112 research outputs found
Global simulations of strongly magnetized remnant massive neutron stars formed in binary neutron star mergers
We perform a general-relativistic magnetohydrodynamics simulation for
ms after merger of a binary neutron star to a remnant massive
neutron star (RMNS) with a high spatial resolution of the finest grid
resolution m. First, we estimate that the Kelvin-Helmholtz instability
at merger could amplify the magnetic-field energy up to of the
thermal energy. Second, we find that the magnetorotational instability in the
RMNS envelope and torus with sustains
magneto-turbulent state and the effective viscous parameter in these regions is
likely to converge to -- with respect to the grid
resolution. Third, the current grid resolution is not still fine enough to
sustain magneto-turbulent state in the RMNS with .Comment: 18 pages, 10 figures, PRD in pres
Constraining self-interactions of a massive scalar field using scalar gravitational waves from stellar core collapse
We perform a comprehensive numerical study of gravitational waves from
stellar core collapse in the massive scalar-tensor theory with the cubic and
quartic self-interactions of the scalar field. We investigate the dependence of
gravitational waves on the self-interaction as well as the mass of the scalar
field and the conformal factor. We find that gravitational-wave spectra show a
systematic difference between the cubic and quartic self-interactions. We also
find that this systematic difference is insensitive to the mass of the scalar
field and the conformal factor. Our results indicate that the type of the
self-interaction could be constrained by observations of gravitational waves
using the future-planned detectors.Comment: 16 pages, 16 figures, 1 tabl
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