School of Astronomy (SoA) - Weekly Seminar 

Sudden Future Singularity models as an alternative to Dark Energy?

Hoda Ghodsi (University of Glasgow, UK)

Abstract:
Current observational evidence suggests that dark energy could be in the
form of phantom energy. A universe consisting of a phantom constituent
will be driven toward a drastic end known as the Big Rip singularity where
all the matter in the universe will be destroyed. Motivated by this John
Barrow's search for other possible evolutions for the Universe resulted in
discovering phenomena which he called Sudden Future Singularities (SFS). A
model accommodating an SFS must assume no equation of state linking the
pressure and density, or else such an event will not occur. In such a
model it is possible to have a blow up of the pressure occurring at
sometime in the future evolution of the Universe while the energy density
would remain unaffected. The particular evolution of the scale factor of
the Universe in this model that results in a singular behaviour of the
pressure also admits acceleration in the current era as required. Could
these models therefore serve as an alternative to dark energy? In this
talk I will present the results of our confrontation of an example class
of SFS models with the available cosmological data from high redshift
supernovae, baryon acoustic oscillations (BAO) and the cosmic microwave
background (CMBR). I will then discuss the viability of the model in
question as an alternative to dark energy.

Wednesday / 30-June-2010 / 9-Tir-1389/ 2:00 PM