Past Events

Abstract
 

As of now, dark matter is about 85% of the mass in our Universe, but we do not know its true nature. In galaxies and galaxy clusters, it is thought to be distributed in the form of a halo which surrounds the galactic disc and extends beyond the visible component of a galaxy. The conventional model, known as 'cold dark matter', albeit its many successful predictions, has trouble explaining two main observations, first of which is the shallow mass density profiles for galaxies. It also predicts many low-mass galaxies which are yet to be observed. A new model called wave dark matter, composed of a non-relativistic Bose-Einstein condensate has been shown to address these issues. Simulations have shown that self-interference within the condensate produces solitonic cores at the center of galaxies, along with mass granulations at smaller scales. Our work theoretically investigates the gravitational lensing signatures of wave dark matter in observations, particularly those of the granulation patterns, using high-performance computing facilities for numerical simulations. We discover complex patterns created in the critical curves (regions of theoretically infinite magnification) of lenses, which can produce significant changes in image magnification as well as image position. These features are capable of explaining many observations where current lens models are not so successful, such as the long-standing quasar flux anomalies.

Anyone interested is welcome to attend.