Meet a Scientist

Particle physics, cosmology, and the study of a wide variety of theoretical models – most notably ones involving extra dimensions of space. Randall works on several of the competing models of string theory in the quest to explain the fabric of the universe.

Implications of high-energy elementary particle physics for physics of the early universe and its evolution (Big Bang, creation of matter, formation of galaxies, etc). And vice-versa: implications of observable cosmological data for fundamental physics.

Theoretical models for cosmology – from standard to exotic (e.g. cosmic strings and monopoles). “Quantum creation” of multiple universes out of nothing; eternal inflation and the anthropic selection of a world that would ultimately become hospitable to life.

Applying the lessons learned in quantum information theory to gain a better understanding of quantum mechanics itself. Is quantum theory simply a new type of probability theory? Exploring new directions towards combining quantum theory with 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.

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.

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 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.

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.

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.

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.

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.