Dark Matter-admixed Rotating White Dwarfs as Peculiar Compact Objects
- Creators
- Chan, Ho-Sang
- Chu, Ming-chung
- Leung, Shing-Chi
Abstract
Discoveries of anomalous compact objects challenge our understanding of the standard theory of stellar structures and evolution, so they serve as an excellent laboratory for searching for new physics. Earlier studies on spherically symmetric dark matter (DM)–admixed compact stars could explain a handful of anomalies. In this paper, we investigate the observational signatures of DM-admixed rotating white dwarfs, and make connections to observed peculiar compact objects. We compute the equilibrium structures of DM-admixed rotating white dwarfs using a self-consistent, two-fluid method, with the DM component being a nonrotating degenerate Fermi gas. We find that admixing DM to rotating white dwarfs could: (1) account for some peculiar white dwarfs that do not follow their usual mass–radius relation; (2) allow stable rapid-rotating white dwarfs that are free from thermonuclear runaway to exist, which could explain some soft gamma-ray repeaters/anomalous X-ray pulsars; and (3) produce universal I (moment of inertia)–Love (tidal Love number)–Q (quadrupole moment) relations that span bands above those without DM admixture, thus providing an indirect way of searching for DM in white dwarfs through gravitational-wave detection. To conclude, DM-admixed rotating white dwarfs can account for some peculiar compact objects. Our results suggest a systematic approach to accounting for the unusual compact objects that upcoming surveys could discover.
Additional Information
We thank stellarcollapse.org for providing the electron fraction table for the VUL EOS. We acknowledge Dr. Lap-Ming Lin for providing valuable comments and suggestions on the I–Love–Q relations and for choosing the WD EOS. This work is partially supported by a grant from the Research Grant Council of the Hong Kong Special Administrative Region, China (Project No. 14300320). S.-C.L. acknowledges support from NASA grants HST-AR-15021.001-A and 80NSSC18K1017.Additional details
- Eprint ID
- 118623
- Resolver ID
- CaltechAUTHORS:20230103-817548100.21
- 14300320
- Research Grants Council of Hong Kong
- HST-AR-15021.001-A
- NASA Hubble Fellowship
- 80NSSC18K1017
- NASA
- Created
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2023-01-27Created from EPrint's datestamp field
- Updated
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2023-01-27Created from EPrint's last_modified field
- Caltech groups
- TAPIR