Constraining the kinetically dominated Universe.
Lead Research Organisation:
University of Cambridge
Department Name: Physics
Abstract
In this project we explore alternative initial conditions for inflation and their consequences within different cosmological models for observables such as the cosmic microwave background (CMB). As a first step, we place ourselves in the standard LCDM cosmology and investigate the effects of an initially kinetically dominated universe on the primordial power spectrum (PPS) of scalar and tensor perturbations. This can then be extended to closed universes, where we can place an upper bound on the overall amount of inflation and thus expect the effects of kinetic dominance to be observable. These features in the PPS are translated through to the angular power spectrum of the CMB where we investigate their potential to match features in the data from the Planck satellite such as an overall lack of power on large scales and a dip in power at multipoles of 20 to 30. To that end we use Bayesian analysis tools such as MCMC and nested sampling to perform parameter estimates and model comparisons. The modern tools we use allow for a fully Bayesian approach for more complex models than considered previously.
Organisations
People |
ORCID iD |
Anthony Lasenby (Primary Supervisor) | |
Lukas Hergt (Student) |
Publications
Hergt L
(2019)
Case for kinetically dominated initial conditions for inflation
in Physical Review D
Hergt L
(2019)
Constraining the kinetically dominated universe
in Physical Review D
Agocs F. J.
(2020)
Quantum initial conditions for inflation and canonical invariance
in arXiv e-prints
Studentship Projects
Project Reference | Relationship | Related To | Start | End | Student Name |
---|---|---|---|---|---|
ST/N50399X/1 | 01/10/2015 | 31/03/2021 | |||
2139376 | Studentship | ST/N50399X/1 | 01/01/2017 | 31/12/2020 | Lukas Hergt |
Description | 34th Physics at Work Exhibition |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Schools |
Results and Impact | The Cavendish Laboratory was hosting the 34th Physics at Work Exhibition where school classes came to visit and learn about physics research at University. I hosted a stall for the astrophysics group giving a presentation on "The Expansion of the Universe" to 6 school classes. |
Year(s) Of Engagement Activity | 2018 |
Description | Institute of Astronomy Open Day |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | The Institute of Astronomy and the Kavli Institute for Cosmology held their annual open day with games, activities, talks and demonstrations about astronomy and astrophysics and suitable for all ages. I was helping at the station for gravitational lensing. |
Year(s) Of Engagement Activity | 2018,2019 |