Stable vortex in Bose–Einstein condensate dark matter
Y. O. Nikolaieva1, A. O. Olashyn1,2, Y. I. Kuriatnikov1,3, S. I. Vilchynskii1,4, and A. I. Yakimenko1
1Department of Physics, Taras Shevchenko National University of Kyiv, Kyiv 01601, Ukraine
2Instituut-Lorentz, Universiteit Leiden, Leiden 2300 RA, The Netherlands
3Atominstitut, TU Wien, Vienna 1020, Austria
4Institute of Physics, Laboratory for Particle Physics and Cosmology (LPPC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
Received March 9, 2021, published online June 25, 2021
The nature of dark matter (DM) is one of the most fascinating unresolved challenges of modern physics. One of the perspective hypotheses suggests that DM consists of ultralight bosonic particles in the state of Bose–Einstein condensate (BEC). The superfluid nature of BEC must dramatically affect the properties of DM including quantization of the angular momentum. Angular momentum quantum in the form of a vortex line is expected to produce a considerable impact on the luminous matter in galaxies including density distribution and rotation curves. We investigate the evolution of spinning DM cloud with typical galactic halo mass and radius. Analytically and numerically stationary vortex soliton states with different topological charges have been analyzed. It has been shown that while all multi-charged vortex states are unstable, a single-charged vortex soliton is extremely robust and survives during the lifetime of the Universe.
Key words: ultra-light dark matter, Bose–Einstein condensate, galactic halo, vortex soliton.