In this book the authors gather and present current research in the study of cosmology. Topics discussed include the mysteries of the geometrization of gravitation; relativistic viscous Universe models; cosmology and science; a discussion on whether science has established if the cosmos are physically comprehensible?; Mach, Einstein, dark matter and knowability; implementing Hilltop F-term hybrid inflation in supergravity; and relative velocities, geometry and the expansion of space.