author={Nils Andersson and Kostas D. Kokkotas},
  journal={International Journal of Modern Physics D},
In this review we summarize the current understanding of the gravitational-wave driven instability associated with the so-called r-modes in rotating neutron stars. We discuss the nature of the r-modes, the detailed mechanics of the instability and its potential astrophysical significance. In particular we discuss results regarding the spin-evolution of nascent neutron stars, the detectability of r-mode gravitational waves and mechanisms limiting the spin-rate of accreting neutron stars in… 

Gravitational waves from isolated neutron stars: Mass dependence of r -mode instability

In this work we study the r-mode instability windows and the gravitational wave signatures of neutron stars in the slow rotation approximation using the equation of state obtained from the density

R-mode instability in compact stars

  • Cui ZhuYu-Bin WangXia Zhou
  • Physics
  • 2019
R-mode oscillations have been identified as viable and promising targets for continuous gravitational wave searches, meanwhile, it would allow us to probe the interior of compact stars directly. As

R-mode instability of strange stars and observations of neutron stars in LMXBs

Using a realistic equation of state (EOS) of strange quark matter, namely, the modified bag model, and considering the constraints on the parameters of EOS by the observational mass limit of neutron

Oscillations and instabilities of fast rotating neutron stars

We present our results of our study of the oscillations and instabilities of rapidly rotating relativistic stars in the Cowling approximation. This is the first study of its kind and provides

R-modes in neutron stars: Theory and observations

In this article I will review the theory behind the gravitational wave driven r-mode instability in rapidly rotating neutron stars and discuss which constraints can be derived from observations of

r-Mode Oscillations and Rocket Effect in Rotating Superfluid Neutron Stars. I. Formalism

We derive the hydrodynamical equations of r-mode oscillations in neutron stars in the presence of a novel damping mechanism related to particle number changing processes. The change in the number

Constraining the physics of the r-mode instability in neutron stars with X-ray and ultraviolet observations

Rapidly rotating neutron stars in low-mass X-ray binaries may be an interesting source of gravitational waves (GWs). In particular, several modes of stellar oscillation may be driven unstable by GW

Temperature-dependent oscillation modes in rotating superfluid neutron stars

We calculate the spectrum of inertial oscillation modes in a slowly rotating superfluid neutron star, including, for the first time, both the effects of finite temperatures and entrainment between

Magnetic fields generated by r-modes in accreting quark stars

We show that the r-mode instability can generate strong toroidal fields in the core of accreting millisecond quark stars by inducing differential rotation. We follow the spin frequency evolution on a

w-mode instability of ultracompact relativistic stars

In this article we show that the mainly spacetime w modes may become unstable in a rotating ultracompact (R<3M) relativistic star. We provide results for the axial modes of a rotating star in the



Secular instability of g‐modes in rotating neutron stars

Gravitational radiation tends to drive gravity modes in rotating neutron stars to become unstable. For an inviscid star, the instability sets in when the rotation frequency is about 0.7 times the

A numerical study of the r‐mode instability of rapidly rotating nascent neutron stars

The first results of numerical analysis of classical r-modes of {\it rapidly} rotating compressible stellar models are reported. The full set of linear perturbation equations of rotating stars in

Gravitational Radiation Instability in Hot Young Neutron Stars

We show that gravitational radiation drives an instability in hot young rapidly rotating neutron stars. This instability occurs primarily in the l=2 r-mode and will carry away most of the angular

Gravitational Radiation Limit on the Spin of Young Neutron Stars

A newly discovered instability in rotating neutron stars, driven by gravitational radiation reaction acting on the stars' r-modes, is shown here to set an upper limit on the spin rate of young

r-Mode Oscillations and Spin-down of Young Rotating Magnetic Neutron Stars

Recent work has shown that a young, rapidly rotating neutron star loses angular momentum to gravitational waves generated by unstable r-mode oscillations. We study the spin evolution of a young,

Nonlinear r-modes in rapidly rotating relativistic stars.

It is found that on dynamical time scales, there is no strong nonlinear coupling of r-modes to other modes at amplitudes of order one-the maximum r-mode amplitude is of order unity.

Gravitational waves from the r-modes of rapidly rotating neutron stars

Since the last Amaldi meeting in 1997 we have learned that the r-modes of rapidly rotating neutron stars are unstable to gravitational radiation reaction in astrophysically realistic conditions.

Vorticity affects the stability of neutron stars

This work calculates a coupling of vorticity to shear viscosity and shows that it can in principle significantly modify the stability diagram at lower temperatures, so that colder stars can remain stable at higher spin rates.

Superfluid Hydrodynamics in Rotating Neutron Stars. II. Dissipative Effects

The Newtonian superfluid hydrodynamic equations describing the outer-core regions of neutron stars are generalized to include dissipation. The effects of viscosity, thermal conductivity, and mutual

Gravitational Waves and Pulsating Stars: What Can We Learn from Future Observations?

It is shown that the so-called gravitational-wave modes of a neutron star can be excited when a gravitational wave impinges on the star, and numerical simulations suggest that the modes may be astrophysically relevant.