cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The halo mass function conditioned on density from the Millennium Simulation: insights into missing baryons and galaxy mass functions
Creators: name: Faltenbacher, A.
name: Finoguenov, A.
name: Drory, N.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The baryon content of high-density regions in the universe is relevant to two critical unanswered questions: the workings of nurture effects on galaxies and the whereabouts of the missing baryons. In this paper, we analyze the distribution of dark matter and semianalytical galaxies in the Millennium Simulation to investigate these problems. Applying the same density field reconstruction schemes as used for the overall matter distribution to the matter locked in halos we study the mass contribution of halos to the total mass budget at various background field densities, i.e., the conditional halo mass function. In this context, we present a simple fitting formula for the cumulative mass function accurate to ~ 5% for halo masses between 10^{10} and 10^{15}Msol/h. We find that in dense environments the halo mass function becomes top heavy and present corresponding fitting formulae for different redshifts. We demonstrate that the major fraction of matter in high-density fields is associated with galaxy groups. Since current X-ray surveys are able to nearly recover the universal baryon fraction within groups, our results indicate that the major part of the so-far undetected warm-hot intergalactic medium resides in low-density regions at low temperatures. Similarly, we show that the differences in galaxy mass functions with environment seen in observed and simulated data stem predominantly from differences in the mass distribution of halos. In particular, the hump in the galaxy mass function is associated with the central group galaxies, and the bimodality observed in the galaxy mass function is therefore interpreted as that of central galaxies versus satellites.
description: aligned with version published in ApJ
Mini-Workshop: Relativistic Fluids at the Intersection of Mathematics and Physics (online meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2020
Subjects: subject: Konferenzschrift
subject: 510

description: Relativistic Hydrodynamics is the description of fluid motion in regimes where relativistic effects are important. This is the case for fluids moving at high velocities or interacting with very strong gravitational fields, such as in the physics of black hole accretion disks or neutron star mergers but also in the microscopic dynamics of high-energy heavy-ion collisions. Although the first formulation of hydrodynamic equations dates back to the beginning stages of relativity theory, many mathematical problems remain wide open. In particular, the development of the theory of relativistic "viscous" fluids was slow and mathematical progress only made recently. The purpose of this Mini-Workshop was to bring together a diverse group of researchers, including specialists in nonlinear PDEs and physicists, to jump-start the mathematical development of this field. This allowed for a vital exchange of ideas between mathematics and physics communities.
Predicting Geothermal Heat Flow in Antarctica With a Machine Learning Approach
Creators: name: Lösing, M.
name: Ebbing, J.
Publisher: name: FID GEO
Year: 2021

description: We present a machine learning approach to statistically derive geothermal heat flow (GHF) for Antarctica. The adopted approach estimates GHF from multiple geophysical and geological data sets, assuming that GHF is substantially related to the geodynamic setting of the plates. We apply a Gradient Boosted Regression Tree algorithm to find an optimal prediction model relating GHF to the observables. The geophysical and geological features are primarily global data sets, which are often unreliable in polar regions due to limited data coverage. Quality and reliability of the data sets are reviewed and discussed in line with the estimated GHF model. Predictions for Australia, where an extensive database of GHF measurements exists, demonstrate the validity of the approach. In Antarctica, only a sparse number of direct GHF measurements are available. Therefore, we explore the use of regional data sets of Antarctica and its tectonic Gondwana neighbors to refine the predictions. With this, we demonstrate the need for adding reliable data to the machine learning approach. Finally, we present a new geothermal heat flow map, which exhibits intermediate values compared to previous models, ranging from 35 to 156 mW/m2, and visible connections to the conjugate margins in Australia, Africa, and India.
description: Plain Language Summary: The heat energy transferred from the Earth's interior to the surface (geothermal heat flow) can substantially affect the dynamics of an overlying ice sheet. It can lead to melting at the base and hence, decouple the ice sheet from the bedrock. In Antarctica, this parameter is poorly constrained, and only a sparse number of thermal gradient measurements exist. Indirect methods, therefore, try to estimate the continental Antarctic heat flow. Here, we use a machine learning approach to combine multiple information on geology, tectonic setting, and heat flow measurements from all continents to predict Antarctic values. We further show that using reliable data is crucial for the resulting prediction and a mindful choice of features is recommendable. The final result exhibits values within the range of previously proposed heat flow maps and shows local similarities to the continents once connected to East Antarctica within the supercontinent Gondwana. We suggest a minimum and maximum heat flow map, which can be used as input for ice sheet modeling and sea level rise predictions.
description: Key Points: A new geothermal heat flow map of Antarctica is established by adopting a machine learning approach. Input features include both global and regional geological and tectonic information, and heat flow observations. A Gondwana reconstruction shows connections of heat flow at the conjugate margins of East Antarctica.
description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
On the nature of faint Low Surface Brightness galaxies in the Coma cluster
Creators: name: Adami, C.
name: Pello, R.
name: Ulmer, M. P.
name: Cuillandre, J. C.
name: Durret, F.
name: Mazure, A.
name: Picat, J. P.
name: Scheidegger, R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: This project is the continuation of our study of faint Low Surface Brightness Galaxies (fLSBs) in one of the densest nearby galaxy regions known, the Coma cluster. Our goal is to improve our understanding of the nature of these objects by comparing the broad band spectral energy distribution with population synthesis models. The data were obtained with the MEGACAM and CFH12K cameras at the CFHT. We used the resulting photometry in 5 broad band filters (u*, B, V, R, and I), that included new u*-band data, to fit spectral models. With these spectral fits we inferred a cluster membership criterium, as well as the ages, dust extinctions, and photometric types of these fLSBs. We show that about half of the Coma cluster fLSBs have a spectral energy distribution well represented in our template library while the other half present a flux deficit at ultraviolet wavelengths. Among the well represented, ~80% are probably part of the Coma cluster based on their spectral energy distribution. They are relatively young (younger than 2.3 Gyrs for 90% of the sample) non-starburst objects. The later their type, the younger fLSBs are. A significant part of the fLSBs are quite dusty objects. fLSBs are low stellar mass objects (the later their type the less massive they are), with stellar masses comparable to globular clusters for the faintest ones. Their characteristics are correlated with infall directions, confirming the disruptive origin for part of them.
description: Accepted for publication in A&A, 10 pages, 10 figures
Dynamics of Waves and Patterns (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: The dynamics of waves and patterns play a significant role in the sciences, especially in fluid mechanics, material science, neuroscience and ecology. The mathematical treatment interconnects several areas, ranging from evolution equations and functional analysis to dynamical systems, geometry, topology, and stochastic as well as numerical analysis. This workshop has specifically focussed on dynamic stability on extended domains, bifurcations of waves and patterns, effects of stochastic driving, and spatio-temporal inhomogenities. During the workshop, multiple new directions, collaborations, and very interesting scientific conversations arose across the entire field.
Computational Group Theory (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: This was the eighth Oberwolfach Workshop on Computational Group Theory. It demonstrated how an increasing number and variety of deep theoretical results are being used to devise powerful and practical algorithms in Computational Group Theory. The talks also presented connections with and applications to Number Theory, Combinatorics, Geometry, and Geometric Group Theory.
Temporal and spatial changes in distribution and abundance of macro-zooplankton in a large British Columbia lake
Creators: name: Zyblut, Edward Ronald
Publisher: name: University of British Columbia
Year: 2011

description: Annual and seasonal changes in distribution and abundance of six species of macro-zooplankton (Cyclops bicuspidatus thomasi, Diaptomus ashlandi, Daphnia galeata mendotae, Diaph- anosoma leuchtenbergianum, Bosmina coregoni, and Mysxs relicta.) twgre studied in Kootenay Lake, a body of water extending over 105 km in southeastern British Columbia. Differences between two years, 1949 and 1964, were examined as well as changes in midsummer distribution and abundance between three consecutive years (1964 to 1966). Seasonal changes during one year and within a summer were also noted as well as diel changes in distribution and abundance. A large increase in zooplankton abundance occurred during the fifteen year period from 1949 to 1964, and this was attributed to an increased inflow of primary nutrients from a major tributary at the south end of the lake. A change in species composition, formerly dominated by Daphnia but now by Diaphanosoma, was related with eutrophication. Changes in food availability due to eutoophication, competition for food with Mysis relicta, and heavy predation by kokanee (Oncorhynchus nerka), were examined as factors possibly responsible for changes in the spatial distribution of Daphnia since 1949. Differences in the midsummer zooplankton distribution and abundance between three consecutive years (1964 to 1966) were minor, suggesting that the changes noted between 1949 and 1964 were attributable to large changes in limnological conditions and not merely the result of annual fluctuations. Examination of seasonal trends in zooplankton distribution and abundance indicated that zooplankton, with the exception of Mysis relicta, were most abundant during the summer. Mysids were most abundant in May when the young mysids were released from the brood pouch. Spatial differences in summer zooplankton abundance was examined in relation to wind-driven currents, and food availability. Spatial differences during the rest of the year were minor, possibly a result of similar limnological conditions at all stations then. Abundance of Mysis relicta was greatest in the north arm of the lake, whereas all other species were most abundant in the central area of the lake. Changes that occurred within the summer were largely due to high turbidity in the south arm during June and July. Diel changes in the vertical distribution of zooplankton, with the exception of Mysis relicta, were not detected.
A wide angle view of the Sagittarius dwarf Spheroidal Galaxy. I: VIMOS photometry and radial velocities across Sgr dSph major and minor axis
Creators: name: Giuffrida, G.
name: Sbordone, L.
name: Zaggia, S.
name: Marconi, G.
name: Bonifacio, P.
name: Izzo, C.
name: Szeifert, T.
name: Buonanno, R.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Sagittarius dwarf Spheroidal Galaxy (Sgr dSph) provides us with a unique possibility of studying a dwarf galaxy merging event while still in progress. Due to its low distance (25 kpc), the main body of Sgr dSph covers a vast area in the sky (roughly 15 x 7 degrees). Available photometric and spectroscopic studies have concentrated either on the central part of the galaxy or on the stellar stream, but the overwhelming majority of the galaxy body has never been probed. The aim of the present study is twofold. On the one hand, to produce color magnitude diagrams across the extension of Sgr dSph to study its stellar populations, searching for age and/or composition gradients (or lack thereof). On the other hand, to derive spectroscopic low-resolution radial velocities for a subsample of stars to determine membership to Sgr dSph for the purpose of high resolution spectroscopic follow-up. We used VIMOS-VLT to produce V and I photometry and spectroscopy on 7 fields across the Sgr dSph minor and major axis, plus 3 more centered on the associated globular clusters Terzan 7, Terzan 8 and Arp 2. A last field has been centered on M 54, lying in the center of Sgr dSph. We present photometry for 320,000 stars across the main body of Sgr dSph, one of the richest, and safely the most wide-angle sampling ever produced for this fundamental object. We also provide robust memberships for more than one hundred stars, whose high resolution spectroscopic analysis will be the object of forthcoming papers. Sgr dSph appears remarkably uniform among the observed fields. We confirm the presence of a main Sgr dSph population characterized roughly by the same metallicity of 47 Tuc, but we also found the presence of multiple populations on the peripheral fields of the galaxy, with a metallicity spanning from [Fe/H]=-2.3 to a nearly solar value.
description: 10 pages, 12 figures, accepted for publication in A&A
Data‐Driven Medium‐Range Weather Prediction With a Resnet Pretrained on Climate Simulations: A New Model for WeatherBench
Creators: name: Rasp, Stephan
name: Thuerey, Nils
Publisher: name: FID GEO
Year: 2021

description: Numerical weather prediction has traditionally been based on the models that discretize the dynamical and physical equations of the atmosphere. Recently, however, the rise of deep learning has created increased interest in purely data‐driven medium‐range weather forecasting with first studies exploring the feasibility of such an approach. To accelerate progress in this area, the WeatherBench benchmark challenge was defined. Here, we train a deep residual convolutional neural network (Resnet) to predict geopotential, temperature and precipitation at 5.625° resolution up to 5 days ahead. To avoid overfitting and improve forecast skill, we pretrain the model using historical climate model output before fine‐tuning on reanalysis data. The resulting forecasts outperform previous submissions to WeatherBench and are comparable in skill to a physical baseline at similar resolution. We also analyze how the neural network creates its predictions and find that, for the case studies analyzed, the model has learned physically reasonable correlations. Finally, we perform scaling experiments to estimate the potential skill of data‐driven approaches at higher resolutions.
description: Plain Language Summary: Weather forecasts are created by running hugely complex computer simulations that encapsulate our knowledge of how the atmosphere works. This approach has served us well but is there a different way? The paradigm of machine learning proposes learning an algorithm from data rather than building it from physical principles. For several areas like computer vision and natural language processing this has worked exceedingly well, so it just makes sense to try it as well for weather forecasting. This paper presents the latest attempt at training a machine learning weather forecasting model. It is shown that the learned model produces reasonable forecasts, approximately on par with traditional models run on much lower resolution. However, there is still a large gap to current state–of–the–art high–resolution weather models that is unlikely to be closed with a purely data–driven approach because not enough training data exists.
description: Key Points: A large convolutional neural network is trained for the WeatherBench challenge. Pretraining on climate model data improves skill and prevents overfitting. The model sets a new state‐of‐the‐art for data‐driven medium‐range forecasting.
description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
Automorphic Forms, Geometry and Arithmetic (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: The workshop on automorphic forms, geometry and arithmetic focused on important recent developments within the research area, in particular, on the different recent approaches towards the Langlands functoriality principle and the Langlands correspondence, on their relative analogues, and on the relations between those advances and more arithmetic questions.
Quantum light in the turbulent atmosphere
Creators: name: Semenov, A. A.
name: Vogel, W.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Nonclassical properties of light propagating through the turbulent atmosphere are studied. We demonstrate by numerical simulation that the probability distribution of the transmission coefficient, which characterizes the effects of the atmosphere on the quantum state of light, can be reconstructed by homodyne detection. Nonclassical photon-statistics and, more generally, nonclassical Glauber-Sudarshan functions appear to be more robust against turbulence for weak light fields rather than for bright ones.
description: 4 pages, 3 figures; published version
Detecting Majorana bound states
Creators: name: Benjamin, Colin
name: Pachos, Jiannis K.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We propose a set of interferometric methods on how to detect Majorana bound states induced by a topological insulator. The existence of these states can be easily determined by the conductance oscillations as function of magnetic flux and/or electric voltage. We study the system in the presence and absence of Majorana bound states and observe strikingly different behaviors. Importantly, we show that the presence of coupled Majorana bound states can induce a persistent current in absence of any external magnetic field.
description: 7 pages, 6 figures, 1 table, revised and expanded, accepted for publication in Phys. Rev. B
Of things dark and distant : mythic unknowing through installation practice
Creators: name: Waller, PH
Publisher: name: University Of Tasmania
Year: 2023

description: This research investigates the perceptual and imaginative implications of my practice of interior air-drawn sculpture gardens. Neurologists, psychologists and philosophers suggest that we can only ever know the world by way of imagination and illusion ‚Äö- whether it's the illusion that the world is full of sprites and spirits, or that we know what the world is through accumulated 'facts' about it. But some illusions are more life-sustaining than others. I refer in the writing to Iain McGilchrist and David Abram who share a concern that the kinds of illusions we have inherited in the West may be responsible for a growing alienation between ourselves and the mysterious more-than-human world, with potentially devastating consequences. So my project has been an effort to take an ostensibly formalist arrangement and nudge it a little beyond the limitations of such language structures, to suggest that nothing is ever nothing but- but always more than our assumptions about it. The work is thus in pursuit of an open-endedness and a subtle unworldliness. These up-in-the-air installation-compositions rely on out-of-consciousness manoeuvres, degrees of unknowing and cohesive ambiguity, rather than utter bewilderment, for their effects. To this end I find help from the Ryoan-ji stone garden in Kyoto, the architecture of Carlo Scarpa, the writings of Rudolph Arnhiem and others on perceptual psychology, and the spatial theories of Edward T. Hall and Yi Fu Tuan. Underneath all these sources lies the stabilising influence of composer Arvo P‚àö¬ßrt and his careful, methodical approach to a music of resolute harmony and austerity. P‚àö¬ßrt's practice suggests that a work need not be chaotic or challenging, indeed may have deep structure, and still engage and transport. For P‚àö¬ßrt musical notes have cosmological implications, which for the purposes of my project needn't be over specified, but here help identify my effort as one not of nonsense or nihilism, but of mythical strangeness and poetic unknowing. The exegesis should not be thought of as a necessary companion to the artwork, any more than compositional analysis should be thought necessary for musical appreciation. The writing spells out what should, if I have played my hand right, occur prior to or underneath words in the experience of the installation.
Quantifying Tectonic and Glacial Controls on Topography in the Patagonian Andes (46.5°S) From Integrated Thermochronometry and Thermo‐Kinematic Modeling
Creators: name: Andrić‐Tomašević, Nevena
name: Falkowski, Sarah
name: Georgieva, Viktoria
name: Glotzbach, Christoph
name: Strecker, Manfred R.
name: Ehlers, Todd A.
Publisher: name: FID GEO
Year: 2021

description: The Patagonian Andes have been used to illustrate the dependency of major topographic changes in response to glacial erosion processes dominating over tectonic deformation and uplift. Here, we investigate tectonic and glacial contributors to the erosion history and evolution of topography in the Patagonian Andes at 46.5°S. We present 33 new apatite and zircon (U‐Th)/He (AHe and ZHe, respectively) and fission track (AFT and ZFT, respectively) ages integrated with 46 previously published bedrock thermochronometric ages in a 3D thermo‐kinematic model. Observed thermochronometer ages increase from the eastern flank of the topographic crest of the orogen toward the eastern retro‐foreland basin (from AFT 4–10 Ma, ZHe 4–12 Ma, ZFT 6–14 Ma to AFT 28–32 Ma, ZHe 68–117 Ma). Thermo‐kinematic modeling indicates that spatial gradients in thermochronometric ages can be explained by an up to 100‐km‐wide, parabolic‐shaped pattern in exhumation rates with a maximum rate of 0.5 mm/yr from 15 Ma until the onset of glaciation at ∼7 Ma. Furthermore, model results suggest that the youngest AHe ages require a localized acceleration in erosion from ∼0.5 mm/yr to ∼2.2 mm/yr starting between ∼5 and ∼3 Ma, coeval with intensified glaciation and subduction of the Chile Rise. Our results suggest that the long‐wavelength (∼100 km) topography and erosion patterns are likely controlled by rock uplift above mid‐crustal ramp(s) and subsequent transpression along the Liquiñe‐Ofqui Fault. Superposed on these tectonic processes, Late Cenozoic glaciation resulted in localized and accelerated erosion over wavelengths of <20 km.
description: Key Points: Low‐temperature thermochronology records non‐uniform erosion in the retro‐wedge of the Southern Patagonian Andes. Erosion pattern and long‐wavelength topography are largely a function of regional tectonic activity over the last 15 Myr. Glaciation has modified erosion rates and topography on sub‐valley scales over the last 5–3 Myr.
description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
description: MINEDUC | CONICYT | Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) http://dx.doi.org/10.13039/501100002850
Study of the Large-scale Temperature Structure of the Perseus Cluster with Suzaku
Creators: name: Nishino, Sho
name: Fukazawa, Yasushi
name: Hayashi, Katsuhiro
name: Nakazawa, Kazuhiro
name: Tanaka, Takaaki
Publisher: name: arXiv
Year: 2010
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report on a study of the large-scale temperature structure of the Perseus cluster with Suzaku, using the observational data of four pointings of 30' offset regions, together with the data from the central region. Thanks to the Hard X-ray Detector (HXD-PIN: 10 - 60 keV), Suzaku can determine the temperature of hot galaxy clusters. We performed the spectral analysis, by considering the temperature structure and the collimator response of the PIN correctly. As a result, we found that the upper limit of the temperature in the outer region is $\sim$ 14 keV, and an extremely hot gas, which was reported for RXJ 1347.5-1145 and A 3667, was not found in the Perseus cluster. This indicates that the Perseus cluster has not recently experienced a major merger.
description: 17 pages, 25 figures, accepted for Publications of the Astronomical Society of Japan, references added
The use of illegal guns: security implications for Papua New Guinea
Creators: name: Singirok, Jerry
Publisher: name: Canberra, ACT: State, Society and Governance in Melanesia (SSGM) Program, Research School of Pacific and Asian Studies, The Australian National University
Year: 2005
Subjects: governance
conflict
Papua New Guinea

description: "The use of illegal guns in Papua New Guinea is of growing concern, with broad ranging social and economic impacts. In the following paper, Major General Jerry Singirok explores the dimensions of illegal gun use in Papua New Guinea, examining patterns of gun use, sources of guns and firearms administration and control. Drawing upon a variety of sources, including personal experience, Singirok calls for a collaborative approach to gun control between state and society." - page 1
The effect of diethylstilbestrol implants and ration protein/energy ratios on the water requirements of growing sheep
Creators: name: Thompson, Ann Bernice
Publisher: name: University of British Columbia
Year: 2011

description: The feeding of 1 mcg. diethylstilbestrol (DES) per g. dry matter of feed to mature intact and castrated or ovariectomized male and female Wistar strain rats indicated that hormone treatment tends to reduce the water requirements of rats. Implantation of 3 mg., 6 mg., and 9 mg. DES in growing wether lambs did not affect the relationship of total water intake to dry matter intake, gross energy intake, apparent digestible energy, nitrogen intake, apparent digestible nitrogen and nitrogen retention. Feeding of rations of differing protein level, gross energy content, and protein to calorie ratios, did not alter the ratios of total water intake to dry matter intake, apparent digestible energy, nitrogen intake, apparent digestible nitrogen and nitrogen retention in growing wether lambs.
Comment on "Entanglement on Demand through Time Reordering"
Creators: name: Pathak, P. K.
name: Hughes, S.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In a recent Letter [Phys. Rev. Lett. {\bf 100}, 120501 (2008)], Avron {\em et al.} discuss a time reordering scheme to achieve efficient "across-generation" of entangled photon pairs in a semiconductor quantum dot with a suppressed biexciton binding energy. They demonstrate that the scheme can be implemented using time delay between the generated photons. In this Comment, we derive an exact expression for the concurrence of the time delayed photons, and show that the predicted values by Avron {\em et al.} are not achievable, which stems from an approximation used in their approximate theoretical analysis.
description: small comment paper
Spatial Networks and Percolation (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: The classical percolation problem is to find whether there is an infinite connected component in a random set created by removing edges from a $d$-dimensional lattice, independently at random. Since its introduction into the mathematical literature by Broadbent and Hammersley (1957) the subject of percolation has developed in many ways and is now one of the most exciting and active research areas in probability and statistical mechanics. In this workshop, we focused on current trends, including percolation on point sets with correlations, on spatial random graphs and networks with scale-free degree distribution or long-range edge distribution, percolation of random sets like level set of Gaussian fields or the vacant set of interlacements, conformally invariant percolation structures in the plane, and random walks or information diffusion on percolation clusters. The workshop brought together more than sixty experts and promising young researchers from probability, statistical mechanics and computer science working on all aspects of percolation and spatial networks for an unprecedented exchange of new ideas and methods, with outstanding high quality online talks.
Mathematical Aspects of General Relativity (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: General relativity is an area that naturally combines differential geometry, partial differential equations, global analysis and dynamical systems with astrophysics, cosmology, high energy physics, and numerical analysis. It is rapidly expanding and has witnessed remarkable developments in recent years.
Lattice QCD Thermodynamics on the Grid
Creators: name: Mościcki, Jakub T.
name: Woś, Maciej
name: Lamanna, Massimo
name: de Forcrand, Philippe
name: Philipsen, Owe
Publisher: name: arXiv
Year: 2009
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: We describe how we have used simultaneously ${\cal O}(10^3)$ nodes of the EGEE Grid, accumulating ca. 300 CPU-years in 2-3 months, to determine an important property of Quantum Chromodynamics. We explain how Grid resources were exploited efficiently and with ease, using user-level overlay based on Ganga and DIANE tools above standard Grid software stack. Application-specific scheduling and resource selection based on simple but powerful heuristics allowed to improve efficiency of the processing to obtain desired scientific results by a specified deadline. This is also a demonstration of combined use of supercomputers, to calculate the initial state of the QCD system, and Grids, to perform the subsequent massively distributed simulations. The QCD simulation was performed on a $16^3\times 4$ lattice. Keeping the strange quark mass at its physical value, we reduced the masses of the up and down quarks until, under an increase of temperature, the system underwent a second-order phase transition to a quark-gluon plasma. Then we measured the response of this system to an increase in the quark density. We find that the transition is smoothened rather than sharpened. If confirmed on a finer lattice, this finding makes it unlikely for ongoing experimental searches to find a QCD critical point at small chemical potential.
The Geomagnetic Kp Index and Derived Indices of Geomagnetic Activity
Creators: name: Matzka, J.
name: Stolle, C.
name: Yamazaki, Y.
name: Bronkalla, O.
name: Morschhauser, A.
Publisher: name: FID GEO
Year: 2021

description: The geomagnetic Kp index is one of the most extensively used indices of geomagnetic activity, both for scientific and operational purposes. This article reviews the properties of the Kp index and provides a reference for users of the Kp index and associated data products as derived and distributed by the GFZ German Research Centre for Geosciences. The near real‐time production of the nowcast Kp index is of particular interest for space weather services and here we describe and evaluate its current setup.
description: Key Points: Production and distribution of nowcast and definitive Kp index and derived products. Kp is estimated to have decreased from 1932 to 2020 by one third of a unit due to geomagnetic secular variation. Improved agreement between nowcast and definitive Kp since August 2020.
Renormalization group analysis of competing orders and the pairing symmetry in Fe-based superconductors
Creators: name: Chubukov, A. V.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We analyze antiferromagnetism and superconductivity in novel Fe-based superconductors within the weak-coupling, itinerant model of electron and hole pockets near (0,0) and (π,π) in the folded Brillouin zone. We discuss the interaction Hamiltonian, the nesting, the RG flow of the couplings at energies above and below the Fermi energy, and the interplay between SDW magnetism, superconductivity and charge orbital order. We argue that SDW antiferromagnetism wins at zero doping but looses to superconductivity upon doping. We show that the most likely symmetry of the superconducting gap is A_{1g} in the folded zone. This gap has no nodes on the Fermi surface but changes sign between hole and electron pockets. We also argue that at weak coupling, this pairing predominantly comes not from a spin fluctuation exchange but from a direct pair hopping between hole and electron pockets.
description: A review on RG approach for the special issue of Physica C on Fe-based superconductors. 15 pp, 8 figures
Small Collaboration: Advanced Numerical Methods for Nonlinear Hyperbolic Balance Laws and Their Applications (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: This small collaborative workshop brought together experts from the Sino-German project working in the field of advanced numerical methods for hyperbolic balance laws. These are particularly important for compressible fluid flows and related systems of equations. The investigated numerical methods were finite volume/finite difference, discontinuous Galerkin methods, and kinetic-type schemes. We have discussed challenging open mathematical research problems in this field, such as multidimensional shock waves, interfaces with different phases or efficient and problem suited adaptive algorithms. Consequently, our main objective was to discuss novel high-order accurate schemes that reliably approximate underlying physical models and preserve important physically relevant properties. Theoretical questions concerning the convergence of numerical methods and proper solution concepts were addressed as well.
Role of ATP-hydrolysis in the dynamics of a single actin filament
Creators: name: Ranjith, Padinhateeri
name: Mallick, Kirone
name: Joanny, Jean-Francois
name: Lacoste, David
Publisher: name: arXiv
Year: 2009
Subjects: subject: Biomolecules (q-bio.BM)
subject: Subcellular Processes (q-bio.SC)
subject: FOS: Biological sciences

description: We study the stochastic dynamics of growth and shrinkage of single actin filaments taking into account insertion, removal, and ATP hydrolysis of subunits either according to the vectorial mechanism or to the random mechanism. In a previous work, we developed a model for a single actin or microtubule filament where hydrolysis occurred according to the vectorial mechanism: the filament could grow only from one end, and was in contact with a reservoir of monomers. Here we extend this approach in several ways, by including the dynamics of both ends and by comparing two possible mechanisms of ATP hydrolysis. Our emphasis is mainly on two possible limiting models for the mechanism of hydrolysis within a single filament, namely the vectorial or the random model. We propose a set of experiments to test the nature of the precise mechanism of hydrolysis within actin filaments.
description: To appear in Biophysical Journal (2010)
Autocatalytic reaction-diffusion processes in restricted geometries
Creators: name: Agliari, E.
name: Burioni, R.
name: Cassi, D.
name: Neri, F. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the dynamics of a system made up of particles of two different species undergoing irreversible quadratic autocatalytic reactions: $A + B \to 2A$. We especially focus on the reaction velocity and on the average time at which the system achieves its inert state. By means of both analytical and numerical methods, we are also able to highlight the role of topology in the temporal evolution of the system.
MATRIX-MFO Tandem Workshop: Invariants and Structures in Low-Dimensional Topology (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: The first ever MATRIX-MFO tandem workshop addressed several research questions in low-dimensional topology and related areas.
MFO-RIMS Tandem Workshop: Symmetries on Polynomial Ideals and Varieties (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: The study of symmetry as a structural property of algebraic objects is one of the fundamental pillows of the developments of modern mathematics, most prominently beginning with the work of Abel and Galois. The focus of the workshop was on permutation actions of the symmetric group on polynomial rings and algebraic and semi-algebraic sets. More concretely, it was centered around recent developments in the asymptotic setup of symmetric ideals in the polynomial ring in infinitely many variables.
Quantum Groups - Algebra, Analysis and Category Theory (hybrid meeting)
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2021
Subjects: subject: Konferenzschrift
subject: 510

description: The meeting was devoted to discussing the state of the art of different branches of tensor categories and quantum groups, with emphasis on the exchange of ideas between the purely algebraic and operator algebraic sides of these theories.
Controls on Asymmetric Rift Dynamics: Numerical Modeling of Strain Localization and Fault Evolution in the Kenya Rift
Creators: name: Richter, Maximilian J. E. A.
name: Brune, Sascha
name: Riedl, Simon
name: Glerum, Anne
name: Neuharth, Derek
name: Strecker, Manfred R.
Publisher: name: FID GEO
Year: 2021

description: Complex, time‐dependent, and asymmetric rift geometries are observed throughout the East African Rift System (EARS) and are well documented, for instance, in the Kenya Rift. To unravel asymmetric rifting processes in this region, we conduct 2D geodynamic models. We use the finite element software ASPECT employing visco‐plastic rheologies, mesh‐refinement, distributed random noise seeding, and a free surface. In contrast to many previous numerical modeling studies that aimed at understanding final rifted margin symmetry, we explicitly focus on initial rifting stages to assess geodynamic controls on strain localization and fault evolution. We thereby link to geological and geophysical observations from the Southern and Central Kenya Rift. Our models suggest a three‐stage early rift evolution that dynamically bridges previously inferred fault‐configuration phases of the eastern EARS branch: (1) accommodation of initial strain localization by a single border fault and flexure of the hanging‐wall crust, (2) faulting in the hanging‐wall and increasing upper‐crustal faulting in the rift‐basin center, and (3) loss of pronounced early stage asymmetry prior to basinward localization of deformation. This evolution may provide a template for understanding early extensional faulting in other branches of the East African Rift and in asymmetric rifts worldwide. By modifying the initial random noise distribution that approximates small‐scale tectonic inheritance, we show that a spectrum of first‐order fault configurations with variable symmetry can be produced in models with an otherwise identical setup. This approach sheds new light on along‐strike rift variability controls in active asymmetric rifts and proximal rifted margins.
description: Key Points: 2D numerical models elucidate evolution of asymmetric Kenya Rift segments. Intrabasinal faulting is caused by bending of the central block and does not reach the brittle‐ductile transition. Small‐scale crustal inheritance can exert decisive control on first‐order rift architecture.
description: Helmholtz Young Ivestigators Group
description: National Science Foundation
All-sky search for gravitational-wave bursts in the first joint LIGO-GEO-Virgo run
Creators: name: The LIGO Scientific Collaboration
name: The Virgo Collaboration
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present results from an all-sky search for unmodeled gravitational-wave bursts in the data collected by the LIGO, GEO 600 and Virgo detectors between November 2006 and October 2007. The search is performed by three different analysis algorithms over the frequency band 50-6000 Hz. Data are analyzed for times with at least two of the four LIGO-Virgo detectors in coincident operation, with a total live time of 266 days. No events produced by the search algorithms survive the selection cuts. We set a frequentist upper limit on the rate of gravitational-wave bursts impinging on our network of detectors. When combined with the previous LIGO search of the data collected between November 2005 and November 2006, the upper limit on the rate of detectable gravitational-wave bursts in the 64-2048 Hz band is 2.0 events per year at 90% confidence. We also present event rate versus strength exclusion plots for several types of plausible burst waveforms. The sensitivity of the combined search is expressed in terms of the root-sum-squared strain amplitude for a variety of simulated waveforms and lies in the range 6x10^-22 1/sqrt(Hz) to 2x10^-20 1/sqrt(Hz). This is the first untriggered burst search to use data from the LIGO and Virgo detectors together, and the most sensitive untriggered burst search performed so far.
description: 20 pages, 9 figures, 8 tables; submitted to Phys. Rev. D
Some evolutionary and ecological implications of colour variation in the sea urchin Heliocidaris erythrogramma
Creators: name: Growns, J
Publisher: name: University Of Tasmania
Year: 2023

description: An investigation into the evolutionary and ecological implications of variation in the external colouration of the sea urchin Hefiocidaris erythrogramma was made. Two different pigment systems create a complex polymorphism; red granules of echlnochrome A in the dermis occur in varying densities, and purple and green naphthoquinone pigments are found in the calcareous test and spines. Many morphs may occur within one population, but the proportions of morphs vary markedly between sites. Evidence from the observed variability and chemistry of the pigments strongly indicates that the variation has a genetic basis. Breeding studies which would have resolved this question were unsuccessful, but did show that all crosses between morphs developed and metamorph osed successfully. Repeated sampling of 15 sites showed that morph proportions were stable at most sites ove r the 35 months of the study. Geographic variationin the proportions of morphs was determined from samples from 49 sites. Environmental variables were recorded and the exposure of each site to wave action was estimated using algal communities to develop an Algal Exposure Index (A.E.I.). Stepwise linear regressi on analysis indicated that the A.E.I. and amount of algal cover were the only environmental factors noted that were useful predictors dermis colour proportions. Five hypotheses were developed (two selective and three stochastic) of processes which might be affecting morph proportions in the study area; these were tested using Mantel's non-para metric test. The results suggest that fou r geograph ical regions each ¬¨‚àëhave different patterns of morph distribution which are controlled by unique combinations of selection (related to exposure) and gene flow. These results are generally supported by what is known of water currents in each region, as most gene flow in H. erythrogramma will occur due t o movement of pelagic larvae. Morphological data showed slight differences between urchins of different dermis colour at one site, but no differences between urchins with different coloured spines. Th ere were significant differences between urchins at different sites. Surveys of urchin microha bitats indicated that (I) urchins of the same derm is colour tend to occur next to each other, (2) white dermis urchins tend to occur under rocks more often than red dermis urchins, and (3) urch ins which are hidden under rocks tend to 'cover' wit h pieces of shell, algae or pebbles to a lesser extent than urchins which occur on the upper surfaces of rocks. A laboratory experi ment indicated that, although the podia (tu be feet) of red and white dermis urchins were initially of compara ble strength, red dermis urchins tended to tire more quickly. No diff erences between morphs were fo und in the time of matu ration of gonads or the size of gonads re lative to body weight.
Induced gravitational wave background and primordial black holes
Creators: name: Bugaev, Edgar
name: Klimai, Peter
Publisher: name: arXiv
Year: 2009
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We calculate the frequency dependence of gravitational wave background arising at second order of cosmological perturbation theory due to mixing of tensor and scalar modes. The calculation of the induced gravitational background is performed for two special cases: for the power spectrum of scalar perturbations which has a peak at some scale and for the scalar spectrum predicted by the inflationary model with the running mass potential. We show that the amplitudes of the induced gravitational background, in the frequency region $\sim 10^{-3} - 10^3 $Hz, are effectively constrained by results of studies of primordial black hole production in early universe. We argue that though today's LIGO bound on ${\cal P}_{\cal R}(k)$ is weaker than the PBH one, Advanced LIGO will be able to set a stronger bound, and in future the ground-based interferometers of LIGO type will be suitable for obtaining constraints on PBH number density in the mass range $\sim 10^{11} - 10^{15}$ g.
description: v2: 14 pages, 7 figures; revised version of the manuscript, accepted for publication in Phys. Rev. D
AstroSim: Collaborative Visualization of an Astrophysics Simulation in Second Life
Creators: name: Nakasone, Arturo
name: Prendinger, Helmut
name: Holland, Simon
name: Hut, Piet
name: Makino, Jun
name: Miura, Kenichi
Publisher: name: arXiv
Year: 2009
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We introduce AstroSim, a Second Life based prototype application for synchronous collaborative visualization targeted at astronomers.
description: For more information about AstroSim, visit: http://www.prendingerlab.net/globallab/?page_id=17. You can download the source code of the project at: http://sourceforge.net/projects/astrosim