Cosmology and cosmological implications of quantum gravity. Observable effects in cosmology help to identify the limits of general relativity, which could potentially be surpassed by modified theories of gravity and/or quantum gravity.

Many aspects of string theory, ranging from its mathematical structure and various formulations, to possible implications for black holes and cosmology. Using string phenomenology to connect theory with reality, i.e. string mathematics with elementary particle physics.

Observational cosmology, with particular focus on the formation and evolution of large scale structures in our universe like clusters of galaxies as large as 500 million light years. “Weighing” the universe, and mapping out the mysterious dark matter it contains.

Physics beyond the standard model: theories of elementary particles with extra space dimensions (large, small, warped and flat); supersymmetry; grand unification; dark matter; inflation and dark energy; as well as relationships between the different subjects.

String- and M-theory inspired scenarios for the cosmology of the early universe. Replacing the unphysical Big Bang-like beginning of our universe with bouncing scenarios of accelerated expansion followed by familiar evolution.

What, exactly, happened around the time of the Big Bang? Exploring new models inspired by superstring theory and supergravity, e.g. ones in which we live on “branes” that collide with a “big bang”. Satellite experiments to test such models.

Cosmology as a natural meeting ground for fundamental theory (e.g. superstring theory or quantum gravity) and observations. Exploring how seeds laid down in the very early universe developed into the large scale structure we observe in the universe today.

The origin and evolution of the largest observable structures in the universe (much larger than entire galaxies); understanding why the expansion of the universe is accelerating. Observational techniques: cosmic microwave background, gravitational lensing and gravity waves.

Mathematical aspects of modern theories of elementary particles and gravitation. Replacing the notion of particles with fundamental abstract fields (magnetic monopoles, vortices and Skyrmions) in an attempt to approach a formulation for quantum gravity.

Cosmology of the early universe; theory and detection of gravitational waves, e.g. from the violent last stages of inspiral as two orbiting black holes coalesce. Using cutting edge quantum physics in designing practical, ultra sensitive gravitational wave detectors.