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Disputation: Trygve Leithe Svalheim

Doctoral candidate Kristian Joten Andersen at the Institute of Theoretical Astrophysics, Faculty of Mathematics and Natural Sciences, is defending the thesis "Closing the Loop, Joint Analysis of CMB Systematics and Foregrounds" for the degree of Philosophiae Doctor.

Portrait photo of a young, smiling man
Doctoral candidate Trygve Leithe Svalheim. Photo: Private.

The PhD defence and trial lecture will be hybrid. Attendees can therefor participate either in-person or via Zoom. The link will be available the day before the disputation. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.

Ex auditorio questions: the chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants -> Raise hand'. 

Join the disputation

The meeting opens for participation just before the disputation starts, and closes for new participants approximately 15 minutes after the defence has begun.

Trial lecture - July 1st at 10:15 (GE Aud. 1 / Zoom)

"The hunt for planet 9"

Conferral summary

I læren om universets opprinnelse observerer vi sporene fra de tidligste fysiske prosessene som fant sted. Det første slike sporet er den kosmiske bakgrunnsstrålingen, som viser universet slik det så ut i spedbarns-fasen. Trygve har bidratt til å utvikle nyskapende verktøy for å renvaske observasjoner av dette signalet for forstyrrende instrumentelle effekter og støy fra vår egen galakse, som videre resulterte i de mest nøyaktige tallene på universets tidlige ekspansjonsfase per dags dato.

Main research findings: "Lifting the galactic veil on the early universe"

The Cosmic Microwave Background (CMB) radiation is the oldest signal in the universe. It teaches us about the first moments after the universe came into existence, and thus informs us about its subsequent evolution.

The CMB serves as the faint backdrop of the night sky, obscured by all the other astrophysical objects (primarily clouds of gas), which we call foregrounds. For precise measurements of the CMB, we require detailed characterization of these, and also of the observing instruments' systematics. Furthermore, the problems of foreground separation and instrument systematics are tightly interwoven.

This thesis presents my work on disentangling this relationship. This is done by leveraging observations from several different experiments and simultaneous consideration of systematics and foregrounds in a “loop”-like manner. Through the application of these methods, my colleagues and I have created some of the cleanest maps of the sky in the microwave range, in the world. These maps in turn inform us about important properties of the universe. 


Contact information for the Department

Tags: PhD defense, disputas, Cosmic Microwave Background (CMB)
Published June 17, 2022 10:27 AM - Last modified June 20, 2022 1:58 PM