[photo credit: Carnegie Science]
His lunchtime talk at Carnegie Observatories, titled “Core Collapse and Cloud Collapse,” draws on two recent breakthroughs that challenge conventional models.
Working with fellow Perimeter researcher Simon May, Gurian developed a computational code called KiSS-SIDM that simulates self-interacting dark matter halos undergoing “gravothermal collapse.” Their findings, accepted to Physical Review Letters on Oct. 30, show unexpected results. “We show that the gravothermal collapse of self-interacting dark matter halos can deviate from local thermodynamic equilibrium,” the researchers wrote. “As a consequence, the self-similar evolution predicted by the commonly adopted conducting fluid model can be altered or broken.”
“By assuming spherical symmetry and adopting a new-to-the-field scattering algorithm, the code dramatically improves on the speed and accuracy of previous N-body methods, enabling exploration of parameter space on a laptop,” Gurian notes.
His second topic addresses Population III stars, the universe’s first generation born from metal-free primordial gas more than 13 billion years ago. “While gravitational instability in present day star forming clouds is understood to be driven by supersonic turbulence, Population III star forming clouds are weakly turbulent and thermal pressure dominated,” Gurian explains.
Gurian earned his Ph.D. in Astronomy and Astrophysics at Pennsylvania State University in 2023. He can be reached at jgurian@perimeterinstitute.ca.
“Core Collapse and Cloud Collapse” will run on Friday, Nov. 7, at 12:15 p.m. to 1:15 p.m. PST. William T. Golden Auditorium, Carnegie Observatories, 813 Santa Barbara St., in Pasadena. For more information, call (626) 577-1122 or visit https://carnegiescience.edu/events/james-gurian-perimeter. Ticket prices: Free admission.
