STellar Astrophysics & Relativity research cluster/Physics Department seminar
The Dynamics of Modified Gravities
Dr. Vincenzo Vitagliano
Centro Multidisciplinar de Astrofísica (CENTRA)
Instituto Superior Técnico, Lisboa, Portugal
Tuesday, November 27, 2012
2:30 p.m.
Johnson 103
I will review Metric-Affine theories of Gravity (MAG), that is, theories for which the metric and the affine (not necessarily symmetric) connection are independent quantities (namely in the Palatini approach) and whose actions include covariant derivatives of the matter fields, with the covariant derivative naturally defined using the independent connection. As a result, in MAG a direct coupling involving matter and connection is also present. I will summarize some physical consequences of such theories. I will then show that the connection stays non-dynamical for the most general action containing second order invariants of the curvature and the torsion. However, including higher order terms excites new degrees of freedom, making the connection (or parts of it) dynamical. Some peculiarities of f(R) versions of MAG will also be considered.
Coffee and donuts will be served.
