First results from 2+1 dynamical quark flavors on an anisotropic lattice: light-hadron spectroscopy and setting the strange-quark mass

We present the first light-hadron spectroscopy on a set of $N_f=2+1$ dynamical, anisotropic lattices. A convenient set of coordinates that parameterize the two-dimensional plane of light and strange-quark masses is introduced. These coordinates are used to extrapolate data obtained at the simulated values of the quark masses to the physical light and strange-quark point. A measurement of the Sommer scale on these ensembles is made, and the performance of the hybrid Monte Carlo algorithm used for generating the ensembles is estimated.Comment: 24 pages. Hadron Spectrum Collaboratio

Copper isotope constraints on the genesis of the Keweenaw Peninsula Native Copper District, Michigan, USA

The Keweenaw Peninsula native copper district of Michigan, USA is the largest concentration of native copper in the world. The copper isotopic composition of native copper was measured from stratabound and vein deposits, hosted by multiple rift-filling basalt-dominated stratigraphic horizons over 110 km of strike length. The δ65Cu of the native copper has an overall mean of +0.28‰ and a range of −0.32‰ to +0.80‰ (excluding one anomalous value). The data appear to be normally distributed and unimodal with no substantial differences between the native copper isotopic composition from the wide spread of deposits studied here. This suggests a common regional and relatively uniform process of derivation and precipitation of the copper in these deposits. Several published studies indicate that the ore-forming hydrothermal fluids carried copper as Cu1+, which is reduced to Cu0 during the precipitation of native copper. The δ65Cu of copper in the ore-forming fluids is thereby constrained to +0.80‰ or higher in order to yield the measured native copper values by reductive precipitation. The currently accepted hypothesis for the genesis of native copper relies on the leaching of copper from the rift-filling basalt-dominated stratigraphic section at a depth below the deposits during burial metamorphism. Oxidative dissolution of copper from magmatic source rocks with magmatic δ65Cu of 0‰ ± 0.3‰ is needed to obtain the copper isotopic composition of the metamorphogenic ore-forming hydrothermal fluids. In order to accommodate oxidative dissolution of copper from the rift-filling basalt source rocks, the copper needs to have been sited in native copper. Magmatic native copper in basalt is likely stable when the magma is low in sulfur. Low sulfur is predicted by the lack of sulfide minerals in the ore deposits and in the rift-filling basalt-dominated section, which are source rocks, the same rocks through which the ore fluids moved upwards, and the host rocks for the native copper ores. When combined with geologic evidence and inferences, the copper isotopic composition of native copper helps to further constrain the genetic model for this unique mining district

A note on black hole masses estimated by the second moment in Narrow Line Seyfert 1 Galaxies

The second moment of the H$\beta$ emission line is calculated for 329 narrow line Seyfert 1 galaxies (NLS1s) selected from the Sloan Digital Sky Survey (SDSS), which is used to calculate the central supermassive black hole (SMBHs) mass of each. We find that the second moment depends strongly on the broader component of the H$\beta$ line profile. We find that for the NLS1s requiring two Gaussians to fit the H$\beta$ line the mean value of the SMBH mass from the H$\beta$ second moment is larger by about 0.50 dex than that from the full width at half maximum (FWHM). Using the gas velocity dispersion of the core/narrow component of \oiii $\lambda$ 5007 to estimate the stellar velocity dispersion, $\sigma_{*}$, the new mass makes NLS1s fall very close to the \mbh - \sigma_{*} relation for normal AGNs. By using $\sigma_{*}$ measured directly from SDSS spectra with a simple stellar population synthesis method, we find that for NLS1s with mass lower than 10^7 \msun, they fall only marginally below the \mbh - \sigma_{*} relation considering the large scatter in the mass calculation.Comment: 8 paper, 5 figures, 1 tables, accepted for publication in MNRA

From the discrete to the continuous - towards a cylindrically consistent dynamics

Discrete models usually represent approximations to continuum physics. Cylindrical consistency provides a framework in which discretizations mirror exactly the continuum limit. Being a standard tool for the kinematics of loop quantum gravity we propose a coarse graining procedure that aims at constructing a cylindrically consistent dynamics in the form of transition amplitudes and Hamilton's principal functions. The coarse graining procedure, which is motivated by tensor network renormalization methods, provides a systematic approximation scheme towards this end. A crucial role in this coarse graining scheme is played by embedding maps that allow the interpretation of discrete boundary data as continuum configurations. These embedding maps should be selected according to the dynamics of the system, as a choice of embedding maps will determine a truncation of the renormalization flow.Comment: 22 page

A ferroelectric memristor

Memristors are continuously tunable resistors that emulate synapses. Conceptualized in the 1970s, they traditionally operate by voltage-induced displacements of matter, but the mechanism remains controversial. Purely electronic memristors have recently emerged based on well-established physical phenomena with albeit modest resistance changes. Here we demonstrate that voltage-controlled domain configurations in ferroelectric tunnel barriers yield memristive behaviour with resistance variations exceeding two orders of magnitude and a 10 ns operation speed. Using models of ferroelectric-domain nucleation and growth we explain the quasi-continuous resistance variations and derive a simple analytical expression for the memristive effect. Our results suggest new opportunities for ferroelectrics as the hardware basis of future neuromorphic computational architectures

The Central Cemetery at Ingombe Ilede, Zambia: Chronology and Connections

Ingombe Ilede is located just north of the Zambezi River, and has often been seen as a trading station connected to Central Africa, the Zimbabwe Plateau and the Indian Ocean. Discussion of the richly appointed burials in its Central Cemetery has been hindered by uncertainty over their ages. In this article, we report four new radiocarbon dates from Ingombe Ilede and six new dates from sites in northern Zimbabwe that are relevant to a wider understanding of Ingombe Ilede and its connections. These ten dates are all on organic fiber cores within copper and bronze jewelry, for which we also report chemical compositions, lead isotope ratios, and (for bronzes) tin isotopic ratios. We show that the richer burials in the Central Cemetery were interred no earlier than the mid fifteenth century. By this time copper from the Central African Copperbelt, 500–700 km north of the Zambezi, had been transported into northern Zimbabwe for at least two centuries, as had tin from the Bushveld Large Igneous Province (BLIP) 900–1000 km south of the Zambezi. The rich burials at Ingombe Ilede represent a late phase of a longstanding trade in copper from the Copperbelt to the Zimbabwean plateau

Revisiting "Tin in South-eastern Europe?"

Obnovom arheoloških iskopavanja antičkog kastela Timakum Minus 2019. godine stvorile su se nove mogućnosti za tumačenja njegovih građevina koje su istraživane pre više decenija. Među ostacima građevina oko antičkog kastela Timacum Minus-a posebnu pažnju privlači delimično istražen "objekat sa hipokaustom", naročito u pogledu njegovih konstruktivnih karakteristika. Pored inače čestih antičkih konstrukcija hipokausta i zidnog grejanja, među ostacima ove građevine uočena je i posebna vrsta građevinskih elemenata - keramičke cevi za svodove. Velika količina otkrivenih cevi ukazala je na to da je ova građevina zaista imala svodove izrađene od njih. Iako je pojava cevi za svodove prilikom istraživanja antičkih lokaliteta na tlu jugoistočne Evrope registrovana, ona nije dovoljno dokumentovana, kao što ni sama funkcija cevi često nije prepoznata. Jedan od razloga za to jeste nedovoljna upućenost istraživača u specifične karakteristike cevi za svodove i njihovu funkciju, usled čega se one mešaju sa vodovodnim cevima, tubulusima ili kalemovima vezanim za zidno grejanje - budući da svaki od tih elemenata pripada keramičkim proizvodima koji su namenjeni građevinarstvu. U radu su razmatrane karakteristike cevi za svodove na Timakum Minusu, kao i kontekst u kome su pronađene unutar "objekta sa hipokaustom". Na osnovu nalaza pečata kohorte Aurelije II Daradanorum određeno je da "objekat sa hipokaustom" i konstrukcija svodova od keramičkih cevi potiču iz III veka - u kome je i inače pojava tih svodova širom Rimskog carstva bila česta. Prilikom sistematizacije vrsta keramičkih cevi na Timakum Minusu posebno je izdvojena ona koje je bilo najviše u "objektu sa hipokaustom". U sklopu nje je prepoznat i sasvim specifičan centralni element koji je omogućavao da se dva niza cevi na istom pravcu, ali iz suprotnih smerova, međusobno spoje. Taj element je definisao oblik svoda kojim su bile pokrivene prostorije čiju je rekonstrukciju osnove bilo moguće izvršiti. Arhitektonske analize "objekta sa hipokaustom", kao i karakteristike uočene na samim cevima ukazale su na to da su prostorije bile pokrivene poluobličastim svodom, izgrađenim od lučnih vertikalnih nizova cevi koje su u temenu bile ,,zaključane" centralnim elementom. Rekonstrukcija izgleda cevi i načina njihovog ređanja uklapa se u hronologiju izvođenja objekta i svoda tokom III veka. Daljim statičkim analizama došlo se do još nekoliko saznanja. Pokazalo se da je preko svoda morao biti nanesen određen sloj malterne mase da bi debljina svoda dosegla optimalnu vrednost u opsegu 20-30 cm. Na osnovu proporcija objekta koje su određene u njegovoj osnovi ispitana je visina objekta, gde je grupa slučajeva takođe definisana proporcionalno. Prema našim analizama, zidovi prostorija "objekta sa hipokaustom" u kojima su cevi registrovane mogli su dosezati visinu do 3,08 m, dok je visina prostorija u temenu svoda mogla biti 6,16 m. Ovim istraživanjem pokušali smo da ukažemo na veliki značaj pojedinačnih arhitektonsko-građevinskih elemenata, a među njima i keramičkih cevi za svodove, kojima se često ne pridaje dovoljna pažnja. Nalazi keramičkih cevi za svodove u Timakum Minusu, uz izvršene arhitektonske analize, upotpunjuju sliku otkrivenog "objekta sa hipokaustom" iz više aspekata. Posebno je značajno definisanje njegove visine, koje je veoma teško za antičke građevine profane arhitekture na našem tlu budući da su najčešće sačuvane u prizemnoj ili temeljnoj zoni. Značaj nalaza keramičkih cevi za svodove u Timakum Minusu veliki je stoga što je on omogućio kako konkretno definisanje konteksta njihovog nalaza tako i rekonstrukciju oblika određenih delova građevine pomoću tog elementa, što do sada nije istraživano prilikom analiza antičke arhitekture na tlu jugoistočne Evrope.The important role of the Balkans in the origin and development of metallurgy is well established with respect to copper. In addition, Aleksandar Durman, in his 1997 paper "Tin in South-eastern Europe?", essentially initiated studies into the role of the Balkans in Europe's Bronze Age tin economy. He identified six geologically favourable sites for tin mineralisation and associated fluvial placer deposits in the former Yugoslavian republics, and suggested that these may have added to the tin supply of the region. The viability of two of these sites has been confirmed (Mt Cer and Bukulja, Serbia) but the exploitation potential for the other locations has remained untested. River gravels from these four sites (Motajica and Prosara in Bosnia and Herzegovina; Bujanovac in Serbia; Ogražden in North Macedonia) were obtained by stream sluicing and panning. The sites of Prosara and Bujanovac were found to be barren with respect to cassiterite (SnO 2). Streams flowing from Motajica and Ogražden were both found to contain cassiterite, but in amounts several orders of magnitude less than at Mt Cer and Bukulja. Although it is possible that minor tin recovery occurred at Motajica and Ogražden, it is unlikely that they could have contributed meaningfully to regional tin trade. This is supported by the fact that the isotopic signature (d 124 Sn) of cassiterite from Motajica is highly enriched in light isotopes of tin compared to that associated with Late Bronze Age artefacts of the region

The Giant Chalukou Porphyry Mo Deposit, Northeast China: The Product of a Short-Lived, High Flux Mineralizing Event

Whether giant porphyry ore deposits are the products of single, short-lived magmatic-hydrothermal events or multiple events over a prolonged interval is a topic of considerable debate. Previous studies, however, have all been devoted to porphyry Cu and Cu-Mo deposits. In this paper, we report high-precision isotope dilution-negative-thermal ionization mass spectrometric (ID-N-TIMS) molybdenite Re-Os ages for the newly discovered, world-class Chalukou porphyry Mo deposit (reserves of 2.46 Mt @ 0.087 wt % Mo) in NE China. Samples were selected based on a careful evaluation of the relative timing of the different vein types (i.e., A, B, and D veins), thereby ensuring that the suite of samples analyzed could be used to reliably determine the age and duration of mineralization. The molybdenite Re-Os geochronology reveals that hydrothermal activity at Chalukou involved two magmatic-hydrothermal events spanning an interval of 6.92 ± 0.16 m.y. The first event (153.96 ± 0.08/0.63/0.79 Ma, molybdenite ID-N-TIMS Re-Os age) was associated with the emplacement of a granite porphyry dated at 152.1 ± 2.2 Ma (zircon laser ablation-inductively coupled plasma-microscopic [LA-ICP-MS] U-Pb ages), and led to only minor Mo mineralization, accounting for 90%) was deposited in less than 650 kyr, between 147.67 ± 0.10/0.60/0.76 and 147.04 ± 0.12/0.72/0.86 Ma (molybdenite ID-N-TIMS Re-Os ages), coincident with the emplacement of a fine-grained porphyry at 148.1 ± 2.6 Ma (zircon LA-ICP-MS U-Pb ages). The high-precision Re-Os age determinations presented here show, contrary to the finding of a number of studies of porphyry Cu and Cu-Mo systems, that the giant Chalukou porphyry Mo deposit primarily formed in a single, short-lived (<650 kyr) hydrothermal event, suggesting that this may also have been the case for other giant porphyry Mo deposits