cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Dynamical Tadpoles, Stringy Cobordism, and the SM from Spontaneous Compactification
Creators: name: Buratti, Ginevra
name: Delgado, Matilda
name: Uranga, Angel M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider string theory vacua with tadpoles for dynamical fields and uncover universal features of the resulting spacetime-dependent solutions. We argue that the solutions can extend only a finite distance $Δ$ away in the spacetime dimensions over which the fields vary, scaling as $Δ^n\sim {\cal T}$ with the strength of the tadpole ${\cal T}$. We show that naive singularities arising at this distance scale are physically replaced by ends of spacetime, related to the cobordism defects of the swampland cobordism conjecture and involving stringy ingredients like orientifold planes and branes, or exotic variants thereof. We illustrate these phenomena in large classes of examples, including AdS$_5\times T^{1,1}$ with 3-form fluxes, 10d massive IIA, M-theory on K3, the 10d non-supersymmetric $USp(32)$ strings, and type IIB compactifications with 3-form fluxes and/or magnetized D-branes. We also describe a 6d string model whose tadpole triggers spontaneous compactification to a semirealistic 3-family MSSM-like particle physics model.
description: 31 pages + appendix. v2: typos corrected, references added, matches with published version
Phonon- and defect-limited electron and hole mobility of diamond and cubic boron nitride: a critical comparison
Creators: name: Sanders, Nocona
name: Kioupakis, Emmanouil
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Diamond and cBN are two of the most promising ultra-wide-band-gap (UWBG) semiconductors for applications in high-power high-frequency electronic devices. Yet despite extensive studies on carrier transport in these materials, there are large discrepancies in their reported carrier mobilities. In this work, we investigate the phonon- and dopant-limited electron and hole mobility of cBN and diamond with atomistic first-principles calculations in order to understand their fundamental upper bounds to carrier transport. Our results show that although the phonon-limited electron mobilities are comparable between cBN and diamond, the hole mobility is significantly lower in cBN due to its heavier hole effective mass. Moreover, although lattice scattering dominates the mobility at low doping, neutral impurity scattering becomes the dominant scattering mechanism at higher dopant concentrations due to the high dopant ionization energies. Our analysis provides critical insights and reveals the intrinsic upper limits to the carrier mobilities of diamond and cBN as a function of doping and temperature for applications in high-power electronic devices.
description: 18 pages, 7 figures
title: EFFECT OF REFERENCE GROUPS ON GREEN CONSUMPTION INTENTION: A CASE OF ORGANIC FOODS IN YUNNAN, CHINA
Creators: name: ZHANG, Jie
Publisher: name: Asian Interdisciplinary and Sustainability Review
publisherIdentifierScheme: ROR
Year: 2025
Subjects: Supply Chain Trust
Green Consumption Intentions
Reference Groups
Organic Food
Product Trust

description: Asian Interdisciplinary and Sustainability Review, 14, 1, Article 8
The Deep and Low-Mass-Ratio Contact Binary CSS J022914.4+044340 with A Luminous Additional Companion
Creators: name: Liu, Liang
name: Li, Xu-Zhi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The first B-, V-, Rc-, and Ic-band light curves of CSS J022914.4+044340 are presented and analyzed. It is found that CSS J022914.4+044340 is a low mass ratio (0.198 +- 0.005) deep (63.7 +- 7.9%) contact binary, indicating that it has been already at the end evolutionary stage of tidally-locked evolution via magnetized wind. Because of the totally eclipsing character, the photometric solutions are reliable. The temperature and the metallicity are determined from the spectroscopic data as T = 5855 +- 15 K, and [Fe/H] = -0.842 +- 0.031, respectively. Based on the parallax of Gaia EDR3, the physical parameters of CSS J022914.4+044340 are estimated as M1 = 1.44 (+0.25,-0.22) solar mass, M2 = 0.29 (+0.05,-0.05) solar mass, R1 = 1.26 (+0.08,-0.06) solar radius, R2 = 0.65 (+0.03,-0.04) solar radius, L1 = 1.718 (+0.186,-0.191) solar luminosity, L2 = 0.416 (+0.039,-0.050) solar luminosity. Combined the fraction in light of the third body via the photometric solution (54%), the luminosity of the third body is estimated as 2.705 solar luminosity. The third body may be inferred as a subgiant. Thus, it is explained that why the primary component of CSS J022914.4+044340 has higher mass among the similar systems, and why its metallicity is so poor.
description: Accepted
A note on minimal matching covered graphs
Creators: name: Mkrtchyan, V. V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: A graph is called matching covered if for its every edge there is a maximum matching containing it. It is shown that minimal matching covered graphs contain a perfect matching.
description: 4 pages
Site guidelines for multi-purpose GNSS reflectometry stations
Creators: name: Geremia-Nievinski, Felipe
name: Hobiger, Thomas
Publisher: name: Zenodo
Year: 2019

description: The following special site guidelines are for station operators interested in sharing their installations for multiple purposes, specially for GNSS Reflectometry (GNSS-R) applications. They complement the International GNSS Service (IGS) Site Guidelines and its Clarifications in a voluntary non-official way. It was produced by the Working Group 4.3.9 on GNSS-R of International Association of Geodesy (IAG) during the 2015-2019 term. Updates:
 2020-11-15: general language
Site guidelines for multi-purpose GNSS reflectometry stations
Creators: name: Geremia-Nievinski, Felipe
name: Hobiger, Thomas
Publisher: name: Zenodo
Year: 2019

description: The following special site guidelines are for station operators interested in sharing their installations for multiple purposes, specially for GNSS Reflectometry (GNSS-R) applications. They complement the International GNSS Service (IGS) Site Guidelines and its Clarifications in a voluntary non-official way. It was produced by the Working Group 4.3.9 on GNSS-R of International Association of Geodesy (IAG) during the 2015-2019 term. Updates:
 2021-02-16: site photographs
 2020-11-15: general language
Time dependent electric transport in nodal-loop semimetals
Creators: name: Okvátovity, Zoltán
name: Oroszlány, László
name: Dóra, Balázs
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Close to the Fermi energy, nodal loop semimetals have a torus-shaped, strongly anisotropic Fermi surface which affects their transport properties. Here we investigate the non-equilibrium dynamics of nodal loop semimetals by going beyond linear response and determine the time evolution of the current after switching on a homogeneous electric field. The current grows monotonically with time for electric fields perpendicular to the nodal loop plane however it exhibits non-monotonical behavior for field orientations aligned within the plane. After an initial non-universal growth $\sim Et$, the current first reaches a plateau $\sim E$. Then, for perpendicular directions, it increases while for in-plane directions it decreases with time to another plateau, still $\sim E$. These features arise from interband processes. For long times or strong electric fields, the current grows as $\sim E^{3/2}t$ or $\sim E^3t^2$ for perpendicular or parallel electric fields, respectively. This non-linear response represents an intraband effect where the large number of excited quasiparticles responds to the electric field. Our analytical results are benchmarked by the numerical evaluation of the current from continuum and tight-binding models of nodal loop semimetals.
description: 12 pages, 10 figures, 1 table
The LuckyCam Survey for Very Low Mass Binaries II: 13 new M4.5-M6.0 Binaries
Creators: name: Law, N. M.
name: Hodgkin, S. T.
name: Mackay, C. D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results from a high-angular-resolution survey of 78 very low mass (VLM) binary systems with 6.0 <= V-K colour <= 7.5 and proper motion >= 0.15 arcsec/yr. 21 VLM binaries were detected, 13 of them new discoveries. The new binary systems range in separation between 0.18 arcsec and 1.3 arcsec. The distance-corrected binary fraction is 13.5% (+6.5%/-4%), in agreement with previous results. 9 of the new binary systems have orbital radii > 10 AU, including a new wide VLM binary with 27 AU projected orbital separation. One of the new systems forms two components of a 2300 AU separation triple system. We find that the orbital radius distribution of the binaries with V-K < 6.5 in this survey appears to be different from that of redder (lower-mass) objects, suggesting a possible rapid change in the orbital radius distribution at around the M5 spectral type. The target sample was also selected to investigate X-ray activity among VLM binaries. There is no detectable correlation between excess X-Ray emission and the frequency and binary properties of the VLM systems.
description: 11 pages, 8 figures. Submitted to MNRAS
Path properties of superprocesses
Creators: name: Tribe, Roger
Publisher: name: University of British Columbia
Year: 2010

description: Superprocesses are measure valued diffusions that arise as high density limits of particle systems undergoing spatial motion and critical branching. The most closely studied superprocess is super Brownian motion where the underlying spatial motion is Brownian. In chapter 1 we describe the approximating particle systems, the nonstandard model for a superprocess and some known path properties of super Brownian motion. Super Brownian motion is effectively determined by its closed support. In chapter 2 we use the approximating particle systems to derive new path properties for the support process. We find the growth rate of the support for the process started at a point mass. We give a representation for the measure at a fixed time in terms of its support. We show that the support at a fixed time is nearly a totally disconnected set. Finally we calculate the Hausdorff dimension of the range of the process over random time sets. A superprocess can be characterised as the solution to a martingale problem and in chapter 3 we use this characterisation to study the properties of general superprocesses. We investigate when the real valued process given by the measure of a half space under a super symmetric stable process is a semimartingale. We give a description of the behaviour of a general superprocess and its support near extinction. Finally we consider the problem of recovering the spatial motion from a path of the superprocess.
On trees with a maximum proper partial 0-1 coloring containing a maximum matching
Creators: name: Mkrtchyan, V. V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: I prove that in a tree in which the distance between any two endpoints is even, there is a maximum proper partial 0-1 coloring such that the edges colored by 0 form a maximum matching.
description: 4 pages
Monad-like structures in 2-categories and soft adjunctions
Creators: name: Stone, Peter
Publisher: name: University of British Columbia
Year: 2010

description: One of the fundamental concepts of ordinary category theory is that of an adjunction. There are analogous notions in 2-category theory one of which is the "soft adjunction" of this thesis. In order to construct examples which exhibit the full generality of this phenomena two constructions for modifying soft adjunctions are described: an "attaching procedure" and a "lifting procedure". These two procedures are shown to be inverses of each other in an suitable sense. A special type of "commutative monad" structure on an object of a 2-category is described and it is shown that this structure can be modelled by the category of finite ordinals and all functions in the same way that the ordinary monad structure can be modelled by the category of finite ordinals and non-decreasing functions. By a standard argument for such a situation where there are 2-category objects with structure a certain "strict" adjunction" is obtained; that is, an adjunction which is essentially the same as an adjunction in ordinary category theory. Starting with a slightly extended version of this strict adjunction examples of soft adjunctions are obtained by means of the attaching and lifting procedures. The relationship between the the various soft adjunctions which arise is investigated.
The Discovery of a Companion to the Lowest Mass White Dwarf
Creators: name: Kilic, Mukremin
name: Brown, Warren R.
name: Prieto, Carlos Allende
name: Pinsonneault, M. H.
name: Kenyon, S. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the detection of a radial velocity companion to SDSS J091709.55+463821.8, the lowest mass white dwarf currently known with M~0.17Msun. The radial velocity of the white dwarf shows variations with a semi-amplitude of 148.8 km/s and a period of 7.5936 hours, which implies a companion mass of M > 0.28Msun. The lack of evidence of a companion in the optical photometry forces any main-sequence companion to be smaller than 0.1Msun, hence a low mass main sequence star companion is ruled out for this system. The companion is most likely another white dwarf, and we present tentative evidence for an evolutionary scenario which could have produced it. However, a neutron star companion cannot be ruled out and follow-up radio observations are required to search for a pulsar companion.
description: ApJ, in press. See the Press Release at http://www.cfa.harvard.edu/press/2007/pr200708.html
A Measure of de Sitter Entropy and Eternal Inflation
Creators: name: Arkani-Hamed, Nima
name: Dubovsky, Sergei
name: Nicolis, Alberto
name: Trincherini, Enrico
name: Villadoro, Giovanni
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that in any model of non-eternal inflation satisfying the null energy condition, the area of the de Sitter horizon increases by at least one Planck unit in each inflationary e-folding. This observation gives an operational meaning to the finiteness of the entropy S_dS of an inflationary de Sitter space eventually exiting into an asymptotically flat region: the asymptotic observer is never able to measure more than e^(S_dS) independent inflationary modes. This suggests a limitation on the amount of de Sitter space outside the horizon that can be consistently described at the semiclassical level, fitting well with other examples of the breakdown of locality in quantum gravity, such as in black hole evaporation. The bound does not hold in models of inflation that violate the null energy condition, such as ghost inflation. This strengthens the case for the thermodynamical interpretation of the bound as conventional black hole thermodynamics also fails in these models, strongly suggesting that these theories are incompatible with basic gravitational principles.
description: 33 pages, 8 figures
The expansion of irrigation infrastructure and efficient agricultural practices provide an effective adaptation strategy for Africa
Creators: name: Giordano, Vittorio
name: Tuninetti, Marta
name: Laio, Francesco
Publisher: name: Zenodo
Year: 2023
Subjects: Water Resources
Agriculture
Water Footprint
Crop Water Footprint
Climate Change
Climate Change Adaptation
Future Scenarios
Water Use Intensity
Intensification
Irrigation
Africa
Food
Food Security

description: Alarming projections of climate change, decline in crop yields, and increased food demand constitute daunting threats to African food production and sustainable water management. Here we map this complex water-food nexus by combining gridded climate data and process-based crop modelling to quantify scenarios of crop water footprint under RCP2.6 and RCP6.0 for time horizons 2040, 2070 and 2100. We show that high-input agricultural management coupled with the expansion of irrigation infrastructure could generate an average reduction of water use intensity up to 64% for staple crops, but only 5% for cash crops, by 2040. Notwithstanding the positive effect of intensification, between 82 Km3 (2040) and 102 Km3 (2100) of additional blue water will be required to sustain the increased yields. Our scenarios are suited for identifying locations where each crop tends to be subject to high climate impacts and where crop production shows trade-off between high-input management and irrigation demand.
D3.2 Integration of Trustworthy Disaggregated  Computing Architecture
Creators: name: Cyberus Technology
Publisher: name: Zenodo
Year: 2024

description: In this COREnext deliverable, the COREnext architecture is finalized, encompassing terminal devices, base stations, and edge cloud components. Feedback from component development has been integrated to support the validation of architectural building blocks in WP6 and to enhance trustworthiness efforts in WP2. This deliverable is submitted and under review. COREnext is a Horizon Europe project under Grant Agreement number 101092598.
Charge injection into the atmosphere by explosive volcanic eruptions through triboelectrification and fragmentation charging
Creators: name: Harper, Joshua Méndez
name: Cimarelli, Corrado
name: Cigala, Valeria
name: Kueppers, Ulrich
name: Dufek, Josef
Publisher: name: arXiv
Year: 2021
Subjects: subject: Geophysics (physics.geo-ph)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Volcanic eruptions are associated with a wide range of electrostatic effects. Increasing evidence suggests that high-altitude discharges (lightning) in maturing plumes are driven by electrification processes that require the formation of ice (analogous to processes underpinning meteorological thunderstorms). However, electrical discharges are also common at or near the volcanic vent. A number of "ice-free" electrification mechanisms have been proposed to account for this activity: fractocharging, triboelectric charging, radioactive charging, and charging through induction. Yet, the degree to which each mechanism contributes to a jet's total electrification and how electrification in the gas-thrust region influences electrostatic processes aloft remains poorly constrained. Here, we use a shock-tube to simulate overpressured volcanic jets capable of producing spark discharges in the absence of ice. These discharges may be representative of the continual radio frequency (CRF) emissions observed at a number of eruptions. Using a suite of electrostatic sensors, we demonstrate the presence of size-dependent bipolar charging (SDBC) in a discharge-bearing flow for the first time. SDBC has been readily associated with triboelectric charging in other contexts and provides direct evidence that contact and frictional electrification play significant roles in electrostatic processes in the vent and near-vent regions of an eruption. Additionally, we find that particles leaving the region where discharges occur remain moderately electrified. This degree of electrification may be sufficient to drive near-vent lightning higher in the column. Thus, near-vent discharges may be underpinned by the same electrification mechanisms driving CRF, albeit involving greater degrees of charge separation.
False sense of security and a flurry of misplaced trust: the construction of trust in and by Facebook
Creators: name: Bodo, Balazs
name: Bene, Marton
name: Boda, Zsolt
Publisher: name: Taylor & Francis
Year: 2025
Subjects: Molecular Biology
Biotechnology
Science Policy
Mental Health

description: In this research, we highlight the fundamental forces that shape the dynamics of trust in the digital society by examining how platform-specific and platform-mediated trust is constructed on Facebook. We define three potential pillars of trust considerations on which user trust in and on the platform may rest: (1) self-confidence in recognizing and hedging platform-related risks, (2) trust in the platform’s self-regulatory capacity, and (3) governmental platform regulation. We test our hypotheses on a unique cross-national survey covering seven European countries. Our results show that platform-specific trust is based on the perceived trustworthiness of the operating company and self-confidence in protection, but these two factors are less effective in building trust when either of them is lower, suggesting their amplifying rather than complementing role in building trust.
Quantized dynamics of a coherent capacitor
Creators: name: Moskalets, M.
name: Samuelsson, P.
name: Buttiker, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A quantum coherent capacitor subject to large amplitude pulse cycles can be made to emit or reabsorb an electron in each half cycle. Quantized currents with pulse cycles in the GHz range have been demonstrated experimentally. We develop a non-linear dynamical scattering theory for arbitrary pulses to describe the properties of this very fast single electron source. Using our theory we analyze the accuracy of the current quantization and investigate the noise of such a source. Our results are important for future scientific and possible metrological applications of this source.
description: 4 pages, 2 figures
Limits on Sub-GeV Dark Matter from the PROSPECT Reactor Antineutrino Experiment
Creators: name: Andriamirado, M.
name: Balantekin, A. B.
name: Band, H. R.
name: Bass, C. D.
name: Bergeron, D. E.
name: Bowden, N. S.
name: Bryan, C. D.
name: Classen, T.
name: Conant, A. J.
name: Deichert, G.
name: Diwan, M. V.
name: Dolinski, M. J.
name: Erickson, A.
name: Foust, B. T.
name: Gaison, J. K.
name: Galindo-Uribarri, A.
name: Gilbert, C. E.
name: Hans, S.
name: Hansell, A. B.
name: Heeger, K. M.
name: Heffron, B.
name: Jaffe, D. E.
name: Jayakumar, S.
name: Ji, X.
name: Jones, D. C.
name: Koblanski, J.
name: Kyzylova, O.
name: Lane, C. E.
name: Langford, T. J.
name: LaRosa, J.
name: Littlejohn, B. R.
name: Lu, X.
name: Maricic, J.
name: Mendenhall, M. P.
name: Meyer, A. M.
name: Milincic, R.
name: Mueller, P. E.
name: Mumm, H. P.
name: Napolitano, J.
name: Neilson, R.
name: Nikkel, J. A.
name: Nour, S.
name: Palomino, J. L.
name: Pushin, D. A.
name: Qian, X.
name: Rosero, R.
name: Surukuchi, P. T.
name: Tyra, M. A.
name: Varner, R. L.
name: Venegas-Vargas, D.
name: Weatherly, P. B.
name: White, C.
name: Wilhelmi, J.
name: Woolverton, A.
name: Yeh, M.
name: Zhang, C.
name: Zhang, X.
name: Cappiello, C. V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: If dark matter has mass lower than around 1 GeV, it will not impart enough energy to cause detectable nuclear recoils in many direct-detection experiments. However, if dark matter is upscattered to high energy by collisions with cosmic rays, it may be detectable in both direct-detection experiments and neutrino experiments. We report the results of a dedicated search for boosted dark matter upscattered by cosmic rays using the PROSPECT reactor antineutrino experiment. We show that such a flux of upscattered dark matter would display characteristic diurnal sidereal modulation, and use this to set new experimental constraints on sub-GeV dark matter exhibiting large interaction cross-sections.
description: 11 pages, 8 figures
Turbulent natural convection coupled with thermal radiation in a boundary layer
Creators: name: Hood, Innes William
Publisher: name: University of British Columbia
Year: 2010

description: Turbulent natural convection coupled with thermal radiation in an absorbing gas, adjacent to a vertical heated plate has been studied. The results of a simplified theoretical model are compared with experimental data obtained using a heated vertical plate in a carbon dioxide and nitrogen gas mixture. The theoretical model assumes a gray, optically thin, nonscattering and infinite gas adjacent to a black, isothermal plate. In addition, the Boussinesq approximation was applied, using the velocity and temperature profiles of Eckert and Jackson. The momentum and energy equations were solved by an integral technique, with the radiation term modelled by two different methods: the mean beam length method; and an exponential kernal approximation. The experimental work consisted of obtaining the temperature and velocity profiles of a turbulent natural boundary layer at one location over a range of carbon dioxide and nitrogen gas compositions, and calculating and comparing the enthalpy flux for the different cases. Results are given in terms of a combined convective and radiative Nusselt number as a function of gas absorptivity. It was found that Eckert and Jackson's velocity profile did not predict the flow accurately. By modifying the profile to fit the data, good ageement between the theory and experiment was obtained.
Kondo-lattice screening in a d-wave superconductor
Creators: name: Sheehy, Daniel E.
name: Schmalian, Joerg
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show that local moment screening in a Kondo lattice with d-wave superconducting conduction electrons is qualitatively different from the corresponding single Kondo impurity case. Despite the conduction-electron pseudogap, Kondo-lattice screening is stable if the gap amplitude obeys $Δ
description: 11 pages, 6 figures, revised version to appear in Physical Review B
The LOFAR and JVLA view of the distant steep spectrum radio halo in MACS J1149.5+2223
Creators: name: Bruno, L.
name: Rajpurohit, K.
name: Brunetti, G.
name: Gastaldello, F.
name: Botteon, A.
name: Ignesti, A.
name: Bonafede, A.
name: Dallacasa, D.
name: Cassano, R.
name: van Weeren, R. J.
name: Cuciti, V.
name: Di Gennaro, G.
name: Shimwell, T.
name: Brüggen, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Radio halos and relics are Mpc-scale diffuse radio sources in galaxy clusters, with a steep spectral index $α>1$ ($S\propto ν^{-α}$). It has been proposed that they arise from particle acceleration induced by turbulence and weak shocks, injected in the intracluster medium (ICM) during mergers. MACS J1149.5+2223 (MACS J1149) is a high redshift ($z=0.544$) galaxy cluster possibly hosting a radio halo and a relic. We analysed LOFAR, GMRT, and JVLA radio data at 144, 323, 1500 MHz, and Chandra X-ray data to characterise the thermal and non-thermal properties of the cluster. We obtained radio images at different frequencies to investigate the spectral properties of the radio halo. We used Chandra X-ray images to constrain the thermal properties of the cluster. We measured a steep spectrum of the halo, with $α=1.49\pm 0.12$ between 144 and 1500 MHz. The radio surface brightness distribution across the halo is found to correlate with the X-ray brightness of the ICM, with a sub-linear slope in the range 0.4 to 0.6. We also report two possible cold fronts in north-east and north-west, but deeper X-ray observations are required to firmly constrain the properties of the upstream emission. We show that the combination of high redshift, steep radio spectrum, and sub-linear radio-X scaling of the halo rules out hadronic models. An old ($\sim 1 $ Gyr ago) major merger likely induced the formation of the halo through stochastic re-acceleration of relativistic electrons. We suggest that the two possible X-ray discontinuities may actually be part of the same cold front. In this case, the coolest gas pushed towards the north-west might be associated with the cool core of a sub-cluster involved in the major merger. The peculiar orientation of the south-east relic might indicate a different nature of this source and requires further investigation.
description: 15 pages, accepted for publication in A&A
Coincident, 100 kpc-scale damped Lyman alpha absorption towards a binary QSO: how large are galaxies at z ~ 3?
Creators: name: Ellison, Sara L.
name: Hennawi, Joseph F.
name: Martin, Crystal L.
name: Sommer-Larsen, Jesper
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report coincident damped Lyman alpha (DLA) and sub-DLA absorption at z = 2.66 and z = 2.94 towards the z ~ 3 13.8 arcsecond separation binary quasar SDSS 1116+4118 AB. At the redshifts of the absorbers, this angular separation corresponds to a proper transverse separation of ~ 110 kpc. A third absorber, a sub-DLA at z = 2.47, is detected towards SDSS 1116+4118 B, but no corresponding high column density absorber is present towards SDSS 1116+4118 A. We use high resolution galaxy simulations and a clustering analysis to interpret the coincident absorption and its implications for galaxy structure at z ~ 3. We conclude that the common absorption in the two lines of sight is unlikely to arise from a single galaxy, or a galaxy plus satellite system, and is more feasibly explained by a group of two or more galaxies with separations ~ 100 kpc. The impact of these findings on single line of sight observations is also discussed; we show that abundances of DLAs may be affected by up to a few tenths of a dex by line of sight DLA blending. From a Keck ESI spectrum of the two quasars, we measure metal column densities for all five absorbers and determine abundances for the three absorbers with log N(HI) > 20. For the two highest N(HI) absorbers, we determine high levels of metal enrichment, corresponding to 1/3 and 1/5 solar. These metallicities are amongst the highest measured for DLAs at any redshift and are consistent with values measured in Lyman break galaxies at 2 < z < 3. For the DLA at z = 2.94 we also infer an approximately solar ratio of alpha-to-Fe peak elements from [S/Zn] = +0.05, and measure an upper limit for the molecular fraction in this particular line of sight of log f(H_2)< -5.5.
description: Accepted for publication in MNRAS. Full resolution simulation images available in pdf copy of the manuscript at http://www.astro.uvic.ca/~sara/1116.pdf
Quantum Monte Carlo diagonalization for many-fermion systems
Creators: name: Yanagisawa, Takashi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In this study we present an optimization method based on the quantum Monte Carlo diagonalization for many-fermion systems. Using the Hubbard-Stratonovich transformation, employed to decompose the interactions in terms of auxiliary fields, we expand the true ground-state wave function. The ground-state wave function is written as a linear combination of the basis wave functions. The Hamiltonian is diagonalized to obtain the lowest energy state, using the variational principle within the selected subspace of the basis functions. This method is free from the difficulty known as the negative sign problem. We can optimize a wave function using two procedures. The first procedure is to increase the number of basis functions. The second improves each basis function through the operators, $e^{-ΔτH}$, using the Hubbard-Stratonovich decomposition. We present an algorithm for the Quantum Monte Carlo diagonalization method using a genetic algorithm and the renormalization method. We compute the ground-state energy and correlation functions of small clusters to compare with available data.
Rotating scalarized black holes in scalar couplings to two topological terms
Creators: name: Zou, De-Cheng
name: Myung, Yun Soo
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The tachyonic instability of the Kerr black holes is analyzed in the Einstein-scalar theory with the quadratic scalar couplings to two topological terms which are parity-even Gauss-Bonnet and parity-odd Chern-Simons terms. For positive coupling $α$, we use the (2+1)-dimensional hyperboloidal foliation method to derive the threshold curve which is the boundary between stable and unstable Kerr black holes by considering a spherically symmetric scalar-mode perturbation. In case of negative coupling, a newly bound of $a\ge0.26$ with $a$ the rotation parameter is found for unstable Kerr black holes and its threshold curve is derived.
description: 13 pages, 3 figures, version to appear in PLB
Dynamics of ships and floating platforms
Creators: name: Ele, Abraham Y.
Publisher: name: University of British Columbia
Year: 2010

description: Three dimensional angular motions of ships and floating platforms are investigated using Euler's dynamical equations. The solution of Euler's equations predict two new oscillatory motions, namely roll and pitch together with a constant yawing or turning-rate. Unlike classical roll and pitch the new motions have a common period of oscillation which depends on the characteristics of the ship and the magnitude of the turning-rate. The possibility that gyroscopic coupling between rolling and pitching induce yawing is considered for unpowered platforms sitting in oblique regular waves. The rotational kinetic energy shows that for some sea states, there could be a non trivial turning-rate which minimizes the peak energy so that the platform rolls and pitches while turning at a constant-rate. Resonance takes place when the frequency of the wave coincides with the frequency of the coupled motions in still water. For ships maneuvering in regular waves, there are infinite combinations of the turning-rate and the frequency of the wave which could cause resonance. Damping, however small it may be, considerably reduces the amplitude at resonance. Regardless of its orientation with respect to the direction of wave propagation, simple rolling or pitching of an unbalanced body is not possible, instead, there is a combined roll-pitch motion having a common frequency, which does not appear to have been investigated previously.
Redefining the Missing Satellites Problem
Creators: name: Strigari, Louis E.
name: Bullock, James S.
name: Kaplinghat, Manoj
name: Diemand, Juerg
name: Kuhlen, Michael
name: Madau, Piero
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Numerical simulations of Milky-Way size Cold Dark Matter (CDM) halos predict a steeply rising mass function of small dark matter subhalos and a substructure count that greatly outnumbers the observed satellites of the Milky Way. Several proposed explanations exist, but detailed comparison between theory and observation in terms of the maximum circular velocity (Vmax) of the subhalos is hampered by the fact that Vmax for satellite halos is poorly constrained. We present comprehensive mass models for the well-known Milky Way dwarf satellites, and derive likelihood functions to show that their masses within 0.6 kpc (M_0.6) are strongly constrained by the present data. We show that the M_0.6 mass function of luminous satellite halos is flat between ~ 10^7 and 10^8 M_\odot. We use the ``Via Lactea'' N-body simulation to show that the M_0.6 mass function of CDM subhalos is steeply rising over this range. We rule out the hypothesis that the 11 well-known satellites of the Milky Way are hosted by the 11 most massive subhalos. We show that models where the brightest satellites correspond to the earliest forming subhalos or the most massive accreted objects both reproduce the observed mass function. A similar analysis with the newly-discovered dwarf satellites will further test these scenarios and provide powerful constraints on the CDM small-scale power spectrum and warm dark matter models.
description: 8 pages, 6 figures
The APOGEE Data Release 16 Spectral Line List
Creators: name: Smith, Verne V.
name: Bizyaev, Dmitry
name: Cunha, Katia
name: Shetrone, Matthew D.
name: Souto, Diogo
name: Prieto, Carlos Allende
name: Masseron, Thomas
name: Meszaros, Szabolcs
name: Jonsson, Henrik
name: Hasselquist, Sten
name: Osorio, Yeisson
name: Garcia-Hernandez, D. A.
name: Plez, Bertrand
name: Beaton, Rachael L.
name: Holtzman, Jon
name: Majewski, Steven R.
name: Stringfellow, Guy S.
name: Sobeck, Jennifer
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The updated H-band spectral line list (from λ15,000 - 17,000Å) adopted by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) for the SDSS IV Data Release 16 (DR16) is presented here. The APOGEE line list is a combination of atomic and molecular lines with data from laboratory, theoretical, and astrophysical sources. Oscillator strengths and damping constants are adjusted using high signal-to-noise, high-resolution spectra of the Sun and alpha Boo (Arcturus) as "standard stars". Updates to the DR16 line list, when compared to the previous DR14 version, are the inclusion of molecular H_2O and FeH lines, as well as a much larger (by a factor of ~4) atomic line list, which includes significantly more transitions with hyperfine splitting. More recent references and line lists for the crucial molecules CO and OH were used, as well as for C_2 and SiH. In contrast to DR14, DR16 contains measurable lines from the heavy neutron-capture elements cerium (as Ce II), neodymium (as Nd II), and ytterbium (as Yb II), as well as one line from rubidium (as Rb I), that may be detectable in a small fraction of APOGEE red giants.
description: 29 pages, 11 figures, accepted by AJ
Constraining bright optical counterparts of Fast Radio Bursts
Creators: name: Nuñez, C.
name: Tejos, N.
name: Pignata, G.
name: Kilpatrick, C. D.
name: Prochaska, J. X.
name: Heintz, K. E.
name: Bannister, K. W.
name: Bhandari, S.
name: Day, C. K.
name: Deller, A. T.
name: Flynn, C.
name: Mahony, E. K.
name: Majewski, D.
name: Marnoch, L.
name: Qiu, H.
name: Ryder, S. D.
name: Shannon, R. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Fast Radio Bursts (FRBs) are extremely energetic pulses of millisecond duration and unknown origin. In order to understand the phenomenon that emits these pulses, targeted and untargeted searches have been performed for multi-wavelength counterparts, including the optical. The objective of this work is to search for optical transients at the position of 8 well-localized FRBs, after the arrival of the burst on different time-scales (typically at one day, several months, and one year after FRB detection) in order to compare with known transient optical light curves. We used the Las Cumbres Observatory Global Telescope Network (LCOGT), which allows us to promptly take images owing to its network of twenty-three telescopes working around the world. We used a template subtraction technique on all the images we collected at different epochs. We have divided the subtractions into two groups, in one group we use the image of the last epoch as a template and in the other group we use the image of the first epoch as a template. We have searched for bright optical transients at the localizations of the FRBs (<1 arcsec) in the template subtracted images. We have found no optical transients, so we have set limiting magnitudes of optical counterparts. Typical limiting magnitudes in apparent (absolute) magnitudes for our LCOGT data are ~22 (-19) mag in the r-band. We have compared our limiting magnitudes with light curves of superluminous supernovae (SLSNe), type Ia supernovae (SNe), supernovae associated with gamma-ray bursts (GRB SNe), a kilonova, and tidal disruption events (TDEs). We rule out that FRBs are associated with SLSN at a confidence of ~99.9%. We can also rule out the brightest sub-types of type Ia SNe, GRB SNe and TDEs (under some conditions) at similar confidence, though we cannot exclude scenarios where FRBs are associated with the faintest sub-type of each of these transient classes.
description: Accepted to Astronomy & Astrophysics on 27 June, 2021. 8 pages, 3 figures, 3 tables
The Low-redshift Lyman-continuum Survey: [S II]-deficiency and the leakage of ionizing radiation
Creators: name: Wang, Bingjie
name: Heckman, Timothy M.
name: Amorín, Ricardo
name: Borthakur, Sanchayeeta
name: Chisholm, John
name: Ferguson, Harry
name: Flury, Sophia
name: Giavalisco, Mauro
name: Grazian, Andrea
name: Hayes, Matthew
name: Henry, Alaina
name: Jaskot, Anne
name: Ji, Zhiyuan
name: Makan, Kirill
name: McCandliss, Stephan
name: Oey, M. S.
name: Östlin, Göran
name: Saldana-Lopez, Alberto
name: Schaerer, Daniel
name: Thuan, Trinh
name: Worseck, Gábor
name: Xu, Xinfeng
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The relationship between galaxy characteristics and the reionization of the universe remains elusive, mainly due to the observational difficulty in accessing the Lyman continuum (LyC) at these redshifts. It is thus important to identify low-redshift LyC-leaking galaxies that can be used as laboratories to investigate the physical processes that allow LyC photons to escape. The weakness of the [S II] nebular emission lines relative to typical star-forming galaxies has been proposed as a LyC predictor. In this paper, we show that the [S II]-deficiency is an effective method to select LyC-leaking candidates using data from the Low-redshift LyC Survey, which has detected flux below the Lyman edge in 35 out of 66 star-forming galaxies with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope. We show that LyC leakers tend to be more [S II]-deficient and that the fraction of their detections increases as [S II]-deficiency becomes more prominent. Correlational studies suggest that [S II]-deficiency complements other LyC diagnostics (such as strong Lyman-$α$ emission and high [O III]/[O II]). Our results verify an additional technique by which reionization-era galaxies could be studied.
description: 15 pages, 6 figures, 3 tables; published in ApJ
Universal fluctuation of polygonal crack geometry in solidified lava
Creators: name: Akiba, Yuri
name: Takashima, Aika
name: Shima, Hiroyuki
Publisher: name: arXiv
Year: 2021
Subjects: subject: Geophysics (physics.geo-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Outcrops of columnar joints made of solidified lava flows are often covered by semi-ordered polygonal cracks. The polygon diameters are fairly uniform at each outcrop, but their shapes largely vary in the number of sides and internal angles. Herein, we unveil that the statistical variation in the polygon shape follows an extreme value distribution class: the Gumbel distribution. The Gumbel law was found to hold for different columnar joints, regardless of the locality, lithologic composition, and typical diameter. A common distribution for columnar joints implies a new universal class that may integrate the polygonal crack networks observed on the surface of various fractured brittle materials.
description: 9 pages, 14 figures
Modeling Affect-Based Relationships and Social Allostasis as Mechanisms for Adaptation in Social Groups
Creators: name: Khan, Imran M.
Publisher: name: UH Research Archive
Year: 2021
Subjects: Artificial Intelligence
Artificial Life
Homeostasis
Social Allostasis
Adaptive Systems
Social Dynamics
Embodied Cognition
Social Simulation
Affective Interaction

description: Artificial social agents are becoming increasingly present in the real world. For these agents, their success is tied to their ability to remain truly autonomous—to appropriately adapt their decisions and behaviours across changing physical and social contexts—and still remains a key area of research in the field of embodied autonomous agents. Numerous approaches towards models of adaptation have been proposed, including biologically-inspired models based on the regulation of an agent’s internal environment. A more recent concept from biological systems, called “(social) allostasis”, proposes a mechanism for the anticipatory adaptation of the internal environment through (affect-based) interactions with the (social) environment. Despite the long-term adaptive benefits proposed by social allostasis, current approaches towards models of adaptation for artificial social agents are yet to consider its principles in their approaches. In this manuscript, we address this shortcoming and investigate how mechanisms of social allostasis through affect-based relationships can be used for long-term adaptation of an embodied agent model. Using a biologically-inspired artificial life approach, we systematically investigate numerous hypothesised, hormonal mechanisms that underpin social allostasis and the survival-related benefits associated with affect-based social relationships. We conduct these investigations using a small society of simulated agents across numerous dynamic physical and social contexts. Our results find that adaptation of an embodied agent model through social allostasis mechanisms can provide survival-related advantages across several dynamic conditions in some contexts through physiological and behavioural adaptation. Throughout the manuscript, we also find numerous social interactions and dynamics that mirror biological systems. Our work addresses limitations in current approaches to adaptive models for embodied artificial agents, and presents a novel framework to guide future work in this field. The work also contributes a biologically-inspired artificial life model as a scientific tool to address some methodological challenges in natural systems. . .