Physics

Imagine going beyond treating the symptoms of disease and instead stopping it and reversing it. This is the promise of regenerative medicine.

In her Perimeter Institute public lecture, Prof. Molly Shoichet will tell three compelling stories that are relevant to cancer, blindness and stroke. In each story, the underlying innovation in chemistry, engineering, and biology will be highlighted with the opportunities that lay ahead. 

To make it personal, Shoichet’s lab has figured out how to grow cells in an environment that mimics that of the native environment. Now she has the opportunity to grow a patient’s cancer cells in the lab and figure out which drugs will be most effective for that individual. 

In blindness, the cells at the back of the eye often die. We can slow the progression of disease but we cannot stop it because there is no way to replace those cells. With a newly engineered biomaterial, Shoichet’s lab can now transplant cells to the back of the eye and achieve some functional repair. 

The holy grail of regenerative medicine is stimulation of the stem cells resident in us. The challenge is to figure out how to stimulate those cells to promote repair. Using a drug-infused “band-aid” applied directly on the brain, Shoichet’s team achieved tissue repair. 

These three stories underline the opportunity of collaborative, multi-disciplinary research. It is exciting to think what we will discover as this research continues to unfold.

 Non-Fermi liquids are exotic metallic states which do not support well defined quasiparticles. Due to strong quantum fluctuations and the presence of extensive gapless modes near the Fermi surface, it has been difficult to understand universal low energy properties of non-Fermi liquids reliably.  In this talk, we will discuss recent progress made on field theories for non-Fermi liquids. Based on a dimensional regularization scheme which tunes the number of co-dimensions of Fermi surface, critical exponents that control scaling behaviors of physical observables can be computed in controlled ways. The systematic expansion also provides important insight into strongly interacting metals. This allows us find the non-perturbative solution for the strange metal realized at the antiferromagnetic quantum critical point in 2+1 dimensions and predict the exact critical exponents.

In recent years, precise cosmological measurements have provided strong evidence for new physics beyond the Standard Model, occurring both in the very early universe and also today.  In the near future, large-scale galaxy surveys will open another window on many different areas of physics, including tests of gravity, probes of dark energy, and cosmic inflation.  However, interpreting galaxy surveys presents new challenges, because galaxies are sensitive to astrophysics that are unimportant for the cosmic microwave background.  I will discuss how galaxies may be used to study cosmology, and will argue that the messy astrophysics in galaxies actually offers entirely new probes of fundamental physics.  I will illustrate this with 3 examples, related to inflation, neutrino masses, and the properties of dark matter.

I will argue that the standard model contains a rather strong hint that -- instead of being simply an ordinary continuous 4D manifold -- spacetime is actually the product of a 4D manifold and a certain discrete/finite 6D space (i.e. there are 6D discrete/finite "extra dimensions").  I will introduce this idea and the evidence for it in simple way, and then discuss various outstanding puzzles and future directions.