The Robert Resnick Lecture Series

The nature of the dark matter in the Universe is among the longest and most important outstanding problems in all of modern physics. The ordinary atoms that make up the known universe, from our bodies and the air we breathe to the planets and stars, constitute only 5% of all matter and energy in the cosmos. The remaining 95% is made up of a recipe of 25% dark matter and 70% dark energy, both nonluminous components whose nature remains a mystery.  I’ll begin by discussing the evidence that dark matter is the bulk of the mass in the Universe, and then turn to the hunt to understand its nature.  Leading candidates are fundamental particles including Weakly Interacting Massive Particles (WIMPs), axions, sterile neutrinos, light dark matter, as well as primordial black holes.  I will discuss multiple experimental searches:  at CERN in Geneva; in underground laboratories; with space telescopes; with gravitational wave detectors; and even with DNA.  I’ll tell you about our novel idea of Dark Stars, early stars made primarily of hydrogen but powered by dark matter heating, and the possibility that the James Webb Space Telescope has already discovered them.  At the end of the talk, I'll turn to dark energy and its effect on the future of the Universe.

This talk reviews some of the applications of topology and topological defects in phase transitions in two-dimensional systems for which Kosterlitz and Thouless split half the 2016 Physics Nobel Prize. The theoretical predictions and experimental verification in two dimensional superfluids, superconductors and crystals will be reviewed because they provide very convincing quantitative agreement with topological defect theories.

Thermoelectrics are semiconductor materials that are used to convert heat flow to electricity, or to convert electricity to heat flow. They are the basis of solid state refrigeration, and solid state power generation. It has become a large technical industry with many new products and applications. In this lecture, I review the science of thermoelectric, and give examples of thermoelectric materials and thermoelectric-based products. I also discuss the nature of the Seebeck coefficient in a typical semiconductor such as silicon.