Pulsar timing arrays seek and study gravitational waves (GWs) through the angular two-point correlation function of timing residuals they induce in pulsars. The two-point correlation function induced by the standard transverse-traceless GWs is the famous Hellings-Downs curve, a function only of the angle between the two pulsars. Additional polarization modes (vector or scalar) that may arise in alternative-gravity theories have different angular correlation functions. Furthermore, anisotropy, linear, or circular polarization in the stochastic GW background gives rise to additional structure in the two-point correlation function that cannot be written simply in terms of the angular separation of the two pulsars. In this Letter, we provide a simple formula for the most general two-point correlation function-or overlap reduction function (ORF)-for a gravitational-wave background with an arbitrary polarization state, possibly containing anisotropies in its intensity and polarization (linear and/or circular). We provide specific expressions for the ORFs sourced by the general-relativistic transverse-traceless GW modes as well as vector (or spin-1) modes that may arise in alternative-gravity theories.
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http://dx.doi.org/10.1103/PhysRevLett.133.151401 | DOI Listing |
Phys Rev Lett
December 2024
Université Paris-Saclay, CNRS, LPTMS, 91405, Orsay, France.
Energy-filtered quantum states are promising candidates for efficiently simulating thermal states. We explore a protocol designed to transition a product state into an eigenstate located in the middle of the spectrum; this is achieved by gradually reducing its energy variance, which allows us to comprehensively understand the crossover phenomenon and the subsequent convergence toward thermal behavior. We introduce and discuss three energy-filtering regimes (short, medium, and long), and we interpret them as stages of thermalization.
View Article and Find Full Text PDFHistopathology
December 2024
Unit of Oral and Maxillofacial Pathology, School of Clinical Dentistry, Faculty of Health, University of Sheffield, Sheffield, UK.
Aims: Oral epithelial dysplasia (OED) carries a risk of malignant transformation to oral squamous cell carcinoma. Clinical risk stratification for these patients is challenging, and reliant upon histological grading. The World Health Organisation (WHO) grading system is the current gold standard, although the binary system, two- and six-point prognostic models have also been proposed.
View Article and Find Full Text PDFJ Chem Theory Comput
December 2024
Fritz Haber Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel.
Kohn-Sham (KS) density functional theory (DFT) is an extremely popular, in-principle exact method, which can describe any many-electron system by introducing an auxiliary system of noninteracting electrons with the same density. When the number of electrons, , changes continuously, taking on both integer and fractional values, the density has to be piecewise-linear, with respect to . In this article, I explore how the piecewise-linearity property of the exact interacting density is reflected in the KS system.
View Article and Find Full Text PDFFront Neurol
November 2024
Department of Neuropsychiatry, Nanjing Meishan Hospital, Nanjing, China.
Objective: The Triglyceride-glucose Index (TyG) index is a dependable metric for assessing the degree of insulin resistance, serving as a standalone predictor of ischemic stroke risk, but its precise relationship with early neurological deterioration (END) remains incompletely expounded within the context of acute mild ischemic stroke patients. This research is to examine the correlation of the TyG index with END among patients experiencing acute mild ischemic stroke in China.
Methods: This retrospective analysis was conducted to systematically gather data regarding patients experiencing their maiden episode of acute mild ischemic stroke and hospitalized at the Neurology Department of Nanjing Meishan Hospital, located in Nanjing, Jiangsu Province, China, over the period extending from January 2020 to December 2022.
Bioresour Technol
December 2024
College of Environmental Engineering, Henan University of Technology, Zhengzhou 450001, China. Electronic address:
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