Member Panel

Your Profile

Manage Your Profile

Manage Your Publications


Useful Links

Internal Documentation

Testing Alternative Cosmological Models with Cosmic Shear, Stefano Camera

Mar. 21 - 20:00 - 2011

<p>The current concordance model (LCDM) fits a large number of cosmological datasets excellently.  However, in order to explain the dynamics of galaxies and galaxy clusters and the large-scale structure of the Universe, as well as the observed pattern of the temperature anisotropies of the cosmic microwave background, we have to postulate that more than 80% of the matter contained in the cosmos is in the form of non-baryonic weakly-interacting cold Dark Matter (DM).  Moreover, the late-time accelerated expansion of the Universe is taken into account by the so-called Dark Energy (DE), a fluid with <br /> negative pressure which acts as a cosmological constant term in Einstein's equation.  DM and DE represents ~95% of the total energy budget of the Universe, nonetheless they have not been observed yet, though a strong effort has been given.  Thus, in the last decades several alternative explanations have been proposed.  They mainly rely on the modification of Einstein's field equations, either by changing the law of gravity (e.g. brane worlds, modified-action theories), or by suggesting the presence of exotic types of <br /> matter (e.g. quintessence, Chaplygin gas).  Here, I present my work on testing the viability of alternative cosmological models with cosmic shear, i.e. the small, coherent distortion of distant galaxy images due to the large-scale distribution of matter in the cosmos.  Specifically, I studied both modified-gravity and modified-matter models.  I show how upcoming cosmic shear surveys, such as the ESA Euclid satellite, could constrain such alternative models, thus being able to discriminate between LCDM and other viable <br /> theories.</p><p> </p><p>Local: Physics Department seminar room </p>

An importable CVS/ICS calendar with all of CENTRA's events is available here