Boris Daszuta, Sebastiano Bernuzzi, Maximilian Jacobi
et al.
We present general-relativistic radiation magnetohydrodynamics simulations of binary neutron star mergers performed with GR-Athena++. Neutrino transport is treated using a moment-based, energy-integrated scheme (M1), augmented by neutrino number density evolution (N0). Our implementation is validated through an extensive suite of standard tests and demonstrated to perform robustly under adaptive mesh refinement. As a first application, we simulate the gravitational collapse of a uniformly rotating, magnetized neutron star, demonstrating stable radiation evolution through apparent-horizon formation using a novel excision technique based on the tapering of state vector evolution inside the horizon. To further test robustness in highly dynamic environments, we apply our code to two demanding binary neutron star merger scenarios. We investigate a long-lived remnant with the DD2 equation of state, evolved with full general-relativistic magnetohydrodynamics and M1 neutrino transport. Following this, a gravitational collapse scenario with the SFHo equation of state is explored. We showcase long-term stable evolution on neutrino cooling time-scales, demonstrating robust handling of excision and stable evolution of the post-collapse accretion phase in three-dimensional mergers with magnetic fields and neutrino radiation.
Estuti Shukla, Alireza Rashti, Rossella Gamba
et al.
We present the second release of the $\texttt{GR-Athena++}$ waveform catalog, comprising four new quasi-circular, non-precessing, spinning binary black hole simulations. These simulations are performed at high resolutions and represent a step toward generating high-fidelity gravitational waveforms that can eventually meet the accuracy requirements of upcoming next-generation detectors, including LISA, Cosmic Explorer, and Einstein Telescope. Gravitational waves are extracted at future null infinity ( $\mathscr{I}^{+}$) using both Cauchy characteristic extraction and finite-radius extraction. For each simulation, we provide strain data across multiple resolutions and analyze waveform accuracy via convergence studies and self-mismatch analyses. The absolute phase and relative amplitude differences reach their largest values near the merger, while the smallest errors are of order $\mathscr{O}(10^{-2})$ and $\mathscr{O}(10^{-3})$, respectively. A self-mismatch analysis of the dominant $(2,2)$ mode yields mismatches between $\mathscr{O}(10^{-5})$ and $\mathscr{O}(10^{-7})$ for a total binary mass of $10^{6}$ $M_{\odot}$ over the frequency range $[0.002, 0.1]$ Hz using LISA noise curve. All waveforms are publicly available via $\texttt{ScholarSphere}$.
AbstractWe aimed to analyse cancer survival and its spatial distribution in Shandong Province. A total of 609,861 cancer cases from 2014 to 2016 were included in the analysis. Survival analysis was performed using strs in Stata. Spatial analysis was performed with GeoDa to determine measures of global and local spatial autocorrelation. Hotspot analysis was used to identify spatial clusters of high values (hotspots) and low values (cold spots) through ArcGIS. The 5-year relative survival rates were 37.85% for all cancers combined, 29.29% for males and 48.88% for females. After age standardisation, the survival rates were 34.47% for all cancers, 28.43% for males and 41.56% for females. Cancers with higher survival rates included thyroid (78.80%), breast (69.52%), uterus (64.51%) and bladder (62.54%) cancers. However, cancers with lower survival rates included pancreatic (11.34%), liver (13.19%), lung (18.39%), bone (19.71%), gallbladder (19.78%), oesophagus (24.52%), and stomach (28.85%) cancers and leukaemia (26.30%). Cancer survival rates in urban areas (37.53%) were higher than those in rural areas (32.83%). From the geographic distribution of cancer survival, we observed that the survival rate displayed a downward trend from east to west and from north to south. The hotspot analysis revealed that some counties of Qingdao, Jinan, Zibo, Dongying and Yantai cities were hotspots, whereas almost all counties of Linyi city and some counties of Weifang, Heze, Rizhao, and Dezhou cities were cold spots. In conclusion, the cancer survival rate in Shandong is still lower than that in China overall. The early diagnosis and treatment of lung and digestive tract cancers need to be further strengthened. Nevertheless, our results reflect a critical first step in obtaining and reporting accurate and reliable estimates of survival in Shandong.
Zuobin Zhang, Honghui Liu, Askar B. Abdikamalov
et al.
The continuum-fitting and the iron-line methods are currently the two leading techniques for measuring the spins of accreting black holes. In the past few years, these two methods have been developed for testing fundamental physics. In the present work, we employ state-of-the-art models to test black holes through the continuum-fitting and the iron-line methods and we analyze three NuSTAR observations of the black hole binary GRS 1716-249 during its outburst in 2016-2017. In these three observations, the source was in a hard-intermediate state and the spectra show both a strong thermal component and prominent relativistic reflection features. Our analysis confirms the Kerr nature of the black hole in GRS 1716-249 and provides quite stringent constraints on possible deviations from the predictions of general relativity.
The Linet–Tian metrics are solutions of the Einstein equations with a cosmological constant, Λ, that can be positive or negative. The linear instability of these metrics in the case Λ 0, it was found in a recent analysis that the perturbation equations admit unstable modes (Gleiser 2018 arXiv:1810.07296v2[gr-qc]). The analysis was based on the construction of a gauge invariant function of the metric perturbation coefficients, called here W(y). This function satisfied a linear second order equation that could be used to set up a boundary value problem determining the allowed, real or purely imaginary frequencies for the perturbations. Nevertheless, the relation of these solutions to the full spectrum of perturbations, and, therefore, to the evolution of arbitrary perturbations, remained open. In this paper we consider again the perturbations of the Linet–Tian metric with Λ > 0, and show, using a form of the Darboux transformation, that one can associate with the perturbation equations a self adjoint problem that provides a solution to the completeness and spectrum of the perturbations. This is also used to construct the explicit relation between the solutions of the gauge invariant equation for W(y), and the evolution of arbitrary initial data, thus solving the problem that remained open in the previous study. Numerical methods are then used to confirm the existence of unstable modes as a part of the complete spectrum of the perturbations, thus establishing the linear gravitational instability of the Linet–Tian metrics with Λ > 0.
M. Rosenbaum, J. Flood, Stacy E. F. Melanson
et al.
Objectives In the United States, minimum standards for quality control (QC) are specified in federal law under the Clinical Laboratory Improvement Amendment and its revisions. Beyond meeting this required standard, laboratories have flexibility to determine their overall QC program. Methods We surveyed chemistry and immunochemistry QC procedures at 21 clinical laboratories within leading academic medical centers to assess if standardized QC practices exist for chemistry and immunochemistry testing. Results We observed significant variation and unexpected similarities in practice across laboratories, including QC frequency, cutoffs, number of levels analyzed, and other features. Conclusions This variation in practice indicates an opportunity exists to establish an evidence-based approach to QC that can be generalized across institutions.
Reference [3] on page 1125, 3. A. A. Grib and Yu. V. Pavlov, “Comparison of particle properties in Kerr metric and in rotating coordinates,” Gen. Rel. Grav., 49, 78 (2017); arXiv:1609.04202v2 [gr-qc] (2016).C. W. Misner, K. S. Thorne, and J. A. Wheeler, Gravitation, Freeman, San Francisco (1973). should be split as 3. A. A. Grib and Yu. V. Pavlov, “Comparison of particle properties in Kerr metric and in rotating coordinates,” Gen. Rel. Grav., 49, 78 (2017); arXiv:1609.04202v2 [gr-qc] (2016). 4. C. W. Misner, K. S. Thorne, and J. A. Wheeler, Gravitation, Freeman, San Francisco (1973). The subsequent reference numbers should incremented (old numbers 4–20 become 5–21). Then the citations in the text will correctly relate to the list of references. The editorial staff apologizes to the authors.
We offer a mathematically rigorous basis for the widely held suspicion that full black hole evaporation is in tension with predictability. Based on conditions expressing the global causal structure of evaporating black hole spacetimes, we prove two theorems in Lorentzian geometry showing that such spacetimes either fail to be causally simple or fail to be causally continuous. These theorems, when combined with recent results (Aké et al 2018 (arXiv:1808.04412 [gr-qc])) on the causal structure of spacetimes with timelike boundary, bear significantly on the question of whether these spacetimes permit for a predictable evolution.
Finnian Gray, Jessica Santiago, Sebastian Schuster
et al.
So-called "twisted" black holes have recently been proposed by Zhang (1609.09721 [gr-qc]), and further considered by Chen and Jing (1610.00886 [gr-qc]), and more recently by Ong (1610.05757 [gr-qc]). While these spacetimes are certainly Ricci-flat, and so mathematically satisfy the vacuum Einstein equations, they are also merely minor variants on Taub--NUT spacetimes. Consequently they exhibit several unphysical features that make them quite unreasonable as realistic astrophysical objects. Specifically, these "twisted" black holes are not (globally) asymptotically flat. Furthermore, they contain closed timelike curves that are not hidden behind any event horizon --- the most obvious of these closed timelike curves are small azimuthal circles around the rotation axis, but the effect is more general. The entire region outside the horizon is infested with closed timelike curves.
Recent perturbative self-force computations (Shah, Friedman & Whiting, submitted to Phys. Rev. {\bf D}, arXiv:1312.1952 [gr-qc]), both numerical and analytical, have determined that half-integral post-Newtonian terms arise in the conservative dynamics of black-hole binaries moving on exactly circular orbits. We look at the possible origin of these terms within the post-Newtonian approximation, find that they essentially originate from non-linear "tail-of-tail" integrals and show that, as demonstrated in the previous paper, their first occurrence is at the 5.5PN order. The post-Newtonian method we use is based on a multipolar-post-Minkowskian treatment of the field outside a general matter source, which is re-expanded in the near zone and extended inside the source thanks to a matching argument. Applying the formula obtained for generic sources to compact binaries, we obtain the redshift factor of circular black hole binaries (without spins) at 5.5PN order in the extreme mass ratio limit. Our result fully agrees with the determination of the 5.5PN coefficient by means of perturbative self-force computations reported in the previously cited paper.
Acute and chronic inflammatory disorders are characterized by detrimental cytokine and chemokine expression. Frequently, the chemotactic activity of cytokines depends on a modified N‐terminus of the polypeptide. Among those, the N‐terminus of monocyte chemoattractant protein 1 (CCL2 and MCP‐1) is modified to a pyroglutamate (pE‐) residue protecting against degradation in vivo. Here, we show that the N‐terminal pE‐formation depends on glutaminyl cyclase activity. The pE‐residue increases stability against N‐terminal degradation by aminopeptidases and improves receptor activation and signal transduction in vitro. Genetic ablation of the glutaminyl cyclase iso‐enzymes QC (QPCT) or isoQC (QPCTL) revealed a major role of isoQC for pE1‐CCL2 formation and monocyte infiltration. Consistently, administration of QC‐inhibitors in inflammatory models, such as thioglycollate‐induced peritonitis reduced monocyte infiltration. The pharmacologic efficacy of QC/isoQC‐inhibition was assessed in accelerated atherosclerosis in ApoE3*Leiden mice, showing attenuated atherosclerotic pathology following chronic oral treatment. Current strategies targeting CCL2 are mainly based on antibodies or spiegelmers. The application of small, orally available inhibitors of glutaminyl cyclases represents an alternative therapeutic strategy to treat CCL2‐driven disorders such as atherosclerosis/restenosis and fibrosis.
Pyroglutamate-modified Aβ (AβpE3–42) peptides are gaining considerable attention as potential key players in the pathology of Alzheimer disease (AD) due to their abundance in AD brain, high aggregation propensity, stability, and cellular toxicity. Overexpressing AβpE3–42 induced a severe neuron loss and neurological phenotype in TBA2 mice. In vitro and in vivo experiments have recently proven that the enzyme glutaminyl cyclase (QC) catalyzes the formation of AβpE3–42. The aim of the present work was to analyze the role of QC in an AD mouse model with abundant AβpE3–42 formation. 5XFAD mice were crossed with transgenic mice expressing human QC (hQC) under the control of the Thy1 promoter. 5XFAD/hQC bigenic mice showed significant elevation in TBS, SDS, and formic acid-soluble AβpE3–42 peptides and aggregation in plaques. In 6-month-old 5XFAD/hQC mice, a significant motor and working memory impairment developed compared with 5XFAD. The contribution of endogenous QC was studied by generating 5XFAD/QC-KO mice (mouse QC knock-out). 5XFAD/QC-KO mice showed a significant rescue of the wild-type mice behavioral phenotype, demonstrating the important contribution of endogenous mouse QC and transgenic overexpressed QC. These data clearly demonstrate that QC is crucial for modulating AβpE3–42 levels in vivo and prove on a genetic base the concept that reduction of QC activity is a promising new therapeutic approach for AD.
We employ the techniques introduced in the companion papers (Bodendorfer et al 2011 arXiv:1105.3703 [gr-qc]; arXiv:1105.3704 [gr-qc]; arXiv:1105.3705 [gr-qc]) to derive a connection formulation of Lorentzian general relativity coupled to Dirac fermions in dimensions D + 1 ⩾ 3 with a compact gauge group. The technique that accomplishes that is similar to the one that has been introduced in 3 + 1 dimensions already. First one performs a canonical analysis of Lorentzian general relativity using the time gauge and then introduces an extension of the phase space analogous to the one employed in [1] to obtain a connection theory with SO(D + 1) as the internal gauge group subject to additional constraints. The success of this method rests heavily on the strong similarity of the Lorentzian and Euclidean Clifford algebras. A quantization of the Hamiltonian constraint is provided.
Integrable flows on the Grassmannians Gr(N-1,N+1) are defined by the requirement of closedness of the differential N-1 forms $Ω_{N-1}$ of rank N-1 naturally associated with Gr(N-1,N+1). Gauge-invariant parts of these flows, given by the systems of the N-1 quasi-linear differential equations, describe coisotropic deformations of (N-1)-dimensional linear subspaces. For the class of solutions which are Laurent polynomials in one variable these systems coincide with N-dimensional integrable systems such as Liouville equation (N=2), dispersionless Kadomtsev-Petviashvili equation (N=3), dispersionless Toda equation (N=3), Plebanski second heavenly equation (N=4) and others. Gauge invariant part of the forms $Ω_{N-1}$ provides us with the compact form of the corresponding hierarchies. Dual quasi-linear systems associated with the projectively dual Grassmannians Gr(2,N+1) are defined via the requirement of the closedness of the dual forms $Ω_{N-1}^{\star}$. It is shown that at N=3 the self-dual quasi-linear system, which is associated with the harmonic (closed and co-closed) form $Ω_{2}$, coincides with the Maxwell equations for orthogonal electric and magnetic fields.
Peter Wolf, Luc Blanchet, Christian J. Bordé
et al.
Hohensee, Chu, Peters and Müller have submitted a comment (arXiv:1112.6039 [gr-qc]) on our paper "Does an atom interferometer test the gravitational redshift at the Compton frequency?", Classical and Quantum Gravity 28, 145017 (2011), arXiv:1009.2485 [gr-qc]. Here we reply to this comment and show that the main result of our paper, namely that atom interferometric gravimeters do not test the gravitational redshift at the Compton frequency, remains valid.