Nicholas Galitzki

Probing the beginning of the universe with precision microwave polarimetry observations

We are in an exhilarating era in which cosmological models are being tested by cutting-edge instruments that push the boundaries of theoretical predictions and technological innovation. Observations of polarized light from the cosmic microwave background (CMB) will enable us to detect, or constrain, the elusive CMB primordial B-mode signal that is key to understanding the first fraction of a second of our Universe’s existence. However, CMB observations are occluded by polarized emission from dust in the galaxy’s interstellar medium that aligns with galactic magnetic fields. The spectral dependence of the dust signal is not well understood, motivating investigations to constrain its properties. I will present preliminary results from the Simons Observatory, which began observations from Chile’s Atacama Desert in 2023. I will also give an overview of the balloon-borne BLAST Observatory, which will characterize the foreground galactic signals which prevent more sensitive CMB measurements. My talk will cover the current status of these projects as well as a look to the future with CMB-S4. Together, these experiments will vastly improve our understanding of the primordial Universe over the next decade.

Image credit: Nicholas Galitzki
The Simons Observatory small aperture telescope in Chile’s Atacama Desert

Nicholas Galitzki focuses on experimental cosmology, astrophysical instrumentation, data analysis, polarimetry, cosmic microwave background, interstellar medium, dust, cryogenics and balloon-borne telescopes. An experimental cosmologist with a focus on detecting primordial gravitational waves through observations of the cosmic microwave background (CMB), his research encompasses the design, implementation, and characterization of cryogenic cameras for millimeter and submillimeter observations, as well as data analysis from on-sky observations. He is actively involved with the Simons Observatory, particularly with the small aperture telescopes aimed at observing the polarized CMB signal at large angular scales. To enhance the capabilities of these instruments and pursue ambitious scientific goals like cosmic birefringence, he is also part of the Hover-Cal project, which employs drones for calibration. Both projects are conducted at a site in Chile’s Atacama Desert, situated at an altitude of 5,200 meters.