Sicim kuramlarından esinlenen bazı kütleçekim kuramlarının kozmolojik çözümleri

Some modified theories of gravity in four and higher dimensions that are motivated by the low energy effective string field theories are considered. The corresponding variational field equations are derived using the method of Lagrange multipliers in the language of exterior differential forms over the space-time manifold. Cosmological solutions are discussed, paying special attention to the anisotropy and the late-time acceleration of the expansion of our three dimensional space. Comments on recent observational data are made.