Uroš Seljak Explained

Uroš Seljak
Birth Date:1966 5, df=yes
Citizenship:Slovenian, United States
Known For:E and B-modes, CMBFAST code [1]
Alma Mater:
Thesis Title:Light propagation in a weakly perturbed expanding universe [2]
Thesis Year:1995
Doctoral Advisor:Edmund Bertschinger

Uroš Seljak (born 13 May 1966 in Nova Gorica) is a Slovenian cosmologist and a professor of astronomy and physics at University of California, Berkeley.[3] He is particularly well-known for his research in cosmology and approximate Bayesian statistical methods.

Biography

Seljak completed his secondary education at the Nova Gorica Grammar School and carried out his undergraduate studies at the University of Ljubljana, Slovenia. He graduated in 1989 and later received a Master's degree from the same institution in 1991. Seljak conducted his doctoral research at Massachusetts Institute of Technology and received his PhD in 1995.

After postdoctoral studies at the Center for Astrophysics Harvard & Smithsonian, he held faculty positions at Princeton University, the International Centre for Theoretical Physics in Trieste, Italy, and the University of Zurich, before joining the UC Berkeley physics and astronomy departments in 2008. He holds a joint appointment with the Lawrence Berkeley National Laboratory.

Career

Seljak is a cosmologist who is particularly well-known for his research on cosmic microwave background radiation,[4] [5] galaxy clustering and weak gravitational lensing,[6] and the implications of these observations for the large scale structure of the universe.[7]

In 1997, Seljak predicted the existence of B-modes in CMB polarization that are a tracer of primordial gravitational waves from inflation.[8] Together with Matias Zaldarriaga, he developed the CMBFAST code for CMB Temperature, E and B-mode polarization, and for gravitational lensing effects on CMB.

In 2000, he developed the halo model for dark matter[9] [10] and galaxy clustering statistics.[11]

Much of Seljak's recent work has been focused on how to extract fundamental properties of our universe from cosmological observations using analytical methods and numerical simulations. He has developed cosmological generative models of dark matter, stars and cosmic gas distributions.

Seljak is actively developing methods for accelerated approximate Bayesian methodologies, and applying them to cosmology, astronomy, and other sciences. Examples of this work are the MicroCanonical Hamiltonian and Langevin Monte Carlo and Deterministic Langevin Monte Carlo samplers.

Seljak is developing machine learning methods with applications to cosmology, astronomy, and other sciences. Notable examples include Fourier-based Gaussian processes for analysis of time and/or spatially ordered data, generative models with explicit physics symmetries (translation, rotation), and sliced iterative transport methods for density estimation and sampling.

Honours and awards

Seljak was awarded the 2021 Gruber Prize in Cosmology jointly with Marc Kamionkowski and Matias Zaldarriaga, who together "introduced numerous techniques for the study of the large-scale structure of the universe as well as the properties of its first instant of existence."[12]

Notable students

Notes and References

  1. Web site: Overview of CMBFAST . . September 15, 2023 .
  2. Light propagation in a weakly perturbed expanding universe . 1995 . . 1721.1/37767 . September 18, 2023 . Thesis . Seljak . Uros̆ .
  3. https://physics.berkeley.edu/people/faculty/uros-seljak Faculty profile
  4. Seljak. Uroš. Zaldarriaga. Matias. 1996. A Line-of-Sight Integration Approach to Cosmic Microwave Background Anisotropies. The Astrophysical Journal. 469. 437–444. 10.1086/177793. astro-ph/9603033. 1996ApJ...469..437S. 3015599.
  5. Sincell. Mark. A New Lens on Dark Matter. 30 March 1999. Physical Review Focus. 3. .
  6. .
  7. .
  8. Seljak. Uroš. 10 June 1997. Measuring Polarization in the Cosmic Microwave Background. The Astrophysical Journal. en. 482. 1. 6–16. 10.1086/304123. 0004-637X. astro-ph/9608131. 1997ApJ...482....6S. 16825580.
  9. Seljak. Uroš. Makarov. Alexey. McDonald. Patrick. Trac. Hy. 8 November 2006. Can Sterile Neutrinos Be the Dark Matter?. Physical Review Letters. en. 97. 19. 191303. 10.1103/PhysRevLett.97.191303. 17155611. astro-ph/0602430. 2006PhRvL..97s1303S. 22565444. 0031-9007.
  10. Seljak. Uroš. Makarov. Alexey. McDonald. Patrick. Anderson. Scott F.. Bahcall. Neta A.. Brinkmann. J.. Burles. Scott. Cen. Renyue. Doi. Mamoru. Gunn. James E.. Ivezić. Željko. 20 May 2005. Cosmological parameter analysis including SDSS Ly α forest and galaxy bias: Constraints on the primordial spectrum of fluctuations, neutrino mass, and dark energy. Physical Review D. en. 71. 10. 103515. 10.1103/PhysRevD.71.103515. astro-ph/0407372. 2005PhRvD..71j3515S. 15237151. 1550-7998.
  11. Seljak. Uroš. 11 October 2000. Analytic model for galaxy and dark matter clustering. Monthly Notices of the Royal Astronomical Society. en. 318. 1. 203–213. 10.1046/j.1365-8711.2000.03715.x. astro-ph/0001493. 2000MNRAS.318..203S. 0035-8711. free.
  12. Web site: 2021 Gruber Cosmology Prize . 6 May 2021 . gruber.yale.edu.
  13. http://aas.org/prizes/warner Warner prize recipients
  14. Web site: Commons:Wiki Science Competition 2019/Winners - Wikimedia Commons.
  15. Web site: Lab Cosmologist Wins Science Photo Competition . July 31, 2020 . Elements Archive . August 15, 2023.