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.
Venue
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 https://uio.zoom.us/j/2702868506 .
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.