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We present the first neutron star merger simulations performed with the newly developed Numerical Relativity code SPHINCS_BSSN. This code evolves the spacetime on a mesh using the BSSN formulation, but matter is evolved via Lagrangian…

High Energy Astrophysical Phenomena · Physics 2022-05-11 P. Diener , S. Rosswog , F. Torsello

Next-generation gravitational wave detectors are expected to increase their sensitivity in the kHz band where binary neutron star remnants are expected to emit. In this context, robust predictions of oscillation modes of the post-merger…

General Relativity and Quantum Cosmology · Physics 2025-05-23 Gaël Servignat , Jérôme Novak

The dynamics and observable signatures of neutron star mergers are governed by physics under the most extreme conditions. They are particularly impacted by the high-density equation of state, which for the most sophisticated models is…

High Energy Astrophysical Phenomena · Physics 2026-03-30 Swapnil Shankar , Stephan Rosswog , Peter Diener

We perform binary neutron star (BNS) merger simulations in full dynamical general relativity with IllinoisGRMHD, on a Cartesian grid with adaptive-mesh refinement. After the remnant black hole has become nearly stationary, the evolution of…

Characterizing noisy quantum devices requires methods for learning the underlying quantum Hamiltonian which governs their dynamics. Often, such methods compare measurements to simulations of candidate Hamiltonians, a task which requires…

Quantum Physics · Physics 2021-10-13 Assaf Zubida , Elad Yitzhaki , Netanel H. Lindner , Eyal Bairey

A numerical solution scheme for the Einstein field equations based on generalized harmonic coordinates is described, focusing on details not provided before in the literature and that are of particular relevance to the binary black hole…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Frans Pretorius

This work introduces advanced computational techniques for modeling the time evolution of compact binary systems using machine learning. The dynamics of compact binary systems, such as black holes and neutron stars, present significant…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-08 Jianqi Yan , Junjie Luo , Yifan Zeng , Alex P. Leung , Jie Feng , Hong-Hao Zhang , Weipeng Lin

We present numerical hydrodynamical evolutions of rapidly rotating relativistic stars, using an axisymmetric, nonlinear relativistic hydrodynamics code. We use four different high-resolution shock-capturing (HRSC) finite-difference schemes…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Jose A. Font , Nikolaos Stergioulas , Kostas D. Kokkotas

To study binary neutron star systems and to interpret observational data such as gravitational-wave and kilonova signals, one needs an accurate description of the processes that take place during the final stages of the coalescence, e.g.,…

General Relativity and Quantum Cosmology · Physics 2022-07-12 Henrique Gieg , Federico Schianchi , Tim Dietrich , Maximiliano Ujevic

We study the problem of simulating the dynamics of spin systems when the initial state is supported on a subspace of low energy of a Hamiltonian $H$. This is a central problem in physics with vast applications in many-body systems and…

Quantum Physics · Physics 2021-09-10 Burak Şahinoğlu , Rolando D. Somma

Neutron star mergers hold the key to several grand challenges of contemporary (astro-)physics. In view of the upcoming next generation of ground-based detectors, it is crucial to keep improving theoretical predictions to harvest the full…

High Energy Astrophysical Phenomena · Physics 2026-01-06 Bhaskar Biswas , Stephan Rosswog , Peter Diener , Lukas Schnabel

The reduction of Hamiltonian systems aims to build smaller reduced models, valid over a certain range of time and parameters, in order to reduce computing time. By maintaining the Hamiltonian structure in the reduced model, certain…

Numerical Analysis · Mathematics 2024-09-17 Raphaël Côte , Emmanuel Franck , Laurent Navoret , Guillaume Steimer , Vincent Vigon

This paper proposes an effective diffusion equation method to analyze nuclear magnetic resonance (NMR) relaxation. NMR relaxation is a spin system recovery process, where the evolution of the spin system is affected by the random field due…

Chemical Physics · Physics 2021-03-31 Guoxing Lin

We present initial results of our study of numerical methods for modeling neutron star mergers (NSMs) with simulations that perform the full hydrodynamic evolution required to capture tidal effects, particularly in the last several orbits.…

Astrophysics · Physics 2007-05-23 Alan C. Calder , F. Douglas Swesty , Edward Y. M. Wang

We report on numerical results from a revised hydrodynamic simulation of binary neutron-star orbits near merger. We find that the correction recently identified by Flanagan significantly reduces but does not eliminate the neutron-star…

General Relativity and Quantum Cosmology · Physics 2009-10-31 G. J. Mathews , J. R. Wilson

We propose a numerical method for approximate calculations of the time evolution of point particle systems given only the system's Hamiltonian function and initial conditions. The method both generates and solves the equations of motion…

Computational Physics · Physics 2022-12-27 José M. L. Amoreira , Luís J. M. Amoreira

Gravitational waves observation with electromagnetic counterparts provides an approach to measure the Hubble constant which is also known as the bright siren method. Great hope has been put into this method to arbitrate the Hubble tension.…

High Energy Astrophysical Phenomena · Physics 2023-02-21 Y. F. Du , S. X. Yi , S. N. Zhang , Shu Zhang

The construction of accurate and consistent initial data for various binary parameters is a critical ingredient for numerical relativity simulations of the compact binary coalescence. In this article, we present an upgrade of the…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Wolfgang Tichy , Alireza Rashti , Tim Dietrich , Reetika Dudi , Bernd Brügmann

In this paper, we have reviewed the present status of the theory of equilibrium configurations of compact binary star systems in Newtonian gravity. Evolutionary processes of compact binary star systems due to gravitational wave emission can…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yoshiharu Eriguchi , Koji Uryu

Hamiltonian formalisms provide powerful tools for the computation of approximate analytic solutions of the Einstein field equations. The post-Newtonian computations of the explicit analytic dynamics and motion of compact binaries are…

General Relativity and Quantum Cosmology · Physics 2024-05-20 Gerhard Schäfer , Piotr Jaranowski