cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A binary model for the UV-upturn of elliptical galaxies (MNRAS version)
Creators: name: Han, Z.
name: Podsiadlowski, Ph.
name: Lynas-Gray, A. E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The discovery of a flux excess in the far-ultraviolet (UV) spectrum of elliptical galaxies was a major surprise in 1969. While it is now clear that this UV excess is caused by an old population of hot helium-burning stars without large hydrogen-rich envelopes, rather than young stars, their origin has remained a mystery. Here we show that these stars most likely lost their envelopes because of binary interactions, similar to the hot subdwarf population in our own Galaxy. We have developed an evolutionary population synthesis model for the far-UV excess of elliptical galaxies based on the binary model developed by Han et al (2002, 2003) for the formation of hot subdwarfs in our Galaxy. Despite its simplicity, it successfully reproduces most of the properties of elliptical galaxies with a UV excess: the range of observed UV excesses, both in $(1550-V)$ and $(2000-V)$, and their evolution with redshift. We also present colour-colour diagrams for use as diagnostic tools in the study of elliptical galaxies. The model has major implications for understanding the evolution of the UV excess and of elliptical galaxies in general. In particular, it implies that the UV excess is not a sign of age, as had been postulated previously, and predicts that it should not be strongly dependent on the metallicity of the population, but exists universally from dwarf ellipticals to giant ellipticals.
description: accepted for publication in MNRAS, 24 pages, 15 figures, 2 tables
The manifestation of quantum resonances and antiresonances in a finite temperature dilute atomic gas
Creators: name: Saunders, M.
name: Halkyard, P. L.
name: Challis, K. J.
name: Gardiner, S. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We investigate the effect of temperature on resonant and antiresonant dynamics in a dilute atomic gas kicked periodically by a standing wave laser field. Our numerical calculations are based on a Monte Carlo method for an incoherent mixture of non-interacting plane waves, and show that the atomic dynamics are highly sensitive to the initial momentum width of the gas. We explain this sensitivity by examining the time evolution of individual atomic centre of mass momentum eigenstates with varying quasimomentum, and we have determined analytic expressions for the evolution of the second-order momentum moment to illustrate the range of behaviours.
description: 15 pages, 7 figures
การยอมรับและวัฒนธรรมเทคโนโลยีสารสนเทศและการสื่อสารในองค์การภาครัฐของประเทศไทย
Creators: name: สุทธิลักษณ์ ชนะสุข
Publisher: name: มหาวิทยาลัยมหาสารคาม
Year: 2556
Subjects: วัฒนธรรมไอซีที, การยอมรับเทคโนโลยี, ไอซีทีในองค์การภาครัฐของประเทศไทย

description: 3, 32, วารสารวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยมหาสารคาม
การวิเคราะห์ทัศนภาพจากการขยายตัวของเทคโนโลยียานยนต์ไฟฟ้า : กรณีศึกษาสำหรับภาคการขนส่งทางถนนในกรุงเทพมหานคร
Creators: name: พีรวัฒน์ สายสิริรัตน์
Publisher: name: มหาวิทยาลัยมหาสารคาม
Year: 2556
Subjects: การเดินทางในเขตเมือง, การวิเคราะห์ทัศนภาพ, ความต้องการพลังงานไฟฟ้า, ปัญหาการจราจร

description: 5, 32, วารสารวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยมหาสารคาม
Bitcoin: สกุลเงินของการเข้ารหัสลับที่น่าจับตามอง
Creators: name: อัญชณา เหมือนคิด
Publisher: name: มหาวิทยาลัยมหาสารคาม
Year: 2557
Subjects: บิทคอยน์, เงินดิจิตอล, การเข้ารหัส

description: 6, 33, วารสารวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยมหาสารคาม
Stability of the Grabert master equation
Creators: name: Buks, Eyal
name: Schwartz, Dvir
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the dynamics of a quantum system having Hilbert space of finite dimension $d_{\mathrm{H}}$. Instabilities are possible provided that the master equation governing the system's dynamics contain nonlinear terms. Here we consider the nonlinear master equation derived by Grabert. The dynamics near a fixed point is analyzed by using the method of linearization, and by evaluating the eigenvalues of the Jacobian matrix. We find that all these eigenvalues are non-negative, and conclude that the fixed point is stable. This finding raises the question: under what conditions instability is possible in a quantum system having finite $d_{\mathrm{H}}$?
Bs Mixing and decays at the Tevatron
Creators: name: Talby, Mossadek
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: This short review reports on recent results from CDF and D0 experiments at the Tevatron collider on Bs mixing and the lifetimes of Bs and Lambdab.
description: 6 pages, 8 figures
Searching for lepton portal dark matter with colliders and gravitational waves
Creators: name: Liu, Jia
name: Wang, Xiao-Ping
name: Xie, Ke-Pan
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the lepton portal dark matter (DM) model in which the relic abundance is determined by the portal coupling among the Majorana fermion DM candidate $χ$, the singlet charged scalar mediator $S^\pm$ and the Standard Model (SM) right-handed lepton. The direct and indirect searches are not sensitive to this model. This article studies the lepton portal coupling as well as the scalar portal coupling (between $S^\pm$ and SM Higgs boson), as the latter is generally allowed in the Lagrangian. The inclusion of scalar portal coupling not only significantly enhances the LHC reach via the $gg\to h^*\to S^+S^-$ process, but also provides a few novel signal channels, such as the exotic decays and coupling deviations of the Higgs boson, offering new opportunities to probe the model. In addition, we also study the Drell-Yan production of $S^+S^-$ at future lepton colliders, and find out that the scenario where one $S^\pm$ is off-shell can be used to measure the lepton portal coupling directly. In particular, we are interested in the possibility that the scalar potential triggers a first-order phase transition and hence provides the stochastic gravitational wave (GW) signals. In this case, the terrestrial collider experiments and space-based GW detectors serve as complementary approaches to probe the model.
description: 23 pages+references, 15 figures. To appear on JHEP
Learning swimming escape patterns for larval fish under energy constraints
Creators: name: Mandralis, Ioannis
name: Weber, Pascal
name: Novati, Guido
name: Koumoutsakos, Petros
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: Robotics (cs.RO)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Swimming organisms can escape their predators by creating and harnessing unsteady flow fields through their body motions. Stochastic optimization and flow simulations have identified escape patterns that are consistent with those observed in natural larval swimmers. However, these patterns have been limited by the specification of a particular cost function and depend on a prescribed functional form of the body motion. Here, we deploy reinforcement learning to discover swimmer escape patterns for larval fish under energy constraints. The identified patterns include the C-start mechanism, in addition to more energetically efficient escapes. We find that maximizing distance with limited energy requires swimming via short bursts of accelerating motion interlinked with phases of gliding. The present, data efficient, reinforcement learning algorithm results in an array of patterns that reveal practical flow optimization principles for efficient swimming and the methodology can be transferred to the control of aquatic robotic devices operating under energy constraints.
การประยุกต์ใช้วิธีหาการค่าที่เหมาะสมที่สุดแบบกลุ่มอนุภาคเพื่อหาค่าที่เหมาะสม ของโค้งกฎปฏิบัติการอ่างเก็บนํ้าลำปาว
Creators: name: วิรัตน์ นวนนุกูล
Publisher: name: มหาวิทยาลัยมหาสารคาม
Year: 2558
Subjects: โค้งกฎปฏิบัติการอ่างเก็บน้ำ, ค่าเหมาะสมที่สุดแบบกลุ่มอนุภาค, การจัดการอ่างเก็บน้ำ, การจำลองปฏิบัติการอ่างเก็บน้ำ

description: 1, 34, วารสารวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยมหาสารคาม
Suicide-Gene Transfection of Tumor-tropic Placental Stem Cells employing Ultrasound-Responsive Nanoparticles
Creators: name: Paris, Juan L.
name: de la Torre, Paz
name: Cabanas, M. Victoria
name: Manzano, Miguel
name: Flores, Ana I.
name: Vallet-Regi, Maria
Publisher: name: arXiv
Year: 2021
Subjects: subject: Tissues and Organs (q-bio.TO)
subject: FOS: Biological sciences

description: A Trojan-horse strategy for cancer therapy employing tumor-tropic mesenchymal stem cells transfected with a non-viral nanovector is here presented. In this sense, ultrasound-responsive mesoporous silica nanoparticles were coated with a polycation (using two different molecular weights), providing them with gene transfection capabilities that were evaluated using two different plasmids. First, the expression of Green Fluorescent Protein was analyzed in Decidua-derived Mesenchymal Stem Cells after incubation with the silica nanoparticles. The most successful nanoparticle was then employed to induce the expression of two suicide genes: cytosine deaminase and uracil phosphoribosyl transferase, which allow the cells to convert a non-toxic pro-drug (5-fluorocytosine) into a toxic drug (5-Fluorouridine monophosphate). The effect of the production of the toxic final product was also evaluated in a cancer cell line (NMU cells) co-cultured with the transfected vehicle cells, Decidua-derived Mesenchymal Stem Cells.
description: 24 pages, 6 figures
การผลิตนํ้าร้อนจากความร้อนทิ้งของเครื่องปรับอากาศด้วยเครื่องแลกเปลี่ยนความร้อน ชนิดท่อความร้อนชนิดสั่นวงรอบที่ติดตั้งวาล์วกันกลับ
Creators: name: พัฒนพล มีนา
Publisher: name: มหาวิทยาลัยมหาสารคาม
Year: 2558
Subjects: ท่อความร้อนแบบสั่นวงรอบ, วาล์วกันกลับ, เครื่องแลกเปลี่ยนความร้อน, เครื่องปรับอากาศ, น้ำร้อน

description: 1, 34, วารสารวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยมหาสารคาม
WISDOM project -- VIII. Multi-scale feedback cycles in the brightest cluster galaxy NGC 0708
Creators: name: North, Eve V.
name: Davis, Timothy A.
name: Bureau, Martin
name: Gaspari, Massimo
name: Cappellari, Michele
name: Iguchi, Satoru
name: Liu, Lijie
name: Onishi, Kyoko
name: Sarzi, Marc
name: Smith, Mark D.
name: Williams, Thomas G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present high-resolution (synthesised beam size 0."088x0."083 or 25x23 pc$^2$) Atacama Large Millimetre/submillimetre Array (ALMA) $^{12}$CO(2-1) line and 236 GHz continuum observations, as well as 5 GHz enhanced Multi-Element Radio Linked Interferometer Network (e-MERLIN) continuum observations, of NGC 0708; the brightest galaxy in the low-mass galaxy cluster Abell 262. The line observations reveal a turbulent, rotating disc of molecular gas in the core of the galaxy, and a high-velocity, blue-shifted feature ~0."4 (~113 pc) from its centre. The sub-millimetre continuum emission peaks at the nucleus, but extends towards this anomalous CO emission feature. No corresponding elongation is found on the same spatial scales at 5 GHz with e-MERLIN. We discuss potential causes for the anomalous blue-shifted emission detected in this source, and conclude that it is most likely to be a low-mass in-falling filament of material condensing from the hot intra-cluster medium via chaotic cold accretion, but it is also possible that it is a jet-driven molecular outflow. We estimate the physical properties this structure has in these two scenarios, and show that either explanation is viable. We suggest future observations with integral field spectrographs will be able to determine the true cause of this anomalous emission, and provide further evidence for interaction between quenched cooling flows and mechanical feedback on both small and large scales in this source.
description: 16 pages, 10 figures, MNRAS accepted
On the Origin of Asymmetries in Bilateral Supernova Remnants
Creators: name: Orlando, S.
name: Bocchino, F.
name: Reale, F.
name: Peres, G.
name: Petruk, O.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: AIMS: We investigate whether the morphology of bilateral supernova remnants (BSNRs) observed in the radio band is determined mainly either by a non-uniform interstellar medium (ISM) or by a non-uniform ambient magnetic field. METHODS: We perform 3-D MHD simulations of a spherical SNR shock propagating through a magnetized ISM. Two cases of shock propagation are considered: 1) through a gradient of ambient density with a uniform ambient magnetic field; 2) through a homogeneous medium with a gradient of ambient magnetic field strength. From the simulations, we synthesize the synchrotron radio emission, making different assumptions about the details of acceleration and injection of relativistic electrons. RESULTS: We find that asymmetric BSNRs are produced if the line-of-sight is not aligned with the gradient of ambient plasma density or with the gradient of ambient magnetic field strength. We derive useful parameters to quantify the degree of asymmetry of the remnants that may provide a powerful diagnostic of the microphysics of strong shock waves through the comparison between models and observations. CONCLUSIONS: BSNRs with two radio limbs of different brightness can be explained if a gradient of ambient density or, most likely, of ambient magnetic field strength is perpendicular to the radio limbs. BSNRs with converging similar radio arcs can be explained if the gradient runs between the two arcs.
description: 14 pages, 8 Figures; paper accepted for publication in A&A; the paper with high-resolution figures can be downloaded at http://www.astropa.unipa.it/~orlando/PAPERS/sorlando_6045.pdf
On Cognitive Interference Networks
Creators: name: Lapidoth, Amos
name: Shamai, Shlomo
name: Wigger, Michele A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We study the high-power asymptotic behavior of the sum-rate capacity of multi-user interference networks with an equal number of transmitters and receivers. We assume that each transmitter is cognizant of the message it wishes to convey to its corresponding receiver and also of the messages that a subset of the other transmitters wish to send. The receivers are assumed not to be able to cooperate in any way so that they must base their decision on the signal they receive only. We focus on the network's pre-log, which is defined as the limiting ratio of the sum-rate capacity to half the logarithm of the transmitted power. We present both upper and lower bounds on the network's pre-log. The lower bounds are based on a linear partial-cancellation scheme which entails linearly transforming Gaussian codebooks so as to eliminate the interference in a subset of the receivers. Inter alias, the bounds give a complete characterization of the networks and side-information settings that result in a full pre-log, i.e., in a pre-log that is equal to the number of transmitters (and receivers) as well as a complete characterization of networks whose pre-log is equal to the full pre-log minus one. They also fully characterize networks where the full pre-log can only be achieved if each transmitter knows the messages of all users, i.e., when the side-information is "full".
description: to appear in Proceedings of 2007 IEEE Information Theory Workshop (ITW) in Lake Tahoe
Reactor Monitoring with Neutrinos
Creators: name: Cribier, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The fundamental knowledge on neutrinos acquired in the recent years open the possibility of applied neutrino physics. Among it the automatic and non intrusive monitoring of nuclear reactor by its antineutrino signal could be very valuable to IAEA in charge of the control of nuclear power plants. Several efforts worldwide have already started.
description: 5 pages - XXII International Conference On Neutrino Physics And Astrophysics (Neutrino 2006)
OH Masers in G11.904-0.141
Creators: name: Fish, Vincent L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The massive star-forming region G11.904-0.141 is one of only 11 sources to show maser emission in the highly-excited 13441 MHz transition of OH. VLBA observations of the 1665, 1667, 4765, and 13441 MHz transitions of OH toward G11.904-0.141 are presented. Masers are detected at 1665, 1667, and 4765 MHz, but the 13441 MHz masers are not detected. Consistent magnetic field strengths of approximately +3.5 mG are detected in the ground-state masers, in contrast with a possible -3.0 mG magnetic field previously detected at 13441 MHz. The variable 13441 MHz masers may be associated with an outflow.
description: 3 pages using emulateapj.cls including 1 table, accepted to ApJL
A Galactic survey of radio jets from massive protostars
Creators: name: Purser, S. J. D.
name: Lumsden, S. L.
name: Hoare, M. G.
name: Kurtz, S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In conjunction with a previous southern-hemisphere work, we present the largest radio survey of jets from massive protostars to date with high-resolution, ($\sim 0.04^{\prime\prime}$) VLA observations towards two subsamples of massive star-forming regions of different evolutionary statuses: 48 infrared-bright, massive YSOs and 8 IRDCs containing 16 luminous (${\rm L_{bol}}>10^3\,{\rm L_\odot}$) cores. For $94\%$ of the MYSO sample we detect thermal radio ($α\geq -0.1$ whereby $S_ν\propto ν^α$) sources coincident with the protostar, of which $84\%$ (13 jets and 25 candidates) are jet-like. Radio luminosity is found to scale with ${\rm L_{bol}}$ similarly to the low-mass case supporting a common mechanism for jet production across all masses. Associated radio lobes tracing shocks are seen towards $52\%$ of jet-like objects and are preferentially detected towards jets of higher radio and bolometric luminosities, resulting from our sensitivity limitations. We find jet mass loss rate scales with bolometric luminosity as $\dot{m}_{\rm jet} \propto {\rm L_{bol}}^{0.9\pm0.2}$, thereby discarding radiative, line-driving mechanisms as the dominant jet-launching process. Calculated momenta show that the majority of jets are mechanically capable of driving the massive, molecular outflow phenomena since $p_{\rm jet}>p_{\rm outflow}$. Finally, from their physical extent we show that the radio emission can not originate from small, optically-thick \textsc{Hii} regions. Towards the IRDC cores, we observe increasing incidence rates/radio fluxes with age using the proxy of increasing luminosity-to-mass $\left( \frac{L}{M} \right)$ and decreasing infrared flux ratios $\left(\frac{S_{70 \rm μm}}{S_{24 \rm μm}}\right)$. Cores with $\frac{L}{M}<40\,{\rm L_{sol}}{\rm M_{sol}}^{-1}$ are not detected above ($5.8{\rm GHz}$) radio luminosities of $\sim1{\rm mJy\,kpc}^2$.
description: To be published in MNRAS. 20 pages main text (4 tables, 14 figures), 90 pages appendices (6 tables, 66 figures)
Statistical Phases and Momentum Spacings for One-Dimensional Anyons
Creators: name: Greiter, Martin
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Anyons and fractional statistics are by now well established in two-dimensional systems. In one dimension, fractional statistics has been established so far only through Haldane's fractional exclusion principle, but not via a fractional phase the wave function acquires as particles are interchanged. At first sight, the topology of the configuration space appears to preclude such phases in one dimension. Here we argue that the crossings of one-dimensional anyons are always unidirectional, which makes it possible to assign phases consistently and hence to introduce a statistical parameter theta. The fractional statistics then manifests itself in fractional spacings of the single-particle momenta of the anyons when periodic boundary conditions are imposed. These spacings are given by Delta p = 2 pi hbar/L (|theta|/pi+non-negative integer) for a system of length L. This condition is the analogue of the quantisation of relative angular momenta according to l_z=hbar(-theta/pi+2integer) for two-dimensional anyons.
description: 16 pages, 1 figure
Force11: Future of Research Communications and E-Scholarship
Creators: name: Chodacki, John
name: del Rio Riande, Gimena
Publisher: name: Zenodo
Year: 2021
Subjects: OIAR
Open Science

description: Part of the Bazaar, a showcase of different approaches to the mobilisation and dissemination of Open Science.
description: Primary funding was provided by the Social Science and Humanities Research Council of Canada (SSHRC), with addition financial and in-kind support provided by Eclac, FORCE11, and the Sloan Foundation through the Reimagining Educational Practices for Open (REPO) project.
Topological phase for spin-orbit transformations on a laser beam
Creators: name: Souza, C. E. R.
name: Huguenin, J. A. O.
name: Milman, P.
name: Khoury, A. Z.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the topological phase associated with the double connectedness of the SO(3) representation in terms of maximally entangled states. An experimental demonstration is provided in the context of polarization and spatial mode transformations of a laser beam carrying orbital angular momentum. The topological phase is evidenced through interferometric measurements and a quantitative relationship between the concurrence and the fringes visibility is derived. Both the quantum and the classical regimes were investigated.
description: 4 pages, 4 figures
V-type asteroids in the middle Main Belt
Creators: name: Roig, F.
name: Nesvorny, D.
name: Gil-Hutton, R.
name: Lazzaro, D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The recent discovery of the first V-type asteroid in the middle belt, (21238) 1995WV7, located at ~2.54 AU, raises the question of whether it came from (4) Vesta or not. In this paper, we present spectroscopic observations indicating the existence of another V-type asteroid at ~2.53 AU, (40521) 1999RL95, and we investigate the possibility that these two asteroids evolved from the Vesta family to their present orbits by drifting in semi-major axis due to the Yarkovsky effect. The main problem with this scenario is that the asteroids need to cross the 3/1 mean motion resonance with Jupiter, which is highly unstable. Combining numerical simulations of the orbital evolution, that include the Yarkovsky effect, with Monte Carlo models, we compute the probability of an asteroid of given diameter D to evolve from the Vesta family and to cross over the 3/1 resonance, reaching a stable orbit in the middle belt. Our results indicate that an asteroid like (21238) 1995WV7 has a low probability of having evolved through this mechanism due to its large size (~5 km). However, the mechanism might explain the orbit of smaller bodies like (40521) 1999RL95 (~3 km), provided that we assume that the Vesta family formed > 3.5 Gy ago. We estimate that about 10% or more of the V-type bodies with D>1 km may come from the Vesta family by crossing over the 3/1 resonance. The remaining 90% must have a different origin.
description: Submitted to Icarus - 4 tables, 8 figures
Decoding of Variable Length PLH Codes
Creators: name: Morini, Marco
name: Ugolini, Alessandro
name: Colavolpe, Giulio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Information Theory (cs.IT)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this paper, we address the problem of the decoding of variable length physical layer header (PLH) codes. We take as a case study the DVB-S2X standard, and, after selecting a suitable PLH code with variable codeword length, we propose two alternative noncoherent decoding strategies. The proposed decoding strategies allow to estimate the length of the transmitted PLH field, which is unknown at the receiver, jointly with the decoding of the PLH code. We demonstrate that it is possible to achieve an excellent decoding performance while significantly reducing the overhead due to the transmission of the PLH field with respect to a standard fixed-length PLH.
description: IEEE Transactions on Broadcasting, in press
The Solar Neighborhood. XIX. Discovery and Characterization of 33 New Nearby White Dwarf Systems
Creators: name: Subasavage, John P.
name: Henry, Todd J.
name: Bergeron, P.
name: Dufour, P.
name: Hambly, Nigel C.
name: Beaulieu, Thomas D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present spectra for 33 previously unclassified white dwarf systems brighter than V = 17 primarily in the southern hemisphere. Of these new systems, 26 are DA, 4 are DC, 2 are DZ, and 1 is DQ. We suspect three of these systems are unresolved double degenerates. We obtained VRI photometry for these 33 objects as well as for 23 known white dwarf systems without trigonometric parallaxes, also primarily in the southern hemisphere. For the 56 objects, we converted the photometry values to fluxes and fit them to a spectral energy distribution using the spectroscopy to determine which model to use (i.e. pure hydrogen, pure helium, or metal-rich helium), resulting in estimates of effective temperature and distance. Eight of the new and 12 known systems are estimated to be within the NStars and Catalogue of Nearby Stars (CNS) horizons of 25 pc, constituting a potential 18% increase in the nearby white dwarf sample. Trigonometric parallax determinations are underway via CTIOPI for these 20 systems. One of the DCs is cool so that it displays absorption in the near infrared. Using the distance determined via trigonometric parallax, we are able to constrain the model-dependent physical parameters and find that this object is most likely a mixed H/He atmosphere white dwarf similar to other cool white dwarfs identified in recent years with significant absorption in the infrared due to collision-induced absorptions by molecular hydrogen.
description: 33 pages, 10 figures, accepted for publication in the Astronomical Journal
Internal mobility edge in doped graphene: frustration in a renormalized lattice
Creators: name: Naumis, G. G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that an internal localization mobility edge can appear around the Fermi energy in graphene by introducing impurities in the split-band regimen, or by producing vacancies in the lattice. The edge appears at the center of the spectrum and not at the band edges, in contrast with the usual picture of localization. Such result is explained by showing that the bipartite nature of lattice allows to renormalize the Hamiltonian, and the internal edge appears because of frustration effects in the renormalized lattice. The size in energy of the spectral region with localized states is similar in value to that observed in narrow gap semiconductors.
Glomus tumor. A case report
Creators: name: Daniel Arreola Pérez M.D.
name: Josué Vásquez Simón M.D.
name: Luis Enrique Cortés Gutiérrez M.D.
name: Sebastián Villalobos Solís M.D.
name: Ana Cristina Rosales Nieto M.D.
name: Álvaro José Cortés Salazar M.D.
name: Yaneli Madrid Ferto M.D.
Publisher: name: Zenodo
Year: 2024

description: Background: Introduction: Glomus tumor is a rare, benign soft tissue neoplasm that is usually located in the subungual tissues of the hands and feet; it is rarely found extradigitally.

Case report: 54-year-old male patient with an asymptomatic tumor in the head of the first metatarsal of the left foot. It was only until the histopathological study that the lesion could be identified as a glomus tumor.

Conclusion: Glomus tumors can be found in extradigital locations and can be asymptomatic.

 

Keywords: Glomus tumor.
Model C critical dynamics of random anisotropy magnets
Creators: name: Dudka, M.
name: Folk, R.
name: Holovatch, Yu.
name: Moser, G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the relaxational critical dynamics of the three-dimensional random anisotropy magnets with the non-conserved n-component order parameter coupled to a conserved scalar density. In the random anisotropy magnets the structural disorder is present in a form of local quenched anisotropy axes of random orientation. When the anisotropy axes are randomly distributed along the edges of the n-dimensional hypercube, asymptotical dynamical critical properties coincide with those of the random-site Ising model. However structural disorder gives rise to considerable effects for non-asymptotic critical dynamics. We investigate this phenomenon by a field-theoretical renormalization group analysis in the two-loop order. We study critical slowing down and obtain quantitative estimates for the effective and asymptotic critical exponents of the order parameter and scalar density. The results predict complex scenarios for the effective critical exponent approaching an asymptotic regime.
description: 8 figures, style files included
The Half-Filled One-Dimensional Extended Hubbard Model: Phase diagram and Thermodynamics
Creators: name: Glocke, S.
name: Klümper, A.
name: Sirker, J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the thermodynamics of the one-dimensional extended Hubbard model at half-filling using a density-matrix renormalization group method applied to transfer matrices. We show that the various phase transitions in this system can be detected by measuring usual thermodynamic quantities like the isothermal compressibility and the uniform magnetic susceptibility. For the isothermal compressibility we show that universal crossing points exist which allow to accurately determine the line where the charge gap vanishes. By studying in addition several correlation functions, we confirm the existence of a phase with long-range dimer order (bond order) which has been a matter of debate for several years. According to our calculations this phase is located in a narrow region between the spin-density and charge-density wave phases up to a tricritical point which we estimate to be at $U_t=6.7\pm 0.2$, $V_t =3.5\pm 0.1$. Our results for the phase diagram are in good agreement with the most recent zero-temperature density-matrix renormalization group study, however, they disagree in some important aspects from the most recent Quantum-Monte-Carlo study.
description: Reference and figure added
Spatial and spectral shape of inhomogeneous non-equilibrium exciton-polariton condensates
Creators: name: Wouters, M.
name: Carusotto, I.
name: Ciuti, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We develop a mean-field theory of the spatial profile and the spectral properties of polariton condensates in nonresonantly pumped semiconductor microcavities in the strong coupling regime. Predictions are obtained for both the continuous-wave and the pulsed excitation regimes and the specific signatures of the non-equilibrium character of the condensation process are pointed out. A striking sensitivity of the condensate shape on the optical pump spot size is demonstrated by analytical and numerical calculations, in good quantitative agreement with recent experimental observations.
description: 5 pages, 3 figures
Nambu monopoles in lattice Electroweak theory
Creators: name: Bakker, B. L. G.
name: Veselov, A. I.
name: Zubkov, M. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We considered the lattice electroweak theory at realistic values of $α$ and $θ_W$ and for large values of the Higgs mass. We investigated numerically the properties of topological objects that are identified with quantum Nambu monopoles. We have found that the action density near the Nambu monopole worldlines exceeds the density averaged over the lattice in the physical region of the phase diagram. Moreover, their percolation probability is found to be an order parameter for the transition between the symmetric and the broken phases. Therefore, these monopoles indeed appear as real physical objects. However, we have found that their density on the lattice increases with increasing ultraviolet cutoff. Thus we conclude, that the conventional lattice electroweak theory is not able to predict the density of Nambu monopoles. This means that the description of Nambu monopole physics based on the lattice Weinberg - Salam model with finite ultraviolet cutoff is incomplete. We expect that the correct description may be obtained only within the lattice theory that involves the description of TeV - scale physics.
description: LATEX
Working from Home: Impact on Wellbeing and Work-Life Balance
Creators: name: Gorjifard, Roya
name: Crawford, Joanne
Publisher: name: Open Access Victoria University of Wellington | Te Herenga Waka
Year: 2021
Subjects: subject: 220299 History and Philosophy of Specific Fields not elsewhere classified
subject: FOS: Philosophy, ethics and religion
subject: Sociology
subject: FOS: Sociology
subject: 150399 Business and Management not elsewhere classified
subject: FOS: Economics and business

description: Working from home (WFH), teleworking, or telecommuting has become a new work norm since the Covid-19 pandemic. Many organisations are showing an interest in testing a hybrid work style when the pandemic is over; a mix of WFH with office-based work has the potential to improve work-life balance (WLB). Organisations across the globe quickly adopted WFH to maintain their business continuity during the pandemic. However, it co-concurred with particular occupational health and safety (OHS) concerns. Our research review shows that the frequency of WFH is significantly related to its impact on WLB. Women, specifically, are more likely to find it challenging to maintain balance between office work and domestic responsibilities. Additionally, WFH leads to personal costs for many, for example, maintaining a suitable workstation setup at home. The continuous demand for up-skilling/re-skilling due to fast improving technology and job satisfaction is another example of the risk to workers’ wellbeing. This research paper reviews the most important risk determinants of WLB due to WFH. We discuss that workplaces should align their strategies in the longer term to support employees’ wellbeing risk management. Employers, employees – women particularly – should use this rapid change as an opportunity to learn and grow.
Electronic structure of LaNiO$_{2}$ and CaCuO$_{2}$ from self consistent vertex corrected GW approach
Creators: name: Kutepov, Andrey L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Electronic structure of one of the nickelates (LaNiO$_{2}$) and one of the cuprates (CaCuO$_{2}$) is studied with three self consistent GW-based methods: scGW, sc(GW+Vertex), and quasiparticle self-consistent GW. Low energy features obtained in our study are in many respects similar to the features reported in previous DFT+DMFT studies. Consistent with the DFT+DMFT conclusion, we find LaNiO$_{2}$ as more correlated than CaCuO$_{2}$. However, correlation effects included in our study change the DFT Fermi surface near the $Γ$ point differently than it was reported in the DMFT studies. Features which are a few electron-volts away from the Fermi level are broader in our calculations than in the DFT+DMFT which reflects the differences between the DFT and the GW methods. Our results are in qualitative agreement with previous G0W0 results, but the self-consistency brings in the quantitative differences. Generally, correlation effects are found to be sufficiently weak in both materials which allows one to use totally ab-initio diagrammatic approaches like sc(GW+Vertex) and to avoid the methods with adjustable parameters (DFT+U or DFT+DMFT). However, the possibility of some strong correlations at low energy which cannot be captured by perturbative methods cannot be completely excluded. For instance, differences in the Fermi surface should be resolved: experimental studies are necessary.
description: 11 pages, 10 figures
CalFUSE v3: A Data-Reduction Pipeline for the Far Ultraviolet Spectroscopic Explorer
Creators: name: Dixon, W. V.
name: Sahnow, D. J.
name: Barrett, P. E.
name: Civeit, T.
name: Dupuis, J.
name: Fullerton, A. W.
name: Godard, B.
name: Hsu, J. C.
name: Kaiser, M. E.
name: Kruk, J. W.
name: Lacour, S.
name: Lindler, D. J.
name: Massa, D.
name: Robinson, R. D.
name: Romelfanger, M. L.
name: Sonnentrucker, P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Since its launch in 1999, the Far Ultraviolet Spectroscopic Explorer (FUSE) has made over 4600 observations of some 2500 individual targets. The data are reduced by the Principal Investigator team at the Johns Hopkins University and archived at the Multimission Archive at Space Telescope (MAST). The data-reduction software package, called CalFUSE, has evolved considerably over the lifetime of the mission. The entire FUSE data set has recently been reprocessed with CalFUSE v3.2, the latest version of this software. This paper describes CalFUSE v3.2, the instrument calibrations upon which it is based, and the format of the resulting calibrated data files.
description: To appear in PASP; 29 pages, 13 figures, uses aastex, emulateapj
Optically detected flip-flops between different spin ensembles in diamond
Creators: name: Masis, Sergei
name: Hazanov, Sergey
name: Alfasi, Nir
name: Shtempluck, Oleg
name: Buks, Eyal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We employ the technique of optical detection of magnetic resonance to study dipolar interaction in diamond between nitrogen-vacancy color centers of different crystallographic orientations and substitutional nitrogen defects. We demonstrate optical measurements of resonant spin flips-flips (second Larmor line), and flip-flops between different spin ensembles in diamond. In addition, the strain coupling between the nitrogen-vacancy color centers and bulk acoustic modes is studied using optical detection. Our findings may help optimizing cross polarization protocols, which, in turn, may allow improving the sensitivity of diamond-based detectors.
Solutions to the 1d Klein-Gordon equation with cutoff Coulomb potentials
Creators: name: Hall, Richard L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In a recent paper by Barton (J. Phys. A40, 1011 (2007)), the 1-dimensional Klein-Gordon equation was solved analytically for the non-singular Coulomb-like potential V_1(|x|) = -α/(|x|+a). In the present paper, these results are completely confirmed by a numerical formulation that also allows a solution for an alternative cutoff Coulomb potential V_2(|x|) = -α/|x|, ~|x| > a, and otherwise V_2(|x|) = -α/a.
description: 8 pages, 4 figures
Voltage-Current curves for small Josephson junction arrays
Creators: name: Doucot, Benoit
name: Ioffe, Lev B.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We compute the current voltage characteristic of a chain of identical Josephson circuits characterized by a large ratio of Josephson to charging energy that are envisioned as the implementation of topologically protected qubits. We show that in the limit of small coupling to the environment it exhibits a non-monotonous behavior with a maximum voltage followed by a parametrically large region where $V\propto 1/I$. We argue that its experimental measurement provides a direct probe of the amplitude of the quantum transitions in constituting Josephson circuits and thus allows their full characterization.
description: 12 pages, 4 figures
A model of COVID-19 pandemic evolution in African countries
Creators: name: Amouzouvi, Kossi
name: Assamagan, Kétévi A.
name: Azote, Somiéalo
name: Connell, Simon H.
name: Fankam, Jean Baptiste Fankam
name: Fanomezana, Fenosoa
name: Guga, Aluwani
name: Haliya, Cyrille E.
name: Mabote, Toivo S.
name: Macucule, Francisco Fenias
name: Mathebula, Dephney
name: Muronga, Azwinndini
name: Mwale, Kondwani C. C.
name: Njeri, Ann
name: Onyie, Ebode F.
name: Rakotondravohitra, Laza
name: Zimba, George
Publisher: name: arXiv
Year: 2021
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: We studied the COVID-19 pandemic evolution in selected African countries. For each country considered, we modeled simultaneously the data of the active, recovered and death cases. In this study, we used a year of data since the first cases were reported. We estimated the time-dependent basic reproduction numbers, $R_0$, and the fractions of infected but unaffected populations, to offer insights into containment and vaccine strategies in African countries. We found that $R_0\leq 4$ at the start of the pandemic but has since fallen to $R_0 \sim 1$. The unaffected fractions of the populations studied vary between $1-10$\% of the recovered cases.
description: 27 pages, 9 figures and 1 table
Stroemgren photometry of Galactic Globular Clusters. I. New Calibrations of the metallicity index
Creators: name: Calamida, A.
name: Bono, G.
name: Stetson, P. B.
name: Freyhammer, L. M.
name: Cassisi, S.
name: Grundahl, F.
name: Pietrinferni, A.
name: Hilker, M.
name: Primas, F.
name: Richtler, T.
name: Romaniello, M.
name: Buonanno, R.
name: Caputo, F.
name: Castellani, M.
name: Corsi, C. E.
name: Ferraro, I.
name: Iannicola, G.
name: Pulone, L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a new calibration of the Stroemgren metallicity index m1 using red giant (RG) stars in 4 globular clusters (GCs:M92,M13,NGC1851,47Tuc) with metallicity ranging from [Fe/H]=-2.2 to -0.7, marginally affected by reddening (E(B-V)<0.04) and with accurate u,v,b,y photometry.The main difference between the new metallicity-index-color (MIC) relations and similar relations available in the literature is that we adopted the u-y/v-y colors instead of the b-y.These colors present a stronger sensitivity to effective temperature, and the MIC relations show a linear slope. The difference between photometric estimates and spectroscopic measurements for RGs in M71,NGC288,NGC362,NGC6397, and NGC6752 is 0.04+/-0.03dex (sigma=0.11dex). We also apply the MIC relations to 85 field RGs with metallicity raning from [Fe/H]=-2.4 to -0.5 and accurate reddening estimates. We find that the difference between photometric estimates and spectroscopic measurements is-0.14+/-0.01dex (sig=0.17dex). We also provide two sets of MIC relations based on evolutionary models that have been transformed into the observational plane by adopting either semi-empirical or theoretical color-temperature relations. We apply the semi-empirical relations to the 9 GCs and find that the difference between photometric and spectroscopic metallicities is 0.04+/-0.03dex (sig=0.10dex).A similar agreement is found for the sample of field RGs, with a difference of -0.09+/-0.03dex (sig=0.19dex).The difference between metallicity estimates based on theoretical relations and spectroscopic measurements is -0.11+/-0.03dex (sig=0.14dex) for the 9 GGCs and -0.24+/-0.03dex (sig=0.15dex) for the field RGs. Current evidence indicates that new MIC relations provide metallicities with an intrinsic accuracy better than 0.2dex.
description: 51 pages, 19 figures, accepted for submission to ApJ
Editorial for NZJER Special Edition
Creators: name: Peace, Christopher
name: Crawford, Joanne
Publisher: name: Open Access Victoria University of Wellington | Te Herenga Waka
Year: 2021
Subjects: subject: 220299 History and Philosophy of Specific Fields not elsewhere classified
subject: FOS: Philosophy, ethics and religion
subject: Sociology
subject: FOS: Sociology
subject: 150399 Business and Management not elsewhere classified
subject: FOS: Economics and business

description: No description supplied
The density of critical percolation clusters touching the boundaries of strips and squares
Creators: name: Simmons, Jacob J. H.
name: Kleban, Peter
name: Dahlberg, Kevin
name: Ziff, Robert M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider the density of two-dimensional critical percolation clusters, constrained to touch one or both boundaries, in infinite strips, half-infinite strips, and squares, as well as several related quantities for the infinite strip. Our theoretical results follow from conformal field theory, and are compared with high-precision numerical simulation. For example, we show that the density of clusters touching both boundaries of an infinite strip of unit width (i.e. crossing clusters) is proportional to $(\sin πy)^{-5/48}\{[\cos(πy/2)]^{1/3} +[\sin (πy/2)]^{1/3}-1\}$. We also determine numerically contours for the density of clusters crossing squares and long rectangles with open boundaries on the sides, and compare with theory for the density along an edge.
description: 11 pages, 6 figures. Minor revisions
Gutzwiller-RVB Theory of High Temperature Superconductivity: Results from Renormalised Mean Field Theory and Variational Monte Carlo Calculations
Creators: name: Edegger, B.
name: Muthukumar, V. N.
name: Gros, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We review the Resonating Valence Bond (RVB) theory of high temperatur e superconductivity using Gutzwiller projected wave functions that incorporate strong correlations. After a general overview of the phenomenon of high temperature superconductivity, we discuss Anderson's RVB picture and its implementation by renormalised mean field theory (RMFT) and variational Monte Carlo (VMC) techniques. We review RMFT and VMC results with an emphasis on recent development s in extending VMC and RMFT techniques to excited states. We compare results obtained from these methods with angle resolved photoemission spectroscopy (ARPES) and scanning tunnelling microscopy (STM). We conclude by summarising recent successes of this approach and discuss open problems that need to be solved for a consistent and complete description of high temperature superconductivity using Gutzwiller projected wave functions.
description: Review, Adv. Phys. (in press)