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Primordial Gravitational Waves and ultra-light Dark Matter in a complex singlet extended Standard Model

Wildenor, Sara LU (2021) FYTK02 20211
Particle and nuclear physics
Theoretical Particle Physics - Undergoing reorganization
Abstract
In this thesis, the consequences of extending the internal symmetries of the standard model with a complex singlet scalar field, are investigated in terms of dark matter phenomenology and the possibility of primordial gravitational wave detection utilizing space based laser interferometry. The scalar potential of the model is constructed with a Z2 symmetry, which allows for the retainment of a linear and a quadratic coupling parameter, as well as a stable dark matter candidate, and an additional non-zero vacuum expectation value for the real component of the scalar field. The gravitational wave power spectrum is then calculated by implementing cosmoTransition packages, which identifies the phase transition profiles, tunneling solutions and... (More)
In this thesis, the consequences of extending the internal symmetries of the standard model with a complex singlet scalar field, are investigated in terms of dark matter phenomenology and the possibility of primordial gravitational wave detection utilizing space based laser interferometry. The scalar potential of the model is constructed with a Z2 symmetry, which allows for the retainment of a linear and a quadratic coupling parameter, as well as a stable dark matter candidate, and an additional non-zero vacuum expectation value for the real component of the scalar field. The gravitational wave power spectrum is then calculated by implementing cosmoTransition packages, which identifies the phase transition profiles, tunneling solutions and minimum of the effective potential.
The results are discussed and compared to the sensitivity curves of the proposed gravitational wave facilities LISA, BBO and DECIGO. (Less)
Popular Abstract
The Universe is a large and mysterious place. So large that it would take light 93 billion years to cross it (comparable with the rather short 8 minute distance to the Sun), and so mysterious that what little we do know about it, only concerns about 4\% of the mass of the Universe - the rest is dark and unknown.
What follows here, is a plausible scenario, a little story of what might have happened as the Universe was born, and unimaginable forces replaced some kind of Nothingness with some other kind of Something.
It takes place in the aftermath of the Big Bang, during the so called inflation period, where the dynamics of the early Cosmos could provide crucial insight - not only to the true nature of our world, but also regarding the... (More)
The Universe is a large and mysterious place. So large that it would take light 93 billion years to cross it (comparable with the rather short 8 minute distance to the Sun), and so mysterious that what little we do know about it, only concerns about 4\% of the mass of the Universe - the rest is dark and unknown.
What follows here, is a plausible scenario, a little story of what might have happened as the Universe was born, and unimaginable forces replaced some kind of Nothingness with some other kind of Something.
It takes place in the aftermath of the Big Bang, during the so called inflation period, where the dynamics of the early Cosmos could provide crucial insight - not only to the true nature of our world, but also regarding the dark aspects of reality; dark matter and dark energy. Little is known about this era, as this part of history is shielded by an opaque veil of light (known as the cosmic microwave background), which our current methods of observation are unable to penetrate. However, gravitational waves have the peculiar ability to propagate freely through all sorts of seemingly impervious obstacles, and with their detection and deciphering, we would be able to open a new window of physics, and look out into a whole new world - or rather a different time of our present world; into the early epochs of the cosmological evolution.

Once upon a long long time ago (more or less the longest time ago it has ever been), in the first millionth of a millionth of a second of what has become an almost 14 billion year long life, the Universe was a hot, boiling primordial soup of primarily radiation and light, with very few similarities to the world we know today. One may think of this rather chaotic state of the Universe as symmetric with respect to its potential energy, but then something happened which where to break this symmetry. As the rapid expansion of the Universe caused it to cool down, bubbles composed of an asymmetric state started to form, move and burst in this boiling soup, which eventually transformed the potential energy of the entire Cosmos into an asymmetric shape. Rather like a phase transition causing a face transition, the appearance of the Universe, was forever changed. The bursting bubbles and the turbulence caused by the bubble walls moving through the blazing plasma, initiated a process so violent that the fabric of space-time itself was disrupted, resulting in the formation of gravitational waves.

For the entire age of the Universe (minus the millionth of a millionth of a second which took place before the considered event), these primordial waves have propagated through the vastness of cosmos at the speed of light, and will most likely continue to do so forever, since nothing seems to slow them down. Thus, clues to the history of the Universe and reality itself, might not be a remote goal, but lie in the nature of these waves, this omnipresent humming echo of the early world dynamics which is causing the space-time around us to gently vibrate.
The great technological advancement in experimental research and gravitational wave detection, means it might not be long before (at least hopefully some of) the unknowns concerning the early Universe are unraveled. (Less)
Please use this url to cite or link to this publication:
author
Wildenor, Sara LU
supervisor
organization
course
FYTK02 20211
year
type
M2 - Bachelor Degree
subject
keywords
theoretical physics, gravitational waves, dark matter, complex singlet extended standard model, LISA, BBO, DECIGO
language
English
id
9052046
date added to LUP
2021-06-14 18:56:52
date last changed
2021-06-14 18:56:52
@misc{9052046,
  abstract     = {{In this thesis, the consequences of extending the internal symmetries of the standard model with a complex singlet scalar field, are investigated in terms of dark matter phenomenology and the possibility of primordial gravitational wave detection utilizing space based laser interferometry. The scalar potential of the model is constructed with a Z2 symmetry, which allows for the retainment of a linear and a quadratic coupling parameter, as well as a stable dark matter candidate, and an additional non-zero vacuum expectation value for the real component of the scalar field. The gravitational wave power spectrum is then calculated by implementing cosmoTransition packages, which identifies the phase transition profiles, tunneling solutions and minimum of the effective potential.
The results are discussed and compared to the sensitivity curves of the proposed gravitational wave facilities LISA, BBO and DECIGO.}},
  author       = {{Wildenor, Sara}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Primordial Gravitational Waves and ultra-light Dark Matter in a complex singlet extended Standard Model}},
  year         = {{2021}},
}