相关论文: Nonlinear evolution of r-modes in rotating relativ…
Non-axisymmetric oscillations of rapidly rotating relativistic stars are studied using the Cowling approximation. The oscillation spectra have been estimated by Fourier transforming the evolution equations describing the perturbations. This…
We calculate non-axisymmetric oscillations of neutron stars magnetized by purely poloidal magnetic fields. We use polytropes of index $n=1$ and 1.5 as a background model, where we ignore the equilibrium deformation due to the magnetic…
We calculate the finite-temperature r-mode spectrum of a slowly rotating superfluid Newtonian neutron star neglecting the entrainment between neutron and proton liquid components (i.e., neglecting the off-diagonal element of the entrainment…
In order to understand the periodic and semi-periodic variations of luminous O- B- A-type stars, linear nonadiabatic stability analyses for radial and nonradial oscillations have been performed for massive evolutionary models ($8M_\odot -…
In this review article, we present the main results from our most recent research concerning the oscillations of fast rotating neutron stars. We derive a set of time evolution equations for the investigation of non-axisymmetric oscillations…
The post-bounce oscillations of newly-born relativistic stars are expected to lead to gravitational-wave emission through the excitation of nonradial oscillation modes. At the same time, the star is oscillating in its radial modes, with a…
We report the finding of a linear, non-axisymmetric, global instability in gas discs around stars, which may be relevant to other astrophysical discs. It takes the form of an $m=1$ mode that grows in the disc density distribution while the…
In this review we focus on non-linear phenomena in pulsating stars the mode selection and amplitude limitation. Of many linearly excited modes only a fraction is detected in pulsating stars. Which of them and why (the problem of mode…
We present results concerning adiabatic inertial-mode oscillations of non-stratified superfluid neutron stars in Newtonian gravity, using the anelastic and slow-rotation approximations. We consider a simple two-fluid model of a superfluid…
We investigate the dynamical stability of relativistic, differentially rotating, quasi-toroidal models of neutron stars through hydrodynamical simulations in full general relativity. We find that all quasi-toroidal configurations studied in…
In this article, we investigate inertial modes of rigidly rotating neutron stars, i.e. modes for which the Coriolis force is dominant. This is done using the assumption of a fixed spacetime (Cowling approximation). We present frequencies…
Neutron stars undergoing r-mode oscillation emit gravitational radiation that might be detected on earth. For known millisecond pulsars the observed spindown rate imposes an upper limit on the possible gravitational wave signal of these…
We present a theoretical investigation on periods and amplitudes of RR Lyrae pulsators by adopting stellar parameters which cover the range of theoretical evolutionary expectations. Extensive grids of nonlinear, nonlocal and time-dependent…
We extend the study of Papaloizou & Savonije of the tidal interactions of close orbiting giant planets with a central solar type star to the situation where the spin axis of the central star and the orbital angular momentum are misaligned.…
Binary neutron star mergers produce massive, hot, rapidly differentially rotating neutron star remnants; electromagnetic and gravitational wave signals associated with the subsequent evolution depend on the stability of these remnants.…
In part I, we use the post-Newtonian (pn) order of Liouville's equation to study the normal modes of oscillation of a spherically symmetric relativistic system. Perturbations that are neutral in Newtonian approximation develop into a new…
A linear stability analysis of models for evolved primordial stars with masses between 150 and 250 M$_{\odot}$ is presented. Strange mode instabilities with growth rates in the dynamical range are identified for stellar models with…
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 neutron stars. We calculate the timescales…
Gravitational waves emitted in the late inspiral of binary neutron stars are affected by their tidal deformation. We study the tidal dynamics in full general relativity through matched-asymptotic expansions and prove that the dynamical…
Tidal dissipation in stars is one of the key physical mechanisms that drive the evolution of binary and multiple stars. As in the Earth oceans, it corresponds to the resonant excitation of their eigenmodes of oscillation and their damping.…