Cosmology helsinki

Aug 31, 2023This is the basic course on cosmology. It is divided into two parts, Cosmology I and II, of which Cosmology I should be easier. Unlike most

How synchronous gauge is used in cosmological perturbation theory?

We shall later use the spatially at gauge to solve perturbation equations for scalar elds.
The synchronous gauge was the rst one to be used in cosmological perturbation theory (by Lifshitz in 1946) and it is often used in numerical work.
The synchronous gauge is de ned by the requirement A = Bi = 0.

Is cosmology 2 based on general relativity?

In Cosmology II we accepted many results as given; now they are derived rigorously from general relativity.
Topics not covered:

Quantum eld theory is not used

except for a brief discussion of gener- ation of primordial perturbations during in ation in CPT II.
Non-linear e ects or higher-order perturbation theory are not covered.

What is a cosmological UID?

Exercise:

Derive the synchronous gauge Einstein equations and continuity equations from the cor- responding Newtonian gauge equations by gauge transformation.
In practice, the cosmological uid consists of many components (e.g., particle species:photons, baryons, CDM, neutrinos, . .

The Helsinki Institute of Physics is a physics research institute operated jointly by University of Helsinki, Aalto University, University of Jyväskylä, Lappeenranta University of Technology and Tampere University of Technology.
The operations of the institute began on September 1, 1996.
The foundation of the institute was provided by the three previous Helsinki-based institutes: SEFT, TFT and HTI, which were merged into the new organization.
The current director of the institute since 2017 has been prof.
Katri Huitu.
The institute is responsible for the Finnish research collaboration with CERN and Facility for Antiproton and Ion Research in Europe GmbH (FAIR).