cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
High Open-Circuit Voltages in Lead-Halide Perovskite Solar Cells - Experiment, Theory and Open Questions
Creators: name: Kirchartz, Thomas
Publisher: name: arXiv
Year: 2019
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: One of the most significant features of lead-halide perovskites are their ability to have comparably slow recombination despite the fact that these materials are mostly processed from solution at room temperature. The slow recombination allows achieving high open-circuit voltages when the lead-halide perovskite layers are used in solar cells. This perspective discusses the state of the art of our understanding and of experimental data with regard to recombination and open-circuit voltages in lead-halide perovskites. A special focus is put onto open questions that the community has to tackle to design future photovoltaic and optoelectronic devices based on lead-halide perovskites and other semiconductors with similar properties.
D3.1 User Research Reports and Scenarios
Creators: name: Wilson, Anna
name: Sachy, Marco
name: Ottaviano, Stefania
name: Paoli, Stefano De
name: Pellegrini, Francesco De
Publisher: name: Zenodo
Year: 2019

description: This deliverable reports on the empirical research carried out as part of the PIE News project Work Package 3.
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Gravitational stability and fragmentation condition for discs around accreting supermassive stars
Creators: name: Matsukoba, Ryoki
name: Takahashi, Sanemichi Z.
name: Sugimura, Kazuyuki
name: Omukai, Kazuyuki
Publisher: name: arXiv
Year: 2019
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Supermassive stars (SMSs) with mass $\sim10^{5}~\rm{M}_{\odot}$ are promising candidates for the origin of supermassive black holes observed at redshift $\gtrsim6$. They are supposed to form as a result of rapid accretion of primordial gas, although it can be obstructed by the time variation caused by circum-stellar disc fragmentation due to gravitational instability. To assess the occurrence of fragmentation, we study the structure of marginally gravitationally unstable accretion discs, by using a steady one-dimensional thin disc model with detailed treatment of chemical and thermal processes. Motivated by two SMS formation scenarios, i.e., those with strong ultraviolet radiation background or with large velocity difference between the baryon and the dark matter, we consider two types of flows, i.e., atomic and molecular flows, respectively, for a wide range of the central stellar mass $10-10^5~\rm{M}_{\odot}$ and the accretion rate $10^{-3}-1~\rm{M}_{\odot}~\rm{yr}^{-1}$. In the case of a mostly atomic gas flowing to the disc outer boundary, the fragmentation condition is expressed as the accretion rate being higher than the critical value of $10^{-1}~\rm{M}_{\odot}~\rm{yr}^{-1}$ regardless of the central stellar mass. On the other hand, in the case of molecular flows, there is a critical disc radius outside of which the disc becomes unstable. Those conditions appears to be marginally satisfied according to numerical simulations, suggesting that disc fragmentation can be common during SMS formation.
description: 17 pages, 10 figures, accepted for publication in MNRAS
On N=1,2,4 Higher Spin Gauge Theories in Four Dimensions
Creators: name: Engquist, J.
name: Sezgin, E.
name: Sundell, P.
Publisher: name: arXiv
Year: 2002
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study N=1,2,4 higher spin superalgebras in four dimensions and higher spin gauge theories based on them. We extend the existing minimal N=2,4 theories and find a minimal N=1 theory. Utilizing the basic structure of the minimal N=8 theory, we express the full field equations for the N=1,2,4 theories in a universal form without introducing Kleinian operators. We also use a non-minimal N=4 higher spin algebra tensored with U(3) to describe a higher spin extension of N=4 supergravity coupled to the massless vector multiplets arising in the KK spectrum of 11D supergravity on the N=3 supersymmetric AdS_4 x N^{010} background. The higher spin theory also contains a triplet of vector multiplets which may play a role in the super-Higgs effect in which N=4 is broken down to N=3.
description: Latex, 36 pages, remarks, footnotes and references added
The Unsolved Legacy of Forced Labour during World War II in Asia
Creators: Lee, Juana Wai Sum
Publisher: name: Columbia University
Year: 2020
Subjects: Human rights
Forced labor
World War (1939-1945)
War reparations

description: Five decades after the end of WWII, a wave of WWII reparations lawsuits swept across Asia, targeting the Japanese government and over one hundred Japanese companies that toiled brutal forced labour during the war. For years, plaintiffs and their legal representatives travelled across Korea, Japan, China and the United States to fight for redress in court. But with more survivors passing away during court proceedings, historical justice became exceedingly urgent. In 2014, the Beijing No.1 Intermediate People’s Court agreed to hear lawsuits by Chinese forced labourers, with dozens of pending cases awaiting trial. And on October 30, 2018, the South Korean Supreme Court ordered Nippon Steel Corporation to pay four Korean forced labourers ₩100 million won (USD$84,000), escalating tensions and hostilities between victim countries and Japan. But despite progress towards redress in courts, the author finds that while retributive justice is necessary to advance the WWII forced labour redress movement, it is not sufficient to obtain acceptable reparations in the case of Japan. Notwithstanding court decisions ruling in favour of the plaintiffs in South Korea and Japan, the Shinzō Abe administration and the longstanding historical resentment between Japan and victim countries have created a strong barrier impeding postwar redress and accountability. In light of these rapid developments, this article highlights the voices of fourteen individuals, including one Korean forced labour survivor, bereaved family members, their legal representatives and academics. The lessons learned, recommendations and reforms within Japan’s economic, social and political sphere are applicable to furthering historical justice and accountability and move towards memorializing this chapter of history.
Transient dynamics of nonlinear magneto-optical rotation in the presence of transverse magnetic field
Creators: name: Grewal, Raghwinder Singh
name: Pustelny, Szymon
Publisher: name: arXiv
Year: 2019
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Nonlinear magneto-optical rotation is studied under non-equilibrium conditions. The polarization rotation of linearly polarized light traversing a rubidium vapor cell is observed versus the time-dependent (swept) longitudinal magnetic field in the presence of static transverse magnetic fields. Presence of the transverse fields modifies the character of the observed signals. In particular, for weaker transverse fields, field sweep leads two-harmonic oscillation of the polarization rotation while crossing zero. Unlike the steady-state, it was found that two-frequency oscillations observed in the transient signals, are independent of the transverse-field direction. For stronger transverse fields, the oscillations deteriorate eventually reaching a situation when no-oscillating dynamic signal, with distinct minimum close to zero field, is observed. Experimental results are supported with theoretical analysis based on the density-matrix formalism. The analysis confirms all the features of experimental results while providing an provide intuitive explanation of the observed behavior based on angular-momentum probability surfaces used for density-matrix visualization.
Cereeae Salm-Dyck 1840
Creators: name: Walter, Helmut E.
name: Guerrero, Pablo C.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Caryophyllales
Cactaceae

description: Tribe Cereeae Salm-Dyck:
 — Nyffeler & Eggli (2010) proposed a broader circumscription of the tribe Cereeae than traditional concepts (see e.g., Anderson 2001, 2005, Hunt et al. 2013). Lendel (2006) and Ritz et al. (2007) showed, in fact, that the traditionally circumscribed Cereeae and Trichocereeae are not monophyletic. Therefore, we follow Nyffeler & Eggli’s (2010) concept of a tribe Cereeae with three subtribes, i.e. Cereinae Britton & Rose, Rebutiinae Donald (incl. Browningieae Buxb.) and Trichocereinae Britton & Rose.
description: Published as part of Walter, Helmut E. & Guerrero, Pablo C., 2022, Towards a unified taxonomic catalogue for the Chilean cacti: assembling molecular systematics and classical taxonomy, pp. 79-98 in Phytotaxa 550 (2) on page 95, DOI: 10.11646/phytotaxa.550.2.1, http://zenodo.org/record/6641038
Parametric level statistics in random matrix theory: Exact solution
Creators: name: Kanzieper, E.
Publisher: name: arXiv
Year: 1999
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chaotic Dynamics (nlin.CD)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: An exact solution to the problem of parametric level statistics in non-Gaussian ensembles of N by N Hermitian random matrices with either soft or strong level confinement is formulated within the framework of the orthogonal polynomial technique. Being applied to random matrices with strong level confinement, the solution obtained leads to emergence of a new connection relation that makes a link between the parametric level statistics and the scalar two-point kernel in the thermodynamic limit.
description: 4 pages (revtex)
Halo Concentrations and the Fundamental Plane of Galaxy Clusters
Creators: name: Fujita, Yutaka
name: Donahue, Megan
name: Ettori, Stefano
name: Umetsu, Keiichi
name: Rasia, Elena
name: Meneghetti, Massimo
name: Medezinski, Elinor
name: Okabe, Nobuhiro
name: Postman, Marc
Publisher: name: arXiv
Year: 2019
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: According to the standard cold dark matter (CDM) cosmology, the structure of dark halos including those of galaxy clusters reflects their mass accretion history. Older clusters tend to be more concentrated than younger clusters. Their structure, represented by the characteristic radius $r_s$ and mass $M_s$ of the Navarro--Frenk--White (NFW) density profile, is related to their formation time. In~this study, we showed that $r_s$, $M_s$, and the X-ray temperature of the intracluster medium (ICM), $T_X$, form a thin plane in the space of $(\log r_s, \log M_s, \log T_X)$. This tight correlation indicates that the ICM temperature is also determined by the formation time of individual clusters. Numerical simulations showed that clusters move along the fundamental plane as they evolve. The plane and the cluster evolution within the plane could be explained by a similarity solution of structure formation of the universe. The angle of the plane shows that clusters have not achieved "virial equilibrium" in the sense that mass/size growth and pressure at the boundaries cannot be ignored. The distribution of clusters on the plane was related to the intrinsic scatter in the halo concentration--mass relation, which originated from the variety of cluster ages. The well-known mass--temperature relation of clusters ($M_Δ\propto T_X^{3/2}$) can be explained by the fundamental plane and the mass dependence of the halo concentration without the assumption of virial equilibrium. The fundamental plane could also be used for calibration of cluster masses.
description: Invited review article, to be published in "From Dark Haloes to Visible Galaxies", special issue of Galaxies
Rebutiinae Donald.
Creators: name: Walter, Helmut E.
name: Guerrero, Pablo C.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Caryophyllales
Cactaceae

description: Subtribe Rebutiinae Donald. (incl. Browningieae Buxb.):
 —Various molecular-based studies (e.g. Lendel et al. 2006, Ritz et al. 2007) showed that Browningia Britton & Rose is closely related to Rebutia K.Schum., while other authors using only morphology-based characters (e.g. Hunt et al. 2013, Anderson 2001, 2005) placed the two genera in different tribes: Hunt et al. (2013) placed Browningia in tribe Cereeae and Rebutia in tribe Trichocereeae, whereas Anderson (2001, 2005) placed Rebutia in Trichocereeae and Browningia in Browningieae (together with Stetsonia Britton & Rose, Jasminocereus Britton & Rose, Armatocereus Backeb. and Neoraimondia Britton & Rose). We here accept to include Browningieae in the tribe Rebutiinae.
description: Published as part of Walter, Helmut E. & Guerrero, Pablo C., 2022, Towards a unified taxonomic catalogue for the Chilean cacti: assembling molecular systematics and classical taxonomy, pp. 79-98 in Phytotaxa 550 (2) on page 95, DOI: 10.11646/phytotaxa.550.2.1, http://zenodo.org/record/6641038
Plane Light-Like Shells and Impulsive Gravitational Waves in Scalar-Tensor Theories of Gravity
Creators: name: Bressange, G. F.
Publisher: name: arXiv
Year: 1997
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study gravitational plane impulsive waves and electromagnetic shock waves in a scalar-tensor theory of gravity of the Brans-Dicke type. In vacuum, we present an exact solution of Brans-Dicke's field equations and give an example in which a plane impulsive gravitational wave and a null shell of matter coexist on the same hypersurface. In the homogenous case, we characterize them by their surface energy density and wave amplitude and discuss the inhomogenous case. We also give an exact solution of the Brans-Dicke's field equations in the electrovacuum case which admits a true curvature singularity and use it to built an example where a plane impulsive gravitational wave and an electromagnetic shock wave have the same null hypersurface as history of their wave fronts and propagate independently and decoupled from a null shell of matter. This last solution is shown to correspond to the space-time describing the interaction region resulting from the collision of two electromagnetic shock waves leading to the formation of two gravitational impulsive waves. The properties of this solution are discussed and compared to those of the Bell-Szekeres solution of general relativity.
description: 19 pages, latex, 1 figure, accepted for publication in Class. Quant. Grav
Unveiling Hidden Orders: Magnetostriction as a Probe of Multipolar-Ordered States
Creators: name: Patri, Adarsh S.
name: Sakai, Akito
name: Lee, SungBin
name: Paramekanti, Arun
name: Nakatsuji, Satoru
name: Kim, Yong Baek
Publisher: name: arXiv
Year: 2019
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Broken symmetries in solids involving higher order multipolar degrees of freedom are historically referred to as "hidden orders" due to the formidable task of detecting them with conventional probes. Examples of such hidden orders include spin-nematic order in quantum magnets, and quadrupolar or higher multipolar orders in various correlated quantum materials. In this work, we theoretically propose that the study of magnetostriction provides a powerful and novel tool to directly detect higher-order multipolar symmetry breaking $-$ such as the elusive octupolar order $-$ by examining its scaling behaviour with respect to an applied magnetic field $h$. As an illustrative example, we examine such key scaling signatures in the context of Pr-based cage compounds with strongly correlated $f$-electrons, Pr(Ti,V,Ir)$_2$(Al,Zn)$_{20}$, whose low energy degrees of freedom are composed of purely higher-order multipoles: quadrupoles $\mathcal{O}_{20,22}$ and octupole $\mathcal{T}_{xyz}$. Employing a symmetry-based Landau theory of multipolar moments coupled to lattice strain fields, we demonstrate that a magnetic field applied along the [111] direction results in a length change with a distinct linear-in-$h$ scaling behaviour, accompanied by hysteresis, below the octupolar ordering temperature. We show that the resulting "magnetostriction coefficient" is directly proportional to the octupolar order parameter, providing the first clear access to this subtle order parameter. Along other field directions, we show that the field dependence of the magnetostriction provides a window into quadrupolar orders. Our work provides a springboard for future experimental and theoretical investigations of multipolar orders and their quantum phase transitions in a wide variety of systems.
description: 10 pages (including References), 5 figures, 3 pages Supplementary Information
Topography of (exo)planets
Creators: name: Landais, François
name: Schmidt, Frederic
name: Lovejoy, Shaun
Publisher: name: arXiv
Year: 2019
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Current technology is not able to map the topography of rocky exoplanets, simply because the objects are too faint and far away to resolve them. Nevertheless, indirect effect of topography should be soon observable thanks to photometry techniques, and the possibility of detecting specular reflections. In addition, topography may have a strong effect on Earth-like exoplanet climates because oceans and mountains affect the distribution of clouds \citep{Houze2012}. Also topography is critical for evaluating surface habitability \citep{Dohm2015}. We propose here a general statistical theory to describe and generate realistic synthetic topographies of rocky exoplanetary bodies. In the solar system, we have examined the best-known bodies: the Earth, Moon, Mars and Mercury. It turns out that despite their differences, they all can be described by multifractral statistics, although with different parameters. Assuming that this property is universal, we propose here a model to simulate 2D spherical random field that mimics a rocky planetary body in a stellar system. We also propose to apply this model to estimate the statistics of oceans and continents to help to better assess the habitability of distant worlds.
Brane world supersymmetry, detuning, flipping and orbifolding
Creators: name: Brax, Philippe
name: Lalak, Zygmunt
Publisher: name: arXiv
Year: 2002
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We emphasize the necessity of a delicate interplay between the gauge and gravitational sectors of five-dimensional brane worlds in creating phenomenologically relevant vacua. We discuss locally supersymmetric brane worlds with unflipped and flipped fermionic boundary conditions and with matter on the branes. We point out that a natural separation between the gauge and gravity sectors, very difficult in models with true extra dimensions, may be achieved in 4d models with deconstructed dimensions.
description: 17 pages, Dedicated to Stefan Pokorski on his 60th birthday
The Urban Political Ecologies of Vancouver: Sustainable Development and Affordability
Creators: Sham, Fred
Publisher: name: Columbia University
Year: 2012
Subjects: City planning
Sustainable development--Government policy
Human ecology

description: Urban political ecology combines the approaches of political economy and the study of human ecology. One subfield of this subject focuses on critically examining state policies relating to urban environmental and economic governance through a lens of distributional justice. This thesis investigates how political, economic, and social processes have collectively (re)created inequitable urban natures in Vancouver, Canada, under the banner of sustainability. In 2008, Vancouver's City Council unanimously voted to pass the EcoDensity Initiative, a comprehensive policy and vision document that strategically used increased densities and high performance green design to not only reduce the city's ecological footprint, but also simultaneously enhance housing affordability and livability. Using case studies, interviews and comparing assessed property value changes, this thesis demonstrates that Vancouver's urban environmental governance policies have contributed to dramatically increasing property values, effectively exacerbating the city's housing affordability crisis for low-to-middle income earners. At its core, EcoDensity strategically mandates high performance green design not only to meet ecological goals, but also to buttress markets of green enterprise and enforce its consumption as a means of economic development. While the pursuit of ecological sustainability and economic development are worthy priorities, without a realignment of institutional capacities to address social equity, the city's ecological and economic gains may be eroded.
title: Digitale Wissenschaftsvermittlung: Hürden und Chancen. Interview mit Ulla Menke, Wissenschaftskommunikatorin
Creators: name: Menke, Ulla
Publisher: name: ZZF - Centre for Contemporary History: Zeitgeschichte online
Year: 2020

description: Interview mit Ulla Menke, Wissenschaftskommunikatorin, über ihren Weg in die Wissenschaftskommunikation, Hierarchien, Social Media, weibliche Vorbilder und die Frage der Promotion.
Cylindropuntieae Doweld 1999
Creators: name: Walter, Helmut E.
name: Guerrero, Pablo C.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Caryophyllales
Cactaceae

description: Tribe Cylindropuntieae Doweld:
 —The only species in this tribe occurring in Chile [Cylindropuntia tunicata (Lehmann) Knuth] has been introduced from Northern Mexico and Arizona.
description: Published as part of Walter, Helmut E. & Guerrero, Pablo C., 2022, Towards a unified taxonomic catalogue for the Chilean cacti: assembling molecular systematics and classical taxonomy, pp. 79-98 in Phytotaxa 550 (2) on page 82, DOI: 10.11646/phytotaxa.550.2.1, http://zenodo.org/record/6641038
Near-Infrared Survey and Photometric Redshifts in the Extended GOODS-North field
Creators: name: Hsu, Li-Ting
name: Lin, Lihwai
name: Dickinson, Mark
name: Yan, Haojing
name: Bau-Ching, Hsieh
name: Wang, Wei-Hao
name: Lee, Chien-Hsiu
name: Yan, Chi-Hung
name: Scott, Douglas
name: Willner, S. P.
name: Ouchi, Masami
name: Ashby, Matthew L. N.
name: Chen, Yi-Wen
name: Daddi, Emanuele
name: Elbaz, David
name: Fazio, Giovanni G.
name: Foucaud, Sebastien
name: Huang, Jiasheng
name: Koo, David C.
name: Morrison, Glenn
name: Owen, Frazer
name: Pannella, Maurilio
name: Pope, Alexendra
name: Simard, Luc
name: Wang, Shiang-Yu
Publisher: name: arXiv
Year: 2019
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present deep $J$ and $H$-band images in the extended Great Observatories Origins Deep Survey-North (GOODS-N) field covering an area of 0.22 $\rm{deg}^{2}$. The observations were taken using WIRCam on the 3.6-m Canada France Hawaii Telescope (CFHT). Together with the reprocessed $K_{\rm s}$-band image, the $5σ$ limiting AB magnitudes (in 2" diameter apertures) are 24.7, 24.2, and 24.4 AB mag in the $J$, $H$, and $K_{\rm s}$ bands, respectively. We also release a multi-band photometry and photometric redshift catalog containing 93598 sources. For non-X-ray sources, we obtained a photometric redshift accuracy $σ_{\mathrm{NMAD}}=0.036$ with an outlier fraction $η= 7.3\%$. For X-ray sources, which are mainly active galactic nuclei (AGNs), we cross-matched our catalog with the updated 2M-CDFN X-ray catalog from Xue et al. (2016) and found that 658 out of 683 X-ray sources have counterparts. $GALEX$ UV data are included in the photometric redshift computation for the X-ray sources to give $σ_{\mathrm{NMAD}} = 0.040$ with $η=10.5\%$. Our approach yields more accurate photometric redshift estimates compared to previous works in this field. In particular, by adopting AGN-galaxy hybrid templates, our approach delivers photometric redshifts for the X-ray counterparts with fewer outliers compared to the 3D-HST catalog, which fit these sources with galaxy-only templates.
N-fold Supersymmetry for a Periodic Potential
Creators: name: Aoyama, Hideaki
name: Sato, Masatoshi
name: Tanaka, Toshiaki
name: Yamamoto, Mariko
Publisher: name: arXiv
Year: 2000
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We report a new type of supersymmetry, "N-fold supersymmetry", in one-dimensional quantum mechanics. Its supercharges are N-th order polynomials of momentum: It reduces to ordinary supersymmetry for N=1, but for other values of N the anticommutator of the supercharges is not the ordinary Hamiltonian, but is a polynomial of the Hamiltonian. (For this reason, the original Hamiltonian is referred to as the "Mother Hamiltonian".) This supersymmetry shares some features with the ordinary variety, the most notable of which is the non-renormalization theorem. An N-fold supersymmetry was earlier found for a quartic potential whose supersymmetry is spontaneously broken. Here we report that it also holds for a periodic potential, albeit with somewhat different supercharges, whose supersymmetry is not broken.
description: 10 pages, 2 figures
Renormalization of Long-wavelength Solution of Einstein Equation
Creators: name: Nambu, Yasusada
name: Yamaguchi, Yoshiyuki Y.
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Using the renormalization group method, we improved the first order solution of the long-wavelength expansion of the Einstein equation. By assuming that the renormalization group transformation has the property of Lie group, we can regularize the secular divergence caused by the spatial gradient terms and absorb it to the background seed metric. The solution of the renormalization group equation shows that the renormalized metric describes the behavior of gravitational collapse in the expanding universe qualitatively well.
description: 12 pages, 1 figure, typeset by REVTeX
Clustering and synchronization with positive Lyapunov exponents
Creators: name: Mendes, R. Vilela
Publisher: name: arXiv
Year: 1998
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: Clustering and correlation effects are frequently observed in chaotic systems in situations where, because of the positivity of the Lyapunov exponents, no dimension reduction is to be expected. In this paper, using a globally coupled network of Bernoulli units, one finds a general mechanism by which strong correlations and slow structures are obtained at the synchronization edge. A structure index is defined, which diverges at the transition points. Some conclusions are drawn concerning the construction of an ergodic theory of self-organization.
description: 10 pages Latex, 2 ps figures
Tephrocacteae Doweld 1999
Creators: name: Walter, Helmut E.
name: Guerrero, Pablo C.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Caryophyllales
Cactaceae

description: Tribe Tephrocacteae Doweld:
 —According to phylogenetic analyses (Ritz et al. 2012, Walker et al. 2018, Majure et al. 2019), the monophyletic clade “ Tephrocacteae ” represents a widely distributed group which includes the genera Pterocactus K.Schum., Maihueniopsis Speg., Tephrocactus Lem., Austrocylindropuntia Backeb., and Cumulopuntia F.Ritter. The study by Ritz et al. (2012) retrieved two main clades, one of which comprises Pterocactus and Maihueniopsis and the other one harbours Tephrocactus and the sister pair Cumulopuntia and Austrocylindropuntia. Former taxonomic concepts (e.g. Hunt et al. 2006: p. 12) suggested a close relationship between Maihueniopsis and Cumulopuntia mainly for their shared gross morphology. Wallace & Dickie’s (2002) results suggest a close relationship between Maihueniopsis and Thephrocactus and, furthermore, Pterocactus was treated as a tribe, an opinion shared by Nyffeler & Eggli (2010). Yet, in Griffith & Porter (2009), Pterocactus was not isolated but was placed together with Maihueniopsis in a basal grade to the rest of the terete-stemmed Opuntioideae. Ritz et al. (2012) showed that Pterocactus is not isolated, appearing as sister to Maihueniopsis. This finding supports Stuppy’s (2001) assumption that the genus might be closely related to Maihueniopsis. Although some morphological characters of Pterocactus are unique in the tribe and the Opuntioideae (the base of the glochids is rounded; the flowers are immersed into the apex of the segment; at an early oncological stage the fruit is not clearly separated from the surrounding tissue of the segment; the funicular girdle of the seed forms a broad papery and undulating wing), it shares some important morphological characters with Maihueniopsis. According to all these findings our classification follows the results of Ritz et al. (2012). According to the results of Ritz et al. one large species-complex was split: Cumulopuntia boliviana (Salm-Dyck) F.Ritter (Table 2).
description: Published as part of Walter, Helmut E. & Guerrero, Pablo C., 2022, Towards a unified taxonomic catalogue for the Chilean cacti: assembling molecular systematics and classical taxonomy, pp. 79-98 in Phytotaxa 550 (2) on page 82, DOI: 10.11646/phytotaxa.550.2.1, http://zenodo.org/record/6641038
Coarse-graining the dynamics of immersed and driven fiber assemblies
Creators: name: Stein, David B.
name: Shelley, Michael J.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: An important class of fluid-structure problems involve the dynamics of ordered arrays of immersed, flexible fibers. While specialized numerical methods have been developed to study fluid-fiber systems, they become infeasible when there are many, rather than a few, fibers present, nor do these methods lend themselves to analytical calculation. Here, we introduce a coarse-grained continuum model, based on local-slender body theory, for elastic fibers immersed in a viscous Newtonian fluid. It takes the form of an anisotropic Brinkman equation whose skeletal drag is coupled to elastic forces. This model has two significant benefits: (1) the density effects of the fibers in a suspension become analytically manifest, and (2) it allows for the rapid simulation of dense suspensions of fibers in regimes inaccessible to standard methods. As a first validation, without fitting parameters, we achieve very reasonable agreement with 3D Immersed Boundary simulations of a bed of anchored fibers bent by a shear flow. Secondly, we characterize the effect of density on the relaxation time of fiber beds under oscillatory shear, and find close agreement to results from full numerical simulations. We then study buckling instabilities in beds of fibers, using our model both numerically and analytically to understand the role of fiber density and the structure of buckling transitions. We next apply our model to study the flow-induced bending of inclined fibers in a channel, as has been recently studied as a flow rectifier, examining the nature of the internal flows within the bed, and the emergence of inhomogeneous permeability. Finally, we extend the method to study a simple model of metachronal waves on beds of actuated fibers, as a model for ciliary beds. Our simulations reproduce qualitatively the pumping action of coordinated waves of compression through the bed.
Pre-big bang on the brane
Creators: name: Foffa, Stefano
Publisher: name: arXiv
Year: 2002
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The equations of motion and junction conditions for a gravi-dilaton brane world scenario are studied in the string frame. It is shown that they allow Kasner-like solutions on the brane, which makes the dynamics of the brane very similar to the low curvature phase of pre-big bang cosmology. Analogies and differences of this scenario with the Randall-Sundrum one and with the standard bulk pre-big bang dynamics are also discussed.
description: Final version published on PRD; one reference added
Holographic Complexity Equals Which Action?
Creators: name: Goto, Kanato
name: Marrochio, Hugo
name: Myers, Robert C.
name: Queimada, Leonel
name: Yoshida, Beni
Publisher: name: arXiv
Year: 2019
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We revisit the complexity$=$action proposal for charged black holes. We investigate the complexity for a dyonic black hole, and we find the surprising feature that the late-time growth is sensitive to the ratio between electric and magnetic charges. In particular, the late-time growth rate vanishes when the black hole carries only a magnetic charge. If the dyonic black hole is perturbed by a light shock wave, a similar feature appears for the switchback effect, e.g., it is absent for purely magnetic black holes. We then show how the inclusion of a surface term to the action can put the electric and magnetic charges on an equal footing, or more generally change the value of the late-time growth rate. Next, we investigate how the causal structure influences the late-time growth with and without the surface term for charged black holes in a family of Einstein-Maxwell-Dilaton theories. Finally, we connect the previous discussion to the complexity=action proposal for the two-dimensional Jackiw-Teitelboim theory. Since the two-dimensional theory is obtained by a dimensional reduction from Einstein-Maxwell theory in higher dimensions in a near-extremal and near-horizon limit, the choices of parent action and parent background solution determine the behaviour of holographic complexity in two dimensions.
description: 51 +15 pages, 10 figures
The Urge to Transcend: An Analysis of Pharmacological Cognitive Enhancer Use in Modern Society
Creators: Zahid, Soombal
Publisher: name: Columbia University
Year: 2010
Subjects: subject: Psychology
subject: FOS: Psychology
subject: Ethics

description: Cognition, a phenomenon that constitutes the life of the mind, is often considered to be
the self-defining feature of humans and a point of pride for many individuals. The term
“cognition” can refer to a combination of processes an organism uses to manage information,
including perception, attention, learning, memory, language, skilled motor behaviors, and socalled
executive functions, such as decision-making, goal-setting, planning, and judgment
(Whitehouse, Juengst, Mehlman, and Murray, 1997). It is common to hear people complain that
their memory is inadequate or that they cannot pay attention in certain cognitively demanding
situations; however, the concept of pharmacological cognitive enhancers (PCEs) did not arise to
alleviate these people of their typical complaints. Rather, PCEs were originally developed to help
people suffering from brain injuries and neuropsychiatric disorders (e.g. attention deficit
hyperactivity disorder) or neurodegenerative disorders (e.g. Alzheimer’s disease) regain control
over their memory, attention, and executive function abilities which are frequently affected in a
negative way by their condition (Sahakian and Morein-Zamir, 2010).
Decoherence of dipolar spin ensembles in diamond
Creators: name: Bauch, Erik
name: Singh, Swati
name: Lee, Junghyun
name: Hart, Connor A.
name: Schloss, Jennifer M.
name: Turner, Matthew J.
name: Barry, John F.
name: Pham, Linh
name: Bar-Gill, Nir
name: Yelin, Susanne F.
name: Walsworth, Ronald L.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We present a combined theoretical and experimental study of solid-state spin decoherence in an electronic spin bath, focusing specifically on ensembles of nitrogen vacancy (NV) color centers in diamond and the associated substitutional nitrogen spin bath. We perform measurements of NV spin free induction decay times $T_2^*$ and spin-echo coherence times $T_2$ in 25 diamond samples with nitrogen concentrations [N] ranging from 0.01 to 300\,ppm. We introduce a microscopic model and perform numerical simulations to quantitatively explain the degradation of both $T_2^*$ and $T_2$ over four orders of magnitude in [N]. Our results resolve a long-standing discrepancy observed in NV $T_2$ experiments, enabling us to describe NV ensemble spin coherence decay shapes as emerging consistently from the contribution of many individual NV.
description: 6 pages, 4 figures + supplement
The Causal Interpretation of Dust and Radiation Fluids Non-Singular Quantum Cosmologies
Creators: name: de Barros, J. Acacio
name: Pinto-Neto, N.
name: Sagioro-Leal, M. A.
Publisher: name: arXiv
Year: 1997
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We apply the causal interpretation of quantum mechanics to homogeneous and isotropic quantum cosmology where the sources of the gravitational field are either dust or radiation perfect fluids. We find non-singular quantum trajectories which tends to the classical one when the scale factor becomes much larger then the Planck length. In this situation, the quantum potential becomes negligible. There are no horizons. As radiation is a good approximation for the matter content of the early universe, this result suggests that the universe can be eternal due to quantum effects.
description: 10 pages, LaTeX, 5 figures in postscript, requires epsf
BO'LAJAK BOSHLANG'ICH SINF O'QITUVCHILARIDA NUTQIY KOMPETENSIYALARNI RIVOJLANTIRISH PEDAGOGIK MUAMMO SIFATIDA
Creators: name: Nuradilova, Aselxan
Publisher: name: Zenodo
Year: 2024

description: Ushbu tezisda bo‘lajak boshlang‘ich sinf o‘qituvchilarida nutqiy kompetensiyalarni rivojlantirish masalasi pedagogik muammo sifatida o‘rganiladi. O‘qituvchining nutqiy kompetensiyalari, o‘quv jarayonida muvaffaqiyatli ta’lim berish va o‘quvchilar bilan samarali muloqot o‘rnatishda muhim ahamiyatga ega. Tadqiqotda nutqiy kompetensiyalarni rivojlantirishdagi mavjud muammolar, ta’lim tizimidagi an’anaviy yondashuvlar va innovatsion metodlarning ahamiyati tahlil qilinadi. Tezisda shuningdek, o‘qituvchilarni tayyorlash jarayonida nutqiy kompetensiyalarni rivojlantirish uchun samarali pedagogik yondashuvlar va metodlar taklif etiladi. Olingan natijalar bo‘lajak o‘qituvchilarni tayyorlashda nutqiy kompetensiyalarni rivojlantirishga qaratilgan strategiyalarni ishlab chiqishga yordam beradi.
The Use of Battle Rap As a Way to Engage Students in STEM
Creators: Parker, Jamie Thomas
Publisher: name: Columbia University
Year: 2020
Subjects: Science--Study and teaching
Music in education
Rap (Music)
Hip-hop

description: This qualitative, multi-case study examined the process of lyric creation and nontraditional modes of communication (using themes from hip-hop and battle rap) as a mechanism for developing a teaching and learning strategy in STEM education. This manuscript style dissertation, examines the experiences of 24 postsecondary students and five battle rappers who created science-themed lyrics, used them as a learning strategy, and delivered content in a college and community setting. Insights into teaching and learning were revealed through the study of these lyrics from a constructivist and intellectual warrior theoretical framework. This research showed that as a result of utilizing battle rap, learning spaces were improved. Students’ interviews, lyrics, and reflections uncovered that they appreciated the opportunity to be more creative in class were more engaged, communicated and networked more than they did in their traditional science classroom. The battle rappers discussed and displayed the characteristics that allow them to engage audiences in hopes that teachers can learn how to incorporate engaging techniques within their own classrooms. Through interviews and a performance, battle rappers’ attempt to keep students engaged revealed their transparency; ability to freestyle; get hyped; and demonstrate charisma, presence, character, and energy. This information helped to explain, describe, and understand the experiences of both students and battle rappers and their potential relationships to science and the community. This work supports arguments for the use of culture (art/music/experiences) through music in the science classroom.
Time Evolution in Open String Theory
Creators: name: Sen, Ashoke
Publisher: name: arXiv
Year: 2002
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss a general iterative procedure for constructing time dependent solutions in open string theory describing rolling of a generic tachyon field away from its maximum. These solutions are characterized by two parameters labelling the initial position and velocity of the tachyon field, but one of these parameters can be removed by using time translation symmetry. The Wick rotated version of the resulting one parameter family of inequivalent solutions describes a one parameter family of boundary conformal field theories, each member of which is related to the boundary conformal field theory describing the original D-brane system by a nearly marginal deformation. We apply this technique to construct a time dependent solution on a D-brane in bosonic string theory which can be interpreted as the creation of a lower dimensional brane during the decay of an unstable D-brane.
description: LaTeX file, 35 pages, 2 figures, discussion on multiple rolling tachyons expanded to include the general case, references added; v4: typos corrected
Quantum-mechanical tunneling: differential operators, zeta-functions and determinants
Creators: name: Casahorran, J.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We consider in detail the quantum-mechanical problem associated with the motion of a one-dimensional particle under the action of the double-well potential. Our main tool will be the euclidean (imaginary time) version of the path-integral method. Once we perform the Wick rotation, the euclidean equation of motion is the same as the usual one for the point particle in real time, except that the potential at issue is turned upside down. In doing so, our double-well potential becomes a two-humped potential. As required by the semiclassical approximation we may study the quadratic fluctuations over the instanton which represents in this context the localised finite-action solutions of the euclidean equation of motion. The determinants of the quadratic differential operators are evaluated by means of the zeta-function method. We write in closed form the eigenfunctions as well as the energy eigenvalues corresponding to such operators by using the shape-invariance symmetry. The effect of the multi-instantons configurations is also included in this approach.
description: 27 pages, RevTex
The Urban, Social, and Environmental Impact of Centralized Waste Systems: A Study on Segregation and Local Alternatives for the Doña Juana Landfill in Bogotá, Colombia
Creators: Moreno, Juan Sebastián
Publisher: name: Columbia University
Year: 2021
Subjects: City planning
Refuse and refuse disposal--Planning
Sanitary landfills--Planning

description: Waste has been concealed and misallocated as a consequence of urban growth. While many residents of cities rarely think about refuse beyond a quotidian scale, the spatial consequences of waste management systems are disproportionately dire for the neighbors of landfills – often, the urban poor. In Latin American cities, the entanglement of waste and urban informality is a driving force behind peripheral urbanization, a process in which the margins of cities are contested and appropriated by those who have nowhere else to go. This thesis explores the consequences of centralizing waste in Bogotá, Colombia. The Doña Juana landfill, the only facility serving the city, has operated since 1988 and has radically changed the social dynamics and the landscape of its environment. As more land gets devoured to bury trash, contamination and informality spread at a similar pace, creating opportunities for increased peripheral development and reinforcing patterns of segregation. Placing centralized landfills, such as Doña Juana, is equivalent to discarding pieces of cities, marking them as disposable. In order to repair the urban fabrics ruptured by waste, urban planners need to create strategies that account for the spatial inequities of landfills, but also to understand the role of these pieces of infrastructure in the expansion of informal development.
On Geometry and Matrix Models
Creators: name: Dijkgraaf, Robbert
name: Vafa, Cumrun
Publisher: name: arXiv
Year: 2002
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We point out two extensions of the relation between matrix models, topological strings and N=1 supersymmetric gauge theories. First, we note that by considering double scaling limits of unitary matrix models one can obtain large N duals of the local Calabi-Yau geometries that engineer N=2 gauge theories. In particular, a double scaling limit of the Gross-Witten one-plaquette lattice model gives the SU(2) Seiberg-Witten solution, including its induced gravitational corrections. Secondly, we point out that the effective superpotential terms for N=1 ADE quiver gauge theories is similarly computed by large multi-matrix models, that have been considered in the context of ADE minimal models on random surfaces. The associated spectral curves are multiple branched covers obtained as Virasoro and W-constraints of the partition function.
description: 24 pages
Lattice-QCD Determination of the Hyperon Axial Couplings in the Continuum Limit
Creators: name: Savanur, Aditya
name: Lin, Huey-Wen
Publisher: name: arXiv
Year: 2019
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present the first continuum extrapolation of the hyperon octet axial couplings ($g_{ΣΣ}$ and $g_{ΞΞ}$) from $N_f=2+1+1$ lattice QCD. These couplings are important parameters in the low-energy effective field theory description of the octet baryons and fundamental to the nonleptonic decays of hyperons and to hyperon-hyperon and hyperon-nucleon scattering with application to neutron stars. We use clover lattice fermion action for the valence quarks with sea quarks coming from configurations of $N_f=2+1+1$ highly improved staggered quarks (HISQ) generated by MILC Collaboration. Our work includes the first calculation of $g_{ΣΣ}$ and $g_{ΞΞ}$ directly at the physical pion mass on the lattice, and a full account of systematic uncertainty, including excited-state contamination, finite-volume effects and continuum extrapolation, all addressed for the first time. We find the continuum-limit hyperon coupling constants to be $g_{ΣΣ}=0.4455(55)_\text{stat}(65)_\text{sys}$ and $g_{ΞΞ} =-0.2703(47)_\text{stat}(13)_\text{sys}$, which correspond to low-energy constants of $D = 0.708(10)_\text{stat}(6)_\text{sys}$ and $F = 0.438(7)_\text{stat}(6)_\text{sys}$. The corresponding SU(3) symmetry breaking is 9\% which is about a factor of 2 smaller than the earlier lattice estimate.
description: 5 pages, 3 figures