• What is dark matter?
• How much is there and what are its properties?
• How is it distributed in space?
• What is the relationship between galaxies and the dark matter halos in which they live?
• How do galaxies and their dark matter halos co-evolve?
• How are galaxies affected by their environment?

These are some of the questions that I am trying to answer. I use the following techniques to probe these questions.

• Gravitational Lensing is the distortion of the shapes of distant background galaxies by matter in between those galaxies and the Earth. 
• Cosmic Flows are the distortions of the expansion of the Universe by superclusters. By studing these flows we can measure the dark matter content of the Universe. 
• Galaxy formation