http://arxiv.org/abs/1911.13216
We study time evolution of complex scalar field in the symmetry broken phase in presence of oscillating spacetime metric background. In our (2+1)-dimensional simulations, we show that the spacetime oscillations excite the initial ‘small’ fluctuations of the field configuration. This field excitations occur for a wide range of frequencies of spacetime metric. For smaller frequencies mostly the transverse excitations(Goldstone modes) dominate, while for larger frequencies longitudinal excitations(radial modes) of the field also get generated. For a given system size, there is a lower cut-off of the frequency of spacetime oscillations below which we do not see large enhancement in the fluctuations of the field. At a particular stage of field evolution, spacetime oscillation generates a periodic variation of phase of field in the physical space. This periodic spatial variation of phase of field oscillates in some time duration about its initial configuration with the frequency of spacetime oscillation, which shows that these excitations arise due to the phenomena of parametric resonance. We find that these field excitations at later stage lead to the formation of vortex-antivortex pairs. At sufficient large time of field evolution, field configuration achieves a disorder state. For some parameters of the theory, we see the formation of vortex-antivortex lattice structure in the system. This study suggests that spacetime oscillations may play an important role in the time evolution of the superfluid phase inside neutron stars during the binary neutron star (BNS) merger.
S. Dave and S. Digal
Wed, 4 Dec 19
2/58
Comments: 12 pages, 10 figures