Life After Retirement: Albert Schwarz

I retired on July 1, 2019 and immediately started a long trip: seven countries in seven months. (I had needed to stay in Davis since 2012.) I visited the Simons Center (Stony Brook, NY), the Institute for Theoretical Physics (Sao Paulo, Brazil), IHES (Bures-sur-Yvette, France), Skolkovo (Moscow, Russia), MPIM (Bonn, Germany), a conference in Luxembourg, Hebrew University (Jerusalem, Israel), Weizmann Institute (Rehovot, Israel), and University of Warwick (UK).

I have finished the work on translating my book, "Mathematical Foundations of Quantum Field Theory" published by World Scientific in 2020. The book was translated by Dmitry Shemetov and I am very grateful for his work. I have added a chapter with new results to this book.

I retired from teaching, not from research. I am working in various directions. I have written a short paper where I have proposed a new geometric approach to quantum theory. The starting point of this approach is a convex cone of states; the standard formulas for probabilities can be derived from the first principles in this approach. Convex cones are closely related to Jordan algebras; I am writing now a longer paper where I am analyzing, in particular, scattering theory in geometric approach and in the approach based on Jordan algebras. The scattering matrix in this situation is a generalization of inclusive scattering matrix, defined in my recent papers. (Inclusive cross-sections can be calculated as linear combinations of matrix elements of inclusive scattering matrix. The conventional scattering matrix cannot be used to consider the scattering of quasiparticles.)

Due to the pandemic, I was forced to reschedule my visits to Germany and France. I am not sure that the new dates in 2021 are realistic, but for now, I can attend seminars and give talks while sitting in my living room. 

Most people want to live long, but they want to remain young. It is very difficult to reconcile these desires. I am trying! Thanking my Facebook friends for congratulations with my 85th birthday, I wrote: "If I could disregard the cataract, knee pain, etc, I would say that I am 85 years young." Since then, I had cataract surgery, and my knee is fine (fingers crossed). I know that the life expectancy tables give me less than 6 years. However, at this moment, I am 86 years young!