Phase transition phenomenology with nonparametric representations of the neutron star equation of state
-
1.
California Institute of Technology
Abstract
Astrophysical observations of neutron stars probe the structure of dense nuclear matter and have the potential to reveal phase transitions at high densities. Most recent analyses are based on parametrized models of the equation of state with a finite number of parameters and occasionally include extra parameters intended to capture phase-transition phenomenology. However, such models restrict the types of behavior allowed and may not match the true equation of state. We introduce a complementary approach that extracts phase transitions directly from the equation of state without relying on, and thus being restricted by, an underlying parametrization. We then constrain the presence of phase transitions in neutron stars with astrophysical data. Current pulsar mass, tidal deformability, and mass-radius measurements disfavor only the strongest of possible phase transitions (latent energy per particle ≳100 MeV). Weaker phase transitions are consistent with observations. We further investigate the prospects for measuring phase transitions with future gravitational-wave observations and find that catalogs of O(100) events will (at best) yield Bayes factors of ∼10:1 in favor of phase transitions even when the true equation of state contains very strong phase transitions. Our results reinforce the idea that neutron star observations will primarily constrain trends in macroscopic properties rather than detailed microscopic behavior. Fine-tuned equation of state models will likely remain unconstrained in the near future.
Copyright and License
© 2023 American Physical Society.
Acknowledgement
The authors thank Aditya Vijaykumar for reviewing this manuscript within the LIGO Scientific Collaboration. R. E. and P. L. are supported by the Natural Sciences and Engineering Research Council of Canada (NSERC). Research at Perimeter Institute is supported in part by the Government of Canada through the Department of Innovation, Science and Economic Development Canada and by the Province of Ontario through the Ministry of Colleges and Universities. R. E. also thanks the Canadian Institute for Advanced Research (CIFAR) for support. The work of S. H. was supported by Startup Funds from the T. D. Lee Institute and Shanghai Jiao Tong University. S. H. also acknowledges support from the Network for Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) during the early stages of this project, funded by the National Science Foundation under cooperative Agreements No. 2020275 and No. 1630782 and by the Heising-Simons Foundation under Award No. 00F1C7. I. L. and K. C. acknowledge support from the Department of Energy under Award No. DE-SC0023101 and the Sloan Foundation. The authors gratefully acknowledge the program "Neutron Rich Matter on Heaven and Earth" (INT-22-2a) held at the Institute for Nuclear Theory, University of Washington for useful discussion. They also thank the LIGO laboratory for providing computational resources supported by National Science Foundation Grants No. PHY-0757058 and No. PHY-0823459. This material is based upon work supported by NSF's LIGO Laboratory which is a major facility fully funded by the National Science Foundation.
Files
PhysRevD.108.043013.pdf
Files
(4.2 MB)
| Name | Size | Download all |
|---|---|---|
|
md5:78967a891e9fc713610c80369596c9ff
|
4.2 MB | Preview Download |
Additional details
Identifiers
- ISSN
- 2470-0029
Funding
- Natural Sciences and Engineering Research Council
- Innovation, Science and Economic Development Canada
- Ministry of Colleges and Universities
- Canadian Institute for Advanced Research
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University
- National Science Foundation
- PHY-2020275
- National Science Foundation
- PHY-1630782
- National Science Foundation
- PHY-0757058
- Heising-Simons Foundation
- 00F1C7
- United States Department of Energy
- DE-SC0023101
- Alfred P. Sloan Foundation
- National Science Foundation
- PHY-0823459
- National Science Foundation
- PHY-0823459