Talks

Inflation, a postulated epoch of accelerated expansion in the early universe, has become a principal component of the standard model of cosmology. From a wide variety of initial conditions, inflation produces a nearly homogeneous universe populated by density fluctuations that seed large-scale structure. However, inflation is such a good homogenizer that, once unleashed, in many cases it becomes eternal, ending only within spontaneously nucleated bubbles. In this scenario, our observable universe resides inside one such bubble. Surprisingly, it is possible to perform direct observational tests of eternal inflation. The most dramatic and detectable signatures of eternal inflation arise from the collision between bubbles in the very early universe, which leave an imprint on the cosmic microwave background (CMB) radiation. In this talk, I will motivate and describe the eternal inflation scenario and present the results of a search for the signatures of eternal inflation in CMB data from the Wilkinson Microwave Anisotropy Probe.

In this talk, I will briefly review the recent progress on quantum computation and simulation in the trapped ion system, with particular emphasis on the idea of scaling (how to scale up the number of qubits). I will discuss ideas towards large-scale quantum computation/simulation based on the network approach or the use of transverse phonon modes in anharmonic traps and then review the recent experimental progress along this direction.  At the end of the talk, I will also briefly mention recent activities in Tsinghua-Michigan Joint Institute for quantum information.