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Related papers: Neutron Stars as Perfect Fluids: Extracting the Li…

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Motivated by future opportunities in gravitational-wave astronomy and the ongoing effort to constrain physics under extreme conditions, we consider the signature of individual mode resonances excited during the inspiral of binary systems…

General Relativity and Quantum Cosmology · Physics 2025-08-11 P. Pnigouras , N. Andersson , F. Gittins , A. R. Counsell

Tidal deformabilities are one of the observable quantities characterizing neutron stars, which are strongly associated with the stellar compactness, the ratio of the stellar mass to the radius. In addition to the tidal deformability, the…

High Energy Astrophysical Phenomena · Physics 2026-02-24 Hajime Sotani

We present new numerical algorithms for the coupled Einstein-perfect fluid system in axisymmetry. Our framework uses a foliation based on a family of light cones, emanating from a regular center, and terminating at future null infinity.…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Florian Siebel , Jose A. Font , Ewald Mueller , Philippos Papadopoulos

We study the tidal problem and the resulting $I$-Love-$Q$ approximate universal relations for rotating superfluid neutron stars in the Hartle-Thorne formalism. Superfluid stars are described in this work by means of a two-fluid model…

General Relativity and Quantum Cosmology · Physics 2023-11-23 Eneko Aranguren , José A. Font , Nicolas Sanchis-Gual , Raül Vera

With the first detections of binary neutron star mergers by gravitational-wave detectors, it proves timely to consider how the internal structure of neutron stars affects the way in which they can be asymmetrically deformed. Such…

High Energy Astrophysical Phenomena · Physics 2020-05-27 Fabian Gittins , Nils Andersson , Jonas P. Pereira

The tidal deformation of a neutron star in a binary inspiral driven by the emission of gravitational waves affects the orbital dynamics and produces a measurable modulation of the waves. Late in the inspiral, a regime of dynamical tides…

General Relativity and Quantum Cosmology · Physics 2025-06-11 Tristan Pitre , Eric Poisson

It was recently revealed that a rotating compact body responds dynamically when it is subjected to a gravitomagnetic tidal field, even when this field is idealized as time-independent. The dynamical response is characterized by…

General Relativity and Quantum Cosmology · Physics 2017-02-22 Eric Poisson , Jean Doucot

We study the effect of superfluidity on the tidal response of a neutron star in a general relativistic framework. In this work, we take a dual-layer approach where the superfluid matter is confined in the core of the star. Then, the…

General Relativity and Quantum Cosmology · Physics 2020-09-16 Sayak Datta , Prasanta Char

We elaborate on a powerful tidal interaction formalism where the multipole dynamics is kept generic and encoded in a linear response function. This response function is the gravitational counterpart of the atomic spectrum and can become of…

General Relativity and Quantum Cosmology · Physics 2013-05-22 Sayan Chakrabarti , Térence Delsate , Jan Steinhoff

Tidal interactions in coalescing binary neutron stars modify the dynamics of the inspiral and hence imprint a signature on their gravitational wave (GW) signals in the form of an extra phase shift. We need accurate models for the tidal…

General Relativity and Quantum Cosmology · Physics 2023-01-10 Hang Yu , Nevin N. Weinberg , Phil Arras , James Kwon , Tejaswi Venumadhav

Next-generation gravitational-wave detectors are expected to constrain the properties of extreme density matter via observations of static and dynamical tides in binary neutron star inspirals. The required modelling is straightforward in…

General Relativity and Quantum Cosmology · Physics 2025-04-10 Shanshan Yin , Nils Andersson , Fabian Gittins

Quasi-universal relations are known to exist among various neutron star observables that do not depend sensitively on the underlying nuclear matter equations of state. For example, some of these relations imply that the tidally induced…

General Relativity and Quantum Cosmology · Physics 2025-07-15 Takuya Katagiri , Gowtham Rishi Mukkamala , Kent Yagi

We develop a relativistic multifluid dynamics appropriate for describing neutron star cores at finite temperatures based on Carter's convective variational procedure. The model includes seven fluids, accounting for both normal and…

High Energy Astrophysical Phenomena · Physics 2020-09-14 Peter B. Rau , Ira Wasserman

We have developed a theoretical model and a numerical code for stationary rotating superfluid neutron stars in full general relativity. The underlying two-fluid model is based on Carter's covariant multi-fluid hydrodynamic formalism. The…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Reinhard Prix , Jerome Novak , G. L. Comer

We employ an approximate treatment of dissipative hydrodynamics in three dimensions to study the coalescence of binary neutron stars driven by the emission of gravitational waves. The stars are modeled as compressible ellipsoids obeying a…

Astrophysics · Physics 2009-10-22 Dong Lai , Stu Shapiro

We study the tidal response of a superfluid neutron star in a binary system, focussing on Newtonian models with superfluid neutrons present throughout the star's core and the inner crust. Within the two-fluid formalism, we consider the main…

High Energy Astrophysical Phenomena · Physics 2022-06-22 Andrea Passamonti , Nils Andersson , Pantelis Pnigouras

We present a variational formalism for describing the dynamical evolution of an oscillating star with a point-mass companion in the linear, non-relativistic regime. This includes both the excitation of normal modes and the back-reaction of…

Astrophysics · Physics 2009-11-07 Yasser Rathore , Avery E. Broderick , Roger Blandford

The non-linear behaviour of oscillation modes in compact stars is a topic of considerable current interest. Accurate numerical studies of such phenomena are likely to require powerful new approaches to both fluid and spacetime computations.…

Astrophysics · Physics 2007-05-23 Uli Sperhake , Philippos Papadopoulos , Nils Andersson

This work develops the dynamics of perfectly elastic solid model for application to the outer crust of a magnetised neutron star. Particular attention is given to the Noether identities responsible for energy-momentum conservation, using a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Brandon Carter , Elie Chachoua , Nicolas Chamel

We describe the cosmological dynamics of perfect fluids within the framework of effective field theories. The effective action is a derivative expansion whose terms are selected by the symmetry requirements on the relevant long-distance…

High Energy Physics - Theory · Physics 2013-05-23 Guillermo Ballesteros , Brando Bellazzini