4 papers
Dynamics of quadratic f(R) cosmology with a perfect fluid: Jordan and Einstein frames
Artur Alho, Margarida Lima, Filipe C. Mena
We investigate the global dynamics of the field equations of (pure) quadratic theories of gravity which generalise Einstein's theory in spatially flat homogeneous and isotropic cos…
Quintessence: Quadratic potentials
Artur Alho, Claes Uggla
Arguably one can use a canonical scalar field , minimally coupled to gravity, with quadratic potentials to explore some general features of slow-rol…
Quintessence
Artur Alho, Elsa Bernholm, Claes Uggla
Recent observations suggest that the accelerated expansion of the Universe at late times is caused by a temporally changing dark energy component, rather than the constant one in t…
New simple and accurate quintessence approximations
Artur Alho, Claes Uggla
We derive new approximations for quintessence solutions that are simpler and an order of magnitude more accurate than anything available in the literature, which from an observatio…