Participants can choose to join one of the three groups listed below. No registration is needed.

**Time: **Tuesday – Friday, 14:00 – 15:30.

### Discussion Session on Plenary Talks

Chair: Mario Hubert.

This group is an extended Q&A session on the plenary talks. The aim is to provide an informal environment to discuss in more detail the morning talks and related topics directly with the speakers.

Tuesday | Nick Huggett and Christian Wüthrich | Quantum Gravity |

Wednesday | Michael Esfeld | On the Metaphysics of a Minimalist Ontology |

Thursday | Dirk-André Deckert | The Ontology of QFT |

Friday | Jeffrey Barrett | Probabilities in Pure Wave Mechanics (download paper) |

### Selected Topics of Shape Dynamics

Organizers: Paula Reichert and Antonio Vassallo.

We will start by considering the philosophical motivations behind the general framework of shape dynamics (a theory adopting a Leibnizian/Machian stance with respect to the ontology of space and time). We will then analyze some of the technical details of the framework. We will discuss Newton’s theory of gravity on shape space focusing, in particular, on the role of scale and the notion of time. A uniform measure on shape space (called the entaxy) will allow us to explain the homogeneous initial state of the (Newtonian) universe and the gravitational arrow of time. Moving on to dynamical geometry, we will present the respective shape dynamical description of gravity and its link to general relativistic physics. A special emphasis will be placed on the problem of time in general relativity (and quantum gravity) and its resolution in shape dynamics.

**Recommended readings:**

H. Gomes, T. Koslowski (2013) – « Frequently Asked Questions About Shape Dynamics », *Foundations of Physics* 43(12):1428-1458, arxiv.org/abs/1211.5878v2.

F. Mercati (2014) – « A Shape Dynamics Tutorial », arxiv.org/abs/1409.0105.

J. Barbour (1982) – « Relational Concepts of Space and Time », *The British Journal for the Philosophy of Science* 33(3):251-274.

J. Barbour, T. Koslowski, F. Mercati (2014) – « The Solution to the Problem of Time in Shape Dynamics », *Classical and Quantum Gravity* 31(15):155001, arxiv.org/abs/1302.6264v1.

J. Barbour, T. Koslowski, F. Mercati (2015) – « Entropy and the Typicality of Universes », arxiv.org/abs/1507.06498.

S. Gryb, K. Thébault (2016) – « Time Remains », *The British Journal for the Philosophy of Science* 67(3):663-705, arxiv.org/abs/1408.2691.

### Primitive Ontology of Matter and Laws

Organizers: Matthias Egg, Tiziano Ferrando, and Dustin Lazarovici.

A fundamental physical theory has to make precise statements about what there is in the world and what it does. This sounds trivial but is actually the starting point of many hotly contested debates in contemporary philosophy. The reading group will focus on two of these debates: The notion of primitive ontology and the metaphysics of laws. With respect to the latter, we will discuss two important positions: nomic primitivism, which regards fundamental laws as primitive and part of the fundamental ontology. And Humeanism (respectively the Best System Account) which regards laws as merely descriptive and supervenient on contingent regularities. The rest of the discussion will focus on the notion of Primitive Ontology: whether it has to be fundamental, what are the relations between primitive and derivative, whether one should adopt a pluralist or a monist framework and, more generally, what does “material” mean.

**Readings**

Tim Maudlin, A Modest Proposal Concerning Laws, Counterfactuals and Explanations. In: Tim Maudlin, *The Metaphysics Within Physics*, Oxford University Press (2007).

Barry Loewer, Two accounts of laws and time. *Philosophical Studies* 160 (1):115-137 (2012).

John Bell, The theory of local beables. Reprinted in John S. Bell: *Speakable and Unspeakable in Quantum Mechanics*. Cambridge University Press. Chapter 7. (1987).

Valia Allori, Primitive Ontology and the Structure of Fundamental Physical Theories. In Alyssa Ney & David Z. Albert (eds.), *The Wave Function: Essays in the Metaphysics of Quantum Mechanics*. Oxford University Press (2013).