Le contenu de cette page n’est pas disponible en français. Veuillez nous en excuser.

Indefinite Causal Structure

Indefinite Causal Structure

 

Vendredi déc 13, 2019
Speaker(s): 

 

Vendredi déc 13, 2019
Speaker(s): 

The approach to quantum theory known as QBism notoriously asserts that the quantum state is not even a partial representation of reality, but instead quantifies an agent's subjective degrees of belief about future experiences. Despite its counter-intuitive premise, QBists argue that this interpretation has the potential to illuminate and demystify certain aspects of quantum theory. In this talk I will discuss how `causality' might be interpreted by a QBist, and whether doing so might help us understand the bizarre hypothetical phenomenon of `indefinite causality'.

Collection/Series: 

 

Jeudi déc 12, 2019
Speaker(s): 

 

Jeudi déc 12, 2019
Speaker(s): 

The possibility of indefinite causal order has garnered considerable interest in recent years, both for its promise as a resource, e.g. for communication, and for its role in exploring the fundamental physical constraints on causal structure. In order to gain a better understanding of the phenomenon, one approach is to design experiments that implement – or at least simulate – scenarios with indefinite causal order. While post-selection is one way to simulate exotic causal structures, this approach may not provide the desired insights.

Collection/Series: 

 

Jeudi déc 12, 2019
Speaker(s): 

 

Jeudi déc 12, 2019
Speaker(s): 

The standard formulation of quantum theory relies on a fixed space-time metric determining the localisation and causal order of events. In general relativity, the metric is influenced by matter, and it is expected to become indefinite when matter behaves quantum mechanically. Here we explore the problem of operationally defining events and their localisation in the presence of gravitating quantum systems. We develop a framework for "time reference frames," in which events are defined in terms of quantum operations with respect to a quantum clock.

Collection/Series: 

 

Jeudi déc 12, 2019
Speaker(s): 

I will discuss various models of how quantum systems might interact with Closed Time-like Curves and some of the curious effects that can arise. I will then use this to motivate a speculative gravitational decoherence model and describe a recent space-based experiment which made the first test of such models.

Collection/Series: 

 

Mercredi déc 11, 2019
Speaker(s): 

Pages