Related papers: Neutron Star Pulsations and Instabilities
(abridged) $R$-modes are oscillations in rotating stars, primarily restored by the Coriolis force. These oscillations are the most susceptible to the Chandrasekhar-Friedman-Schutz (CFS) instability driven by gravitational wave emission,…
Neutron star-white dwarf (NS-WD) binaries evolve into either ultra-compact X-ray binaries undergoing stable mass transfer or direct mergers by unstable mass transfer. While much attention has been on gravitational wave (GW) emissions from…
The limiting rotational frequency of neutron stars may be determined by the strength of their crusts. As a star spins up from accretion, centrifugal forces will cause the crust to fail. If the crust breaks unevenly, a rotating mass…
We study gravitational waves from a spinning test particle scattered by a relativistic star using a perturbation method. The present analysis is restricted to axial modes. By calculating the energy spectrum, the waveforms and the total…
We study the low T/W instability associated with the f-mode of differentially rotating stars. Our stellar models are described by a polytropic equation of state and the rotation profile is given by the standard j-constant law. The…
We study the oscillations of neutron and strange stars in $R^2$ gravity. More precisely the nonradial $f$-modes are examined and the differences with pure general relativity are investigated. Using these results we build several…
Gravitational, magnetic and superfluid forces can stress the crust of an evolving neutron star. Fracture of the crust under these stresses could affect the star's spin evolution and generate high-energy emission. We study the growth of…
Rotation in massive stars has been studied on the main sequence and during helium burning for decades, but only recently have realistic numerical simulations followed the transport of angular momentum that occurs during more advanced stages…
The standard explanation for large pulsar glitches involves transfer of angular momentum from an internal superfluid component to the star's crust. This model requires an instability to trigger the sudden unpinning of the vortices by means…
Recent asteroseismic advances have allowed for direct measurements of the internal rotation rates of many sub-giant and red giant stars. Unlike the nearly rigidly rotating Sun, these evolved stars contain radiative cores that spin faster…
Glitches -- sudden increases in spin rate -- are observed in many pulsars. One mechanism advanced to explain glitches in the youngest pulsars is that they are caused by a starquake, a sudden rearrangement of the crust of the neutron star.…
We study in detail the f-mode secular instability for rapidly rotating neutron stars, putting emphasis on supermassive models which do not have a stable nonrotating counterpart. Such neutron stars are thought to be the generic outcome of…
In this work, we study the influence of $f(R,T)$ gravity on rapidly rotating neutron stars. First we discuss the main aspects of this modified theory of gravity where the gravitational Lagrangian is an arbitrary function of the Ricci scalar…
We calculate static and spherically symmetric solutions for the Rastall modification of gravity to describe Neutron Stars (NS). The key feature of the Rastall gravity is the non-conservation of the energy-momentum tensor proportionally to…
Rotating relativistic stars are receiving significant attention in recent years, because of the information they can yield about the equation of state of matter at extremely high densities and because they are one of the more possible…
We present a simplified description of a rotating neutron star emitting gravitational waves. We describe the system by an uniformly rotating triaxial homogeneous ellipsoid to catch the main aspects of the evolution. We construct an…
Neutron star interiors are a fantastic laboratory for high density physics in extreme environments. Probing this system with standard electromagnetic observations is, however, a challenging endeavour, as the radiation tends to be scattered…
The presence of a viscous boundary layer under the solid crust of a neutron star dramatically increases the viscous damping rate of the fluid r-modes. We improve previous estimates of this damping rate by including the effect of the…
Spinning neutron stars, when observed as pulsars, are seen to undergo occasional spin-up events known as glitches. Despite several decades of study, the physical mechanisms responsible for glitches are still not well understood, but…
We study oscillations and instabilities of relativistic stars using perturbation theory in general relativity and take into account the contribution of a dynamic spacetime. We present the oscillation spectrum as well as the critical values…