Abstract: Symmetry is doing something that looks like doing nothing. An antisymmetry operation switches between two different states of a trait, such as two time-states, position-states, charge-states, spin-states, chemical-species etc.

This talk will cover the fundamental concept of antisymmetry, with brief mentions of two well-established antisymmetries, namely spatial inversion in point groups and time reversal. Then it will introduce a new one, namely, distortion reversal. Applications of these antisymmetries will be presented such as crystallography, property tensors, transition state theory, magnetic structures, ferroelectric and multiferroic switching, and classifying physical quantities in arbitrary dimensions. I will end with an intriguing note on new symmetries insights into spacetime crystals.

Bio: Venkatraman Gopalan is a full professor in Materials Science and Engineering at Pennsylvania State University. He received his PhD in Materials Science and Engineering at Cornell University.