Research

Manuscripts and publications

Do the EPR correlations pose a problem for causal decision theory? A. Koberinski, L. Dunlap, and W. Harper.

Quantum theory as a principle theory: lessons from an information-theoretic reconstruction. M. Müller and A. Koberinski. Forthcoming in Physical perspectives on computation, computational perspectives on physics. arXiv Preprint

Reconciling axiomatic quantum field theory with cutoff-dependent particle physics. Preprint

The Higgs mechanism and superconductivity: A case study of formal analogies. D. Fraser and A. Koberinski. Studies in History and Philosophy of Modern Physics. Preprint/Journal

Schmidt number effects on Rayleigh-Taylor instability in a thin channel. A. Koberinski, A. Baglaenko, and M. Stastna. Physics of Fluids. Journal

 

 

Below is a (non-exhaustive) list of research projects I am currently working on. Anyone interested in the topics or wanting to collaborate can contact me via email (see home page).

Formal and physical analogies between condensed matter physics and quantum field theory


This work is a continuation of the research assistantship I held with Prof. Doreen Fraser, focusing on interpreting the physical content that is preserved in the fruitful exchange of methods and ideas between condensed matter physics (CMP) and quantum field theory (QFT). Some of the techniques that have been exchanged are spontaneous symmetry breaking (SSB) from CMP to QFT, renormalization procedures from QFT to CMP, and the path integral perturbative formalism developed by Feynman from QFT to CMP.

The first project that has arisen from this study is a paper coauthored by myself and Doreen Fraser on the role of SSB in the Higgs mechanism. Originally developed in the BCS model of superconductivity, SSB plays a major role in the SU(2) × U(1) QFT of the electroweak force, and stories are often told as though SSB is a temporal process here, as it is in superconductivity. We argue (in our CSHPS talk and the most recent draft of the paper) that the analogy is purely formal, and thus no interpretive conclusions can be carried over from CMP to QFT.


Theory construction in high energy physics


Much of the current literature in philosophy of QFT focuses more on the logic and coherence of theories as finished products, rather than the process of theory development and the role QFT plays in particle physics more broadly. QFT plays the role of a guiding theoretical framework for the discipline. My work will be in the spirit of much of the work of Harper and Smith on theory construction in the framework of Newtonian gravity. Harper’s work focuses on the process of turning phenomena into evidence for the Newtonian law of gravitation, while Smith’s focus is on the elaboration of a complete model of the solar system within the Newtonian framework. My project will mix these two approaches, since much of the progress of particle physics was a complex combination of the two; the QFT framework was being elaborated, constructed, and questioned even as the phenomena were being used as evidence for it. The rapid experimental progress, and its tight link to theory construction make the details of particle physics a bit messier than the case of Newtonian gravity. In particular, I will focus on the ways in which the phenomena of particle physics are transformed into evidence for dynamical models within QFT, while simultaneously informing and constraining the framework in new ways.

My dissertation will aim to examine the history of two episodes central to the development of the Standard Model of particle physics, in order to elaborate a more nuanced account of theory construction in physics. The rapid developments that led to the establishment of the Standard Model serve as an excellent case study for how theories in physics are in fact developed, and provides normative guidance for future theory construction.

My dissertation will examine case studies from the history of high energy particle physics: the discovery of parity violation and the invention of the renormalization group techniques for understanding scaling behaviour. The papers will share a common structure: each case study will be used to elaborate a more nuanced account of the relationship between theory, models, and experiment. I will then argue that the more nuanced account generalizes, and is descriptive of other productive eras of physics. The third paper will assume the details of the analysis in the previous two papers, and use the newly developed account of theory construction to examine issues of current interest in the foundations of physics. In particular, I will shed light on the role that the framework of QFT plays in the dynamical models of the Standard Model, and use this case of theory construction to speculate on the best methods for theory construction beyond the Standard Model.


Foundational issues in QFT


I am interested in QFTs of all types—both the perturbative approaches used in physics and the axiomatic formulations used to try to clarify the structure of QFTs. Since QFTs are at the heart of the standard model of particle physics, it is of great importance that their content and structure be clarified. QFTs are notoriously confusing, being riddled with seemingly ad hoc regularization procedures in order to generate predictions. In order to move forward to grand unified theories (if possible) or some other standard model successor, it is important to fully understand exactly what it is that QTFs tell us the world is like.

Though this list is preliminary, I aim to explore the following

  • The significance of differences in the path integral and canonical formulations of QFT.
  • How do we understand QFT in its proper context—as a framework in which to make predictions in high energy particle physics?
  • What sorts of things to effective field theories tell us about the world? If the standard model is a collection of low energy EFTs, do we expect the hierarchy to stop? Is there a fundamental highest energy field theory, or do we need to abandon the field theory approach if we aim for a grand unified theory?
  • The best way to understand formal mechanisms and procedures that aren’t straightforwardly temporal: are they processes which hint at dynamical Lagrangian evolution as the energy scale changes, or are they simply formal heuristics that guide physicists to the right equations?
  • How do we reconcile the fundamental dependence on perturbative methods with the manifestly nonperturbative structures (e.g. instantons, low-energy quark phenomena, etc.). Are anomalies really anomalous? Compared to what?
  • Is finite temperature field theory a natural extension of QFT? Or is the structure importantly different?

 

The problems with the cosmological constant problem


The cosmological constant problem is widely viewed as an important barrier and hint to merging quantum field theory and general relativity. It is a barrier insofar as it remains unsolved, and a solution may hint at a fuller theory of quantum gravity. I critically examine the arguments used to pose the cosmological constant problem, and find many of the steps poorly justified. In particular, there is little reason to accept an absolute zero point energy scale in quantum field theory, and standard calculations are badly divergent. It is also unclear exactly how a semiclassical treatment of gravity would include a vacuum energy contribution to the total stress-energy. Large classes of solution strategies are also found to be conceptually wanting. I conclude that one should not accept the cosmological constant problem as standardly stated.

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