Gordon Ritter

Learn More
The multistage model, introduced by Armitage and Doll, was very successful at describing many features of cancer development. Doll and Peto noted a significant departure below the prediction of the model and suggested that this could be due to undercounting of cases at older ages, or to the 'biology of extreme old age.' Moolgavkar pointed out that it could(More)
We study space-time symmetries in scalar quantum field theory on an arbitrary static space-time. We first consider Euclidean quantum field theory, and show that the isometry group is generated by one-parameter subgroups which have either self-adjoint or unitary quantizations. We then show that the self-adjoint semigroups thus constructed can be analytically(More)
Let G be a Kac-Moody group over a finite field corresponding to a generalized Cartan matrix A, as constructed by Tits. It is known that G admits the structure of a BN-pair, and acts on its corresponding building. We study the complete Kac-Moody group G which is defined to be the closure of G in the automorphism group of its building. Our main goal is to(More)
We give a mathematical construction of Euclidean quantum field theory on certain curved backgrounds. We focus on generalizing Oster-walder Schrader quantization, as these methods have proved useful to establish estimates for interacting fields on flat space-times. In this picture, a static Killing vector generates translations in Euclidean time, and(More)
We prove the most general reflection positivity results for both scalar fields and Dirac fields on a Riemannian manifold, and comment on applications to quantum field theory. As another application, we prove the inequality C D ≤ C N between Dirichlet and Neumann covariance operators on a manifold with a reflection.
  • 1