cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Direct observation of electron emission as a result of a VVV Auger transition in the valence band of Graphene
Creators: name: Chirayath, V. A.
name: Callewaert, V.
name: Chrysler, M. D.
name: Fairchild, A. J.
name: Gladen, R. W.
name: Mcdonald, A. D.
name: Imam, S. K.
name: Shastry, K.
name: Koymen, A. R.
name: Saniz, R.
name: Barbiellini, B.
name: Rajeshwar, K.
name: Partoens, B.
name: Weiss, A. H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report the first direct observation of electron emission into the vacuum as a result of a VVV Auger transition resulting from the relaxation of a deep hole in the valence band. A beam of low energy (<1.25eV) positrons was used to deposit positrons onto the surface of samples consisting of single layer graphene, multi-layer graphene and graphite. The distribution of electrons emitted from the samples as a result of the annihilation of the positron showed peak extending up to ~12 eV with a maximum at ~4eV. The observed peak was ~17 times larger than the previously observed annihilation induced C KVV peak. An analysis based upon a density functional theory calculation of the positron annihilation rates indicates that the width and intensity of the peak is consistent with electron emission resulting from VVV Auger transition excited by the annihilation of valence band electrons. Good agreement was found between the data from the single layer graphene on Cu surface with a theoretical line shape found from a self-folding of the density of states for a free standing graphene layer. The agreement between the theoretical and measured intensities for the KVV and VVV transitions indicates that the branching ratio for holes to decay via an Auger transition is nearly the same in both cases (i.e. close to 100%). Our results suggest the possibility of using annihilation induced VVV Auger spectroscopy to study the properties of the local density of states and the hole decay processes in materials in which the valence band width exceeds the work function.
description: Version 2 - Corrected minor typos. Inconsistency with title fixed, Author list changed
High-precision nuclear chronometer for the cosmos
Creators: name: Wu, X. H.
name: Zhao, P. W.
name: Zhang, S. Q.
name: Meng, J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Nuclear chronometer, which predicts the ages of the oldest stars by comparing the present and initial abundances of long-lived radioactive nuclides, provides an independent dating technique for the cosmos. A new nuclear chronometer called Th-U-X chronometer is proposed, which imposes stringent constraints on the astrophysical conditions in the $r$-process simulation by synchronizing the previous Th/X, U/X and Th/U chronometers. The astrophysical uncertainties of nuclear chronometer are significantly reduced from more than $\pm2$ billion years to within 0:3 billion years by the Th-U-X chronometer. The proposed chronometer is then applied to estimate the ages of the six metal-poor stars with observed uranium abundances, and the predicted ages are compatible with the cosmic age 13.8 billion years predicted from the cosmic microwave background radiation, but in contradictory with the new cosmic age 11.4 billion years from the gravitational lenses measurement.
description: 5 pages, 4 figures
Magnetic fields and hot gas in M101
Creators: name: Wezgowiec, M.
name: Beck, R.
name: Hanasz, M.
name: Soida, M.
name: Ehle, M.
name: Dettmar, R. -J.
name: Urbanik, M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Studies of nearby spiral galaxies in radio and X-ray wavelengths reveal the structure and energy balance of the magnetic fields and the hot interstellar medium (ISM). In some spiral galaxies, large-scale ordered magnetic fields have been found between the spiral stellar arms (the so-called magnetic arms). One of the considered explanations of their origin is magnetic reconnection, which according to theoretical studies can efficiently heat the low-density ISM. We present, for the first time, high-resolution C-band (5GHz) radio maps of the nearby face-on spiral galaxy M101 to study the magnetic fields and verify the existence of the magnetic arms. The analysis of the archival XMM-Newton X-ray data is performed to search for signatures of gas heating by magnetic reconnection effects in the disk and the halo of this galaxy. We combine the Very Large Array (VLA) and Effelsberg radio maps of M101 to restore the large-scale emission lost in the interferometric observations. From the obtained maps, we derive magnetic field strengths and energy densities, and compare them with the properties of the hot gas found with the spectral analysis of the X-ray data. Most of the X-ray emission likely comes from the hot gas in the halo of M101. Its temperature is highest above the massive stellar arm and an inter-arm region with enhanced polarised radio emission, as well as in the inter-arm area where neither Halpha nor HI emission is visible. In regions outside of the spiral arms lower strengths, energy densities and higher orders of the magnetic fields were observed. Although M101 does not possess well-defined magnetic arms, a rudimentary magnetic arm was identified in one of the inter-arm regions. We found weak signatures of additional heating of the ISM there, as well as in the galactic halo, which could be explained by the action of magnetic reconnection.
description: 16 pages, 10 figures, 11 tables. Accepted to A&A
Exploratory scenarios for the differential nuclear and tidal evolution of TZ Fornacis
Creators: name: Claret, A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: TZ Fornacis is a double-lined eclipsing binary system with similar masses (2.057$\pm$0.001 and 1.958$\pm$0.001 $M_{\odot}$) but characterized by very different radii (8.28$\pm$0.22 and 3.94$\pm$0.17 $R_{\odot}$). This similarity in terms of mass makes it possible to study the system's differential stellar evolution as well as some aspects of its tidal evolution. With regard to its orbital elements, it was recently confirmed that its orbit is circular with an orbital period of 75.7 days. The less massive component rotates about 17 times faster than the primary one, which is synchronized with the mean orbital angular velocity. Our main objective in this work is to study both the nuclear and the tidal evolution of the system. We explored two scenarios regarding the initial eccentricities: a high one (0.30) and a case of an initial circular orbit. A good agreement has been found between the observational values of the eccentricity, synchronism levels, and orbital period with the values predicted by the integration of the tidal evolution equations. The influence of the friction timescale on the evolution of the orbital elements of TZ For is also studied here. The orbital elements most affected by the uncertainties in the friction timescale are the synchronism levels of the two components. On the other hand, we used the properties of the rotating models generated by the GRANADA code as the initial angular velocities instead of using trial values. In this case, comparisons between the theoretical values of the orbital elements and their observed counterparts also lead to a good interagreement.
Giant magnetoanisotropy in the Josephson effect and switching of staggered order in antiferromagnets
Creators: name: Falch, Vemund
name: Linder, Jacob
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We predict that the amplitude of the Josephson current through an antiferromagnetic weak link changes by several orders of magnitude upon rotation of the Néel order parameter characterizing the staggered magnetic order. This occurs due the presence of spin-orbit coupling arising from structural inversion asymmetry which makes the band gap in the antiferromagnet highly sensitive to the staggered order parameter direction. We also demonstrate that when phase-biasing the junction, magnetization dynamics is induced which switches the direction of the Néel vector in the antiferromagnet. These results reveal an interesting versatility of antiferromagnetic Josephson junctions as they offer both a large tunability of the supercurrent magnitude via the staggerered magnetization and phase-coherent control over the Néel order parameter.
description: 6 pages, 7 figures. To appear in Phys. Rev. B
Thermally induced passage and current of particles in a highly unstable optical potential
Creators: name: Ryabov, Artem
name: Zemanek, Pavel
name: Filip, Radim
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We discuss the statistics of first-passage times of a Brownian particle moving in a highly unstable nonlinear potential proportional to an odd power of position. We observe temperature-induced shortening of the mean first-passage time and its dependence on the power of nonlinearity. We propose a passage-time fraction as both a simple and experimentally detectable witness of the nonlinearity. It is advantageously independent of all other parameters of the experiment and observable for a small number of trajectories. To better characterize the stochastic passage in the unstable potential, we introduce an analogy of the signal-to-noise ratio for the statistical distribution of the first-passage times. Interestingly, the upper bound for the signal-to-noise ratio is temperature independent in the unstable potential. Finally, we describe the nonequilibrium steady state of the particle cyclically passing through unstable odd nonlinearity. The maximum of the steady-state probability distribution shifts against the directions of the current and this counterintuitive effect increases with temperature. All these thermally induced effects are very promising targets for experimental tests of highly nonlinear stochastic dynamics of particles placed into optical potential landscapes of shaped optical tweezers.
Predicting the Geoeffectiveness of CMEs Using Machine Learning
Creators: name: Pricopi, Andreea-Clara
name: Paraschiv, Alin Razvan
name: Besliu-Ionescu, Diana
name: Marginean, Anca-Nicoleta
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Coronal mass ejections (CMEs) are the most geoeffective space weather phenomena, being associated with large geomagnetic storms, having the potential to cause disturbances to telecommunication, satellite network disruptions, power grid damages and failures. Thus, considering these storms' potential effects on human activities, accurate forecasts of the geoeffectiveness of CMEs are paramount. This work focuses on experimenting with different machine learning methods trained on white-light coronagraph datasets of close to sun CMEs, to estimate whether such a newly erupting ejection has the potential to induce geomagnetic activity. We developed binary classification models using logistic regression, K-Nearest Neighbors, Support Vector Machines, feed forward artificial neural networks, as well as ensemble models. At this time, we limited our forecast to exclusively use solar onset parameters, to ensure extended warning times. We discuss the main challenges of this task, namely the extreme imbalance between the number of geoeffective and ineffective events in our dataset, along with their numerous similarities and the limited number of available variables. We show that even in such conditions, adequate hit rates can be achieved with these models.
description: 25 pages, 7 figures, and 10 tables, The Astrophysical Journal, In Press
Problems in the establishment and maintenance of pathogen-tested schemes for ornamental plants and some aspects of their effectiveness
Creators: name: Moran, Jane Robina.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Poisson-Boltzmann study of the effective electrostatic interaction between colloids at an electrolyte interface
Creators: name: Majee, Arghya
name: Bier, Markus
name: Dietrich, S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The effective electrostatic interaction between a pair of colloids, both of them located close to each other at an electrolyte interface, is studied by employing the full, nonlinear Poisson-Boltzmann (PB) theory within classical density functional theory. Using a simplified yet appropriate model, all contributions to the effective interaction are obtained exactly, albeit numerically. The comparison between our results and those obtained within linearized PB theory reveals that the latter overestimates these contributions significantly at short inter-particle separations. Whereas the surface contributions to the linear and the nonlinear PB results differ only quantitatively, the line contributions show qualitative differences at short separations. Moreover, a dependence of the line contribution on the solvation properties of the two adjacent fluids is found, which is absent within the linear theory. Our results are expected to enrich the understanding of effective interfacial interactions between colloids.
Assessment of Traditional Practices During Pregnancy, Labour, Delivery and Associated Factorsamong the Reproductive Age Women at Kersa Malima District, South West Shoa Zone, Oromia Regional State, Ethiopia
Creators: name: Tiruneh, Hulemenaye
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2014

description: Introduction:Traditional Practices reflect values and beliefs held by members of a community for periods often spanning generations. Every social grouping in the world has specific Traditional Practices and beliefs,some of which are beneficial to all members, while others are harmful to a specific group. Traditional Practices transmitted through tales, rituals, healing method and customary laws from generation to generation. Traditional Practices are more likely employ in developing countries where health facilities and health education are still behind the rich of the majority of the people.Although Maternal Mortality Ratio in developing countries is still 15 times higher than developed countries. This is because Traditional Practices are the main contributing factors for maternal morbidity and mortality. Objective:Assessment of Traditional Practices during pregnancy, labour and delivery among reproductive age group women and to identify factors related with them. Methods and Materials: The community-based cross-sectional study for the quantitave study and indepth interview for the qualitative study was carried out fromNovember 2013-June 2014 in Kersa Malimma District, South West Shoa Zone, Oromia Regional state. Result:The major Harmful Traditional Practices during pregnancy were intake of kosso with or without tape worm infestation, doing hard work. During labour and delivery the major Harmful Traditional Practices identified were home delivery, shaking the women until placenta deliver, cutting the umbilical cord with unsterilized razor blade, left the umbilical cord without tying, putting butter, vaseline and hair oil on umbilical stump (a short piece of umbilicus after the rest of umbilical cord was cut),giving bath for the newborn immediately after delivery, women taking bath on day 4 or 5 afer delivery and drinking local alcohol while breast feeding. Massaging the abdomen while the women were in labour and drinking "telba" after delivery are Traditional Practicesidentified but their effect is not well known and labelledas neutral practices. Those Traditional Practices that are indicated above have similarity with Traditional Practices described in indepth interview.Family monthly income is associated with kosso intake, abortion an educational status of the women is associated with work during pregnancy and abortion is associated with home delivery practice. Conclusion:Ingeneral, Harmful Traditional Practices during pregnancy, labour and delivery are highly prevalent in this study area and the effects of some of the traditional practices are not well known. Extensive health education towards the eradication of the identified Harmful Traditional Practices, further studies on the effects of Traditional Practices for those that are not well known and similar studies in other areas is therefore recommended.
Synchrotron Self-Compton Afterglow Closure Relations and Fermi-LAT Detected Gamma-Ray Bursts
Creators: name: Fraija, N.
name: Dainotti, M. G.
name: Ugale, S.
name: Jyoti, D.
name: Warren, D. C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The Fermi Large Area Telescope (Fermi-LAT) Collaboration reported the Second Gamma-ray Burst Catalog (2FLGC), which comprises a subset of 29 bursts with photon energies above 10 GeV. Although the standard synchrotron forward-shock model has successfully explained the Gamma-ray burst (GRB) afterglow observations, energetic photons higher than 10 GeV from these transient events can hardly be described in this scenario. We present the closure relations (CRs) of synchrotron self-Compton (SSC) afterglow model in the adiabatic and radiative scenario and when the central engine injects continuous energy into the blastwave to study the evolution of the spectral and temporal indexes of those bursts reported in 2FLGC. We consider the SSC afterglow model evolving in stellar-wind and interstellar medium, and the CRs as a function of the radiative parameter, the energy injection index, and the electron spectral index for $1
description: 14 pages, 2 figures, accepted for publication in ApJ
Completeness of general pp-wave spacetimes and their impulsive limit
Creators: name: Sämann, Clemens
name: Steinbauer, Roland
name: Švarc, Robert
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 83C15, 83C35, 83C10, 34A36

description: We investigate geodesic completeness in the full family of pp-wave or Brinkmann spacetimes in their extended as well as in their impulsive form. This class of geometries contains the recently studied gyratonic pp-waves, modelling the exterior field of a spinning beam of null particles, as well as NPWs, which generalise classical pp-waves by allowing for a general wave surface. The problem of geodesic completeness reduces to the question of completeness of trajectories on a Riemannian manifold under an external force field. Building upon respective recent results we derive completeness criteria in terms of the spatial asymptotics of the profile function in the extended case. In the impulsive case we use a fixed point argument to show that irrespective of the behaviour of the profile function all geometries in the class are complete.
description: 26 pages, 3 figures
The Simulation Model Partitioning Problem: an Adaptive Solution Based on Self-Clustering (Extended Version)
Creators: name: D'Angelo, Gabriele
Publisher: name: arXiv
Year: 2016
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Multiagent Systems (cs.MA)
subject: Performance (cs.PF)
subject: FOS: Computer and information sciences

description: This paper is about partitioning in parallel and distributed simulation. That means decomposing the simulation model into a numberof components and to properly allocate them on the execution units. An adaptive solution based on self-clustering, that considers both communication reduction and computational load-balancing, is proposed. The implementation of the proposed mechanism is tested using a simulation model that is challenging both in terms of structure and dynamicity. Various configurations of the simulation model and the execution environment have been considered. The obtained performance results are analyzed using a reference cost model. The results demonstrate that the proposed approach is promising and that it can reduce the simulation execution time in both parallel and distributed architectures.
Searching for multiple populations in star clusters using the China Space Station Telescope
Creators: name: Li, Chengyuan
name: Zheng, Zhenya
name: Li, Xiaodong
name: Pang, Xiaoying
name: Tang, Baitian
name: Milone, Antonino P.
name: Wang, Yue
name: Wang, Haifeng
name: Jiang, Dengkai
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Multiple stellar populations (MPs) in most star clusters older than 2 Gyr, as seen by lots of spectroscopic and photometric studies, have led to a significant challenge to the traditional view of star formation. In this field, space-based instruments, in particular the Hubble Space Telescope (HST), have made a breakthrough as they significantly improved the efficiency of detecting MPs in crowding stellar fields by images. The China Space Station Telescope (CSST) and the HST are sensitive to a similar wavelength interval, but it covers a field of view which is about 5-8 times wider than that of HST. One of its instruments, the Multi-Channel Imager (MCI), will have multiple filters covering a wide wavelength range from NUV to NIR, making the CSST a potentially powerful tool for studying MPs in clusters. In this work, we evaluate the efficiency of the designed filters for the MCI/CSST in revealing MPs in different color-magnitude diagrams (CMDs). We find that CMDs made with MCI/CSST photometry in appropriate UV filters are powerful tools to disentangle stellar populations with different abundances of He, C, N, O and Mg. On the contrary, the traditional CMDs are blind to multiple populations in globular clusters (GCs). We show that CSST has the potential of being the spearhead instrument for investigating MPs in GCs in the next decades.
description: 21 pages, 16 figures, RAA accepted
Radio evolution of a Type IIb supernova SN 2016gkg
Creators: name: Nayana, A. J.
name: Chandra, Poonam
name: Krishna, Anoop
name: Anupama, G. C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present extensive radio monitoring of a type IIb supernova (SN IIb), SN 2016gkg during $t \sim$ 8$-$1429 days post explosion at frequencies $ν\sim$ 0.33$-$25 GHz. The detailed radio light curves and spectra are broadly consistent with self-absorbed synchrotron emission due to the interaction of the SN shock with the circumstellar medium. The model underpredicts the flux densities at $t \sim$ 299 days post-explosion by a factor of 2, possibly indicating a density enhancement in the CSM due to a non-uniform mass-loss from the progenitor. Assuming a wind velocity $v_{\rm w} \sim$ 200 km s$^{-1}$, we estimate the mass-loss rate to be $\dot{M} \sim$ (2.2, 3.6, 3.8, 12.6, 3.7, and 5.0) $\times$ 10$^{-6}$ $M_{\odot}$ yr$^{-1}$ during $\sim$ 8, 15, 25, 48, 87, and 115 years, respectively before the explosion. The shock wave from SN 2016gkg is expanding from $R \sim$ 0.5 $\times$ 10$^{16}$ to 7 $\times$ 10$^{16}$ cm during $t \sim$ 24$-$492 days post-explosion indicating a shock deceleration index, $m$ $\sim$ 0.8 ($R \propto t^m$), and mean shock velocity $v \sim$ 0.1c. The radio data being inconsistent with free-free absorption model and higher shock velocities are in support of a relatively compact progenitor for SN 2016gkg.
description: 18 pages, 8 figures, accepted for publication in ApJ
Quantification of airborne organic dust and its biologically active constituents in the working environment
Creators: name: Attwood, Peter.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
New Detections of Phosphorus Molecules towards Solar-type Protostars
Creators: name: Wurmser, Serena
name: Bergner, Jennifer B.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Phosphorus is a necessary element for life on Earth, but at present we have limited constraints on its chemistry in star- and planet-forming regions: to date, phosphorus carriers have only been detected towards a few low-mass protostars. Motivated by an apparent association between phosphorus molecule emission and outflow shocking, we used the IRAM 30m telescope to target PN and PO lines towards seven Solar-type protostars with well-characterized outflows, and firmly detected phosphorus molecules in three new sources. This sample, combined with archival observations of three additional sources, enables the first exploration of the demographics of phosphorus chemistry in low-mass protostars. The sources with PN detections show evidence for strong outflow shocks based on their H$_2$O 1$_{10}$-1$_{01}$ fluxes. On the other hand, no protostellar properties or bulk outflow mechanical properties are found to correlate with the detection of PN. This implies that gas-phase phosphorus is specifically linked to shocked gas within the outflows. Still, the PN and PO line kinematics suggest an emission origin in post-shocked gas rather than directly shocked material. Despite sampling a wide range of protostellar properties and outflow characteristics, we find a fairly narrow range of source-averaged PO/PN ratios (0.6-2.2) and volatile P abundances as traced by (PN+PO)/CH$_3$OH ($\sim$1-3%). Spatially resolved observations are needed to further constrain the emission origins and environmental drivers of the phosphorus chemistry in these sources.
description: Accepted to ApJ
Gate-controllable magneto-optic Kerr effect in layered collinear antiferromagnets
Creators: name: Sivadas, Nikhil
name: Okamoto, Satoshi
name: Xiao, Di
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using symmetry arguments and a tight-binding model, we show that for layered collinear anti- ferromagnets, magneto-optic effects can be generated and manipulated by controlling crystal symmetries through a gate voltage. This provides a promising route for electric field manipulation of the magneto-optic effects without modifying the underlying magnetic structure. We further demonstrate the gate control of magneto-optic Kerr effect (MOKE) in bilayer MnPSe3 using first-principles calculations. The field-induced inversion symmetry breaking effect leads to gate-controllable MOKE whose direction of rotation can be switched by the reversal of the gate voltage.
Some theorems on passing from local to global presence of properties of functions
Creators: name: Skordev, Dimiter
Publisher: name: arXiv
Year: 2016
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: D.2.2; F.4.1; G.1.2

description: When given a class of functions and a finite collection of sets, one might be interested whether the class in question contains any function whose domain is a subset of the union of the sets of the given collection and whose restrictions to all of them belong to this class. The collections with the formulated property are said to be strongly join permitting for the given class (the notion of join permitting collection is defined in the same way, but without the words "a subset of"). Three theorems concerning certain instances of the problem are proved. A necessary and sufficient condition for being strongly join permitting is given for the case when, for some $n$, the class consists of the potentially partial recursive functions of $n$ variables, and the collection consists of sets of $n$-tuples of natural numbers. The second theorem gives a sufficient condition for the case when the class consists of the continuous partial functions between two given topological spaces, and the collection consists of subsets of the first of them (the condition is also necessary under a weak assumption on the second one). The third theorem is of a similar character but, instead of continuity, it concerns computability in the spirit of the one in effective topological spaces.
description: 11 pages
Representations of the orthosymplectic Yangian
Creators: name: Molev, A. I.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Representation Theory (math.RT)
subject: Mathematical Physics (math-ph)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We give a complete description of the finite-dimensional irreducible representations of the Yangian associated with the orthosymplectic Lie superalgebra $\frak{osp}_{1|2}$. The representations are parameterized by monic polynomials in one variable, they are classified in terms of highest weights. We give explicit constructions of a family of elementary modules of the Yangian and show that a wide class of irreducible representations can be produced by taking tensor products of the elementary modules.
description: 28 pages, a few changes are made in the last section correcting a mistake in the initial version of the proof
Blanco DECam Bulge Survey (BDBS) V. Cleaning the foreground populations from Galactic bulge colour-magnitude diagrams using Gaia EDR3
Creators: name: Marchetti, Tommaso
name: Johnson, Christian I.
name: Joyce, Meridith
name: Rich, R. Michael
name: Simion, Iulia
name: Young, Michael D.
name: Clarkson, William I.
name: Pilachowski, Catherine A.
name: Michael, Scott
name: Kunder, Andrea
name: Koch-Hansen, Andreas J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Blanco DECam Bulge Survey (BDBS) has imaged more than 200 square degrees of the southern Galactic bulge, providing photometry in the ugrizy filters for $\sim 250$ million unique stars. The presence of a strong foreground disk population, along with complex reddening and extreme image crowding, has made it difficult to constrain the presence of young and intermediate age stars in the bulge population. We employed an accurate cross-match of BDBS with the latest data release (EDR3) from the Gaia mission, matching more than 140 million sources with BDBS photometry and Gaia EDR3 photometry and astrometry. We relied on Gaia EDR3 astrometry, without any photometric selection, to produce clean BDBS bulge colour-magnitude diagrams (CMDs). Gaia parallaxes were used to filter out bright foreground sources, and a Gaussian mixture model fit to Galactic proper motions could identify stars kinematically consistent with bulge membership. We applied this method to 127 different bulge fields of $1$ deg$^2$ each, with $|\ell| \leq 9.5^\circ$ and $-9.5^\circ \leq b \leq -2.5^\circ$. The astrometric cleaning procedure removes the majority of blue stars in each field, especially near the Galactic plane, where the ratio of blue to red stars is $\lesssim 10\%$, increasing to values $\sim 20\%$ at higher Galactic latitudes. We rule out the presence of a widespread population of stars younger than 2 Gyr. The vast majority of blue stars brighter than the turnoff belong to the foreground population, according to their measured astrometry. We introduce the distance between the observed red giant branch bump and the red clump as a simple age proxy for the dominant population in the field, and we confirm the picture of a predominantly old bulge. Further work is needed to apply the method to estimate ages to fields at higher latitudes, and to model the complex morphology of the Galactic bulge.
description: 21 pages, 22 figures, accepted for publication in A&A
Mathematical models of dendritic neurons
Creators: name: Poznanski, Roman R. .
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Multifunctorial Inverse $K$-Theory
Creators: name: Johnson, Niles
name: Yau, Donald
Publisher: name: arXiv
Year: 2021
Subjects: subject: Algebraic Topology (math.AT)
subject: Category Theory (math.CT)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics
subject: Primary: 19D23, Secondary: 18M65, 18M05, 18D20, 55P43

description: We show that Mandell's inverse $K$-theory functor is a categorically-enriched non-symmetric multifunctor. In particular, it preserves algebraic structures parametrized by non-symmetric operads. As applications, we describe how ring categories arise as the images of inverse $K$-theory.
description: 36 pages. Final version. To appear in Annals of K-Theory
Bayesian nonparametric forecasting of monotonic functional time series
Creators: name: Canale, Antonio
name: Ruggiero, Matteo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Applications (stat.AP)
subject: Computation (stat.CO)
subject: FOS: Computer and information sciences

description: We propose a Bayesian nonparametric approach to modelling and predicting a class of functional time series with application to energy markets, based on fully observed, noise-free functional data. Traders in such contexts conceive profitable strategies if they can anticipate the impact of their bidding actions on the aggregate demand and supply curves, which in turn need to be predicted reliably. Here we propose a simple Bayesian nonparametric method for predicting such curves, which take the form of monotonic bounded step functions. We borrow ideas from population genetics by defining a class of interacting particle systems to model the functional trajectory, and develop an implementation strategy which uses ideas from Markov chain Monte Carlo and approximate Bayesian computation techniques and allows to circumvent the intractability of the likelihood. Our approach shows great adaptation to the degree of smoothness of the curves and the volatility of the functional series, proves to be robust to an increase of the forecast horizon and yields an uncertainty quantification for the functional forecasts. We illustrate the model and discuss its performance with simulated datasets and on real data relative to the Italian natural gas market.
description: To appear on the Electronic Journal of Statistics
Surrogate-assisted network analysis of nonlinear time series
Creators: name: Laut, Ingo
name: Räth, Christoph
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: The performance of recurrence networks and symbolic networks to detect weak nonlinearities in time series is compared to the nonlinear prediction error. For the synthetic data of the Lorenz system, the network measures show a comparable performance. In the case of relatively short and noisy real-world data from active galactic nuclei, the nonlinear prediction error yields more robust results than the network measures. The tests are based on surrogate data sets. The correlations in the Fourier phases of data sets from some surrogate generating algorithms are also examined. The phase correlations are shown to have an impact on the performance of the tests for nonlinearity.
description: 9 pages, 5 figures, Chaos (http://scitation.aip.org/content/aip/journal/chaos), corrected typos
Screen oriented query languages
Creators: name: Goh, Guat Khunn.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Infinite-dimensional features of matrices and pseudospectra
Creators: name: Pal, Avijit
name: Yakubovich, Dmitry V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: Given a Hilbert space operator $T$, the level sets of function $Ψ_T(z)=\|(T-z)^{-1}\|^{-1}$ determine the so-called pseudospectra of $T$. We set $Ψ_T$ to be zero on the spectrum of $T$. After giving some elementary properties of $Ψ_T$ (which, as it seems, were not noticed before), we apply them to the study of the approximation. We prove that for any operator $T$, there is a sequence $\{T_n\}$ of finite matrices such that $Ψ_{T_n}(z)$ tends to $Ψ_{T}(z)$ uniformly on $\C$. In this proof, quasitriangular operators play a special role. This is merely an existence result, we do not give a concrete construction of this sequence of matrices. One of our main points is to show how to use infinite-dimensional operator models in order to produce examples and counterexamples in the set of finite matrices of large order. In particular, we get a result, which means, in a sense, that the pseudospectrum of a nilpotent matrix can be anything one can imagine. We also study the norms of the multipliers in the context of Cowen--Douglas class operators. We use these results to show that, to the opposite to the function $Ψ_{S}$, the function $\|\sqrt{S-z}\,\|$ for certain finite matrices $S$ may oscillate arbitrarily fast even far away from the spectrum.
description: 19 pages, To appear, Journal of Mathematical Analysis and Applications, 2016
Fast optical flares from M dwarfs detected by a one-second-cadence survey with Tomo-e Gozen
Creators: name: Aizawa, Masataka
name: Kawana, Kojiro
name: Kashiyama, Kazumi
name: Ohsawa, Ryou
name: Kawahara, Hajime
name: Naokawa, Fumihiro
name: Tajiri, Tomoyuki
name: Arima, Noriaki
name: Jiang, Hanchun
name: Hartwig, Tilman
name: Fujisawa, Kotaro
name: Shigeyama, Toshikazu
name: Arimatsu, Ko
name: Doi, Mamoru
name: Kasuga, Toshihiro
name: Kobayashi, Naoto
name: Kondo, Sohei
name: Mori, Yuki
name: Okumura, Shin-ichiro
name: Takita, Satoshi
name: Sako, Shigeyuki
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We report a one-second-cadence wide-field survey for M-dwarf flares using the Tomo-e Gozen camera mounted on the Kiso Schmidt telescope. We detect 22 flares from M3-M5 dwarfs with rise times and amplitudes ranging from $5\, \mathrm{sec} \lesssim t_\mathrm{rise} \lesssim 100\,\mathrm{sec}$ and $0.5 \lesssim ΔF/F_{\star} \lesssim 20$, respectively. The flare light curves mostly show steeper rises and shallower decays than those obtained from the Kepler one-minute cadence data and tend to have flat peak structures. Assuming a blackbody spectrum with temperatures of $9,000-15,000\,\mathrm{K}$, the peak luminosities and bolometric energies are estimated to be $10^{29}\,\mathrm{erg\,sec^{-1}} \lesssim L_\mathrm{peak} \lesssim 10^{31}\,\mathrm{erg\,sec^{-1}}$ and $10^{31}\,\mathrm{erg} \lesssim E_{\rm bol} \lesssim 10^{34}\,\mathrm{erg}$, which constitutes the bright end of fast optical flares for M dwarfs. We confirm that more than 90\% of the host stars of the detected flares are magnetically active based on their H$α$ emission line intensities obtained by LAMOST. The estimated occurrence rate of the detected flares is $\sim 0.7$ per day per an active star, indicating they are common in magnetically active M dwarfs. We argue that the flare light curves can be explained by the chromospheric compression model; the rise time is broadly consistent with the Alfvén transit time of a magnetic loop with a length scale of $l_\mathrm{loop} \sim 10^4\,\mathrm{km}$ and a field strength of $1,000\,\mathrm{G}$, while the decay time is likely determined by the radiative cooling of the compressed chromosphere down to near the photosphere with a temperature of $\gtrsim 10,000\,\mathrm{K}$. These flares from M dwarfs could be a major contamination source for a future search of fast optical transients of unknown types.
description: 39 pages, 13 figures, accepted for publication in PASJ
Loewner's "forgotten" theorem
Creators: name: Albers, Peter
name: Tabachnikov, Serge
Publisher: name: arXiv
Year: 2021
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 55M25

description: Let $f(t)$ be a smooth and periodic function of one real variable. Then the planar curves $t\mapsto \big(f'(t),f(t)\big)$ and $t\mapsto \big(f''(t)-f(t),f'(t)\big)$ both have non-negative rotation number around every point not on the curve. These are the two simplest cases of a beautiful Theorem by C. Loewner. This article is expository, we prove the two statements by elementary means following work by Bol [3]. After that, we present Loewner's Theorem and his proof from [7].
description: 10 pages, 6 figures
Constraining the ellipticity of new-born magnetar with the observational data of Long gamma-ray bursts
Creators: name: Xie, Lang
name: Wei, Da-Ming
name: Wang, Yun
name: Jin, Zhi-Ping
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The X-ray plateau emission observed in many Long gamma-ray bursts (LGRBs) has been usually interpreted as the spin-down luminosity of a rapidly spinning, highly magnetized neutron star (millisecond magnetar). If this is true, then the magnetar may emit extended gravitational wave (GW) emission associated with the X-ray plateau due to non-axisymmetric deformation or various stellar oscillations. The advanced LIGO and Virgo detectors have searched for long-duration GW transients for several years, no evidence of GWs from any magnetar has been found until now. In this work, we attempt to search for signature of GW radiation in the electromagnetic observation of 30 LGRBs under the assumption of the magnetar model. We utilize the observations of the LGRB plateau to constrain the properties of the new-born magnetar, including the initial spin period $P_0$, diploe magnetic field strength $B_p$ and the ellipticity $ε$. We find that there are some tight relations between magnetar parameters, e.g., $ε\propto B_p^{1.29}$ and $B_p\propto P_0^{1.14}$. In addition, we derive the GW strain for magnetar sample via their spin-down processes, and find that the GWs from these objects may not be detectable by the aLIGO and ET detectors. For a rapidly spinning magnetar ($P\sim 1\mbox{ ms}$, $ B \sim10^{15}\mbox{ G}$), the detection horizon for advanced LIGO O5 detector is $\sim 180\mbox{ Mpc}$. The detection of such GW signal associated with the X-ray plateau would be a smoking gun that the central engine of GRB is a magnetar.
description: 15 pages, 7 figures,accepted for publication in ApJ
Detection of 16 small glitches in 9 pulsars
Creators: name: Zhou, Zu-Rong
name: Wang, Jing-Bo
name: Wang, Na
name: Yuan, Jian-Ping
name: Kou, Fei-Fei
name: Dang, Shi-Jun
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Timing observations from the Nanshan 26-m radio telescope for nine pulsars between 2000 and 2014 have been used to search for glitches. The data span for nine pulsars ranges from 11.6 to 14.2 years. From the total of 114 yr of pulsar rotational history, 16 new glitches were identified in 9 pulsars. Glitch parameters were measured by fitting the timing residuals data. All 16 glitches have a small fractional size. Six new glitches have been detected in PSR J1833-0827, making it another frequent glitching pulsar. Some of the 16 glitches may experience exponential or linear recovery, but it is unlikely for us to make further analyses with the large gap in the data set. All the glitch rates obtained from Nanshan are higher than that from Jodrell Bank Observatory. The small glitch size and high glitch rate could possibly attribute to the high observation cadence.
description: 13 pages, 4 figures, 2 tables, accepted for publication in RAA. arXiv admin note: text overlap with arXiv:1211.2035 by other authors
Nucleotide sequence analysis of mutations in the mitochondrial oli2 gene encoding subunit 6 of the mitochondrial ATPase complex in saccharomyces cerevisiae
Creators: name: John, Ulrik Peter.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
W-exchange contribution to the decays $Ξ_{cc}^{++}\toΞ_{c}^{+(\prime)}π^{+}$ using light-cone sum rules
Creators: name: Shi, Yu-Ji
name: Zhao, Zhen-Xing
name: Xing, Ye
name: Meißner, Ulf-G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We calculate the W-exchange contribution to the $Ξ_{cc}^{++}\toΞ_{c}^{+(\prime)}π^{+}$ decay using light-cone sum rules. The two-particle light-cone distribution amplitudes of the pion are used as non-perturbative input for the sum rules calculation, and the perturbative kernel is calculated at the leading order. We obtain the corresponding decay branching fractions by combining our W-exchange amplitudes with the factorizable amplitudes given by various theoretical methods from the literature. It is shown that with the factorizable amplitudes from heavy quark effective theory, we obtain the branching fraction ratio ${\cal B}(Ξ_{cc}^{++}\toΞ_{c}^{+\prime}π^{+})/{\cal B}(Ξ_{cc}^{++}\toΞ_{c}^{+}π^{+})= 1.42\pm 0.78$, which is consistent with the experimental value of $1.41\pm 0.17\pm 0.1$.
description: 18 pages, 4 figures, 4 tables
Minimal model for the frustrated spin ladder system BiCu$_2$PO$_6$
Creators: name: Splinter, Leanna
name: Drescher, Nils A.
name: Krull, Holger
name: Uhrig, Götz S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: To establish the microscopic model of the compound BiCu$_2$PO$_6$ is a challenging task. Inelastic neutron scattering experiments showed that the dispersion of this material is non-degenerate suggesting the existence of anisotropic interactions. Here we present a quantitative description of the excitation spectrum for BiCu$_2$PO$_6$ on the one-particle level. The solution of the isotropic frustrated spin ladder by continuous unitary transformations is the starting point of our approach. Further couplings such as isotropic interladder couplings and anisotropic interactions are included on the mean-field level. Our aim is to establish a minimal model built on the symmetry allowed interactions and to find a set of parameters, which allow us to describe the low-energy part of the dispersion without assuming unrealistic couplings.
description: 21 pages