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Title: Studies on dark matter dark energy and possible alternate models
Researcher: Arun, Kenath
Guide(s): Gudennavar, Shivappa B and Sivaram, C
Keywords: Alternate models of gravity.
Astronomy and Astrophysics space science
Dark energy,
Dark matter,
Physical Sciences
Space Sciences
University: CHRIST University
Completed Date: 2020
Abstract: The nature of dark matter (DM) and dark energy (DE) which is supposed to constitute about 95% of the energy density of the universe is still a mystery. There is no shortage of ideas regarding the nature of both. While some candidates for DM are clearly ruled out, there is still a plethora of viable particles that fit the bill. In the context of DE, while current observations favour a cosmological constant picture, there are other competing models which may be equally likely. The standard model for the formation of structure assumes that there newlineexisted small fluctuations in the early universe that grew due to gravitational instability. The origin of these fluctuations are still unclear. In this study, we proposed the role of dark matter in providing the seed for star formation in the early universe, which is supported by very recent observations. With this we set observable constraints on luminosities, temperatures, and lifetimes of the early stars with an admixture of dark matter. We also studied the effects of the background repulsive dark energy density for large scale cosmic structures. The relation, and#119872;and#8260;and#119877;2 and#8776; 1and#119892;/and#119888;and#119898;2, seems to hold true for primeval galaxies as well as those at present epoch. From this, we set constraints on the nature and evolution of dark energy. Besides, we also set constraints on the size of galaxy clusters and superclusters due to the repulsive cosmological dark energy. This could indicate as to why large scale cosmic structures much larger than and#8764;200 Mpc are not seen.This study also looked at the evolution of the concept of the cosmological constant from its inception a little over a hundred years ago when Einstein introduced the cosmological constant in his General Theory of Relativity newlinein order to obtain a static universe to conform to the philosophical view of newlinethe universe at that time to it possibly making up close to about 70% of the energy density of the universe.
Pagination: xiii, 112p.
Appears in Departments:Department of Physics and Electronics

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01_title.pdfAttached File28.85 kBAdobe PDFView/Open
02_declaration.pdf274.99 kBAdobe PDFView/Open
03_certificate.pdf554.18 kBAdobe PDFView/Open
04_acknowledgements.pdf82.5 kBAdobe PDFView/Open
05_abstract.pdf294.01 kBAdobe PDFView/Open
06_list_of_tables.pdf187.7 kBAdobe PDFView/Open
07_list_of_figures.pdf193.51 kBAdobe PDFView/Open
08_table_of_contents.pdf55.91 kBAdobe PDFView/Open
09_chapter1.pdf358.73 kBAdobe PDFView/Open
10_chapter2.pdf364.27 kBAdobe PDFView/Open
11_chapter3.pdf753.35 kBAdobe PDFView/Open
12_chapter4.pdf485.79 kBAdobe PDFView/Open
13_chapter5.pdf666.01 kBAdobe PDFView/Open
14_conclusion.pdf327.69 kBAdobe PDFView/Open
15_bibliography.pdf262.41 kBAdobe PDFView/Open
80_recommendation.pdf342.18 kBAdobe PDFView/Open
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