Sökning: "Modified theories for gravity"
Visar resultat 1 - 5 av 6 uppsatser innehållade orden Modified theories for gravity.
1. Gravitational Collapse of a Massless Scalar Field in a Theory of Minimally Modified Gravity
Master-uppsats, KTH/FysikSammanfattning : This thesis explores the spherically symmetric gravitational collapse of a massless scalar field in a minimally modified gravity theory denoted VCDM (V replaces $\Lambda$ in the $\Lambda$CDM abbreviation), a class of theories propagating the same degrees of freedom as general relativity at the expense of broken 4D diffeomorphism invariance. Numerical evolution of the equations of motion reveals that for small initial scalar profile amplitudes, no black hole forms from the collapse. LÄS MER
2. Planes of satellite galaxies
Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisationSammanfattning : The Planes of Satellites Problem is an open question within the field of galaxy formation. It is based on the observations that the Milky Way's satellites, as well as those around the Andromeda (M31) galaxy, align in planes. LÄS MER
3. Markov Chain Monte Carlo (MCMC) and Bayesian Inference for Gravitational Waves
Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisationSammanfattning : The Laser Interferometer Space Antenna (LISA) is a space borne gravitational wave detec- tor set to launch in 2034, with the objective of detecting and studying the Gravitational Waves (GWs) of our universe. So far, ground-based detectors such as the Laser Interferometer Gravitational-Wave Observatory (LIGO) have been successful in detecting GWs, but the limitations of ground based detectors is what makes LISA so special. LÄS MER
4. Effect of chameleons on the mass of a galaxy cluster
Master-uppsats, Uppsala universitet/Teoretisk astrofysikSammanfattning : Chameleons are scalar fields coming from modied gravity theories and can be possible explanations for Dark Energy. They cause a fifth force and have a screening mechanism which allows this force to avoid solar system constraints. In this thesis, astrophysical consequences of the potential presence of the chameleon field will be studied. LÄS MER
5. On the consistency of multigravity theories
Master-uppsats, Stockholms universitet/FysikumSammanfattning : In this thesis a set of recently proposed multigravity theories is analysed. In the special case of bimetric gravity, the theory has been conclusively shown to be ghost-free. On the other hand, for multigravity theories in general, the ghost-issue has not been settled conclusively. LÄS MER