cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Size effects in the toughening of brittle materials by heterogeneities: a non-linear analysis of front deformations
Creators: name: Lebihain, Mathias
name: Vasoya, Manish
name: Lazarus, Véronique
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Traditional computational approaches in simulating crack propagation in perfectly brittle materials rely on the estimate of stress intensity factors along the rupture front. This proves highly challenging in 3D when the crack geometry departs from very specific cases for which analytical solutions are available, like e.g. the penny-shaped crack geometry. Here, we extend the first-order theory of Gao and Rice (1987), and predict the distribution of the mode I stress intensity factor $K_\mathrm{I}$ along the front of a tensile coplanar crack that is slightly perturbed from a reference penny-shaped configuration, up to second order in the perturbation amplitude. Our theory is validated against analytical solutions available for embedded elliptical cracks, and its range of validity is further assessed using numerical simulations performed on cosine front perturbations of varying mode and amplitude. It is then used to develop a homogenization framework for the toughness of weakly disordered media. The effective toughness and its fluctuations are bridged quantitatively to the intensity of the toughness fluctuations and their spatial structure. Our theoretical predictions are compared to the results of ~1 million simulations of crack propagation building on our second-order theory and Fast Fourier Transforms. We show that the impact of toughness heterogeneities is size-dependent, as they generally weaken the material when the crack size is lower or comparable to the typical heterogeneity size, but reinforces it otherwise. It results in an apparent R-curve behavior of the brittle composite at the macroscale.
A stable FSI algorithm for light rigid bodies in compressible flow
Creators: name: Banks, J. W.
name: Henshaw, W. D.
name: Sjogreen, B.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Numerical Analysis (math.NA)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this article we describe a stable partitioned algorithm that overcomes the added mass instability arising in fluid-structure interactions of light rigid bodies and inviscid compressible flow. The new algorithm is stable even for bodies with zero mass and zero moments of inertia. The approach is based on a local characteristic projection of the force on the rigid body and is a natural extension of the recently developed algorithm for coupling compressible flow and deformable bodies. Normal mode analysis is used to prove the stability of the approximation for a one-dimensional model problem and numerical computations confirm these results. In multiple space dimensions the approach naturally reveals the form of the added mass tensors in the equations governing the motion of the rigid body. These tensors, which depend on certain surface integrals of the fluid impedance, couple the translational and angular velocities of the body. Numerical results in two space dimensions, based on the use of moving overlapping grids and adaptive mesh refinement, demonstrate the behavior and efficacy of the new scheme. These results include the simulation of the difficult problem of a shock impacting an ellipse of zero mass.
description: 32 pages, 20 figures
Domain Adaptive Decision Trees: Implications for Accuracy and Fairness
Creators: name: Alvarez, Jose M.
name: Scott, Kristen M.
name: Ruggieri, Salvatore
name: Berendt, Bettina
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In uses of pre-trained machine learning models, it is a known issue that the target population in which the model is being deployed may not have been reflected in the source population with which the model was trained. This can result in a biased model when deployed, leading to a reduction in model performance. One risk is that, as the population changes, certain demographic groups will be under-served or otherwise disadvantaged by the model, even as they become more represented in the target population. The field of domain adaptation proposes techniques for a situation where label data for the target population does not exist, but some information about the target distribution does exist. In this paper we contribute to the domain adaptation literature by introducing domain-adaptive decision trees (DADT). We focus on decision trees given their growing popularity due to their interpretability and performance relative to other more complex models. With DADT we aim to improve the accuracy of models trained in a source domain (or training data) that differs from the target domain (or test data). We propose an in-processing step that adjusts the information gain split criterion with outside information corresponding to the distribution of the target population. We demonstrate DADT on real data and find that it improves accuracy over a standard decision tree when testing in a shifted target population. We also study the change in fairness under demographic parity and equal opportunity. Results show an improvement in fairness with the use of DADT.
description: *Both authors contributed equally to this work. Accepted at FAccT '23
Anomaly Detection in Time Series of Graphs using Fusion of Graph Invariants
Creators: name: Park, Youngser
name: Priebe, Carey E.
name: Youssef, Abdou
Publisher: name: arXiv
Year: 2012
Subjects: subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Given a time series of graphs G(t) = (V, E(t)), t = 1, 2, ..., where the fixed vertex set V represents "actors" and an edge between vertex u and vertex v at time t (uv \in E(t)) represents the existence of a communications event between actors u and v during the tth time period, we wish to detect anomalies and/or change points. We consider a collection of graph features, or invariants, and demonstrate that adaptive fusion provides superior inferential efficacy compared to naive equal weighting for a certain class of anomaly detection problems. Simulation results using a latent process model for time series of graphs, as well as illustrative experimental results for a time series of graphs derived from the Enron email data, show that a fusion statistic can provide superior inference compared to individual invariants alone. These results also demonstrate that an adaptive weighting scheme for fusion of invariants performs better than naive equal weighting.
Inhalt
Creators: name: Redaktion, Die
Publisher: name: Funde und Ausgrabungen im Bezirk Trier
Year: 2019

description: -
description: Funde und Ausgrabungen im Bezirk Trier, Bd. 47 (2015): Funde und Ausgrabungen im Bezirk Trier : Aus der Arbeit des Rheinischen Landesmuseums Trier
Vivien G. Swan, The Pottery Kilns of Roman Britain
Creators: name: Czysz, Wolfgang
Publisher: name: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts
Year: 2019

description: Rezension zu: Vivien G. Swan, The Pottery Kilns of Roman Britain. Royal Commission on Historical Monuments, Supplementary Series: 5. Her Majesty’s Stationery Office, London 1984. ISBN 0-11-701203-3. 179 Seiten, 46 Tafeln, 23 Abbildungen, 18 Karten und 6 Mikrofiches.
description: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts, Bd. 66 Nr. 1 (1988)
Diagonalizing matrices over AW*-algebras
Creators: name: Heunen, Chris
name: Reyes, Manuel L.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L05, 46L10

description: Every commuting set of normal matrices with entries in an AW*-algebra can be simultaneously diagonalized. To establish this, a dimension theory for properly infinite projections in AW*-algebras is developed. As a consequence, passing to matrix rings is a functor on the category of AW*-algebras.
description: 24 pages. Comments very welcome!
On the Origin of the Balmer and Lyman Emission Lines
Creators: name: Stellmacher, G.
name: Wiehr, E.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We show how the observed hydrogen Balmer and Lyman emission lines constrain the modeling of quiescent solar prominences. We compare space observations of Lyman lines with ground-based observations of Balmer lines for quiescent solar prominences of comparable brightness defined by their H-beta emission. The effective number densities of hydrogen atoms emitting from the same upper level u deduced from the corresponding emerging Lyman and Balmer line emissions show large differences that diminish with increasing level number and converge at the highest level numbers. Hydrogen atoms excited in u=5 contribute 250 times less, and those in u=8 still contribute 65 times less to the Lyman than to the corresponding Balmer emission, supporting the idea of distinct spatial origin of the emissions of both series. This is also indicated by the line widths. The high optical thickness of all Lyman members allows the brightness temperature T_b to be estimated from the spectral radiance at line center, where T_b is found to be largely independent of the upper level number, in contrast to the (known) behavior of the Balmer lines.
description: 4 pages, 2 figures, one table
Mesoplodon stejnegeri True 1885
Creators: name: Honacki, James H.
name: Kinman, Kenneth E.
name: Koeppl, James W.
Publisher: name: Zenodo
Year: 1982
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Cetacea
Ziphiidae
Mesoplodon
Mesoplodon stejnegeri

description: Mesoplodon stejnegeri True, 1885. Proc. U.S. Nat. Mus., 8:585. TYPE LOCALITY: U.S. S. R., Commander Isis., Bering Isl. DISTRIBUTION: North Pacific, cold temperate to subarctic waters. PROTECTED STATUS: CITES - Appendix II as Order Cetacea. ISIS NUMBER: 5301411005004011001.
description: Published as part of James H. Honacki, Kenneth E. Kinman & James W. Koeppl, 1982, Order Cetacea, pp. 290-304 in Mammal Species of the World (1 st Edition), Lawrence, Kansas, USA :Alien Press, Inc. & The Association of Systematics Collections on page 301, DOI: 10.5281/zenodo.7352983
Investigation of Monte Carlo Uncertainties on Higgs Boson searches using Jet Substructure
Creators: name: Richardson, Peter
name: Winn, David
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present an investigation of the dependence of searches for boosted Higgs bosons using jet substructure on the perturbative and non-perturbative parameters of the Herwig++ Monte Carlo event generator. Values are presented for a new tune of the parameters of the event generator, together with the an estimate of the uncertainties based on varying the parameters around the best-fit values.
description: 23 pages v2: Minor typos fixed
Record-high-Tc elemental superconductivity in scandium
Creators: name: Ying, Jianjun
name: Liu, Shiqiu
name: Lu, Qing
name: Wen, Xikai
name: Gui, Zhigang
name: Zhang, Yuqing
name: Wang, Xiaomeng
name: Sun, Jian
name: Chen, Xianhui
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Elemental materials provide clean and fundamental platforms for studying superconductivity. However, the highest superconducting critical temperature (Tc) yet observed in elements has not exceeded 30 K. Discovering elemental superconductors with a higher Tc is one of the most fundamental and challenging tasks in condensed matter physics. In this study, by applying high pressure up to approximately 260 GPa, we demonstrate that the superconducting transition temperature of elemental scandium (Sc) can be increased to 36 K, which is a record-high Tc for superconducting elements. The pressure dependence of Tc implies the occurrence of multiple phase transitions in Sc, which is in agreement with previous X-ray diffraction results. Optimization of Tc is achieved in the Sc-V phase, which can be attributed to the strong coupling between d electrons and moderate-frequency phonons, as suggested by our first-principles calculations. This study provides insights for exploring new high-Tc elemental metals.
description: 12 pages, 5 figures
Nucleon momentum distributions, their spin-isospin dependence and short-range correlations
Creators: name: Alvioli, M.
name: Atti, C. Ciofi degli
name: Kaptari, L. P.
name: Mezzetti, C. B.
name: Morita, H.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The nucleon momentum distribution $n_A(k)$ for $A=$2, 3, 4, 16, and 40 nuclei is systematically analyzed in terms of wave functions resulting from advanced solutions of the nonrelativistic Schrödinger equation, obtained within different many-body approaches. Particular attention is paid to the separation of the momentum distributions into the mean-field and short-range correlations (SRC) contributions. It is shown that at high values of the momentum $k$ the high-momentum components ($k\gtrsim 1.5-2$ fm$^{-1}$) of all nuclei considered are very similar, exhibiting the well-known scaling behavior with the mass number $A$, independently of the used many-body approach and the details of the bare $NN$ interaction. The number of $NN$ pairs in a given ($ST$) state, viz., ($ST$)=(10), (00), (01), and (11), and the contribution of these states to the nucleon momentum distributions are calculated. It is shown that, apart from the (00) state, which has very small effects, all other spin-isospin states contribute to the momentum distribution in a wide range of momenta. It is shown that that for all nuclei considered the momentum distributions in the states T=0 and T=1 exhibit at $k\gtrsim 1.5-2$ fm$^{-1}$ very similar behaviors, which represents strong evidence of the A-independent character of SRCs. The ratio $n_A(k)/n_D(k)$ is analyzed in detail stressing that in the SRC region it always increases with the momentum and the origin of such an increase is discussed and elucidated. The relationships between the one- and two-body momentum distributions, considered in a previous paper, are discussed and clarified, pointing out the relevant role played by the center-of-mass motion of a correlated pair in the (10) state. The relationship of the present approach with the many-body methods based upon low-momentum effective interactions is briefly discussed.
description: Title changed; references added; typos corrected. Conclusions, Figures and Tables unchanged. To appear in Phys. Rev. C
Financial, Health, and Caregiving Worries and Experiences Survey: Views from the 50-Plus
Creators: name: AARP
Publisher: name: Roper Center for Public Opinion Research
Year: 2022

description: Current financial health (18); financial impacts of the coronavirus (COVID-19) pandemic (2); future financial goals (1); retirement (27); current overall health (4); healthcare costs (9); financial concerns of caregivers (13); unexpected expense/income (2); political leadership (4); is/has been an unpaid family caregiver (1).
Lucid Existenz During Dreaming
Creators: name: Globus, Gordon
Publisher: name: International Journal of Dream Research
Year: 2019

description: Abstract: In waking Existenz (pace Heidegger) we always find ourselves already thrown amidst the world, whereas in lucid dream Existenz there is this remarkable difference: we actually throw the world. The operation of intentionality—the brain’s self-tuning capability—is discussed with respect to its role in lucid world throwing. The ability to throw authentic worlds while lucidly dreaming raises doubts about the seeming transcendence of world during waking and opens the monadological possibility that we actually throw the world during waking too. To appropriate Freud’s dictum: the lucid dream is via regia not to the unconscious mind but to world as such.
description: International Journal of Dream Research, Vol 12, No 1 (April 2019)
Model-independent test of gravity with a network of ground-based gravitational-wave detectors
Creators: name: Hayama, Kazuhiro
name: Nishizawa, Atsushi
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The observation of gravitational waves with a global network of interferometric detectors such as advanced LIGO, advanced Virgo, and KAGRA will make it possible to probe into the nature of space-time structure. Besides Einstein's general theory of relativity, there are several theories of gravitation that passed experimental tests so far. The gravitational-wave observation provides a new experimental test of alternative theories of gravity because a gravitational wave may have at most six independent modes of polarization, of which properties and number of modes are dependent on theories of gravity. This paper proposes a method to reconstruct the independent modes of polarization in time-series data of an advanced detector network. Since the method does not rely on any specific model, it gives model-independent test of alternative theories of gravity.
ZrNb(CO) RF superconducting thin film with high critical temperature in the theoretical limit
Creators: name: Sun, Zeming
name: Oseroff, Thomas
name: Baraissov, Zhaslan
name: Dare, Darrah K.
name: Howard, Katrina
name: Francis, Benjamin
name: Hire, Ajinkya C.
name: Sitaraman, Nathan
name: Arias, Tomas A.
name: Transtrum, Mark K.
name: Hennig, Richard
name: Thompson, Michael O.
name: Muller, David A.
name: Liepe, Matthias U.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Superconductivity (cond-mat.supr-con)
subject: Accelerator Physics (physics.acc-ph)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Superconducting radio-frequency (SRF) resonators are critical components for particle accelerator applications, such as free-electron lasers, and for emerging technologies in quantum computing. Developing advanced materials and their deposition processes to produce RF superconductors that yield nanoohms surface resistances is a key metric for the wider adoption of SRF technology. Here we report ZrNb(CO) RF superconducting films with high critical temperatures (Tc) achieved for the first time under ambient pressure. The attainment of a Tc near the theoretical limit for this material without applied pressure is promising for its use in practical applications. A range of Tc, likely arising from Zr doping variation, may allow a tunable superconducting coherence length that lowers the sensitivity to material defects when an ultra-low surface resistance is required. Our ZrNb(CO) films are synthesized using a low-temperature (100 - 200 C) electrochemical recipe combined with thermal annealing. The phase transformation as a function of annealing temperature and time is optimized by the evaporated Zr-Nb diffusion couples. Through phase control, we avoid hexagonal Zr phases that are equilibrium-stable but degrade Tc. X-ray and electron diffraction combined with photoelectron spectroscopy reveal a system containing cubic ZrNb mixed with rocksalt NbC and low-dielectric-loss ZrO2. We demonstrate proof-of-concept RF performance of ZrNb(CO) on an SRF sample test system. BCS resistance trends lower than reference Nb, while quench fields occur at approximately 35 mT. Our results demonstrate the potential of ZrNb(CO) thin films for particle accelerator and other SRF applications.
Response to Howard (2018): Comments on ‘A Meta-Reanalysis of Dream-ESP Studies’
Creators: name: Storm, Lance
name: Rock, Adam J.
name: Sherwood, Simon J.
name: Tressoldi, Patrizio E.
name: Roe, Chris A.
Publisher: name: International Journal of Dream Research
Year: 2019

description: Dream-ESP is a form of extra-sensory perception (ESP) in which a dreaming perceiver ostensibly gains information about a randomly selected target without using the normal sensory modalities or logical inference. We conducted a meta-analysis on dream-ESP studies (dating from 1966 to 2016), and found a number of significant effects indicating support for the ESP hypothesis (Storm et al., 2017). Howard (2018) critiqued our study, and found much weaker effects based on a re-analysis of our data, to which he applied inverse-variance weights to the study values. Although Howard replicated a number of our findings, his other findings can be challenged. We discuss meta-analytic approaches, including the controversial issues of publication bias and what to do with outliers, and we present some re-analyses.
description: International Journal of Dream Research, Vol 12, No 1 (April 2019)
Three-dimensional atmospheric circulation of hot Jupiters on highly eccentric orbits
Creators: name: Kataria, Tiffany
name: Showman, Adam P.
name: Lewis, Nikole K.
name: Fortney, Jonathan J.
name: Marley, Mark S.
name: Freedman, Richard S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Of the over 800 exoplanets detected to date, over half are on non-circular orbits, with eccentricities as high as 0.93. Such orbits lead to time-variable stellar heating, which has implications for the planet's atmospheric dynamical regime. However, little is known about this dynamical regime, and how it may influence observations. Therefore, we present a systematic study of hot Jupiters on highly eccentric orbits using the SPARC/MITgcm, a model which couples a three-dimensional general circulation model with a plane-parallel, two-stream, non-grey radiative transfer model. In our study, we vary the eccentricity and orbit-average stellar flux over a wide range. We demonstrate that the eccentric hot Jupiter regime is qualitatively similar to that of planets on circular orbits; the planets possess a superrotating equatorial jet and exhibit large day-night temperature variations. We show that these day-night heating variations induce momentum fluxes equatorward to maintain the superrotating jet throughout its orbit. As the eccentricity and/or stellar flux is increased, the superrotating jet strengthens and narrows, due to a smaller Rossby deformation radius. For a select number of model integrations, we generate full-orbit lightcurves and find that the timing of transit and secondary eclipse viewed from Earth with respect to periapse and apoapse can greatly affect what we see in infrared (IR) lightcurves; the peak in IR flux can lead or lag secondary eclipse depending on the geometry. For those planets that have large day-night temperature variations and rapid rotation rates, we find that the lightcurves exhibit "ringing" as the planet's hottest region rotates in and out of view from Earth. These results can be used to explain future observations of eccentric transiting exoplanets.
description: 20 pages, 18 figures, 2 tables; Accepted to ApJ
Heuristic Modularity Maximization Algorithms for Community Detection Rarely Return an Optimal Partition or Anything Similar
Creators: name: Aref, Samin
name: Mostajabdaveh, Mahdi
name: Chheda, Hriday
Publisher: name: arXiv
Year: 2023
Subjects: subject: Social and Information Networks (cs.SI)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Data Structures and Algorithms (cs.DS)
subject: Machine Learning (cs.LG)
subject: Optimization and Control (math.OC)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 90C90, 90C10, 90C57, 90C59, 90C35, 05C15, 65K05

description: Community detection is a fundamental problem in computational sciences with extensive applications in various fields. The most commonly used methods are the algorithms designed to maximize modularity over different partitions of the network nodes. Using 80 real and random networks from a wide range of contexts, we investigate the extent to which current heuristic modularity maximization algorithms succeed in returning maximum-modularity (optimal) partitions. We evaluate (1) the ratio of the algorithms' output modularity to the maximum modularity for each input graph, and (2) the maximum similarity between their output partition and any optimal partition of that graph. We compare eight existing heuristic algorithms against an exact integer programming method that globally maximizes modularity. The average modularity-based heuristic algorithm returns optimal partitions for only 19.4% of the 80 graphs considered. Additionally, results on adjusted mutual information reveal substantial dissimilarity between the sub-optimal partitions and any optimal partition of the networks in our experiments. More importantly, our results show that near-optimal partitions are often disproportionately dissimilar to any optimal partition. Taken together, our analysis points to a crucial limitation of commonly used modularity-based heuristics for discovering communities: they rarely produce an optimal partition or a partition resembling an optimal partition. If modularity is to be used for detecting communities, exact or approximate optimization algorithms are recommendable for a more methodologically sound usage of modularity within its applicability limits.
description: 15 pages, 3 figures. This is a post-peer-review accepted manuscript from the Proceedings of the 23rd International Conference on Computational Science (ICCS 2023). The publisher authenticated version (version of record) is available on Springer-Nature website https://doi.org/10.1007/978-3-031-36027-5_48
PREPARING EMOTIONALLY INTELLIGENT SCHOOL LEADERS
Creators: name: Christmas, Kathryn E.
Publisher: name: Zenodo
Year: 2022
Subjects: principal
emotional intelligence
self-knowledge
educational leadership preparation

description: There is a negative impact on school functioning and student learning resulting from paying insufficient attention to principals' emotional intelligence in their leadership preparation. Very few resources are currently in place to develop and support principals in the area of emotional intelligence. A principal's ability to manage, express, and regulate their emotions and attitudes may impact leadership success and, in turn, student outcomes. This qualitative case study explores the relationship between the principal's emotional intelligence and their leadership practices. The results of this study may inform principal leadership preparation, in-service training, professional growth opportunities, and hiring practices. This qualitative case study examined the extent to which there is a relationship, if any, between the Leadership Education for Anaheim Union High School District (LEAD) curriculum and the awareness and development of self-knowledge in program graduates in the Anaheim Union High School District. Furthermore, this study explored how this self-knowledge informs the program graduates' leadership practices to understand better how to support educational administrators in developing emotional intelligence and leadership practices through preservice training and in-service professional development. Findings suggest that there is a relationship between the LEAD curriculum and the development of self-knowledge in the program graduates in the areas of self-awareness and social awareness that influences the program graduates’ leadership practices. This conclusion aligns with this study’s conceptual framework, which captures my working theory for how emotional intelligence and leadership preparation affects effective educational leadership and, in turn, student outcomes.
Book Review of “Dreaming in Dark Times” by Sharon Sliwinski
Creators: name: Rotem, Noga
Publisher: name: International Journal of Dream Research
Year: 2019

description: Sharon Sliwinski’s book, Dreaming in Dark Times, reads dreams drawn from six bleak historical moments in the 20th century as texts in political thought. The book convincingly argues that rather than being a purely psychological phenomenon, dreams often dramatize harsh political realities, and might also become a potent political resource for resisting these realities. The book works through a productive tension between the dream that “shield[s] us against the world’s impingements,” and the dream that invites us into the world. However, Sliwinski’s ultimate commitment to a representation of the dream as a last preserve of individuality downplays the great subversive, even conspiratorial political horizon that the book promised by tying our dreams to the collective work of world-building.
description: International Journal of Dream Research, Vol 12, No 1 (April 2019)
Direct observation of a highly spin-polarized organic spinterface at room temperature
Creators: name: Djeghloul, F.
name: Ibrahim, F.
name: Cantoni, M.
name: Bowen, M.
name: Joly, L.
name: Boukari, S.
name: Ohresser, P.
name: Bertran, F.
name: Lefèvre, P.
name: Thakur, P.
name: Scheurer, F.
name: Miyamachi, T.
name: Mattana, R.
name: Seneor, P.
name: Jaafar, A.
name: Rinaldi, C.
name: Javaid, S.
name: Arabski, J.
name: Kappler, J. -P.
name: Wulfhekel, W.
name: Brookes, N. B.
name: Bertacco, R.
name: Taleb-Ibrahimi, A.
name: Alouani, M.
name: Beaurepaire, E.
name: Weber, W.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The design of large-scale electronic circuits that are entirely spintronics-driven requires a current source that is highly spin-polarised at and beyond room temperature, cheap to build, efficient at the nanoscale and straightforward to integrate with semiconductors. Yet despite research within several subfields spanning nearly two decades, this key building block is still lacking. We experimentally and theoretically show how the interface between Co and phthalocyanine molecules constitutes a promising candidate. Spin-polarised direct and inverse photoemission experiments reveal a high degree of spin polarisation at room temperature at this interface. We measured a magnetic moment on the molecules's nitrogen pi orbitals, which substantiates an ab-initio theoretical description of highly spin-polarised charge conduction across the interface due to differing spinterface formation mechanims in each spin channel. We propose, through this example, a recipe to engineer simple organic-inorganic interfaces with remarkable spintronic properties that can endure well above room temperature.
Tasmacetus Oliver 1937
Creators: name: Honacki, James H.
name: Kinman, Kenneth E.
name: Koeppl, James W.
Publisher: name: Zenodo
Year: 1982
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Cetacea
Ziphiidae
Tasmacetus

description: Tasmacetus Oliver, 1937. Proc. Zool. Soc. Lond., 1937:371. PROTECTED STATUS: CITES - Appendix II as Order Cetacea. ISIS NUMBER: 5301411005005000000.
description: Published as part of James H. Honacki, Kenneth E. Kinman & James W. Koeppl, 1982, Order Cetacea, pp. 290-304 in Mammal Species of the World (1 st Edition), Lawrence, Kansas, USA :Alien Press, Inc. & The Association of Systematics Collections on page 301, DOI: 10.5281/zenodo.7352983
Implications of multi-axion dark matter on structure formation
Creators: name: Chen, Chong-Bin
name: Soda, Jiro
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Axions are candidates for dark matter in the universe.We develop an accurate Boltzmann code to calculate the linear growth of the plasma. As an interesting example, we investigate a mixed dark matter model consisting of cold dark matter (CDM) and two-axion dark matter. We analyze the growth of the structure numerically and analytically. We find that an effective single axion with an effective mass and an effective abundance is useful to characterize the two-axion cosmology. Moreover, we generalize the effective single axion description to multi-axion dark matter cosmology. We also compare the results with those of warm dark matter (WDM) model. Moreover, we calculate halo mass functions for the mixed model by using the Press-Schechter model and linear perturbations and then determine the mass function as a function of masses and axion abundance.
description: 33 pages, 17 figures
Low-frequency variations of unknown origin in the Kepler Delta Scuti star KIC 5988140 = HD 188774
Creators: name: Lampens, P.
name: Tkachenko, A.
name: Lehmann, H.
name: Debosscher, J.
name: Aerts, C.
name: Beck, P. G.
name: Bloemen, S.
name: Kochiashvili, N.
name: Derekas, A.
name: Smith, J. C.
name: Tenenbaum, P.
name: Twicken, J. D.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We used high-quality Kepler photometry and spectroscopic data to investigate the Kepler binary candidate KIC 5988140. Using the spectrum synthesis method, we derived the fundamental parameters Teff, log g, [M/H], and v.sini and the abundances. Frequency analyses of both the photometric and the spectroscopic data were performed, revealing the same two dominant frequencies (F_1=0.688 and F_2=0.344 c/d). We also detected in the photometry the signal of nine more, significant frequencies located in the typical range of Delta Scuti pulsation. The light and radial velocity curves follow a similar, stable double-wave pattern which are not exactly in anti-phase but show a relative phase shift of about 0.1 period between the moment of minimum velocity and that of maximum light. We considered three different scenarios: binarity, co-existence of both Gamma Doradus and Delta Scuti pulsations and rotation of the stellar surface with an axisymmetric intensity distribution. However, none of these scenarios is capable of explaining all of the characteristics of the observed variations. We confirm the occurrence of various independent Delta Scuti-type pressure modes in the Kepler light curve. With respect to the low-frequency content, however, we argue that the physical cause of the remaining light and radial velocity variations of this late A-type star remains unexplained by any of the presently considered scenarios.
description: 9 pages, 12 encapsulated Postscript figures. Table~A.1 is available in electronic form only, in press
Texture Zeros for Dirac Neutrinos and Current Experimental Tests
Creators: name: Liu, Xue-wen
name: Zhou, Shun
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The Daya Bay and RENO reactor neutrino experiments have revealed that the smallest neutrino mixing angle is in fact relatively large, i.e., theta_13 ~ 9 degrees. Motivated by this exciting progress, we perform a systematic study of the neutrino mass matrix M_nu with one or two texture zeros, in the assumption that neutrinos are Dirac particles. Among fifteen possible patterns with two texture zeros, only three turn out to be favored by current neutrino oscillation data at the 3 sigma level. Although all the six patterns with one texture zero are compatible with the experimental data at the 3 sigma level, the parameter space of each pattern is strictly constrained. Phenomenological implications of M_nu on the leptonic CP violation and neutrino mass spectrum are explored, and the stability of texture zeros against the radiative corrections is also discussed.
description: 27 pages, 3 figures, one appendix and more references added, to appear in Int. J. Mod. Phys. A
Impossibility of spontaneous vector flavor symmetry breaking on the lattice
Creators: name: Giordano, Matteo
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: I show that spontaneous breaking of vector flavor symmetry on the lattice is impossible in gauge theories with a positive functional-integral measure, for discretized Dirac operators linear in the quark masses, if the corresponding propagator and its commutator with the flavor symmetry generators can be bounded in norm independently of the gauge configuration and uniformly in the volume. Under these assumptions, any order parameter vanishes in the symmetric limit of fermions of equal masses. I show that these assumptions are satisfied by staggered, minimally doubled and Ginsparg-Wilson fermions for positive fermion mass, for any value of the lattice spacing, and so in the continuum limit if this exists. They are instead not satisfied by Wilson fermions, for which spontaneous vector flavor symmetry breaking is known to take place in the Aoki phase. The existence of regularizations unaffected by residual fermion doubling for which the symmetry cannot break spontaneously on the lattice establishes rigorously (at the physicist's level) the impossibility of its spontaneous breaking in the continuum for any number of flavors.
description: Revised version: title changed; added references on the rooting trick; added discussion on improved and on rooted staggered fermions; 16 pages
Dynamical Couplings, Dynamical Vacuum Energy and Confinement/Deconfinement from R^2-Gravity
Creators: name: Guendelman, Eduardo
name: Kaganovich, Alexander
name: Nissimov, Emil
name: Pacheva, Svetlana
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study within Palatini formalism an f(R)-gravity with f(R)= R + αR^2 interacting with a dilaton and a special kind of nonlinear gauge field system containing a square-root of the standard Maxwell term, which is known to produce confinement in flat space-time. Reformulating the model in the physical Einstein frame we find scalar field effective potential with a flat region where the confinement dynamics disappears, while in other regions it remains intact. The effective gauge couplings as well as the induced cosmological constant become dynamical. In particular, a conventional Maxwell kinetic term for the gauge field is dynamically generated even if absent in the original theory. We find few interesting classes of explicit solutions: (i) asymptotically (anti-)de Sitter black holes of non-standard type with additional confining vacuum electric potential even for the electrically neutral ones; (ii) non-standard Reissner-Nordstroem black holes with additional constant vacuum electric field and having non-flat-spacetime "hedgehog" asymptotics; (iii) generalized Levi-Civitta-Bertotti-Robinson "tube-like" space-times.
description: 16 pages
Decentralized Caching under Nonuniform File Popularity and Size: Memory-Rate Tradeoff Characterization
Creators: name: Deng, Yong
name: Dong, Min
Publisher: name: arXiv
Year: 2023
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: This paper aims to characterize the memory-rate tradeoff for decentralized caching under nonuniform file popularity and size. We consider a recently proposed decentralized modified coded caching scheme (D-MCCS) and formulate the cache placement optimization problem to minimize the average rate for the D-MCCS. To solve this challenging non-convex optimization problem, we first propose a successive Geometric Programming (GP) approximation algorithm, which guarantees convergence to a stationary point but has high computational complexity. Next, we develop a low-complexity file-group-based approach, where we propose a popularity-first and size-aware (PF-SA) cache placement strategy to partition files into two groups, taking into account the nonuniformity in file popularity and size. Both algorithms do not require the knowledge of active users beforehand for cache placement. Numerical results show that they perform very closely to each other. We further develop a lower bound for decentralized caching under nonuniform file popularity and size as a non-convex optimization problem and solved it using a similar successive GP approximation algorithm. We show that the D-MCCS with the optimized cache placement attains this lower bound when no more than two active users request files at a time. The same is true for files with uniform size but nonuniform popularity and the optimal cache placement being symmetric among files. In these cases, the optimized DMCCS characterizes the exact memory-rate tradeoff for decentralized caching. For general cases, our numerical results show that the average rate achieved by the optimized D-MCCS is very close to the lower bound.
description: 16 pages, 7 figures, 7 tables. Accepted to IEEE/ACM Transactions on Networking
Direct numerical integration for multi-loop integrals
Creators: name: Becker, Sebastian
name: Weinzierl, Stefan
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a method to construct a suitable contour deformation in loop momentum space for multi-loop integrals. This contour deformation can be used to perform the integration for multi-loop integrals numerically. The integration can be performed directly in loop momentum space without the introduction of Feynman or Schwinger parameters. The method can be applied to finite multi-loop integrals and to divergent multi-loop integrals with suitable subtraction terms. The algorithm extends techniques from the one-loop case to the multi-loop case. Examples at two and three loops are discussed explicitly.
description: 20 pages, v2: version to be published, v3: acknowledgement added
Semiclassical instability of inner-extremal regular black holes
Creators: name: McMaken, Tyler
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The construction of black hole spacetimes that are regular (singularity-free) is plagued by the "mass inflation" instability, a classical perturbation instability induced by the surface gravity at the inner horizon and characterized by exponentially diverging stress-energy there. Recently, a class of "inner-extremal" regular black holes was proposed that possesses a vanishing inner-horizon surface gravity and therefore avoids mass inflation, while still maintaining a horizon separation and a non-zero outer-horizon surface gravity. However, when semiclassical effects are taken into account, it is found that an inner-horizon instability remains for generic inner-extremal regular black holes formed from collapse. This semiclassical divergence is analyzed from the perspective of both the effective Hawking temperature and the renormalized stress-energy tensor, and its origin and genericity are examined in detail.
description: 15 pages, 1 figure
FRA -- A new Fast, Robust and Automated pipeline for the detection and measurement of solar-like oscillations in time-series photometry of red-giant stars
Creators: name: Gehan, C.
name: Campante, T. L.
name: Cunha, M. S.
name: Pereira, F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We developed, tested and validated a new Fast, Robust and Automated (FRA) tool to detect solar-like oscillations. FRA is based on the detection and measurement of the frequency of maximum oscillation power $ν_{max}$, without relying on the detection of a regular frequency spacing to guide the search. We applied the FRA pipeline to 254 synthetic power spectra representative of TESS red giants, as well as 1689 red giants observed by Kepler and 2344 red giants observed by TESS. We obtain a consistency rate for $ν_{max}$ compared with existing measurements of $\sim$ 99% for Kepler red giants and of $\sim$ 98% for TESS red giants. We find that using $ν_{max}$ as an input parameter to guide the search for the large frequency separation $Δν$ through the existing Envelope AutoCorrelation Function (EACF) method significantly improves the consistency of the measured $Δν$ in the case of TESS stars, allowing to reach a consistency rate above 99%. Our analysis reveals that we can expect to get consistent $ν_{max}$ and $Δν$ measurements while minimizing both the false positive measurements and the non-detections for stars with a minimum of four observed sectors and a maximum G magnitude of 9.5.
description: 35 pages, 17 figures. Accepted for publication in Astronomische Nachrichten. This is the pre-peer reviewed (submitted) version
Formation of proto-clusters and star formation within clusters: apparent universality of the initial mass function ?
Creators: name: Hennebelle, Patrick
Publisher: name: arXiv
Year: 2012
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: It is believed that the majority of stars form in clusters. Therefore it is likely that the gas physical conditions that prevail in forming clusters, largely determine the properties of stars that form and in particular the initial mass function. We develop an analytical model to account for the formation of low mass clusters and the formation of stars within clusters. The formation of clusters is determined by an accretion rate, the virial equilibrium and energy as well as thermal balance. For this latter both molecular and dust cooling are considered using published rates. The star distribution is computed within the cluster using the physical conditions inferred from this model and the Hennebelle & Chabrier theory. Our model reproduces well the mass-size relation of low mass clusters (up to few $\simeq 10^3$ M$_\odot$ of stars corresponding to about 5 times more gas) and an initial mass function which is $i)$ very close to the Chabrier's IMF, $ii)$ weakly dependent on the mass of the clusters, $iii)$ relatively robust to (i.e. not too steeply dependent on) variations of physical quantities as accretion rate, radiation and cosmic rays abundances. The weak dependence of the mass distribution of stars with the cluster mass results from the compensation between varying clusters densities, velocity dispersions and temperatures all inferred from first physical principles. This constitutes a possible explanation for the apparent universality of the IMF within the Galaxy though variations with the local conditions could certainly be observed.
description: accepted for publication in A&A
A Novel Universal Statistic for Computing Upper Limits in Ill-behaved Background
Creators: name: Dergachev, Vladimir
Publisher: name: arXiv
Year: 2012
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Optimization and Control (math.OC)
subject: Statistics Theory (math.ST)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 62-07, 62P35, 62G15, 62G32

description: Analysis of experimental data must sometimes deal with abrupt changes in the distribution of measured values. Setting upper limits on signals usually involves a veto procedure that excludes data not described by an assumed statistical model. We show how to implement statistical estimates of physical quantities (such as upper limits) that are valid without assuming a particular family of statistical distributions, while still providing close to optimal values when the data is from an expected distribution (such as Gaussian or exponential). This new technique can compute statistically sound results in the presence of severe non-Gaussian noise, relaxes assumptions on distribution stationarity and is especially useful in automated analysis of large datasets, where computational speed is important.
description: 11 pages; expanded version of the original article