Physicists have developed an unique technique to investigate dark matter utilizing gravitational wave detectors, possibly discovering the results of dark matter particles on neutron stars. This method provides new insights into dark matter, extending beyond the reach of current detectors and leading the way for future discoveries with advanced gravitational wave observatories.
Dark matter is basic to our understanding of deep space, yet its exact nature remains a mystery. Discovering the identity of dark matter is a vital goal in cosmology and particle physics.
A collective effort by physicists from the Tata Institute of Fundamental Research, the Indian Institute for Science, and the University of California at Berkeley has introduced a novel approach to investigate dark matter. This technique makes use of gravitational wave searches to find dark matters potential effects on neutron stars.
New Methodology Explained
Sulagna Bhattacharya, a college student at TIFR and lead author of the research study released in Physical Review Letters, describes– dark matter particles in the galaxy can build up in neutron stars due to their non-gravitational interactions. The accumulated particles form a thick core, that collapses to a minuscule great void in the situation that dark matter particle is heavy and has no antiparticle equivalent; a scenario that has shown hard to test otherwise in lab experiments.
For a large allowed variety of dark matter particle mass, the preliminary seed black hole consumes its host neutron star and transmutes it to a neutron-star-mass black hole. Most importantly, theories of excellent evolution predict that great voids form when neutron stars exceed about 2.5 times the mass of the Sun, as encoded in the Tolman-Oppenheimer-Volkoff limitation, but here dark matter leads to low-mass black holes that are typically smaller than the optimum neutron star.
Gravitational wave detectors as probes of dark matter graphic. Credit: Basudeb Dasgupta
Anupam Ray, who co-led the work, points out that “for dark matter parameters that are not yet eliminated by any other experiment, old binary neutron star systems in thick areas of the galaxy ought to have actually developed into binary black hole systems. If we do not see any anomalously low-mass mergers, it puts brand-new restraints on dark matter.”
Linking Dark Matter and Black Holes
Intriguingly, some of the occasions spotted by LIGO, e.g., GW190814 and GW190425, appear to include a minimum of one low-mass compact object. A tantalizing suggestion, based on pioneering work by Hawking and Zeldovich from the 1960s, is that low-mass black holes could be of a primitive origin, i.e., developed by big however exceedingly rare density variations in the very early universe.
Motivated by these factors to consider, the LIGO partnership has actually undertaken targeted searches for low-mass great voids and set limits. The present study by Bhattacharya and partners reveals that the very same non-detection of low-mass mergers by LIGO also puts stringent constraints on particle dark matter.
The restraints presented in this research study hold substantial value, as they check out criterion space that is well beyond the reach of the current terrestrial dark matter detectors like XENON1T, PANDA, LUX-ZEPLIN, especially for heavy dark matter particles.
Future of Gravitational Wave Observations
Mergers of low-mass black holes are anticipated to be noticeable not only using existing gravitational wave detectors such as LIGO, VIRGO, and KAGRA, but also by upcoming detectors like Advanced LIGO, Cosmic Explorer, and the Einstein Telescope. By thinking about the prepared upgrades of existing gravitational wave experiments, and accounting for their increased level of sensitivity and observation time, the study forecasts the restrictions that might be obtained within the next decade.
In particular, the research study shows, that gravitational wave observations can penetrate incredibly feeble interactions of heavy dark matter, well below the so-called “neutrino floor” where standard dark matter detectors have to compete with the astrophysical neutrino backgrounds.
Rather, if unique low-mass great voids are discovered in the future, it could be a valuable tip about the nature of dark matter. The authors sign off optimistically keeping in mind, “gravitational wave detectors, which have currently proved beneficial for the direct detection of gravitational waves and black holes predicted by Einstein, may wind up as a powerful tool to evaluate theories of dark matter as well.”
Referral: “Can LIGO Detect Nonannihilating Dark Matter?” by Sulagna Bhattacharya, Basudeb Dasgupta, Ranjan Laha and Anupam Ray, 29 August 2023, Physical Review Letters.DOI: 10.1103/ PhysRevLett.131.091401.
The research study was funded by the Department of Atomic Energy (Government of India), the Department of Science and Technology (Government of India) through a Swarnajayanti Fellowship, the Max-Planck- Gesellschaft through a Max Planck Partner Group, the Indian Institute of Science, Bengaluru, the Department of Science and Technology (Government of India), the National Science Foundation, the Heising-Simons Foundation, and the Infosys Foundation (Bengaluru)..