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According to Burrows et al.s acoustic mechanism for core-collapse supernova explosions, the primary, l=1, g-mode in the core of the proto-neutron star is excited to an energy of ~ 10^{50} ergs and damps by the emission of sound waves. Here we calculate the damping of the primary mode by the parametric instability, i.e., by nonlinear, 3-mode coupling between the low-order primary mode and pairs of high-order g-modes. We show that the primary mode is strongly coupled to highly resonant, neutrino damped pairs with n>10; such short wavelength interactions cannot be resolved in the simulations. We find that the parametric instability saturates the primary mode energy at ~10^{48} ergs, well below the energy needed to drive an explosion. We therefore conclude that acoustic power is unlikely to be energetically significant in core-collapse supernova explosions.
We demonstrate a possibility of existence of a peculiar temperature-dependent composition $g$-modes in superfluid neutron stars. We calculate the Brunt-V$ddot{rm a}$is$ddot{rm a}$l$ddot{rm a}$ frequency for these modes, as well as their eigenfrequenc
We suggest a specific new class of low-frequency g-modes in superfluid neutron stars. We determine the Brunt-Vaisala frequency for these modes and demonstrate that they can be unstable with respect to convection. The criterion for the instability ons
We study the dynamical evolution of a large amplitude r-mode by numerical simulations. R-modes in neutron stars are unstable growing modes, driven by gravitational radiation reaction. In these simulations, r-modes of amplitude unity or above are dest
We find that sub-GeV neutrino portal bosons that carry lepton number can condense inside a proto-neutron star (newly born neutron star). These bosons are produced copiously and form a Bose-Einstein condensate for a range of as yet unconstrained coupl
For more than ten years, solar-like oscillations have been detected and frequencies measured for a growing number of stars with various characteristics (e.g. different evolutionary stages, effective temperatures, gravities, metal abundances ...). E