Topological Insulators

This image shows the valence and conduction bands in the phase transition from topological insulator to conventional insulator with increasing tensile strain.


Quintic Calabi-Yau manifold

In superstring theory, the fundamental building block is an extended object, namely a string, whose vibrations would give rise to the particles encountered in nature. In order to solve certain classic problems of unified gauge theories, the 4-dimensional effective theory should be in a space which is a Calabi-Yau manifold of complex dimension 3.


Vector Bundles on Calabi-Yau Manifolds

Supersymmetric vacua of the heterotic string and M-theory are explored through the study of complex algebraic geometry.  The figure is from a recent paper by Prof. Burt Ovrut and collaborators on the Kahler cone substructure associated with the SU(2) bundle for different Kahler moduli.

Jamming and the Glass Transition

Professor Andrea Liu's group studies the theory of jamming - the phenomenon wherein a system that normally flows much like a liquid (as with foams) become solid-like when subjected to shear stress.


PAPER Experiment

The Precision Array for Probing the Epoch of Reionization is a radio interferometer designed to detect 21 cm Hydrogen (HI) fluctuations occuring when the first galaxies ionized intergalactic gas at around 500 million years after the Big Bang.  The Penn PAPER team is led by Professor James Aguirre.