Stephen J. Summers

Learn More
A condition of geometric modular action is proposed as a selection principle for physically interesting states on general space-times. This condition is naturally associated with transformation groups of partially ordered sets and provides these groups with projective representations. Under suitable additional conditions, these groups induce groups of point(More)
Recently, Grosse and Lechner introduced a novel deformation procedure for non–interacting quantum field theories, giving rise to interesting examples of wedge–localized quantum fields with a non–trivial scattering matrix. In the present article we outline an extension of this procedure to the general framework of quantum field theory by introducing the(More)
Employing the algebraic framework of local quantum physics,vacuum states in Minkowski space are distinguished by a property of geometric modular action. This property allows one to construct from any locally generated net of observables and corresponding state a continuous unitary representation of the proper Poincaré group which acts covariantly on the net(More)
The mathematics of classical probability theory was subsumed into classical measure theory by Kolmogorov in 1933. Quantum theory as nonclassical probability theory was incorporated into the beginnings of noncommutative measure theory by von Neumann in the early thirties, as well. To precisely this end, von Neumann initiated the study of what are now called(More)
A novel method of transplanting algebras of observables from de Sitter space to a large class of Robertson–Walker space–times is exhibited. It allows one to establish the existence of an abundance of local nets on these spaces which comply with a recently proposed condition of geometric modular action. The corresponding modular symmetry groups appearing in(More)
If a state is passive for uniformly accelerated observers in n-dimensional (n ≥ 2) anti–de Sitter space–time (i.e. cannot be used by them to operate a perpetuum mobile), they will (a) register a universal value of the Unruh temperature, (b) discover a PCT symmetry, and (c) find that observables in complementary wedge–shaped regions necessarily commute with(More)
If {A(V)} is a net of local von Neumann algebras satisfying standard axioms of algebraic relativistic quantum field theory and V1 and V2 are spacelike separated spacetime regions, then the system (A(V1),A(V2), f) is said to satisfy the Weak Reichenbach’s Common Cause Principle iff for every pair of projections A ¥ A(V1), B ¥A(V2) correlated in the normal(More)
To evaluate the benefit of an antimicrobial prophylaxis protocol using rectal swab cultures in patients undergoing transrectal ultrasound (TRUS)-guided prostate biopsy in our Veterans Affairs population. Between June 1, 2013, and June 1, 2014, we implemented an antimicrobial prophylaxis protocol using rectal swab cultures on selective media containing(More)