Overview

Prof. Piljin Yi works on string theories, field theories, and gravity. He is widely recognized for an existence proof of D0-brane bound states via an index computation, which remains arguably the most direct evidence for the hypothetical M-theory, believed to encompass all known superstring theories as conjectured by E. Witten. He has recently returned to an in-depth investigation of index theorems in physics context, refining this D0-brane study and producing a sweeping generalization of the celebrated Atiyah-Singer theorem to the gauged systems. He is also an expert on supersymmetric solitons, and authored a series of landmark papers. Emergence of closed strings as coherent objects in unstable open string theories is another of his important legacy, with potential applications to stringy cosmology and, more importantly, with far-reaching implications for the elusive string field theory. A holographic study of nucleons, an unusual excursion, with some impact, to real world physics has been presented in plenary sessions of influential nuclear physics meetings. He has been invited for plenary talks at the prestigious Strings Conferences in 2003 and in 2013, respectively, and currently serves in the International Advisory Committee thereof.