You are here: Home Research Areas of Research Cosmology

Cosmology

Main Content

Questions

  • How did our Universe begin? How did our Universe evolve into the current state? What will be the fate of the Universe?
  • What is dark energy? How does it evolve? Is the Cosmological Constant an accurate model for dark energy?
  • What is dark matter? How does it affect large-scale structure formation?
  • Are there systematic errors in the extragalactic distance scale and the Hubble Constant?
  • What is the expansion history of the universe?
  • How did the first galaxies and quasars form and evolve? What are the observational signatures of these first luminous objects?
  • How did the stars and galaxies we know today arise from the initial conditions of the Big Bang, and how did the process of Cosmic Reionization unfold?
  • What are the properties of the supermassive black holes that power the most distant quasars? How did they form at the cosmic dawn?
  • What is the relationships between supermassive black holes and host galaxies?

Discoveries and Milestones

  • Don Schneider played a leading role in the development of the Sloan Digital Sky Survey Catalog, which contains over 105,000 spectroscopically-confirmed quasars found during the first two phases of the Sloan Digital Sky Survey (1999-2008).
  • Yuexing Li has pioneered the numerical modeling of the formation, evolution, and multi-band properties of the most distant galaxies and quasars by combining multi-scale cosmological simulations with multi-wavelength radiative transfer calculations. She has developed essential models of quasar formation, as well as a comprehensive radiative transfer code ART2 ,which has a wide range of applications in modeling both continuum and emission lines from galaxies and quasars.
  • Derek Fox and collaborators discovered the most distant gamma-ray burst at redshift z=8.2, when the Universe was only a few hundred million years old.
  • Robin Ciardullo pioneered the technique of using the Planetary Nebulae Luminosity Function for extragalactic distance measurements, which is only method that can be applied to all large galaxies within ~ 20 Mpc, regardless of Hubble type or stellar population.

Current Projects

  • The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) will measure dark energy between 1.9<z<3.5 and trace the evolution of the component over much of the history of the universe.  The project will also facilitate a large number of other projects, from the measurement of total neutrino mass to the identification of ultra-low metallicity stars in the Milky Way. Drs. Ciardullo, Gronwall, and Schneider are members of the HETDEX team.
  • Yuexing Li is conducting computational work to investigate the formation of the first quasars, accretion onto black holes, Lyman-alpha emission from high-redshift galaxies, fossils of the first black holes and galaxies in the Milky Way, and large-scale structure formation.
  • Don Schneider uses data gathered by the Sloan Digitial Sky Survey, the Chandra satellite, and the Hobby-Eberly Telescope to investigate the properties of active galactic nuclei and the large-scale properties of the universe.

Participants