Inflatorni kosmološki modeli sa tahionskim i radionskim poljima

Abstract

A popular class of the inflationary cosmological models is based on an introduction of a scalar field with nonstandard tachyonic Lagrangian of the Dirac-Born-Infeld (DBI) type. A potentially fundamental role of the tachyon fields in the braneworld cosmology was proposed by A. Sen. Research in this PhD thesis is motivated by Randall-Sundrum (RSII) cosmological model. The main objective of the research is to formulate and solve an analytical- numerical inflationary model with DBI-tachyon field and RSII model with an additional radion field, as well computation of observational parameters. Obtained results are in a good agreement with the real astrophysical data and provide a better understanding of the role of strings and branes in modern cosmology. The results indicated that role of radion in an initial RSII setup is less important than expected.