English
Related papers

Related papers: A new code for computing differentially rotating n…

200 papers

One of main obstacles in verifying the energy dissipation laws of implicit-explicit Runge-Kutta (IERK) methods for phase field equations is to establish the uniform boundedness of stage solutions without the global Lipschitz continuity…

Numerical Analysis · Mathematics 2024-12-11 Hong-lin Liao , Tao Tang , Xuping Wang , Tao Zhou

It is the first step for understanding how RNA structure folds from base sequences that to know how its secondary structure is formed. Traditional energy-based algorithms are short of precision, particularly for non-nested sequences, while…

Quantum Physics · Physics 2023-05-18 Ji Jiang , Qipeng Yan , Ye Li , Min Lu , Ziwei Cui , Menghan Dou , Qingchun Wang , Yu-Chun Wu , Guo-Ping Guo

We study small-amplitude, nonlinear pulsations of uniformly and differentially rotating neutron stars employing a two-dimensional evolution code for general-relativistic hydrodynamics. Using Fourier transforms at several points inside the…

Astrophysics · Physics 2009-11-10 Nikolaos Stergioulas , Theocharis A. Apostolatos , Jose A. Font

In this work we revisit axial perturbations of spherically symmetric and non-rotating neutron stars. Although it has been object of many studies, it still offers new insights that are of potential interest for more realistic scenarios or in…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Sebastian H. Völkel , Kostas D. Kokkotas

We consider a class of Fuchsian equations that, for instance, describes the evolution of compressible fluid flows on a cosmological spacetime. Using the method of lines, we introduce a numerical algorithm for the singular initial value…

General Relativity and Quantum Cosmology · Physics 2021-03-17 Florian Beyer , Philippe G. LeFloch

We investigate the geodesic structure of realistic static and spherically symmetric spacetimes embedding neutron stars in metric $f(R)$ gravity, focusing on the quadratic Starobinsky model $f(R)=aR^2$ with $a<0$. Neutron-star solutions are…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Néstor Rivero González , Álvaro de la Cruz Dombriz , Gonzalo J. Olmo

Linearized numerical stability bounds for solving the nonlinear time-dependent Schr\"odinger equation (NLSE) using explicit finite-differencing are shown. The bounds are computed for the fourth-order Runge-Kutta scheme in time and both…

Numerical Analysis · Computer Science 2013-01-03 Ronald M. Caplan , Ricardo Carretero-González

We have performed a comprehensive parameter study of the collapse of rotating, strongly magnetized stellar cores in axisymmetry to determine their gravitational wave signature based on the Einstein quadrupole formula. We use a Newtonian…

Astrophysics · Physics 2009-11-13 M. Obergaulinger , M. A. Aloy , E. Mueller

This paper describes the design and implementation of our new multi-group, multi-dimensional radiation hydrodynamics (RHD) code Fornax and provides a suite of code tests to validate its application in a wide range of physical regimes.…

Instrumentation and Methods for Astrophysics · Physics 2019-03-06 M. Aaron Skinner , Joshua C. Dolence , Adam Burrows , David Radice , David Vartanyan

We present a new derivation of the perturbation equations governing the oscillations of relativistic non-rotating neutron star models using the ADM-formalism. This formulation has the advantage that it immediately yields the evolution…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Johannes Ruoff

We develop a new method to measure neutron star parameters and derive constraints on the equation of state of dense matter by fitting the frequencies of simultaneous Quasi Periodic Oscillation modes observed in the X-ray flux of accreting…

High Energy Astrophysical Phenomena · Physics 2020-09-02 Andrea Maselli , George Pappas , Paolo Pani , Leonardo Gualtieri , Sara Motta , Valeria Ferrari , Luigi Stella

Using an energy variational method, we calculate quasi-equilibrium configurations of binary neutron stars modeled as compressible triaxial ellipsoids obeying a polytropic equation of state. Our energy functional includes terms both for the…

Astrophysics · Physics 2009-10-30 James C. Lombardi , Frederic A. Rasio , Stuart L. Shapiro

We present a numerical model for uniformly rotating superfluid neutron stars, for the first time with realistic microphysics including entrainment, in a fully general relativistic framework. We compute stationary and axisymmetric…

High Energy Astrophysical Phenomena · Physics 2016-11-04 Aurélien Sourie , Micaela Oertel , Jérôme Novak

We develop a framework for constructing initial data sets for perturbations about spherically symmetric matter distributions. This framework facilitates setting initial data representing astrophysical sources of gravitational radiation…

General Relativity and Quantum Cosmology · Physics 2016-08-25 Nils Andersson , Kostas D. Kokkotas , Pablo Laguna , Philippos Papadopoulos , Michael S. Sipior

In the last few decades, numerical simulation for nonlinear oscillators has received a great deal of attention, and many researchers have been concerned with the design and analysis of numerical methods for solving oscillatory problems. In…

Numerical Analysis · Mathematics 2020-12-25 Yu-Wen Li , Xinyuan Wu

Despite the recent rapid progress in numerical relativity, a convergence order less than the second has so far plagued codes solving the Einstein-Euler system of equations. We report simulations of the inspiral of binary neutron stars in…

General Relativity and Quantum Cosmology · Physics 2013-12-16 David Radice , Luciano Rezzolla , Filippo Galeazzi

We introduce a hybrid oscillator-qubit formulation of linear combination of Hamiltonian simulation (LCHS) for solving linear ordinary differential equations. Instead of representing the quadrature rule with a discrete-variable (DV) ancilla…

Quantum Physics · Physics 2026-05-12 Elin Ranjan Das , Muqing Zheng , Rishab Dutta , Ang Li , Timothy Stavenger , Yuan Liu

Initial-boundary value problems for 1-dimensional `completely integrable' equations can be solved via an extension of the inverse scattering method, which is due to Fokas and his collaborators. A crucial feature of this method is that it…

Analysis of PDEs · Mathematics 2016-09-07 Dimitra C. Antonopoulou , Spyridon Kamvissis

We report simulations of the inspiral and merger of binary neutron stars performed with \texttt{WhiskyTHC}, the first of a new generation of numerical relativity codes employing higher than second-order methods for both the spacetime and…

General Relativity and Quantum Cosmology · Physics 2015-02-03 David Radice , Luciano Rezzolla , Filippo Galeazzi

We present a C++ implementation of a fifth order semi-implicit Runge-Kutta algorithm for solving Ordinary Differential Equations. This algorithm can be used for studying many different problems and in particular it can be applied for…

Computational Engineering, Finance, and Science · Computer Science 2007-05-23 P. Aliani , V. Antonelli , M. Picariello , Emilio Torrente-Lujan