Fredagskollokvium: Probing inflation with the cosmic microwave background and the large-scale structure

Thomas Montandon, Astroparticule et Cosmologie, Université Paris Diderot (France).

Portrettbildet av smilende man
Thomas Montandon, Astroparticule et Cosmologie, Université Paris Diderot (France). Photo: private.

Inflation is the earliest period in the history of our universe corroborated by observations. It explains its the homogeneity, isotropy and flatness of our universe. It also generates small adiabatic and quasi-Gaussian fluctuations. A natural extension of the single-field model is to consider additional fields: this is the so-called multi-field inflation. In these models, it is possible to generate non-adiabatic modes, called isocurvature modes, as well as measurable non-Gaussianities.

In this presentation, I will introduce the (non-)adiabatic and the (non-)Gaussian perturbations and explain how it is possible to probe them. The first probe is the observation of the temperature and polarization anisotropies of the cosmic microwave background (CMB). I will introduce the Planck collaboration constraints and introduce one of my Ph.D. work: a joint analysis of the CMB power spectrum and bispectrum to improve the constraints on non-adiabatic perturbations.

The second probe that I will discuss is the large-scale structure. One of the main challenges for its study is to understand the cosmological perturbation evolution beyond the linear regime.

I will finish this talk by introducing the second work of my Ph.D. thesis, related to the relativistic non-linearities which are a well known systematic effects of primordial non-Gaussianity.

kunsterig illustrasjon av universet
From the center to the border, this illustration shows the Institute of Theoretical Astrophysics (ITA) where this talk will be given, the large-scale structure of the universe (crédit: Illustris Collaboration), the dark ages in black, the cosmic microwave background (Credit Planck collaboration), the primordial plasma ending at the red circle which represents the "reheating". Behind the reheating, I represent the inflation period, which will be the subject of my introduction.


The seminar will take place in Peisestua (room 304) at Svein Rosselands hus, but, due to recent restrictions, will be also streamed online.

Please join via Zoom at .

Attendees will be muted during the colloquium, but will have the opportunity to ask questions at the end by clicking on the "raise hand” button.

Emneord: institute seminar, Cosmic Microwave Background (CMB), Kosmisk bakgrunnsstråling (CMB), universet, Universe
Publisert 3. des. 2021 15:20 - Sist endret 6. des. 2021 13:23