Researchers have actually advanced the understanding of dark matter through simulations supporting the self-interacting dark matter (SIDM) theory. This theory possibly solves inconsistencies in dark matter densities observed in different galaxies, posing an obstacle to the standard cold dark matter (CDM) model and highlighting the dynamic nature of dark matter. Credit: SciTechDaily.comDark matter might be more dynamic than previously thought, UC Riverside study reports.Thought to comprise 85% of matter in the universe, dark matter is nonluminous and its nature is not well understood. While regular matter takes in, shows, and discharges light, dark matter can not be seen straight, making it harder to identify. A theory called “self-interacting dark matter,” or SIDM, proposes that dark matter particles self-interact through a dark force, highly colliding with one another near to the center of a galaxy.In work released in The Astrophysical Journal Letters, a research study group led by Hai-Bo Yu, a professor of physics and astronomy at the University of California, Riverside, reports that SIDM concurrently can discuss two astrophysics puzzles in opposite extremes.Understanding Dark Matter Halos and Gravitational Lensing”The very first is a high-density dark matter halo in a massive elliptical galaxy,” Yu stated. “The halo was found through observations of strong gravitational lensing, and its density is so high that it is very not likely in the dominating cold dark matter theory. The second is that dark matter halos of ultra-diffuse galaxies have exceptionally low densities and they are hard to describe by the cold dark matter theory.”A dark matter halo is the halo of undetectable matter that permeates and surrounds a galaxy or a cluster of galaxies. When light taking a trip across the universe from far-off galaxies gets bent around enormous objects, gravitational lensing takes location. The cold dark matter, or CDM, paradigm/theory presumes dark matter particles are collisionless. As their name recommends, ultra-diffuse galaxies have incredibly low luminosity and the circulation of their stars and gas is spread out.Hai-Bo Yu is a theoretical physicist at UC Riverside with know-how in the particle homes of dark matter. Credit: Samantha TieuYu was signed up with in the research study by Ethan Nadler, a joint postdoctoral fellow at the Carnegie Observatories and University of Southern California, and Daneng Yang, a postdoctoral scholar at UCR.To reveal SIDM can discuss the two astrophysics puzzles, the team performed the first high-resolution simulations of cosmic structure formation with strong dark matter self-interactions on pertinent mass scales for the strong lensing halo and ultra-diffuse galaxies.”These self-interactions result in heat transfer in the halo, which diversifies the halo density in the central areas of galaxies,” Nadler said. “In other words, some halos have greater main densities, and others have lower main densities, compared to their CDM counterparts, with information depending on the cosmic advancement history and environment of individual halos.”Challenging the CDM Paradigm and Future ResearchAccording to the group, the two puzzles pose a formidable obstacle to the basic CDM paradigm.”CDM is challenged to explain these puzzles,” Yang stated. “SIDM is perhaps the engaging candidate to fix up the two opposite extremes. No other explanations are available in the literature. Now there is an interesting possibility that dark matter might be more vibrant and complex than we expected.”The research study also demonstrates the power of penetrating dark matter through astrophysical observations, with the tool of computer system simulations of cosmic structure development.”We hope our work motivates more research studies in this promising research location,” Yu stated. “It will be a particularly timely advancement offered the expected increase of data in the future from huge observatories, including the James Webb Space Telescope and upcoming Rubin Observatory.”Since around 2009, work by Yu and partners has actually assisted popularize SIDM in the particle physics and astrophysics communities.Reference: “A Self-interacting Dark Matter Solution to the Extreme Diversity of Low-mass Halo Properties” by Ethan O. Nadler, Daneng Yang and Hai-Bo Yu, 30 November 2023, The Astrophysical Journal Letters.DOI: 10.3847/ 2041-8213/ ad0e09The research study was supported by the John Templeton Foundation and the U.S. Department of Energy.
Scientists have actually advanced the understanding of dark matter through simulations supporting the self-interacting dark matter (SIDM) theory. Credit: SciTechDaily.comDark matter might be more dynamic than formerly believed, UC Riverside research study reports.Thought to make up 85% of matter in the universe, dark matter is nonluminous and its nature is not well understood. A theory called “self-interacting dark matter,” or SIDM, proposes that dark matter particles self-interact through a dark force, highly clashing with one another close to the center of a galaxy.In work published in The Astrophysical Journal Letters, a research group led by Hai-Bo Yu, a professor of physics and astronomy at the University of California, Riverside, reports that SIDM at the same time can explain two astrophysics puzzles in opposite extremes.Understanding Dark Matter Halos and Gravitational Lensing”The first is a high-density dark matter halo in an enormous elliptical galaxy,” Yu stated. The 2nd is that dark matter halos of ultra-diffuse galaxies have incredibly low densities and they are hard to explain by the cold dark matter theory.