Testing modified gravity at large distances with the HI Nearby Galaxy Survey’s rotation curves

Modified Gravitational Theory and Galaxy Rotation Curves

The nonsymmetric gravitational theory predicts an acceleration law that modifies the Newtonian law of attraction between particles. For weak fields a fit to the flat rotation curves of galaxies is obtained in terms of the mass (massto-light ratio M/L) of galaxies. The fits assume that the galaxies are not dominated by exotic dark matter. The equations of motion for test particles reduce for wea...

Testing Gravity at Short Distances

Various theories of physics beyond the Standard Model, including attempts to resolve the hierarchy problem, include deviations from Newtonian gravity at short distances. Tabletop measurements of gravity can provide constraints on these theories. We have built an apparatus to measure the force between masses separated by tens of microns. The experiment utilizes a micromachined silicon cantilever...

Galaxy Rotation Curves in Covariant Hořava-Lifshitz Gravity

Using the multiplicity of solutions for the projectable case of the covariant extension of Hořava-Lifshitz gravity, we show that an appropriate choice for the auxiliary field allows for an effective description of galaxy rotation curves. This description is based on static and spherically symmetric solutions of covariant Hořava-Lifshitz gravity and does not require Dark Matter.

Cosmology from HI galaxy surveys with the SKA

Filipe B. Abdalla∗1,2, Philip Bull3, Stefano Camera4, Aurélien Benoit-Lévy1, Benjamin Joachimi1, Donnacha Kirk1, Hans-Rainer Klöckner5, Roy Maartens 6,7, Alvise Raccanelli8,9, Mario G. Santos4,6,10, Gong-Bo Zhao11,7 on behalf of the Cosmology SWG. 1Department of Physics and Astronomy, University College London, London WC1E 6BT, UK 2Department of Physics and Electronics, Rhodes University, PO Bo...

Flat rotation curves in Chern-Simons modified gravity