cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Evolution of the Lyman-Alpha Luminosity Function During Reionization
Creators: name: Morales, Alexa
name: Mason, Charlotte
name: Bruton, Sean
name: Gronke, Max
name: Haardt, Francesco
name: Scarlata, Claudia
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The time frame in which hydrogen reionization occurred is highly uncertain, but can be constrained by observations of Lyman-alpha (Ly$α$) emission from distant sources. Neutral hydrogen in the intergalactic medium (IGM) attenuates Ly$α$~photons emitted by galaxies. As reionization progressed the IGM opacity decreased, increasing Ly$α$~visibility. The galaxy Ly$α$~luminosity function (LF) is thus a useful tool to constrain the timeline of reionization. In this work, we model the Ly$α$~LF as a function of redshift, $z=5-10$, and average IGM neutral hydrogen fraction, $\overline{x}_\textsc{hi}$. We combine the Ly$α$~luminosity probability distribution obtained from inhomogeneous reionization simulations with a model for the UV LF to model the Ly$α$~LF. As the neutral fraction increases, the average number density of Ly$α$~emitting galaxies decreases, and are less luminous, though for $\overline{x}_\textsc{hi} \lesssim 0.4$ there is only a small decrease of the Ly$α$~LF. We use our model to infer the IGM neutral fraction at $z=6.6, 7.0, 7.3$ from observed Ly$α$~LFs. We conclude that there is a significant increase in the neutral fraction with increasing redshift: $\overline{x}_\textsc{hi}(z=6.6)=0.08^{+ 0.08}_{- 0.05}, \, \overline{x}_\textsc{hi}(z=7.0)=0.28 \pm 0.05$ and $\overline{x}_\textsc{hi}(z=7.3)=0.83^{+ 0.06}_{- 0.07}$. We predict trends in the Ly$α$~luminosity density and Schechter parameters as a function of redshift and the neutral fraction. We find that the Ly$α$~luminosity density decreases as the universe becomes more neutral. Furthermore, as the neutral fraction increases, the faint-end slope of the Ly$α$~LF steepens, and the characteristic Ly$α$~luminosity shifts to lower values, concluding that the evolving shape of the Ly$α$~LF -- not just its integral -- is an important tool to study reionization.
description: 20 pages, 10 figures, submitted to ApJ
Holographic Wave Functions, Meromorphization and Counting Rules
Creators: name: Radyushkin, A. V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the large-Q^2 behavior of the meson form factor F_M (Q^2) constructed using the holographic light-front wave functions proposed recently by Brodsky and de Teramond. We show that this model can be also obtained within the Migdal's regularization approach (``meromorphization''), if one applies it to 3-point function for scalar currents made of scalar quarks. We found that the asymptotic 1/Q^2 behavior of F_M (Q^2) is generated by soft Feynman mechanism rather than by short distance dynamics, which causes very late onset of the 1/Q^2 asymptotic behavior. Using meromorphization for spin-1/2 quarks, we demonstrated that resulting form factor F^{spinor}_M (Q^2) has 1/Q^4 asymptotic behavior. Now, owing to the late onset of this asymptotic pattern, F^{spinor}_M (Q^2) imitates the 1/Q^2 behavior in the few GeV^2 region. We discuss analogy between meromorphization and local quark-hadron duality model for the pion form factor, and show that adding the O(α_s) correction to the spectral function brings in the hard pQCD contribution that has the dimensional counting $1/Q^2$ behavior at large Q^2. At accessible Q^2, the O(α_s) term is a rather small fraction of the total result. We conclude that the ``observed'' quark counting rules for hadronic form factors is an approximate phenomenon resulting from Feynman mechanism in its preasymptotic regime.
description: Final version published in Physics Letters B
Time discretization and Markovian iteration for coupled FBSDEs
Creators: name: Bender, Christian
name: Zhang, Jianfeng
Publisher: name: arXiv
Year: 2008
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 65C30, 60H10 (Primary); 60H30, 65C05 (Secondary)

description: In this paper we lay the foundation for a numerical algorithm to simulate high-dimensional coupled FBSDEs under weak coupling or monotonicity conditions. In particular, we prove convergence of a time discretization and a Markovian iteration. The iteration differs from standard Picard iterations for FBSDEs in that the dimension of the underlying Markovian process does not increase with the number of iterations. This feature seems to be indispensable for an efficient iterative scheme from a numerical point of view. We finally suggest a fully explicit numerical algorithm and present some numerical examples with up to 10-dimensional state space.
description: Published in at http://dx.doi.org/10.1214/07-AAP448 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Is GRB 050904 a super-long burst?
Creators: name: Zou, Y. C.
name: Dai, Z. G.
name: Xu, D.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: By considering synchrotron radiative process in the internal shock model and assuming that all internal shocks are nearly equally energetic, we analyze the gamma-ray burst (GRB) emission at different radii corresponding to different observed times. We apply this model to GRB 050904 and find that our analytical results can provide a natural explanation for the multi-band observations of GRB 050904. This suggests that the X-ray flare emission and the optical emission of this burst could have originated from internal shocks being due to collisions among nearly-equally-energetic shells ejected from the central engine. Thus GRB 050904 appears to be a burst with super-long central engine activity.
description: 16 pages, 4 figure. Submitted on Oct. 21, 2005, accepted by ApJ
Orbital ordering transition in Ca$_2$RuO$_4$ observed with resonant x-ray diffraction
Creators: name: Zegkinoglou, I.
name: Strempfer, J.
name: Nelson, C. S.
name: Hill, J. P.
name: Chakhalian, J.
name: Bernhard, C.
name: Lang, J. C.
name: Srajer, G.
name: Fukazawa, H.
name: Nakatsuji, S.
name: Maeno, Y.
name: Keimer, B.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Resonant x-ray diffraction performed at the $\rm L_{II}$ and $\rm L_{III}$ absorption edges of Ru has been used to investigate the magnetic and orbital ordering in Ca$_2$RuO$_4$ single crystals. A large resonant enhancement due to electric dipole $2p\to 4d$ transitions is observed at the wave-vector characteristic of antiferromagnetic ordering. Besides the previously known antiferromagnetic phase transition at $\rm T_{N}=110$ K, an additional phase transition, between two paramagnetic phases, is observed around 260 K. Based on the polarization and azimuthal angle dependence of the diffraction signal, this transition can be attributed to orbital ordering of the Ru $t_{2g}$ electrons. The propagation vector of the orbital order is inconsistent with some theoretical predictions for the orbital state of Ca$_2$RuO$_4$.
description: to appear in PRL
Origin of Irradiation Synergistic Effects in Silicon Bipolar Transistors: a Review
Creators: name: Song, Yu
name: Wei, Su-Huai
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The practical damage of silicon bipolar devices subjected to mixed ionization and displacement irradiations is usually evaluated by the sum of separated ionization and displacement damages. However, recent experiments show clear difference between the practical and summed damages, indicating significant irradiation synergistic effects (ISEs). Understanding the behaviors and mechanisms of ISEs is essential to predict the practical damages. In this work, we first make a brief review on the state of the art, critically emphasizing on the difficulty encountered in previous models to understand the dose rate dependence of the ISEs. We then introduce in detail our models explaining this basic phenomenon, which can be described as follows. Firstly, we show our experimental works on PNP and NPN transistors. A variable neutron fluence and $γ$-ray dose setup is adopted. Fluence-dependent `tick'-like and sublinear dose profiles are observed for PNP and NPN transistors, respectively. Secondly, we describe our theoretical investigations on the positive ISE in NPN transistors. We propose an atomistic model of transformation and annihilation of $\rm V_2$ displacement defects in p-type silicon under ionization irradiation, which is totally different from the traditional picture of Coulomb interaction of oxide trapped charges in silica on charge carriers in irradiated silicon. The predicted novel dose and fluence dependences are fully verified by the experimental data. Thirdly, the mechanism of the observed negative ISE in PNP transistors is investigated in a similar way as in the NPN transistor case. The difference is that in n-type silicon, VO displacement defects also undergo an ionization-induced transformation and annihilation process. Our results show that, the evolution of displacement defects due to carrier-enhanced defect diffusion and reaction is the dominating mechanism of the ISEs.
description: 11 pages, 10 figures; accepted by ACS Applied Electronic Materials
Reconstructing three-dimensional densities from two-dimensional observations of molecular gas
Creators: name: Hu, Zipeng
name: Krumholz, Mark R.
name: Federrath, Christoph
name: Pokhrel, Riwaj
name: Gutermuth, Robert A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Star formation has long been known to be an inefficient process, in the sense that only a small fraction $ε_{\rm ff}$ of the mass of any given gas cloud is converted to stars per cloud free-fall time. However, developing a successful theory of star formation will require measurements of both the mean value of $ε_{\rm ff}$ and its scatter from one molecular cloud to another. Because $ε_{\rm ff}$ is measured relative to the free-fall time, such measurements require accurate determinations of cloud volume densities. Efforts to measure the volume density from two-dimensional projected data, however, have thus far relied on treating molecular clouds as simple uniform spheres, while their real shapes are likely filamentary and their density distributions far from uniform. The resulting uncertainty in the true volume density is likely one of the major sources of error in observational estimates of $ε_{\rm ff}$. In this paper, we use a suite of simulations of turbulent, magnetized, radiative, self-gravitating star-forming clouds to examine whether it is possible to obtain more accurate volume density estimates and thereby reduce this error. We create mock observations from simulations, and show that current analysis methods relying on the spherical assumption likely yield ~ 0.26 dex underestimations and ~ 0.51 dex errors in volume density estimates, corresponding to a ~ 0.13 dex overestimation and a ~ 0.25 dex scatter in $ε_{\rm ff}$, comparable to the scatter in observed cloud samples. We build a predictive model that uses information accessible in two-dimensional measurements -- most significantly the Gini coefficient of the surface density distribution -- to estimate volume density with ~ 0.3 dex less scatter. We test our method on a recent observation of the Ophiuchus cloud, and show that it successfully reduces the $ε_{\rm ff}$ scatter.
description: 14 pages, 14 figures. Accepted by MNRAS
Heterotic Strings in Two Dimensions and New Stringy Phase Transitions
Creators: name: Davis, Joshua L.
name: Larsen, Finn
name: Seiberg, Nathan
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss heterotic string theories in two dimensions with gauge groups Spin(24) and Spin(8) x E_8. After compactification the theories exhibit a rich spectrum of states with both winding and momentum. At special points some of these stringy states become massless, leading to new first order phase transitions. For example, the thermal theories exhibit standard thermodynamics below the phase transition, but novel and peculiar behavior above it. In particular, when the radius of the Euclidean circle is smaller than the phase transition point the torus partition function is not given by the thermal trace over the spacetime Hilbert space. The full moduli space of compactified theories is 13 dimensional, when Wilson lines are included; the Spin(24) and Spin(8) x E_8 theories correspond to distinct decompactification limits.
description: 32 pages; v2: references added, minor changes
Randomly switching evolution equations
Creators: name: Klimasara, Paweł
name: Mackey, Michael C.
name: Tomski, Andrzej
name: Tyran-Kamińska, Marta
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 35R60, 60J60, 60K37, 92C40

description: We present an investigation of stochastic evolution in which a family of evolution equations in $L^1$ are driven by continuous-time Markov processes. These are examples of so-called piecewise deterministic Markov processes (PDMP's) on the space of integrable functions. We derive equations for the first moment and correlations (of any order) of such processes. We also introduce the mean of the process at large time and describe its behaviour. The results are illustrated by some simple, yet generic, biological examples characterized by different one-parameter types of bifurcations.
Vafa-Witten Estimates for Compact Symmetric Spaces
Creators: name: Goette, Sebastian
Publisher: name: arXiv
Year: 2006
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C27; 53C35; 58J50

description: We give an optimal upper bound for the first eigenvalue of the untwisted Dirac operator on a compact symmetric space G/H with rk G-rk H\le 1 with respect to arbitrary Riemannian metrics. We also prove a rigidity statement.
description: LaTeX, 11 pages. V2: Rigidity statement added, minor changes. To appear
Active Fire Detection in Landsat-8 Imagery: a Large-Scale Dataset and a Deep-Learning Study
Creators: name: Pereira, Gabriel Henrique de Almeida
name: Fusioka, André Minoro
name: Nassu, Bogdan Tomoyuki
name: Minetto, Rodrigo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Active fire detection in satellite imagery is of critical importance to the management of environmental conservation policies, supporting decision-making and law enforcement. This is a well established field, with many techniques being proposed over the years, usually based on pixel or region-level comparisons involving sensor-specific thresholds and neighborhood statistics. In this paper, we address the problem of active fire detection using deep learning techniques. In recent years, deep learning techniques have been enjoying an enormous success in many fields, but their use for active fire detection is relatively new, with open questions and demand for datasets and architectures for evaluation. This paper addresses these issues by introducing a new large-scale dataset for active fire detection, with over 150,000 image patches (more than 200 GB of data) extracted from Landsat-8 images captured around the world in August and September 2020, containing wildfires in several locations. The dataset was split in two parts, and contains 10-band spectral images with associated outputs, produced by three well known handcrafted algorithms for active fire detection in the first part, and manually annotated masks in the second part. We also present a study on how different convolutional neural network architectures can be used to approximate these handcrafted algorithms, and how models trained on automatically segmented patches can be combined to achieve better performance than the original algorithms - with the best combination having 87.2% precision and 92.4% recall on our manually annotated dataset. The proposed dataset, source codes and trained models are available on Github (https://github.com/pereira-gha/activefire), creating opportunities for further advances in the field
description: 23 pages, 17 figures
The velocity field of baryonic gas in the universe
Creators: name: Kim, Bryan
name: He, Ping
name: Pando, Jesús
name: Feng, Long-Long
name: Fang, Li-Zhi
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The dynamic evolution of the baryonic intergalactic medium (IGM) caused by the underlying dark matter gravity is governed by the Navier-Stokes equations in which many cooling and heating processes are involved. However, it has long been recognized that the growth mode dynamics of cosmic matter clustering can be sketched by a random force driven Burgers' equation if cooling and heating are ignored. Just how well the dynamics of the IGM can be described as a Burgers fluid has not been fully investigated probably because cooling and heating are essential for a detailed understanding of the IGM. Using IGM samples produced by a cosmological hydrodynamic simulation in which heating and cooling processes are properly accounted for, we show that the IGM velocity field in the nonlinear regime shows the features of a Burgers fluid, that is, when the Reynolds number is high, the velocity field consists of an ensemble of shocks. Consequently, (1) the IGM velocity $v$ is generally smaller than that of dark matter; (2) for the smoothed field, the IGM velocity shows tight correlation with dark matter given by $v \simeq s v_{dm}$, with $s<1$, such that the lower the redshift, the smaller $s$; (3) the velocity PDFs are asymmetric between acceleration and deceleration events; (4) the PDF of velocity difference $Δv=v(x+r)-v(x)$ satisfies the scaling relation for a Burgers fluid, i.e., $P(Δv)=(1 r^y)F(Δv/r^y)$. We find the scaling function and parameters for the IGM which are applicable to the entire scale range of the samples (0.26 - 8 h$^{-1}$ Mpc). These properties show that the similarity mapping between the IGM and dark matter is violated on scales much larger than the Jeans length of the IGM.
description: 14 pages, 10 jpg-figures, accepted for publication in the Astrophysical Journal. References added
Perturbation theory for large Stokes number particles in random velocity fields
Creators: name: Olla, Piero
name: Vuolo, Maria Raffaella
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We derive a perturbative approach to study, in the large inertia limit, the dynamics of solid particles in a smooth, incompressible and finite-time correlated random velocity field. We carry on an expansion in powers of the inverse square root of the Stokes number, defined as the ratio of the relaxation time for the particle velocities and the correlation time of the velocity field. We describe in this limit the residual concentration fluctuations of the particle suspension, and determine the contribution to the collision statistics produced by clustering. For both concentration fluctuations and collision velocities, we analyze the differences with the compressible one-dimensional case.
description: Latex, 12 pages, 2 eps figures included
Liquid-gas separation in colloidal electrolytes
Creators: name: Caballero, Jose B.
name: Puertas, Antonio M.
name: Fernandez-Barbero, Antonio
name: Nieves, F. Javier de las
name: Romero-Enrique, J. M.
name: Rull, L. F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The liquid-gas transition of an electroneutral mixture of oppositely charged colloids, studied by Monte Carlo simulations, is found in the low temperature -- low density region. The critical temperature shows a non-monotonous behavior as a function of the interaction range, $κ^{-1}$, with a maximum at $κσ\approx 10$, implying an island of coexistence in the $κ$-$ρ$ plane. The system is arranged in such a way that each particle is surrounded by shells of particles with alternating charge. In contrast with the electrolyte primitive model, both neutral and charged clusters are obtained in the vapor phase
description: 6 pages
Search for eta_c decays into pi pi and K Bar K
Creators: name: Ablikim, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Using 58 million $J/ψ$ events taken with the BESII detector, a search for $eta_{c}$ CP violating decays into $ππ$ and $\bar{K}K$ has been performed. No clear $eta_{c}$ is observed, and upper limits for $B(eta_{c}->ππ)$and $B(eta_{c}->\bar{K} K)$ are given at the 90% confidence level, $B(J/ψ->γη_{c})\times B(eta_{c}->π^{+}π^{-})<1.1\times 10^{-5}$ , $B(J/ψ->γη_{c})\times B(eta_{c}->π^{0}π^{0})<0.71\times 10^{-5}$, $B(J/ψ->γη_{c})\times B(eta_{c}->K^{+}K^{-})<0.96\times 10^{-5}$ and $B(J/ψ->γη_{c})\times B(eta_{c}->{K_{s}}^{0}{K_{s}}^{0})<0.53\times 10^{-5}$.
description: 6 pages,4 figures
Estructura y diseño del mapa de sitio en GOAP del micrositio para la adopción del Acceso Abierto en Angola
Creators: name: United Nations Educational, Scientific and Cultural Organization
name: Ministério Do Ensino Superior, Ciência
name: Redalyc-Universidad Autónoma Del Estado De México
name: AmeliCA
name: Universidade Óscar Ribas
Publisher: name: Zenodo
Year: 2022
Subjects: Acceso Abierto
Angola
África
Repositorios
Ciencia Abierta
Interoperabilidad

description: Trabajo derivado del proyecto de colaboración entre Redalyc UAEM, AmeliCA, MESCTI y U. Óscar Ribas financiado por UNESCO para el desarrollo de una estrategia de Acceso Abierto en Angola. Vol. 35 de 38
Energy cost study for controlling complex social networks with conformity behavior
Creators: name: Chen, Hong
name: Yong, Ee Hou
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: In order to understand controlling a complex system, an estimation of the required effort needed to achieve control is vital. Previous works have addressed this issue by studying the scaling laws of energy cost in a general way with continuous-time linear dynamics. However, continuous-time linear dynamics is unable to capture conformity behavior, which is common in many complex social systems. Therefore, to understand controlling social systems with conformity, discrete-time modelling is used and the energy cost scaling laws are derived. The results are validated numerically with model and real networks. In addition, the energy costs needed for controlling systems with and without conformity are compared, and it was found that controlling networked systems with conformity features always requires less control energy. Finally, it is shown through simulations that heterogeneous scale-free networks are less controllable, requiring a higher number of minimum drivers. Since the conformity-based model relates to various complex systems, such as flocking, or evolutionary games, the results of this paper represent a step forward towards developing realistic control of complex social systems.
Speckle Imaging Characterization of Radial Velocity Exoplanet Systems
Creators: name: Dalba, Paul A.
name: Kane, Stephen R.
name: Howell, Steve B.
name: Horch, Elliott P.
name: Li, Zhexing
name: Hirsch, Lea A.
name: Burt, Jennifer
name: Brandt, Timothy D.
name: Mocnik, Teo
name: Henry, Gregory W.
name: Everett, Mark E.
name: Rosenthal, Lee J.
name: Howard, Andrew W.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We conducted speckle imaging observations of 53 stellar systems that were members of long-term radial velocity (RV) monitoring campaigns and exhibited substantial accelerations indicative of planetary or stellar companions in wide orbits. Our observations were made with blue and red filters using the Differential Speckle Survey Instrument at Gemini-South and the NN-Explore Exoplanet Stellar Speckle Imager at the WIYN telescope. The speckle imaging identifies eight luminous companions within two arcseconds of the primary stars. In three of these systems (HD 1388, HD 87359, and HD 104304), the properties of the imaged companion are consistent with the RV measurements, suggesting that these companions may be associated with the primary and the cause of the RV variation. For all 53 stellar systems, we derive differential magnitude limits (i.e., contrast curves) from the imaging. We extend this analysis to include upper limits on companion mass in systems without imaging detections. In 25 systems, we rule out companions with mass greater than 0.2 $M_{\odot}$, suggesting that the observed RV signals are caused by late M dwarfs or substellar (potentially planetary) objects. On the other hand, the joint RV and imaging analysis almost entirely rules out planetary explanations of the RV signal for HD 19522 and suggests that the companion must have an angular separation below a few tenths of an arcsecond. This work highlights the importance of combined RV and imaging observations for characterizing the outer regions of nearby planetary systems.
description: 15 pages, 6 figures, accepted for publication in AJ
Connectedness matters: Construction and exact random sampling of connected graphs
Creators: name: Horvát, Szabolcs
name: Modes, Carl D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Discrete Mathematics (cs.DM)
subject: Combinatorics (math.CO)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We describe a new method for the random sampling of connected networks with a specified degree sequence. We consider both the case of simple graphs and that of loopless multigraphs. The constraints of fixed degrees and of connectedness are two of the most commonly needed ones when constructing null models for the practical analysis of physical or biological networks. Yet handling these constraints, let alone combining them, is non-trivial. Our method builds on a recently introduced novel sampling approach that constructs graphs with given degrees independently (unlike edge-switching Markov Chain Monte Carlo methods) and efficiently (unlike the configuration model), and extends it to incorporate the constraint of connectedness. Additionally, we present a simple and elegant algorithm for directly constructing a single connected realization of a degree sequence, either as a simple graph or a multigraph. Finally, we demonstrate our sampling method on a realistic scale-free example, as well as on degree sequences of connected real-world networks, and show that enforcing connectedness can significantly alter the properties of sampled networks.
Random anisotropy disorder in superfluid 3He-A in aerogel
Creators: name: Volovik, G. E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The anisotropic superfluid 3He-A in aerogel provides an interesting example of a system with continuous symmetry in the presence of random anisotropy disorder. Recent NMR experiments allow us to discuss two regimes of the orientational disorder, which have different NMR properties. One of them, the (s)-state, is identified as the pure Larkin-Imry-Ma state. The structure of another state, the (f)-state, is not very clear: probably it is the Larkin-Imry-Ma state contaminated by the network of the topological defects pinned by aerogel.
description: JETP Lett. style, 6 pages, no figures, discussion extended, references added, version to be published in JETP Letters
Plasticity in amorphous solids is mediated by topological defects in the displacement field
Creators: name: Baggioli, Matteo
name: Kriuchevskyi, Ivan
name: Sirk, Timothy W.
name: Zaccone, Alessio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The microscopic mechanism by which amorphous solids yield plastically under an externally applied stress or deformation has remained elusive in spite of enormous research activity in recent years. Most approaches have attempted to identify atomic-scale structural "defects" or spatio-temporal correlations in the undeformed glass that may trigger plastic instability. In contrast, here we show that the topological defects which correlate with plastic instability can be identified, not in the static structure of the glass, but rather in the nonaffine displacement field under deformation. These dislocation-like topological defects (DTDs) can be quantitatively characterized in terms of Burgers circuits (and the resulting Burgers vectors) which are constructed on the microscopic nonaffine displacement field. We demonstrate that (i) DTDs are the manifestation of incompatibility of deformation in glasses as a result of violation of Cauchy-Born rules (nonaffinity); (ii) the resulting average Burgers vector displays peaks in correspondence of major plastic events, including a spectacular non-local peak at the yielding transition, which results from self-organization into shear bands due to the attractive interaction between anti-parallel DTDs; (iii) application of Schmid's law to the DTDs leads to prediction of shear bands at 45 degrees for uniaxial deformations, as widely observed in experiments and simulations.
description: v2: matching the published version
Seesaw geometry and leptogenesis
Creators: name: Di Bari, Pasquale
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The representation of the seesaw orthogonal matrix in the complex plane establishes a graphical correspondence between neutrino mass models and geometrical configurations, particularly useful to study relevant aspects of leptogenesis. We first derive the CP asymmetry bound for hierarchical heavy neutrinos and then an expression for the effective leptogenesis phase, determining the conditions for maximal phase and placing a lower bound on the phase suppression for generic models. Reconsidering the lower bounds on the lightest right-handed (RH) neutrino mass M_1 and on the reheating temperature T_reh, we find that models where one of the two heavier neutrino masses is dominated by the lightest right-handed (RH) neutrinos, typically arising from connections with quark masses, undergo both phase suppression and strong wash-out such that M_1 (T_reh)\gtrsim 10^{11} (10^{10}) GeV. The window 10^9 GeV \lesssim M_1,T_reh \lesssim 10^{10}GeV is accessible only for a class of models where m_1 is dominated by the lightest RH neutrino, with no straightforward connections with quark masses. Within this class we describe a new scenario of thermal leptogenesis where the baryon asymmetry of the Universe is generated by the decays of the second lightest RH neutrino, such that the lower bound on M_1 disappears and is replaced by a lower bound on M_2. Interestingly, the final asymmetry is independent on the initial conditions. We also discuss the validity of the approximation of hierarchical heavy neutrinos in a simple analytical way.
description: 48 pages, 11 figures; v2: typos corrected; added 1 figure, references, footnotes, more details at the end of 5.1 and in Section 7; to appear on NPB
Phase boundary near a magnetic percolation transition
Creators: name: Khairnar, Gaurav
name: Lerch, Cameron
name: Vojta, Thomas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Motivated by recent experimental observations [Phys. Rev. 96, 020407 (2017)] on hexagonal ferrites, we revisit the phase diagrams of diluted magnets close to the lattice percolation threshold. We perform large-scale Monte Carlo simulations of XY and Heisenberg models on both simple cubic lattices and lattices representing the crystal structure of the hexagonal ferrites. Close to the percolation threshold $p_c$, we find that the magnetic ordering temperature $T_c$ depends on the dilution $p$ via the power law $T_c \sim |p-p_c|^ϕ$ with exponent $ϕ=1.09$, in agreement with classical percolation theory. However, this asymptotic critical region is very narrow, $|p-p_c| \lesssim 0.04$. Outside of it, the shape of the phase boundary is well described, over a wide range of dilutions, by a nonuniversal power law with an exponent somewhat below unity. Nonetheless, the percolation scenario does not reproduce the experimentally observed relation $T_c \sim (x_c -x)^{2/3}$ in PbFe$_{12-x}$Ga$_x$O$_{19}$. We discuss the generality of our findings as well as implications for the physics of diluted hexagonal ferrites.
description: 9 pages, 11 figures included, final version as published
Thermal desorption of CH4 retained in CO2 ice
Creators: name: Luna, R.
name: Millan, C.
name: Domingo, M.
name: Satorre, M. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: CO2 ices are known to exist in different astrophysical environments. In spite of this, its physical properties (structure, density, refractive index) have not been as widely studied as those of water ice. It would be of great value to study the adsorption properties of this ice in conditions related to astrophysical environments. In this paper, we explore the possibility that CO2 traps relevant molecules in astrophysical environments at temperatures higher than expected from their characteristic sublimation point. To fulfil this aim we have carried out desorption experiments under High Vacuum conditions based on a Quartz Crystal Microbalance and additionally monitored with a Quadrupole Mass Spectrometer. From our results, the presence of CH4 in the solid phase above the sublimation temperature in some astrophysical scenarios could be explained by the presence of several retaining mechanisms related to the structure of CO2 ice.
description: 8 pages, accepted for publication in Astrophysics & Space Science
Cosmological constraints from higher-redshift gamma-ray burst, HII starburst galaxy, and quasar (and other) data
Creators: name: Cao, Shulei
name: Ryan, Joseph
name: Khadka, Narayan
name: Ratra, Bharat
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are mutually consistent. Cosmological constraints from a joint analysis of these data sets are largely consistent with currently-accelerating cosmological expansion as well as with cosmological constraints derived from a combined analysis of Hubble parameter ($H(z)$) and baryon acoustic oscillation (BAO, with Planck-determined baryonic matter density) measurements. A joint analysis of the $H(z)$ + BAO + QSO-AS + HIIG + GRB data provides fairly model-independent determinations of the non-relativistic matter density parameter $Ω_{\rm m_0}=0.313\pm0.013$ and the Hubble constant $H_0=69.3\pm1.2\ \rm{km \ s^{-1} \ Mpc^{-1}}$. These data are consistent with the dark energy being a cosmological constant and with spatial hypersurfaces being flat, but they do not rule out mild dark energy dynamics or a little spatial curvature. We also investigate the effect of including quasar flux measurements in the mix and find no novel conclusions.
description: 20 pages, 16 figures, MNRAS accepted version
A New Population of Planetary Nebulae Discovered in the Large Magellanic Cloud (I): Preliminary Sample
Creators: name: Reid, Warren A.
name: Parker, Quentin A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report our initial discovery of 73 new planetary nebulae (PNe) in the Large Magellanic Cloud (LMC) following confirmatory 2dF spectroscopy on the Anglo-Australian Telescope (AAT). Preliminary candidate sources come from a 10 per cent sub-area of our new deep, high resolution H-alpha map of the central 25 deg. square of the LMC obtained with the UK Schmidt Telescope (UKST). The depth of the high resolution map was extended to Requiv~22 for H-alpha (4.5 x 10-17 ergs cm-2 s-1 Ang-1) by a process of multi-exposure median co-addition of a dozen 2-hour H-alpha exposures. The resulting map is at least 1-magnitude deeper than the best wide-field narrow-band LMC images currently available. This depth, combined with our selection technique, has also led to the discovery of extended AGB halos around many new and previously known LMC PNe for the first time. Once complete, our new survey is expected to triple the LMC PN population and have significant implications for the LMC PN luminosity function, kinematics, abundance gradients chemical evolution and, via study of the AGB halos, the initial to final mass relation for low to intermediate mass stars.
description: 14 pages, 21 figures (zipped). Accepted for publication in Mmonthly Notices of the Royal Astronomical Society
New insights into the formation and growth of boson stars in dark matter halos
Creators: name: Chen, Jiajun
name: Du, Xiaolong
name: Lentz, Erik W.
name: Marsh, David J. E.
name: Niemeyer, Jens C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: This work studies the formation and growth of boson stars and their surrounding miniclusters by gravitational condensation using non-linear dynamical numerical methods. Fully dynamical attractive and repulsive self-interactions are also considered for the first time. In the case of pure gravity, we numerically prove that the growth of boson stars inside halos slows down and saturates as has been previously conjectured, and detail its conditions. Self-interactions are included using the Gross-Pitaevskii-Poisson equations. We find that in the case of strong attractive self-interactions the boson stars can become unstable and collapse, in agreement with previous stationary computations. At even stronger coupling, the condensate fragments. Repulsive self-interactions, as expected, promote boson star formation, and lead to solutions with larger radii.
description: 15 pages, 21 figures
Fractal Stationary Density in Coupled Maps
Creators: name: Jost, Juergen
name: Kolwankar, Kiran M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Dynamical Systems (math.DS)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study the invariant measure or the stationary density of a coupled discrete dynamical system as a function of the coupling parameter ε(0 < ε< 1/4). The dynamical system considered is chaotic and unsynchronized for this range of parameter values. We find that the stationary density, restricted on the synchronization manifold, is a fractal function. We find the lower bound on the fractal dimension of the graph of this function and show that it changes continuously with the coupling parameter
description: 8 pages, 3 figures, uses svmult.cls
Search for Black Hole Merger Families
Creators: name: Veske, Doğa
name: Sullivan, Andrew G.
name: Márka, Zsuzsa
name: Bartos, Imre
name: Corley, K. Rainer
name: Samsing, Johan
name: Buscicchio, Riccardo
name: Márka, Szabolcs
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The origin, environment, and evolution of stellar-mass black hole binaries are still a mystery. One of the proposed binary formation mechanisms is manifest in dynamical interactions between multiple black holes. A resulting framework of these dynamical interactions is the so-called hierarchical triple merger scenario, which happens when three black holes become gravitationally bound, causing two successive black hole mergers to occur. In such successive mergers, the black holes involved are directly related to each other, and hence this channel can be directly tested from the properties of the detected binary black hole mergers. Here we present a search for hierarchical triple mergers among events within the GWTC-1 and GWTC-2 catalogs of LIGO/Virgo, the eccentric localization of GW190521 and those found by the IAS-Princeton group. The search includes improved statistical quantification that also accounts for black hole spins. We perform our analysis for different upper bounds on the mass distribution of first generation BHs. Our results demonstrate the importance of the mass distributions' properties for constraining the hierarchical merger scenario. We present the individually significant merger pairs. The search yields interesting candidate families and hints of its future impact.
description: 4 figures, 7 pages without references
BCS-BEC Crossover Effects and Pseudogap in Neutron Matter
Creators: name: Durel, David
name: Urban, Michael
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Due to the large neutron-neutron scattering length, dilute neutron matter resembles the unitary Fermi gas, which lies half-way in the crossover from the BCS phase of weakly coupled Cooper pairs to the Bose-Einstein condensate of dimers. We discuss crossover effects in analogy with the T-matrix theory used in the physics of ultracold atoms, which we generalize to the case of a non-separable finite-range interaction. A problem of the standard Nozieres-Schmitt-Rink approach and different ways to solve it are discussed. It is shown that in the strong-coupling regime, the spectral function exhibits a pseudo-gap at temperatures above the critical temperature T_c. The effect of the correlated density on the density dependence of T_c is found to be rather weak, but a possibly important effect due to the reduced quasiparticle weight is identified.
description: 16 pages; v2: minor changes, references added
Non-thermal Production of PNGB Dark Matter and Inflation
Creators: name: Abe, Yoshihiko
name: Toma, Takashi
name: Yoshioka, Koichi
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A pseudo Nambu-Goldstone boson (pNGB) is a natural candidate of dark matter in that it avoids the severe direct detection bounds. We show in this paper that the pNGB has another different and interesting face with a higher symmetry breaking scale. Such large symmetry breaking is motivated by various physics beyond the standard model. In this case, the pNGB interaction is suppressed due to the Nambu-Goldstone property and the freeze-out production does not work even with sufficiently large portal coupling. We then study the pNGB dark matter relic abundance from the out-of-equilibrium production via feeble Higgs portal coupling. Further, a possibility is pursued the symmetry breaking scalar in the pNGB model plays the role of inflaton. The inflaton and dark matter are unified in a single field and the pNGB production from inflaton decay is inevitable. For these non-thermally produced relic abundance of pNGB dark matter and successful inflation, we find that the dark matter mass should be less than a few GeV in the wide range of the reheating temperature and the inflaton mass.
description: 23 pages, 8 figures, version to appear in JHEP
An effective field theory of holographic dark energy
Creators: name: Lin, Chunshan
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A general covariant local field theory of the holographic dark energy model is presented. It turns out the low energy effective theory of the holographic dark energy is the massive gravity theory whose graviton has 3 polarisations, including one scalar mode and two tensor modes. The Compton wavelength is the size of the future event horizon of the universe. The UV-IR correspondence in the holographic dark energy model stems from the scalar graviton's strong coupling at the energy scale that marks the breaking down of the effective field theory.
description: 18 pages, no figure; v2: minor revision, results unchanged; v3: published version, a few remarks added, a few typos corrected
ПОШУК СПОСОБІВ КЕРОВАНОГО МОДИФІКУВАННЯ ХАРАКТЕРИСТИК ФУНКЦІОНАЛЬНИХ ВУЗЛІВ БАГАТОСТУПІНЧАТИХ ФОТОКАТАЛІТИЧНИХ КОМПЛЕКСІВ ДЛЯ ОЧИЩЕННЯ ПОВІТРЯ
Creators: name: Дрючко О.Г., Захарченко Р.В., Бунякіна Н.В.,  Іваницька І.О., Ошкодьоров Є.О., Бурда А.Ю.
Publisher: name: Zenodo
Year: 2024

description: Узагальнено важливі для практичного використання відомості про лужні координаційні нітрати рідкісноземельних елементів церієвої підгрупи – прекурсори перспективних сучасних багатофункціональних матеріалів – щодо умов їх утворення й існування, природи хімічного зв’язку, складу, будови, форми координаційних поліедрів Ln, типу координації ліганд, існування ізотипних рядів по стехіометрії складу, структурі, виявляємих характерних властивостей. Одержані дані (як первинна інформація) є основою для виявлення, ідентифікації, контролю фазового стану об’єктів перероблення у підготовчих стадіях, вибору критеріїв сумісності складових при формуванні одношарових і шаруватих наноструктурованих оксидних композитних систем лантаноїдів і перехідних елементів широкого призначення, з каталітичною і фотокаталітичною активністю, покриття здатного самоочищатися з гідрофільними властивостями; розроблення різних комбінованих способів їх активації та встановлення технологічно-функціональних залежностей; керованого модифікування властивостей одержуваних цільових продуктів.

Для підвищення фотокаталітичної активності зразків покриттів на основі високодисперсного TiO2 анатазної модифікації запропонована методологія хімічного модифікування центрів окиснення у їхньому  поверхневому шарі з термооброленням у контакті з продуктами термолізу розплавів лужних координаційних нітратів лантаноїдів.
Kawaiwete Field Materials
Creators: name: Kayabi, Awakatu
name: Kayabi, Emarajup
name: Kayabi, Itarajup
name: Kayabi, Jywateju
name: Kayabi, Kapinua
name: Kayabi, Kupejani
name: Kayabi, Makatu
name: Kayabi, Mu'ni
name: Kayabi, Pikuruk
name: Kayabi, Reá
name: Kayabi, Sirakup
name: Kayabi, Tarejawat
name: Kayabi, Tujat
name: Kayabi, Wyrakatu
name: Lapierre, Myriam
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020

description: Sound recordings of elicitation and texts, field notes.