Quantum Field Theory Workshop Abstracts
Friday - Saturday, 14-15 October 2011
Center for Philosophy of Science
817 Cathedral of Learning
University of Pittsburgh
Pittsburgh, PA USA
**Anthony Duncan**, Department of Physics and Astronomy,
University of Pittsburgh
*Theories within Theories: The Scale Dependence of Lagrangian Field Theories*
Abstract: Relativistic quantum field theory has evolved pursuant to the requirements of a number of mathematical idealizations incorporating our intuitions concerning
the behavior of physical systems both in the large (e.g. the factorization, or
cluster decomposition properties of amplitudes for far separated processes) and
in the small (primarily, the assumption of strict microcausality at arbitrarily
small distance scales). While the assumptions of the former category are on
very solid footing (indeed, can be considered almost as prerequisites for the
success of the experimental enterprise), the specification of quantum field
theories at arbitrarily small scales as Poincare invariant theories with an exact
local structure turns out to be problematic from both a physical and mathematical
standpoint. Fortunately, within the framework of Lagrangian field theory, the
methods of effective field theory and Wilsonian renormalization lead to a deeper
understanding of the sensitivity of observable long-distance physics to unknown
dynamical substructures at very small scales. In particular, the prevalence of
perturbatively renormalizable theories in the description of elementary particle
physics emerges naturally once one adopts the framework of effective Lagrangian
theories.
**Doreen Fraser**, Department of Philosophy,
University of Waterloo
*A Philosopher Defends AQFT*
Abstract: In this talk I will defend the position that the interpretation and foundational analysis of QFT should be based on AQFT rather than LQFT. I will begin by using a result from the history of the AQFT program (Haag’s theorem) to illustrate and motivate the position. After giving a brief overview of what I take to be the most compelling arguments in favour of the position, I will devote most of my time to addressing objections. To date, no rigorous models have been constructed for any realistic interacting systems. This raises two sorts of worries: (1) How do we know that the proposed sets of axioms are correct? (2) By attending to AQFT rather than LQFT, are philosophers overlooking important discoveries about the properties of particular interactions that have been made in LQFT over the past few decades? In response to the second question, I will argue that the achievements of the LQFT program should be regarded as contributing to the articulation of the the empirical content of QFT, but not to illuminating the theoretical content of the theory.
**Stephen Summers**, Department of Mathematics,
University of Florida
*Why Algebraic Quantum Field Theory?*
Abstract: will indicate why those dissatisfied with a largely
instrumentalist view of quantum field theory should also be interested
in AQFT. In the process, I will rebut false claims about AQFT made
in the philosophy of physics literature.
**David Wallace**, Balliol College,
Oxford University
*Taking Particle Physics Seriously: A Critique of the Algebraic Approach to Quantum Field Theory*
Abstract: I argue against the currently prevalent view that algebraic quantum field theory (AQFT) is the correct framework for philosophy of quantum field theory and that “conventional” quantum field theory (CQFT), of the sort used in mainstream particle physics, is not suitable for foundational study. In doing so, I defend that position that AQFT and CQFT should be understood as rival programs to resolve the mathematical and physical pathologies of renormalization theory, and that CQFT has succeeded in this task and AQFT has failed. I also defend CQFT from recent criticisms made by Doreen Fraser. |