372 citations · 3k across the 64 of their papers we have counts for
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Magnetically supramassive and hypermassive compact stars
Koji Uryu, Shijun Yoshida, Eric Gourgoulhon +6
It is known that the mass of magnetized relativistic compact star is larger than that of non-magnetized one for the same equation of state and central density, albeit the excess of…
General Relativistic Stability and Gravitational Wave Content of Rotating Triaxial Neutron Stars
Yufeng Luo, Antonios Tsokaros, Roland Haas +1
Triaxial neutron stars can be sources of continuous gravitational radiation detectable by ground-based interferometers. The amplitude of the emitted gravitational wave can be great…
The Parallel Compact Object CALculator: An Efficient General Relativistic Initial Data Solver for Compact Objects
Lambros Boukas, Antonios Tsokaros, Koji Uryu
Every numerical general relativistic investigation starts from the solution of the initial value equations at a given time. Astrophysically relevant initial values for different sy…
Equilibriums of extremely magnetized compact stars with force-free magnetotunnels
Koji Uryu, Shijun Yoshida, Eric Gourgoulhon +5
We present numerical solutions for stationary and axisymmetric equilibriums of compact stars associated with extremely strong magnetic fields. The interior of the compact stars is…
Methods for relativistic self-gravitating fluids: From binary neutron stars to black hole-disks and magnetized rotating neutron stars
Antonios Tsokaros, Kōji Uryū
The cataclysmic observations of event GW170817, first as gravitational waves along the inspiral motion of two neutron stars, then as a short -ray burst, and later as a kilonova,…
Magnetohydrodynamic simulations of self-consistent rotating neutron stars with mixed poloidal and toroidal magnetic fields
Antonios Tsokaros, Milton Ruiz, Stuart L. Shapiro +1
We perform the first magnetohydrodynamic simulations in full general relativity of self-consistent rotating neutron stars (NSs) with ultrastrong mixed poloidal and toroidal magneti…
Evolution of bare quark stars in full general relativity: Single star case
Enping Zhou, Kenta Kiuchi, Masaru Shibata +2
We introduce our approaches, in particular the modifications of the primitive recovery procedure, to handle bare quark stars in numerical relativity simulations. Reliability and co…
Dynamically stable ergostars exist: General relativistic models and simulations
Antonios Tsokaros, Milton Ruiz, Lunan Sun +2
We construct the first dynamically stable ergostars (equilibrium neutron stars that contain an ergoregion) for a compressible, causal equation of state. We demonstrate their stabil…
New code for equilibriums and quasiequilibrium initial data of compact objects. IV. Rotating relativistic stars with mixed poloidal and toroidal magnetic fields
Koji Uryu, Shijun Yoshida, Eric Gourgoulhon +5
A new code for computing fully general relativistic solutions of strongly magnetized rapidly rotating compact stars is developed as a part of the COCAL (Compact Object CALculator)…
Effect of spin on the inspiral of binary neutron stars
Antonios Tsokaros, Milton Ruiz, Vasileios Paschalidis +2
We perform long-term simulations of spinning binary neutron stars, with our highest dimensionless spin being . To assess the importance of spin during the inspiral we v…
Complete initial value spacetimes containing black holes in general relativity: Application to black hole-disk systems
Antonios Tsokaros, Kōji Uryū, Stuart L. Shapiro
We present a new initial data formulation to solve the full set of Einstein equations for spacetimes that contain a black hole under general conditions. The method can be used to c…
Constant circulation sequences of binary neutron stars and their spin characterization
Antonios Tsokaros, Koji Uryu, Milton Ruiz +1
For isentropic fluids, dynamical evolution of a binary system conserves the baryonic mass and circulation; therefore, sequences of constant rest mass and constant circulation are o…
Gravitational wave content and stability of uniformly, rotating, triaxial neutron stars in general relativity
Antonios Tsokaros, Milton Ruiz, Vasileios Paschalidis +3
Targets for ground-based gravitational wave interferometers include continuous, quasiperiodic sources of gravitational radiation, such as isolated, spinning neutron stars. In this…
Conservation laws and evolution schemes in geodesic, hydrodynamic and magnetohydrodynamic flows
Charalampos Markakis, Kōji Uryū, Eric Gourgoulhon +4
Carter and Lichnerowicz have established that barotropic fluid flows are conformally geodesic and obey Hamilton's principle. This variational approach can accommodate neutral, or c…
Initial-data contribution to the error budget of gravitational waves from neutron-star binaries
Antonios Tsokaros, Bruno C. Mundim, Filippo Galeazzi +2
As numerical calculations of inspiralling neutron-star binaries reach values of accuracy that are comparable with those of binary black holes, a fine budgeting of the various sourc…
New code for quasiequilibrium initial data of binary neutron stars: Corotating, irrotational and slowly spinning systems
Antonios Tsokaros, Koji Uryu, Luciano Rezzolla
We present the extension of our \cocal~- Compact Object CALculator - code to compute general-relativistic initial data for binary compact-star systems. In particular, we construct…
New code for equilibriums and quasiequilibrium initial data of compact objects. II. Convergence tests and comparisons of binary black hole initial data
Koji Uryu, Antonios Tsokaros, Philippe Grandclement
COCAL is a code for computing equilibriums or quasiequilibrium initial data of single or binary compact objects based on finite difference methods. We present the results of supple…
Binary black hole circular orbits computed with COCAL
Antonios Tsokaros, Koji Uryu
In this work we present our first results of binary black hole circular orbits using {\sc cocal}, the Compact Object CALculator. Using the 3+1 decomposition five equations are bein…
Quasi-equilibrium models of magnetized compact objects
Charalampos Markakis, Koji Uryu, Eric Gourgoulhon
We report work towards a relativistic formulation for modeling strongly magnetized neutron stars, rotating or in a close circular orbit around another neutron star or black hole, u…
Neutron star equation of state via gravitational wave observations
Charalampos Markakis, Jocelyn S. Read, Masaru Shibata +4
Gravitational wave observations can potentially measure properties of neutron star equations of state by measuring departures from the point-particle limit of the gravitational wav…
A new code for equilibriums and quasiequilibrium initial data of compact objects
Koji Uryu, Antonios Tsokaros
We present a new code, named COCAL - Compact Object CALculator, for the computation of equilibriums and quasiequilibrium initial data sets of single or binary compact objects of al…
Magnetohydrodynamics in stationary and axisymmetric spacetimes: a fully covariant approach
Eric Gourgoulhon, Charalampos Markakis, Koji Uryu +1
A fully geometrical treatment of general relativistic magnetohydrodynamics (GRMHD) is developed under the hypotheses of perfect conductivity, stationarity and axisymmetry. The spac…
Thermodynamics of magnetized binary compact objects
Koji Uryu, Eric Gourgoulhon, Charalampos Markakis
Binary systems of compact objects with electromagnetic field are modeled by helically symmetric Einstein-Maxwell spacetimes with charged and magnetized perfect fluids. Previously d…
Inferring the neutron star equation of state from binary inspiral waveforms
Charalampos Markakis, Jocelyn S. Read, Masaru Shibata +3
The properties of neutron star matter above nuclear density are not precisely known. Gravitational waves emitted from binary neutron stars during their late stages of inspiral and…