Einstein’s field equations with cosmological constant are analysed for a static, spherically symmetric perfect fluid having constant density. Five new global solutions are described. One of these… (More)

The Kosambi–Cartan–Chern (KCC) theory represents a powerful mathematical method for the analysis of dynamical systems. In this approach, one describes the evolution of a dynamical system in geometric… (More)

We investigate modified theories of gravity in the context of teleparallel geometries with possible Gauss-Bonnet contributions. The possible coupling of gravity with the trace of the energy-momentum… (More)

Static and spherically symmetric perfect fluid solutions of Einstein’s field equations with cosmological constant are analysed. After showing existence and uniqueness of a regular solution at the… (More)

We show that in the framework of the classical general relativity the presence of a positive cosmo-logical constant implies the existence of a minimal mass and of a minimal density in nature. These… (More)

The classical tests of general relativity (perihelion precession, deflection of light, and the radar echo delay) are considered for the Dadhich, Maartens, Papadopoulos and Rezania (DMPR) solution of… (More)

Inflation driven by a single dark spinor field is discussed. We define the notion of a dark spinor field and derive the cosmological field equations for such a matter source. The conditions for… (More)

The Cosserat model generalises an elastic material taking into account the possible microstructure of the elements of the material continuum. In particular, within the Cosserat model the structured… (More)

We consider spherically symmetric static solutions of the Einstein equations with a positive cosmological constant Λ, which are regular at the centre, and we investigate the influence of Λ on the… (More)