•  192
    Quantum Field Theory
    The Stanford Encyclopedia of Philosophy. 2012.
    Quantum Field Theory (QFT) is the mathematical and conceptual framework for contemporary elementary particle physics. In a rather informal sense QFT is the extension of quantum mechanics (QM), dealing with particles, over to fields, i.e. systems with an infinite number of degrees of freedom. (See the entry on quantum mechanics.) In the last few years QFT has become a more widely discussed topic in philosophy of science, with questions ranging from methodology and semantics to ontology. QFT taken…Read more
  •  185
    What Is and Why Do We Need Philosophy of Physics?
    Journal for General Philosophy of Science / Zeitschrift für Allgemeine Wissenschaftstheorie 43 (2): 209-214. 2012.
    Philosophy of physics is a small but thriving research field situated at the intersection between the natural sciences and the humanities. However, what exactly distinguishes philosophy of physics from physics is rarely made explicit in much depth. We provide a detailed analysis in the form of eleven theses, delineating both the nature of the questions asked in philosophy of physics and the methodology with which they are addressed
  •  136
    On the relation between quantum mechanical and neo-mechanistic ontologies and explanatory strategies
    European Journal for Philosophy of Science 4 (3): 337-359. 2014.
    Advocates of the New Mechanicism in philosophy of science argue that scientific explanation often consists in describing mechanisms responsible for natural phenomena. Despite its successes, one might think that this approach does not square with the ontological strictures of quantum mechanics. New Mechanists suppose that mechanisms are composed of objects with definite properties, which are interconnected via local causal interactions. Quantum mechanics calls these suppositions into question. Si…Read more
  •  119
    I argue that algebraic quantum field theory (AQFT) permits an undisturbed view of the right ontology for fundamental physics, whereas standard (or Lagrangian) QFT offers different mutually incompatible ontologies.My claim does not depend on the mathematical inconsistency of standard QFT but on the fact that AQFT has the same concerns as ontology, namely categorical parsimony and a clearly structured hierarchy of entities.
  •  95
    Mechanisms in Dynamically Complex Systems
    In Phyllis McKay Illari Federica Russo (ed.), Causality in the Sciences, Oxford University Press. 2011.
    In recent debates mechanisms are often discussed in the context of ‘complex systems’ which are understood as having a complicated compositional structure. I want to draw the attention to another, radically different kind of complex system, in fact one that many scientists regard as the only genuine kind of complex system. Instead of being compositionally complex these systems rather exhibit highly non-trivial dynamical patterns on the basis of structurally simple arrangements of large numbers of…Read more
  •  91
    Explaining Financial Markets in Terms of Complex Systems
    Philosophy of Science 81 (5): 1117-1130. 2014.
    Large changes of financial market prices without exogenous causes deviate significantly from the Gaussian behavior of random variables. This indicates that financial markets should be treated as complex systems, for which nonlinear interactions of its subunits/agents are crucial. I focus on how the complex systems perspective impacts the notion of explanations in economics. The mechanistic model seems to fit the bill, but problems surface on closer scrutiny. One characteristic of complex systems…Read more
  •  65
    How do microscopic models of financial markets explain?
    Models and Simulations, Proceedings. 2006.
    Financial theory is in trouble. Market crashes and high volatility are only too familiar to everyone, although the standard theories predict that they hardly ever occur. According to the well-known and (partly due to its simplicity) still widely used random-walk model, the probabilities for price changes of, say, stocks should result in a Gaussian distribution. However, experience tells us that large changes occur far more often than ‘allowed’ by a Gaussian distribution. New models are needed wh…Read more
  •  51
    Philosophy of Quantum Physics (edited book)
    with Cord Friebe, Holger Lyre, Paul M. Näger, Oliver Passon, and Manfred Stöckler
    Springer International. 2018.
    This book provides a thorough and up-to-date introduction to the philosophy of quantum physics. Although quantum theory is renowned for its spectacular empirical successes, controversial discussion about how it should be understood continue to rage today. In this volume, the authors provide an overview of its numerous philosophical challenges: Do quantum objects violate the principle of causality? Are particles of the same type indistinguishable and therefore not individual entities? Do quantum …Read more
  •  49
    Dieses Buch liefert dem Leser eine aktuelle und fundierte Einführung in die Philosophie der Quantenphysik. Obwohl sich die Quantentheorie durch spektakuläre empirische Erfolge auszeichnet, wird bis heute kontrovers diskutiert, wie sie zu verstehen ist. In diesem Werk geben die Autoren einen Überblick über die zahlreichen philosophischen Herausforderungen: Verletzen Quantenobjekte das Prinzip der Kausalität? Sind gleichartige Teilchen ununterscheidbar und daher keine Individuen? Behalten Quanteno…Read more
  •  47
    On the Exploratory Function of Agent-Based Modeling
    Perspectives on Science 29 (4): 510-536. 2021.
    Agent-based models derive the behavior of artificial socio-economic entities computationally from the actions of a large number of agents. One objection is that highly idealized ABMs fail to represent the real world in any reasonable sense. Another objection is that they at best show how observed patterns may have come about, because simulations are easy to produce and there is no evidence that this is really what happens. Moreover, different models may well yield the same result. I will rebut t…Read more
  •  29
    GAP.7: Reflections and Projections: Challenges to Philosophy
    with P. Näger and W. Stelzner
    Journal for General Philosophy of Science / Zeitschrift für Allgemeine Wissenschaftstheorie 42 (1): 177-183. 2011.
  •  23
    Unbestimmt und relativ?: Das Weltbild der modernen Physik (edited book)
    with Helmut Fink
    Springer Berlin Heidelberg. 2023.
    Quantentheorie und Relativitätstheorie haben das Weltbild der Physik revolutioniert. Beide Theorien gelten jedoch als unanschaulich und schwer verständlich. Dieses Sachbuch schafft neue Zugänge und lädt zum Mitdenken ein. Renommierte Experten aus Physik und Philosophie erläutern Grundbegriffe, Erkenntnisfortschritte und Deutungsfragen zu Raum, Zeit und Materie. Dabei kommen typische Themen aus der Philosophie der Physik zur Sprache, wie etwa die Interpretationsdebatte der Quantentheorie oder Mod…Read more
  •  18
    Chronologie und Ausblick
    In Cord Friebe, Meinard Kuhlmann, Holger Lyre, Paul M. Näger, Oliver Passon & Manfred Stöckler (eds.), Philosophie der Quantenphysik: Zentrale Begriffe, Probleme, Positionen, Springer Berlin Heidelberg. pp. 277-290. 2018.
    Die folgende Chronologie legt den Fokus auf die Grundlagen und Deutungen der Quantenphysik, sie ist keine Geschichte der Quantenphysik im Ganzen, insbesondere finden die speziellen Entwicklungen der Quantenfeldtheorie und der sich daraus entwickelnden Teilchenphysik keine Berücksichtigung.
  •  18
    Ontological Aspects of Quantum Field Theory (edited book)
    World Scientific. 2002.
    Quantum field theory provides the framework for many fundamental theories in modern physics, and over the last few years there has been growing interest in its historical and philosophical foundations. This anthology on the foundations of QFT brings together 15 essays by well-known researchers in physics, the philosophy of physics, and analytic philosophy.Many of these essays were first presented as papers at the conference?Ontological Aspects of Quantum Field Theory?, held at the Zentrum fr in…Read more
  •  13
    Quantenfeldtheorie
    with Manfred Stöckler
    In Cord Friebe, Meinard Kuhlmann, Holger Lyre, Paul M. Näger, Oliver Passon & Manfred Stöckler (eds.), Philosophie der Quantenphysik: Zentrale Begriffe, Probleme, Positionen, Springer Berlin Heidelberg. pp. 231-275. 2018.
    Viele ihrer philosophischen Probleme teilt die Quantenfeldtheorie mit der Quantenmechanik. Dazu gehören der Messprozess und die damit zusammenhängenden Interpretationsprobleme, zu denen die QFT kaum etwas Neues beiträgt. Auch die Frage, wie die Objekte, die die Theorie beschreibt, in den Raum eingebettet sind, wird schon in der Quantenmechanik diskutiert. Die neuen mathematischen Strukturen der QFT lassen allerdings auch neue Antworten erwarten, so dass die raumzeitliche Interpretation der Theor…Read more
  •  7
    Das sogenannte „Messproblem“ ist das zentrale Problem der Quantenmechanik, dessen Lösung das Potenzial hat, unsere Sicht der physischen Welt fundamental zu verändern. Das Problem besteht darin, dass die Quantenmechanik (QM) nicht zu dem passen will, was wir tatsächlich beobachten. Nach einer qualitativen und einer formalen Darstellung des Messproblems der QM werden in diesem Beitrag die Ansätze von Ghirardi, Rimini und Weber (GRW), von de Broglie und Bohm (dBB) sowie von Everett (Vielweltendeutu…Read more
  •  1
    Two comments on the vacuum in algebraic quantum field theory
    with Holger Lyre and Andrew Wayne
    In Meinard Kuhlmann, Holger Lyre & Andrew Wayne (eds.), Ontological Aspects of Quantum Field Theory, World Scientific. 2002.
  • L'ontologia Della Sostanza È Una Descrizione Adeguata Della Natura?
    Nuova Civiltà Delle Macchine 24 (1): 66-78. 2006.
  • Philosophie der Quantenphysik
    with Cord Friebe, Holger Lyre, Paul Näger, Oliver Passon, and Manfred Stöckler
    Springer Spektrum. 2015.
    Dieses Buch liefert dem Leser eine aktuelle und fundierte Einführung in die Philosophie der Quantenphysik. Obwohl sich die Quantentheorie durch spektakuläre empirische Erfolge auszeichnet, wird bis heute kontrovers diskutiert, wie sie zu verstehen ist. In diesem Werk geben die Autoren einen Überblick über die zahlreichen philosophischen Herausforderungen: Verletzen Quantenobjekte das Prinzip der Kausalität? Sind gleichartige Teilchen ununterscheidbar und daher keine Individuen? Behalten Quanteno…Read more