cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Lower Angular Momentum Limit for Self-Gravitating Protostellar Disc Fragmentation
Creators: name: Forgan, Duncan
name: Rice, Ken
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We attempt to verify recent claims (made using semi-analytic models) that for the collapse of spherical homogeneous molecular clouds, fragmentation of the self-gravitating disc that subsequently forms can be predicted using the cloud's initial angular momentum alone. In effect, this condition is equivalent to requiring the resulting disc be sufficiently extended in order to fragment, in line with studies of isolated discs. We use smoothed particle hydrodynamics with hybrid radiative transfer to investigate this claim, confirming that in general, homogeneous spherical molecular clouds will produce fragmenting self-gravitating discs if the ratio of rotational kinetic energy to gravitational potential energy is greater than ~ 5e-3, where this result is relatively insensitive to the initial thermal energy. This condition begins to fail at higher cloud masses, suggesting that sufficient mass at large radii governs fragmentation. While these results are based on highly idealised initial conditions, and may not hold if the disc's accretion from the surrounding envelope is sufficiently asymmetric, or if the density structure is perturbed, they provide a sensible lower limit for the minimum angular momentum required to fragment a disc in the absence of significant external turbulence.
description: 10 pages, 19 figures, 1 table, accepted for publication in MNRAS
Decoherence of a composite particle induced by a weak quantized gravitational field
Creators: name: Moreira, Thiago Henrique
name: Céleri, Lucas Chibebe
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Despite the fact that we have some proposals for the quantum theory of gravity like string theory or loop quantum gravity, we do not have any experimental evidence supporting any of these theories. Actually, we do not have experimental evidence pointing in the direction that we really need a quantum description of the gravitational field. In this scenario, several proposals for experimentally investigating quantum gravitational effects far from Plank scale have recently appear in literature, like gravitationally induced entanglement, for instance. An important issue of theses approaches is the decoherence introduced by the quantum nature not only of the system under consideration, but also from the gravitational field itself. Here, by means of the Feynman-Vernon influence functional we study the decoherence of a quantum system induced by the quantized gravitational field and by its own quantum nature. Our results may be important in providing a better understanding of many phenomena like the decoherence induced by the gravitational time-dilation, the quantum reference frames and the quantum equivalence principle.
description: Comments are welcome
Supplementary document for Frequency noise measurements using coherent self-heterodyne detection - 6625509.pdf
Creators: name: Thomsen, Simon
name: Brusatori, Mónica Far
name: Arent, Niklas
name: Kumar, Rakesh Ranjan
name: Volet, Nicolas
Publisher: name: Optica Publishing Group
Year: 2023
Subjects: Uncategorized

description: A derivation of the main result of the article
d-wave Superfluid with Gapless Edges in a Cold Atom Trap
Creators: name: Gadsbolle, Anne-Louise
name: Song, H. Francis
name: Hur, Karyn Le
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider a strongly repulsive fermionic gas in a two-dimensional optical lattice confined by a harmonic trapping potential. To address the strongly repulsive regime, we consider the $t-J$ Hamiltonian. The presence of the harmonic trapping potential enables the stabilization of coexisting and competing phases. In particular, at low temperatures, this allows the realization of a d-wave superfluid region surrounded by purely (gapless) normal edges. Solving the Bogoliubov-de Gennes equations and comparing with the local density approximation, we show that the proximity to the Mott insulator is revealed by a downturn of the Fermi liquid order parameter at the center of the trap where the d-wave gap has a maximum. The density profile evolves linearly with distance.
description: 4 pages, 3 figures
Emission of Type II Radio Bursts - Single-Beam versus Two-Beam Scenario
Creators: name: Ganse, Urs
name: Kilian, Patrick
name: Vainio, Rami
name: Spanier, Felix
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The foreshock region of a CME shock front, where shock accelerated electrons form a beam population in the otherwise quiescent plasma is generally assumed to be the source region of type II radio bursts. Nonlinear wave interaction of electrostatic waves excited by the beamed electrons are the prime candidates for the radio waves' emission. To address the question whether a single, or two counterpropagating beam populations are a requirement for this process, we have conducted 2.5D particle in cell simulations using the fully relativistic ACRONYM code. Results show indications of three wave interaction leading to electromagnetic emission at the fundamental and harmonic frequency for the two-beam case. For the single-beam case, no such signatures were detectable.
description: 11 pages, 9 figures, accepted in Solar Physics topical Issue "Advances in European Solar Physics"
Geometric instability of graph neural networks on large graphs
Creators: name: Morris, Emily
name: Shen, Haotian
name: Du, Weiling
name: Sajjad, Muhammad Hamza
name: Shi, Borun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: We analyse the geometric instability of embeddings produced by graph neural networks (GNNs). Existing methods are only applicable for small graphs and lack context in the graph domain. We propose a simple, efficient and graph-native Graph Gram Index (GGI) to measure such instability which is invariant to permutation, orthogonal transformation, translation and order of evaluation. This allows us to study the varying instability behaviour of GNN embeddings on large graphs for both node classification and link prediction.
Nuclear effects on J/ψ production in proton-nucleus collisions
Creators: name: Duan, Chun-Gui
name: Xu, Jian-Chao
name: Song, Li-Hua
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The study of nuclear effects for J/ψ production in proton-nucleus collisions is crucial for a correct interpretation of the J/ψ suppression patterns experimentally observed in heavy-ion collisions. By means of three representative sets of nuclear parton distribution, the energy loss effect in the initial state and the nuclear absorption effect in the final state are taken into account in the uniform framework of the Glauber model. A leading order phenomenological analysis is performed on J/ψ production cross-section ratios RW/Be(xF) for the E866 experimental data. The J/ψ suppression is investigated quantitatively due to the different nuclear effects. It is shown that the energy loss effect with resulting in the suppression on RW/Be(xF) is more important than the nuclear effects on parton distributions in high xF region. The E866 data in the small xF keep out the nuclear gluon distribution with a large anti-shadowing effect. However, the new HERA-B measurement is not in support of the anti-shadowing effect in the nuclear gluon distribution. It is found that the J/ψ-nucleon inelastic cross section σ J/ψ abs depends on the kinematical variable xF, and increases as xF in the region xF > 0.2. 1 Introduction
First-principles demonstration of Roman surface topological multiferroicity
Creators: name: Wang, Ziwen
name: Chai, Yisheng
name: Dong, Shuai
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The concept of topology has been widely applied to condensed matter, going beyond the band crossover in reciprocal spaces. A recent breakthrough suggested unconventional topological physics in a quadruple perovskite TbMn$_3$Cr$_4$O$_{12}$, whose magnetism-induced polarization manifests a unique Roman surface topology [Nat. Commun. \textbf{13}, 2373 (2022)]. However, the available experimental evidence based on tiny polarizations of polycrystalline samples is far from sufficient. Here, this topological multiferroicity is demonstrated by using density functional theory calculations, which ideally confirms the Roman surface trajectory of magnetism-induced polarization. In addition, an alternative material in this category is proposed to systematically enhance the performance, by promoting its magnetism-induced polarization to an easily detectable level.
description: 6 pages, 4 figures
Regular multi-horizon Lee-Wick black holes
Creators: name: Burzillà, Nicolò
name: Giacchini, Breno L.
name: Netto, Tibério de Paula
name: Modesto, Leonardo
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper we carry out a detailed analysis of the static spherically symmetric solutions of a sixth-derivative Lee-Wick gravity model in the effective delta source approximation. Previous studies of these solutions have only considered the particular case in which the real and the imaginary part of the Lee-Wick mass $μ=a +i b$ are equal. However, as we show here, the solutions exhibit an interesting structure when the full parameter space is considered, owing to the oscillations of the metric that depend on the ratio $b/a$. Such oscillations can generate a rich structure of horizons, a sequence of mass gaps and the existence of multiple regimes for black hole sizes (horizon position gaps). In what concerns the thermodynamics of these objects, the oscillation of the Hawking temperature determines the presence of multiple mass scales for the remnants of the evaporation process and may permit the existence of cold black holes with zero Hawking temperature $T$ and quasi-stable intermediate configurations with $T \approx 0$ and a long evaporation lifetime. For the sake of generality, we consider two families of solutions, one with a trivial shift function and the other with a non-trivial one (dirty black hole). The latter solution has the advantage of reproducing the modified Newtonian-limit metric of Lee-Wick gravity for small and large values of $r$.
description: 23 pages, 10 figures, 4 tables. V2: references added; matches the version published in JCAP
Replica Symmetry Broken States of some Glass Models
Creators: name: Yeo, J.
name: Moore, M. A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We have studied in detail the $M$-$p$ balanced spin glass model, especially the case $p=4$. These types of model have relevance to structural glasses. The models possess two kinds of broken replica states; those with one-step replica symmetry breaking (1RSB) and those with full replica symmetry breaking (FRSB). To determine which arises requires studying the Landau expansion to quintic order. There are 9 quintic order coefficients, and 5 quartic order coefficients, whose values we determine for this model. We show that it is only for $2 \leq M < 2.4714 \cdots$ that the transition at mean-field level is to a state with FRSB, while for larger $M$ values there is either a continuous transition to a state with 1RSB (when $ M \leq 3$) or a discontinuous transition for $M > 3$. The Gardner transition from a 1RSB state at low temperatures to a state with FRSB also requires the Landau expansion to be taken to quintic order. Our result for the form of FRSB in the Gardner phase is similar to that found when $2 \leq M < 2.4714\cdots$, but differs from that given in the early paper of Gross et al. [Phys. Rev. Lett. 55, 304 (1985)]. Finally we discuss the effects of fluctuations on our mean-field solutions using the scheme of Höller and Read [Phys. Rev. E 101, 042114 (2020)}] and argue that such fluctuations will remove both the continuous 1RSB transition and discontinuous 1RSB transitions when $8 >d \geq 6$ leaving just the FRSB continuous transition. We suggest values for $M$ and $p$ which might be used in simulations to confirm whether fluctuation corrections do indeed remove the 1RSB transitions.
description: Two new figures; 21 pages, 10 figures
Repulsive Casimir Effects
Creators: name: Milton, K. A.
name: Abalo, E. K.
name: Parashar, Prachi
name: Pourtolami, Nima
name: Brevik, Iver
name: Ellingsen, S. A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Like Casimir's original force between conducting plates in vacuum, Casimir forces are usually attractive. But repulsive Casimir forces can be achieved in special circumstances. These might prove useful in nanotechnology. We give examples of when repulsive quantum vacuum forces can arise with conducting materials.
description: 19 pages, 13 figures, plenary talk at Quantum Field Theory Under the Influence of External Conditions 2011 (QFEXT11)
3d exceptional gauge theories and boundary confinement
Creators: name: Okazaki, Tadashi
name: Smith, Douglas J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We find boundary confining dualities of 3d $\mathcal{N}=2$ supersymmetric gauge theories with exceptional gauge groups. The half-indices which enumerate the boundary BPS local operators in the presence of Neumann and Dirichlet boundary conditions for gauge fields are identified with the Askey-Wilson type $q$-beta integrals and Macdonald type sums respectively. New conjectural identities of $E_6$ and $E_7$ integrals and sums are derived from the boundary confining dualities. We also consider theories with a vector multiplet and adjoint chiral, which correspond to an $\mathcal{N}=4$ vector multiplet, with appropriate boundary conditions. We argue for the boundary confinement of the $\mathcal{N}=4$ vector multiplet and comment on such theories also with classical gauge groups.
description: 39 pages, v2: published version in JHEP
Characterization of the X4 protein of Tomato ringspot virus and analysis of its variability among virus isolates
Creators: name: Jafarpour, Bita
Publisher: name: University of British Columbia
Year: 2010

description: The genome of Tomato ringspot virus (nepovirus) encodes a unique X4 protein of unknown function. X4 is absent from the genome of many other nepoviruses and does not have significant sequence homology with other proteins in available databases. I have studied the possible function(s) of the ToRSV-X4 protein. I used three ToRSV isolates, Rasp2, Rasp1 and PYB. Sequence analysis of the X4 region from these isolates showed a surprising level of sequence variability. The central region of the X4 protein contains two series of amino acid sequence tandem repeats. The number of these repeats varies among ToRSV isolates. N. benthamiana plants inoculated with the ToRSV-Rasp1 recover from infection at temperatures equal to or above 27°C. At 21°C, recovery does not occur and plants eventually die. In ToRSV-PYB1 infection, plants recover from infection at all temperature tested. Since RNA silencing is a ubiquitous plant defence response and was observed in nepovirus infected plants, I used agroinfiltration assays to test the effect of the X4 protein on the induction of RNA silencing directed at a green fluorescent protein reporter gene (GFP). Co-expression of X4-Rasp1 or X4-Rasp2 proteins with GFP in N. benthamiana plants transiently enhanced the expression of GFP. To detect the ToRSV X4 protein in virus infected plants, I used polyclonal antibodies raised against the C-terminal region of the X4-Rasp2 protein. This antibody detected a 60 kDa protein in ToRSV-Rasp1 infected plants. The cross-reactivity of this X 4 (64-65) antibody with the CP suggested that the 60 kDa protein corresponds to the CP. However, X4(3743-44) and X4 (3741-42) antibodies derived from the X4 sequence, did not detect this 60 kDa protein. The predicted 82 kDa X4 full-length protein was not detected by any of the anti-X4 antibodies. This suggests that X4 may be an unstable protein. In conclusion, the variability of the X4 protein among ToRSV isolates combined with different symptomatology and the preliminary evidence that X4 may act as a suppressor of silencing in plants, suggest that X4 may be a multifunctional protein that is involved in protein–protein interaction, host specificity, symptomatology and/or interaction with host defence responses.
Scattering polarization in the CaII Infrared Triplet with Velocity Gradients
Creators: name: Carlin, E. S.
name: Sainz, R. Manso
name: Ramos, A. Asensio
name: Bueno, J. Trujillo
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Magnetic field topology, thermal structure and plasma motions are the three main factors affecting the polarization signals used to understand our star. In this theoretical investigation, we focus on the effect that gradients in the macroscopic vertical velocity field have on the non-magnetic scattering polarization signals, establishing the basis for general cases. We demonstrate that the solar plasma velocity gradients have a significant effect on the linear polarization produced by scattering in chromospheric spectral lines. In particular, we show the impact of velocity gradients on the anisotropy of the radiation field and on the ensuing fractional alignment of the CaII levels, and how they can lead to an enhancement of the zero-field linear polarization signals. This investigation remarks the importance of knowing the dynamical state of the solar atmosphere in order to correctly interpret spectropolarimetric measurements, which is important, among other things, for establishing a suitable zero field reference case to infer magnetic fields via the Hanle effect.
description: 14 pages, 10 figures, 3 appendixes, accepted for publication in ApJ
title: Policy Brief - Student Achievement Growth During the COVID-19 Pandemic: Spring 2022 Update
Creators: name: Sass, Tim
name: Ali, Salma Mohammad
Publisher: name: Georgia Policy Labs
Year: 2022

description: It has been over two years since the COVID-19 pandemic led to school closures and an abrupt shift to remote learning in March 2020. We continue MAPLE’s research agenda analyzing how the pandemic has affected student achievement in math and reading in three metro-Atlanta school districts. We focus on how students fared in school year 2021–22, the first full year of in-person instruction for students since the pandemic began.
Proton, Electron, and Ion Heating in the Fast Solar Wind from Nonlinear Coupling Between Alfvenic and Fast-Mode Turbulence
Creators: name: Cranmer, Steven R.
name: van Ballegooijen, Adriaan A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: In the parts of the solar corona and solar wind that experience the fewest Coulomb collisions, the component proton, electron, and heavy ion populations are not in thermal equilibrium with one another. Observed differences in temperatures, outflow speeds, and velocity distribution anisotropies are useful constraints on proposed explanations for how the plasma is heated and accelerated. This paper presents new predictions of the rates of collisionless heating for each particle species, in which the energy input is assumed to come from magnetohydrodynamic (MHD) turbulence. We first created an empirical description of the radial evolution of Alfven, fast-mode, and slow-mode MHD waves. This model provides the total wave power in each mode as a function of distance along an expanding flux tube in the high-speed solar wind. Next we solved a set of cascade advection-diffusion equations that give the time-steady wavenumber spectra at each distance. An approximate term for nonlinear coupling between the Alfven and fast-mode fluctuations is included. For reasonable choices of the parameters, our model contains enough energy transfer from the fast mode to the Alfven mode to excite the high-frequency ion cyclotron resonance. This resonance is efficient at heating protons and other ions in the direction perpendicular to the background magnetic field, and our model predicts heating rates for these species that agree well with both spectroscopic and in situ measurements. Nonetheless, the high-frequency waves comprise only a small part of the total Alfvenic fluctuation spectrum, which remains highly two-dimensional as is observed in interplanetary space.
description: Accepted for publication in the Astrophysical Journal. 30 pages (emulateapj style), 18 figures
Leveraging Composition-Based Material Descriptors for Machine Learning Optimization
Creators: name: Trezza, Giovanni
name: Chiavazzo, Eliodoro
Publisher: name: Zenodo
Year: 2023
Subjects: Machine Learning, Material Classification, Composition-Based Descriptors, Energy Materials, Superconductors

description: This data repository is for the publication "Leveraging Composition-Based Material Descriptors for Machine Learning Optimization".
Design and Numerical Analysis of Hyperbolic Metamaterial Based Ultrasensitive E. Coli Sensor
Creators: name: Sarker, Dip
name: Zubair, Ahmed
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We proposed an extremely sensitive \textit{E. Coli} sensor based on a hyperbolic metamaterial structure combining ultra-thin Ag-Al$_2$O$_3$ layers to minimize metallic optical loss. The principle relied on detecting the change in the resonance wavelength due to the interaction of bacteria with the surrounding aqueous environment by utilizing the finite-difference time-domain numerical technique. Our proposed hyperbolic metamaterial \textit{E. Coli} sensor operated in the range from visible to near-infrared wavelengths exhibiting strong bulk plasmon polaritons at the hyperbolic regime ($λ\geq$ 460 nm). An anisotropic hyperbolic range was obtained theoretically by solving the effective medium theory. An outstanding sensitivity of 9000 nm per bacteria was achieved for a bulk plasmon-polariton mode. The hyperbolic metamaterial was the origin of obtaining such extremely high sensitivity; no bulk plasmon polaritons were found without hyperbolic metamaterial. We analyzed the effect of different shapes in two-dimensional Ag differential grating on sensing performance. Additionally, we compared the performance parameters of our proposed \textit{E. Coli} sensor with recently demonstrated sensors. Our proposed hyperbolic metamaterial structure has the potential as a highly sensitive \textit{E. Coli} sensor operating in a wide range of wavelengths for label-free detection.
Investment-based optimisation of energy storage design parameters in a grid-connected hybrid renewable energy system
Creators: name: Farah, Sleiman
name: Andresen, Gorm Bruun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: Optimization and Control (math.OC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics

description: Grid-connected hybrid renewable power systems with energy storage can reduce the intermittency of renewable power supply. However, emerging energy storage technologies need improvement to compete with lithium-ion batteries and reduce the cost of energy. Identifying and optimizing the the most valuable improvement path of these technologies is challenging due to the non-linearity of the energy system model when considering parameters as independent variables. To overcome this, a novel investment-based optimization method is proposed. The method involves linear optimization of the hybrid renewable energy system and subsequent investment optimization, accounting for diminishing improvements per investment. Applied to thermal energy, pumped thermal energy, molten salt, and adiabatic compressed air energy storage technologies, the results show that enhancing discharge efficiency is most valuable for all technologies. Reducing discharge capacity costs and energy storage capacity cost can also become important. Charge capacity cost and charge efficiency are found to be of lesser significance. The study provides detailed improvement pathways for each technology under various operational conditions, assisting developers in resource allocation. Overall, the investment-based optimization method and findings contribute to enhancing the competitiveness of emerging energy storage technologies and reducing reliance on batteries in renewable energy systems.
Study of kaonic final states in $π^-p$ at $190\,\textrm{GeV}$
Creators: name: Schlüter, Tobias
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We discuss the status of analyses of data recorded in the 2008 and 2009 runs of the COMPASS experiment at CERN with sepcific focus on final states with $K^0_S K^0_S π^-$ and $K^+K^-π^-$ produced in $π^-(190\,\textrm{GeV})p$ scattering. The interest in such final states is motivated by a summary of some of the relevant literature. We also show first results from the analysis of diffractively produced $K\bar Kπ$ states. Two prominent three-body structures, one around $1.8\,\GeV$, the other at $2.2\,\GeV$ decaying via known $K\bar K$ and $Kπ$ states are seen.
Supercluster states and phase transitions in aggregation-fragmentation processes
Creators: name: Otieno, Wendy
name: Brilliantov, Nikolai V.
name: Krapivsky, P. L.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the evolution of aggregates triggered by collisions with monomers that either lead to the attachment of monomers or the break-up of aggregates into constituting monomers. Depending on parameters quantifying addition and break-up rates, the system falls into a jammed or a steady state. Supercluster states (SCSs) are very peculiar non-extensive jammed states that also arise in some models. Fluctuations underlie the formation of the SCSs. Conventional tools, such as the van Kampen expansion, apply to small fluctuations. We go beyond the van Kampen expansion and determine a set of critical exponents quantifying SCSs. We observe continuous and discontinuous phase transitions between the states. Our theoretical predictions are in good agreement with numerical results.
description: 19 pages, 15 figures
Rigidity of group actions on homogeneous spaces, III
Creators: name: Bader, Uri
name: Furman, Alex
name: Gorodnik, Alex
name: Weiss, Barak
Publisher: name: arXiv
Year: 2012
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: Consider homogeneous G/H and G/F, for an S-algebraic group G. A lattice Γ acts on the left strictly conservatively. The following rigidity results are obtained: morphisms, factors and joinings defined apriori only in the measurable category are in fact algebraically constrained. Arguing in an elementary fashion we manage to classify all the measurable Φ commuting with the Γ-action: assuming ergodicity, we find they are algebraically defined.
Cybercrime Bitcoin Revenue Estimations: Quantifying the Impact of Methodology and Coverage
Creators: name: Gomez, Gibran
name: van Liebergen, Kevin
name: Caballero, Juan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: Multiple works have leveraged the public Bitcoin ledger to estimate the revenue cybercriminals obtain from their victims. Estimations focusing on the same target often do not agree, due to the use of different methodologies, seed addresses, and time periods. These factors make it challenging to understand the impact of their methodological differences. Furthermore, they underestimate the revenue due to the (lack of) coverage on the target's payment addresses, but how large this impact remains unknown. In this work, we perform the first systematic analysis on the estimation of cybercrime bitcoin revenue. We implement a tool that can replicate the different estimation methodologies. Using our tool we can quantify, in a controlled setting, the impact of the different methodology steps. In contrast to what is widely believed, we show that the revenue is not always underestimated. There exist methodologies that can introduce huge overestimation. We collect 30,424 payment addresses and use them to compare the financial impact of 6 cybercrimes (ransomware, clippers, sextortion, Ponzi schemes, giveaway scams, exchange scams) and of 141 cybercriminal groups. We observe that the popular multi-input clustering fails to discover addresses for 40% of groups. We quantify, for the first time, the impact of the (lack of) coverage on the estimation. For this, we propose two techniques to achieve high coverage, possibly nearly complete, on the DeadBolt server ransomware. Our expanded coverage enables estimating DeadBolt's revenue at $2.47M, 39 times higher than the estimation using two popular Internet scan engines.
Fermi Acceleration in anti-integrable limits of the standard map
Creators: name: De Simoi, Jacopo
Publisher: name: arXiv
Year: 2012
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We consider a dynamical system on the semi-infinite cylinder which models the high energy dynamics of a family of mechanical models. We provide conditions under which we ensure that the set of orbits undergoing Fermi acceleration has measure zero.
Particle simulation study of electron heating by counterstreaming ion beams ahead of supernova remnant shocks
Creators: name: Dieckmann, M. E.
name: Bret, A.
name: Sarri, G.
name: Alvaro, E. Perez
name: Kourakis, I.
name: Borghesi, M.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The growth and saturation of Buneman-type instabilities is examined with a particle-in-cell (PIC) simulation for parameters that are representative for the foreshock region of fast supernova remnant (SNR) shocks. A dense ion beam and the electrons correspond to the upstream plasma and a fast ion beam to the shock-reflected ions. The purpose of the 2D simulation is to identify the nonlinear saturation mechanisms, the electron heating and potential secondary instabilities that arise from anisotropic electron heating and result in the growth of magnetic fields. We confirm that the instabilities between both ion beams and the electrons saturate by the formation of phase space holes by the beam-aligned modes. The slower oblique modes accelerate some electrons, but they can not heat up the electrons significantly before they are trapped by the faster beam-aligned modes. Two circular electron velocity distributions develop, which are centred around the velocity of each ion beam. They develop due to the scattering of the electrons by the electrostatic wave potentials. The growth of magnetic fields is observed, but their amplitude remains low.
description: 18 pages, 11 figures, accepted for publication in Plasma Physics and Controlled Fusion
Self-Organization of Wireless Ad Hoc Networks as Small Worlds Using Long Range Directional Beams
Creators: name: Banerjee, Abhik
name: Agarwal, Rachit
name: Gauthier, Vincent
name: Yeo, Chai Kiat
name: Afifi, Hossam
name: Lee, Bu Sung
Publisher: name: arXiv
Year: 2011
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: We study how long range directional beams can be used for self-organization of a wireless network to exhibit small world properties. Using simulation results for randomized beamforming as a guideline, we identify crucial design issues for algorithm design. Subsequently, we propose an algorithm for deterministic creation of small worlds. We define a new centrality measure that estimates the structural importance of nodes based on traffic flow in the network, which is used to identify the optimum nodes for beamforming. This results in significant reduction in path length while maintaining connectivity.
description: Accepted to Joint workshop on complex networks and pervasive group communication (CCNet/PerGroup), in conjunction with IEEE Globecom 2011
No logarithmic corrections to entropy in shift-symmetric Gauss-Bonnet gravity
Creators: name: Liška, Marek
name: Hennigar, Robie A.
name: Kubizňák, David
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Employing the covariant phase space formalism, we discuss black hole thermodynamics in four-dimensional scalar-tensor Einstein-Gauss-Bonnet gravity. We argue that logarithmic corrections to Wald entropy previously reported in this theory do not appear, due to the symmetry of the theory under constant shifts of the scalar field. Instead, we obtain the standard Bekenstein entropy of general relativity. Then, to satisfy the first law of black hole mechanics, the Hawking temperature must be modified. It has been proposed that such temperature modifications occur generically in scalar-tensor theories, due to different propagation speeds of gravitons and photons. We show that the temperature modifications also emerge in the Euclidean canonical ensemble approach to black hole thermodynamics. Notably, the boundary terms of the type we consider here can be considered in any scalar-tensor gravitational theories. Hence, we illustrate that adding a suitable boundary term to action may drastically affect black hole thermodynamics, changing both the entropy and the temperature.
description: 29 pages, text matches the version published in JHEP. Comments welcome
Fully NLO Parton Shower in QCD
Creators: name: Skrzypek, M.
name: Jadach, S.
name: Kusina, A.
name: Placzek, W.
name: Slawinska, M.
name: Gituliar, O.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The project of constructing a complete NLO-level Parton Shower Monte Carlo for the QCD processes developed in IFJ PAN in Krakow is reviewed. Four issues are discussed: (1) the extension of the standard inclusive collinear factorization into a new, fully exclusive scheme; (2) reconstruction of the LO Parton Shower in the new scheme; (3) inclusion of the exclusive NLO corrections into the hard process and (4) inclusion of the exclusive NLO corrections into the evolution (ladder) part.
description: Contribution to the XXXV International Conference of Theoretical Physics "Matter to the Deepest", Ustron, Poland, September 12-18, 2011
Probe nuclear structure using the anisotropic flow at the Large Hadron Collider
Creators: name: Lu, Zhiyong
name: Zhao, Mingrui
name: Jia, Jiangyong
name: Zhou, You
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Recent studies have shown that the shape and radial profile of the colliding nuclei have strong influences on the initial condition of the heavy ion collisions and the subsequent development of the anisotropic flow. Using A Multi-Phase Transport model (AMPT) model, we investigated the impact of nuclear quadrupole deformation $β_2$ and nuclear diffuseness $a_0$ of $^{129}$Xe on various of flow observables in Xe--Xe collisions at $\sqrtnn =$ 5.44 TeV. We found that $β_2$ has a strong influence on central collisions while $a_0$ mostly influences the mid-central collisions. The relative change of flow observables induced by a change in $β_2$ and $a_0$ are also found to be insensitive to the values of parameters controlling the strength of the interaction among final state particles. Our study demonstrates the potential for constraining the initial condition of heavy ion collisions using future system scans at the LHC.
description: 25 pages, for the EPJA Topical Issues
Social norms, social self-efficacy and perceived social status in the expression of social anxiety : a cross-national comparison
Creators: name: Hsu, Lorena
Publisher: name: University of British Columbia
Year: 2010

description: Previous research has consistently shown that Asian-heritage individuals report higher levels of social anxiety compared to their European-heritage counterparts. The goal of this study was to examine whether culturally-influenced social standards, social self-efficacy, and perceived social status account for elevated reports of social anxiety in East Asian-heritage (EAH) individuals. Drawing from cognitive and evolutionary models of social anxiety, two competing hypotheses that encompassed these social contextual variables were tested to explain ethnic differences in social anxiety: the Asian socialization hypothesis proposed that higher self-reported social anxiety in EAH individuals are related to their greater exposure to East Asian cultural values, while the cultural discrepancy hypothesis posited that Asian-Western differences in social anxiety are associated with the bicultural experience of cultural and/or ethnic discrepancy with mainstream Western culture. In a cross-national sample of East Asian- and European-heritage students living in Canada (Ns = 280 and 103, respectively) and East Asian students living in Korea and China (N = 309), participants completed self-report questionnaires that measured social anxiety, depression, and social contextual factors (i.e., cultural norms, social self-efficacy, and perceived social status). Measures of acculturation and self-construal were also included to confirm that the groups differed on cultural values. Planned contrast analyses demonstrated relatively strong support for the cultural discrepancy hypothesis, in which bicultural East Asian groups (i.e., 1st- and 2nd-generation EAH individuals) reported greater social anxiety and depression, as well as lower initiation social self-efficacy and perceived social status compared to members of unicultural groups (i.e., European-heritage and overseas East Asian groups). However, social self-efficacy and perceived social status did not appear to mediate the elevated social anxiety levels in bicultural East Asians. Findings showed limited support for the Asian socialization hypothesis. Overall, the results suggest that higher reports of social anxiety in bicultural East Asians may be associated with the experience of cultural and ethnic discrepancy with Western mainstream culture, and conceptualized as a part of the experience of acculturative and/or bicultural stress. Findings from this study suggest that the role of cultural discrepancy in elevated social anxiety warrants further investigation using longitudinal or experimental designs.
Topological Surface States with Persistent High Spin Polarization across Dirac Point in Bi$_{2}$Te$_{2}$Se and Bi$_{2}$Se$_{2}$Te
Creators: name: Miyamoto, K.
name: Kimura, A.
name: Okuda, T.
name: Miyahara, H.
name: Kuroda, K.
name: Namatame, H.
name: Taniguchi, M.
name: Eremeev, S. V.
name: Menshchikova, T. V.
name: Chulkov, E. V.
name: Kokh, K. A.
name: Tereshchenko, O. E.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Helical spin textures with the marked spin polarizations of topological surface states have been firstly unveiled by the state-of-the-art spin- and angle-resolved photoemission spectroscopy for two promising topological insulators Bi$_2$Te$_2$Se and Bi$_2$Se$_2$Te. The highly spin-polarized natures are found to be persistent across the Dirac point in both compounds. This novel finding paves a pathway to extending their utilization of topological surface state for future spintronic applications.
description: 5 pages, 3 figures
Branching and merging: an investigation into current version control practices
Creators: name: Phillips, Shaun
name: Sillito, Jonathan
name: Walker, Rob
Publisher: name: ACM
Year: 2011

description: The use of version control has become ubiquitous in software development projects. Version control systems facilitate parallel development and maintenance through branching, the creation of isolated codelines. Merging is a consequence of branching and is the process of integrating codelines. However, there are unanswered questions about the use of version control to support parallel development; in particular, how are branching and merging used in practice? What defines a successful branching and merging strategy? As a first step towards answering these questions, we recruited a diverse sample of 140 version control users to participate in an online survey. In this paper, we present the survey results and 4 key observations about branching and merging practices in software development projects.
The Arkansas Poll: October 2020
Creators: name: Politics, Diane D. Blair Center Of Southern
Publisher: name: Roper Center for Public Opinion Research
Year: 2023

description: Most important issue facing people in Arkansas today (1); approval of various public figures (4); opinion on statewide ballot measures (3); preference for the 2020 presidential election (1); preference for the Arkansas 2020 U.S. Senate election (1); approval of the response to the coronavirus (1); feelings toward the Black Lives Matter Movement (1); opinion on abortion laws (2); opinion on gun control laws (1); threat of global warming (2); direction Arkansas is headed in (1); personal financial situation (2).
Carrier Aggregation Enabled Integrated Sensing and Communication Signal Design and Processing
Creators: name: Wei, Zhiqing
name: Liu, Haotian
name: Yang, Xinyi
name: Jiang, Wangjun
name: Wu, Huici
name: Li, Xingwang
name: Feng, Zhiyong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Signal Processing (eess.SP)
subject: Information Theory (cs.IT)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: The future mobile communication systems will support intelligent applications such as Internet of Vehicles (IoV) and Extended Reality (XR). Integrated Sensing and Communication (ISAC) is regarded as one of the key technologies satisfying the high data rate communication and highly accurate sensing for these intelligent applications in future mobile communication systems. With the explosive growth of wireless devices and services, the shortage of spectrum resources leads to the fragmentation of available frequency bands for ISAC systems, which degrades sensing performance. Facing the above challenges, this paper proposes a Carrier Aggregation (CA)-based ISAC signal aggregating high and low-frequency bands to improve the sensing performance, where the CA-based ISAC signal can use four different aggregated pilot structures for sensing. Then, an ISAC signal processing algorithm with Compressed Sensing (CS) is proposed and the Fast Iterative Shrinkage-Thresholding Algorithm (FISTA) is used to solve the reconfiguration convex optimization problem. Finally, the Cram'er-Rao Lower Bounds (CRLBs) are derived for the CA-based ISAC signal. Simulation results show that CA efficiently improves the accuracy of range and velocity estimation.
description: 17pages, 17 figures, already early access in IEEE Transactions on Vehicular Technology
Full-Body Motion-Based Game Interaction for Older Adults
Creators: name: Gerling, K. M.
name: Livingston, I. J.
name: Nacke, L. E.
name: Mandryk, R. L.
Publisher: name: ACM
Year: 2012

description: Older adults in nursing homes often lead sedentary lifestyles, which reduces their life expectancy. Full-body motion-control games provide an opportunity for these adults to remain active and engaged; these games are not designed with age-related impairments in mind, which prevents the games from being leveraged to increase the activity levels of older adults. In this paper, we present two studies aimed at developing game design guidelines for full-body motion controls for older adults experiencing age-related changes and impairments. Our studies also demonstrate how full-body motion-control games can accommodate a variety of user abilities, have a positive effect on mood and, by extension, the emotional well-being of older adults. Based on our studies, we present seven guidelines for the design of full-body interaction in games. The guidelines are designed to foster safe physical activity among older adults, thereby increasing their quality of life.
Impact cratering on Mercury: consequences for the spin evolution
Creators: name: Correia, Alexandre C. M.
name: Laskar, Jacques
Publisher: name: arXiv
Year: 2012
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Dynamical Systems (math.DS)
subject: Geophysics (physics.geo-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Impact basins identified by Mariner 10 and Messenger flyby images provide us a fossilized record of the impactor flux of asteroids on Mercury during the last stages of the early Solar System. The distribution of these basins is not uniform across the surface, and is consistent with a primordial synchronous rotation (Wieczorek et al. 2012). By analyzing the size of the impacts, we show that the distribution for asteroid diameters D < 110 km is compatible with an index power law of 1.2, a value that matches the predicted primordial distribution of the main-belt. We then derive a simple collisional model coherent with the observations, and when combining it with the secular evolution of the spin of Mercury, we are able to reproduce the present 3/2 spin-orbit resonance (about 50% of chances), as well as a primordial synchronous rotation. This result is robust with respect to variations in the dissipation and collisional models, or in the initial spin state of the planet.
description: 6 pages, 3 tables, 2 figures