Episodes
Tim A. Koslowski (New Brunswick) gives a talk at the Mini-Workshop on the Foundations of Shape Dynamics (23 June, 2014) titled "Shape Dynamics". Abstract: Based on the introduction to shape dynamics by Sean Gryb, I will discuss the question: "Given that gravity (from the perspective of shape dynamics) is fundamentally the evolution of spatial conformal geometry and not spacetime: How is the arrow of time generated? How is the illusion of a spacetime generated? What are the limitations of the...
Published 04/18/19
Published 04/18/19
Detlef Dürr (LMU) gives a talk at the MCMP Colloquium (23 January, 2013) titled "Bohmian Mechanics, speakable quantum physics". Abstract: I introduce Bohmian Mechanics, which is a theory of particles in motion. The law of motion is not classical, i.e. the particles do not move on Newtonian trajectories. As this is often not appreciated I shall discuss some features which will help to sharpen one's intuition about this theory of nature.
Published 04/18/19
Karim Thébault (MCMP/LMU) gives a talk at the MCMP Colloquium (9 January, 2013) titled "Quantisation as a guide to ontic structure". Abstract: The ontic structural realist stance is motivated by a desire to do philosophical justice to the success of science, whilst withstanding the metaphysical undermining generated by the various species of ontological underdetermination. We are, however, as yet in want of general principles to provide a scaffold for the explicit construction of...
Published 04/18/19
Igor Khavkine (Utrecht) gives a talk at the MCMP workshop "Quantum Gravity in Perspective" (31 May-1 June, 2013) titled "Gravity. An exercise in quantization". Abstract: The quantization of General Relativity (GR) is an old and chellenging prob- lem that is in many ways still awaiting a satisfactory solution. GR is a partic- ularly complicated field theory in several respects: non-linearity, gauge invari- ance, dynamibal causal structure, renormalization, singularities, infared effects....
Published 04/18/19
Thomas Pashby (Pittsburgh) gives a talk at the MCMP Colloquium (28 May, 2014) titled "Against Dogma: Locality, Conditionalisation, and Collapse in Relativistic Quantum Mechanics". Abstract: I argue here against the widespread view (due to David Malament) that the non-commutativity of non-instantaneous localisation projections implies the existence of act-outcome correlations in relativistic QM. There are two facets to my argument: first, I claim that the interpretation of collapse as a...
Published 04/18/19
Sean Gryb (Nijmegen) gives a talk at the Mini-Workshop on the Foundations of Shape Dynamics (23 June, 2014) titled "An Introduction to Shape Dynamics: a New Perspective on Quantum Gravity". Abstract: Shape Dynamics is a theory of gravity where the fundamental ontology is that of evolving conformally invariant spatial geometry. This implements a notion of local spatial scale invariance such that what is seen to be physically meaningful is the information about the local "shapes" (as opposed to...
Published 04/18/19
Andreas Barrels (Bonn) gives a talk at the MCMP Colloquium (7 May, 2014) titled "How to Bite the Bullet of Quidditism - Why a Standard Argument against Categoricalism in Physics Fails". Abstract: Categoricalism is the statement that fundamental properties of physics are categorical, i.e., they have their dispositional characters not with metaphysical necessity. According to Black (2000), Bird (2005, 2007), and Esfeld (2009), categoricalism entails quidditism, the possible existence of...
Published 04/18/19
Irvine-Munich Workshop on the Foundations of Classical and Quantum Field Theories, Michael Stöltzner (South Carolina) gives a talk at the Irvine-Munich Workshop on the Foundations of Classical and Quantum Field Theories (14 December, 2014) titled "Best Possible Worlds and Random Walks: The Principle of Least Action as a Thought Experiment". Abstract: Over the centuries, no other principle of classical physics has to a larger extent nourished exalted hopes of a universal theory, has constantly...
Published 04/11/18
Michael Stöltzner (South Carolina) gives a talk at the Irvine-Munich Workshop on the Foundations of Classical and Quantum Field Theories (14 December, 2014) titled "Best Possible Worlds and Random Walks: The Principle of Least Action as a Thought Experiment". Abstract: Over the centuries, no other principle of classical physics has to a larger extent nourished exalted hopes of a universal theory, has constantly been plagued by mathematical counterexamples, and has ignited metaphysical...
Published 04/11/18
Workshop on the Problem of Time in Perspective, Carlo Rovelli (Aix-Marseille) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Physics without Fundamental Time". Abstract: Rivers of ink have flown on the basic conceptual structure of quantum gravity -a theory where we expect the notions of classical spacetime, particles, fields, energy and momentum to require substantial revision-. I discuss a specific solution to these questions and apply concretely...
Published 07/10/15
Carlo Rovelli (Aix-Marseille) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Physics without Fundamental Time". Abstract: Rivers of ink have flown on the basic conceptual structure of quantum gravity -a theory where we expect the notions of classical spacetime, particles, fields, energy and momentum to require substantial revision-. I discuss a specific solution to these questions and apply concretely it to a physical calculation, the tunneling...
Published 07/10/15
Workshop on the Problem of Time in Perspective, Donald Salisbury (Austin) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "The Intrinsic Hamilton-Jacobi Dynamics of General Relativity and its Implications for the Semi-Classical Emergence of Time". Abstract: The quantization of the general theory of relativity is notoriously difficult, in particular on account of the underlying general covariance and the consequent appearance of constraints in the...
Published 07/09/15
Donald Salisbury (Austin) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "The Intrinsic Hamilton-Jacobi Dynamics of General Relativity and its Implications for the Semi-Classical Emergence of Time". Abstract: The quantization of the general theory of relativity is notoriously difficult, in particular on account of the underlying general covariance and the consequent appearance of constraints in the classical Hamiltonian theory. The notion of time in...
Published 07/09/15
Workshop on the Problem of Time in Perspective, Francesca Vidotto (Radboud) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Discrete Time in Quantum Gravity". Abstract: We study the quantization of geometry in the presence of a cosmological constant, using a discretiza- tion with constant-curvature simplices. Phase space turns out to be compact and the Hilbert space finite dimensional for each link. Not only the intrinsic, but also the extrinsic...
Published 07/09/15
Francesca Vidotto (Radboud) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Discrete Time in Quantum Gravity". Abstract: We study the quantization of geometry in the presence of a cosmological constant, using a discretiza- tion with constant-curvature simplices. Phase space turns out to be compact and the Hilbert space finite dimensional for each link. Not only the intrinsic, but also the extrinsic geometry turns out to be discrete, pointing to...
Published 07/09/15
Workshop on the Problem of Time in Perspective, Henrique Gomes (Perimeter Institute) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Timeless Quantum Mechanics in Configuration Space: an Outsider View". Abstract: In this talk, I will explore a timeless interpretation of quantum mechanics of closed systems, solely in terms of path integrals in non-relativistic timeless configuration space. What prompts a fresh look at the foundational problems in...
Published 07/09/15
Henrique Gomes (Perimeter Institute) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Timeless Quantum Mechanics in Configuration Space: an Outsider View". Abstract: In this talk, I will explore a timeless interpretation of quantum mechanics of closed systems, solely in terms of path integrals in non-relativistic timeless configuration space. What prompts a fresh look at the foundational problems in this context, is the advent of multiple...
Published 07/09/15
Workshop on the Problem of Time in Perspective, Sean Gryb (Radboud) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "In Favour of a Schrödinger Evolution of the Universe". Abstract: In the canonical formulation of reparametrization invariant systems, time evolution on phase space is generated by a fully constrained Hamiltonian. On the orthodoxy view, the quantum formalism for such systems is constructed through Dirac quantization, which leads to a...
Published 07/09/15
Sean Gryb (Radboud) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "In Favour of a Schrödinger Evolution of the Universe". Abstract: In the canonical formulation of reparametrization invariant systems, time evolution on phase space is generated by a fully constrained Hamiltonian. On the orthodoxy view, the quantum formalism for such systems is constructed through Dirac quantization, which leads to a real, time-independent constraint on the quantum...
Published 07/09/15
Workshop on the Problem of Time in Perspective, Bianca Dittrich (Perimeter Institute) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "The Consistent Boundary Formulation". Abstract: I will introduce the consistent boundary formulation which allows to express renormalization flow in a background independent context. I will discuss consequences of this formulation for the Hamiltonian framework and explore in which sense Hamiltonian constraints do...
Published 07/09/15
Bianca Dittrich (Perimeter Institute) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "The Consistent Boundary Formulation". Abstract: I will introduce the consistent boundary formulation which allows to express renormalization flow in a background independent context. I will discuss consequences of this formulation for the Hamiltonian framework and explore in which sense Hamiltonian constraints do actually exists in this context and how this...
Published 07/09/15
Workshop on the Problem of Time in Perspective, Philipp Hoehn (Perimeter Institute) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Constraints, Dirac Observables and Chaos". Abstract: I will discuss fundamental challenges to the standard relational paradigm arising from chaotic dynamics.
Published 07/09/15
Philipp Hoehn (Perimeter Institute) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Constraints, Dirac Observables and Chaos". Abstract: I will discuss fundamental challenges to the standard relational paradigm arising from chaotic dynamics.
Published 07/09/15
Workshop on the Problem of Time in Perspective, J. Brian Pitts (Cambridge) gives a talk at the Workshop on the Problem of Time in Perspective (3-4 July, 2015) titled "Changing Observables in Canonical General Relativity from Hamiltonian-Lagrangian Equivalence". Abstract: Is change missing in classical canonical General Relativity? If one insists on Hamiltonian-Lagrangian equivalence, then there is Hamiltonian change just when there is no time-like Killing vector field. Change has seemed...
Published 07/09/15