv
Year: 2013
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60F10, 60H15

description: We study the invariant measure of the one-dimensional stochastic Allen-Cahn equation for a small noise strength and a large but finite system. We endow the system with inhomogeneous Dirichlet boundary conditions that enforce at least one transition from -1 to 1. (Our methods can be applied to other boundary conditions as well.) We are interested in the competition between the energy that should be minimized due to the small noise strength and the entropy that is induced by the large system size. Our methods handle system sizes that are exponential with respect to the inverse noise strength, up to the critical exponential size predicted by the heuristics. We capture the competition between energy and entropy through upper and lower bounds on the probability of extra transitions between -1 and 1. These bounds are sharp on the exponential scale and imply in particular that the probability of having one and only one transition from -1 to +1 is exponentially close to one. In addition, we show that the position of the transition layer is uniformly distributed over the system on scales larger than the logarithm of the inverse noise strength. Our arguments rely on local large deviation bounds, the strong Markov property, the symmetry of the potential, and measure-preserving reflections.
description: 81 pages, 7 figures
A gradient estimate for harmonic functions sharing the same zeros
Creators: name: Mangoubi, Dan
Publisher: name: arXiv
Year: 2013
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: Let u, v be two harmonic functions in the disk of radius two which have exactly the same set Z of zeros. We observe that the gradient of \log |u/v| is bounded in the unit disk by a constant which depends on Z only. In case Z is empty this goes back to Li-Yau's gradient estimate for positive harmonic functions. The general boundary Harnack principle gives Hölder estimates on \log |u/v|.
description: 14 pages
GLCM-based chi-square histogram distance for automatic detection of defects on patterned textures
Creators: name: Asha, V.
name: Bhajantri, N. U.
name: Nagabhushan, P.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences
subject: I.0; I.2.10
subject: 65D19, 11K70, 76M55, 93B17, 62H30

description: Chi-square histogram distance is one of the distance measures that can be used to find dissimilarity between two histograms. Motivated by the fact that texture discrimination by human vision system is based on second-order statistics, we make use of histogram of gray-level co-occurrence matrix (GLCM) that is based on second-order statistics and propose a new machine vision algorithm for automatic defect detection on patterned textures. Input defective images are split into several periodic blocks and GLCMs are computed after quantizing the gray levels from 0-255 to 0-63 to keep the size of GLCM compact and to reduce computation time. Dissimilarity matrix derived from chi-square distances of the GLCMs is subjected to hierarchical clustering to automatically identify defective and defect-free blocks. Effectiveness of the proposed method is demonstrated through experiments on defective real-fabric images of 2 major wallpaper groups (pmm and p4m groups).
description: IJCVR, Vol. 2, No. 4, 2011, pp. 302-313
The supergiant B[e] star LHA 115-S 18 - binary and/or luminous blue variable?
Creators: name: Clark, J. S.
name: Bartlett, E. S.
name: Coe, M. J.
name: Dorda, R.
name: Haberl, F.
name: Lamb, J. B.
name: Negueruela, I.
name: Udalski, A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The mechanism by which supergiant (sg)B[e] stars support cool, dense dusty discs/tori and their physical relationship with other evolved, massive stars such as luminous blue variables is uncertain. In order to investigate both issues we have analysed the long term behaviour of the canonical sgB[e] star LHA 115-S 18. We employed the OGLE II-IV lightcurve to search for (a-)periodic variability and supplemented these data with new and historic spectroscopy. In contrast to historical expectations for sgB[e] stars, S18 is both photometrically and spectroscopically highly variable. The lightcurve is characterised by rapid aperiodic `flaring' throughout the 16 years of observations. Changes in the high excitation emission line component of the spectrum imply evolution in the stellar temperature - as expected for luminous blue variables - although somewhat surprisingly, spectroscopic and photometric variability appears not to be correlated. Characterised by emission in low excitation metallic species, the cool circumstellar torus appears largely unaffected by this behaviour. Finally, in conjunction with intense, highly variable HeII emission, X-ray emission implies the presence of an unseen binary companion. S18 provides observational support for the putative physical association of (a subset of) sgB[e] stars and luminous blue variables. Given the nature of the circumstellar environment of S18 and that luminous blue variables have been suggested as SN progenitors, it is tempting to draw a parallel to the progenitors of SN1987A and the unusual transient SN2009ip. Moreover the likely binary nature of S18 strengthens the possibility that the dusty discs/tori that characterise sgB[e] stars are the result of binary-driven mass-loss; consequently such stars may provide a window on the short lived phase of mass-transfer in massive compact binaries.
description: 15 pages, 10 figures; accepted for publication in Astronomy and Astrophysics