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

Quantum Foundations

This series consists of talks in the area of Foundations of Quantum Theory. Seminar and group meetings will alternate.

Seminar Series Events/Videos

Currently there are no upcoming talks in this series.

Statistical Prediction of the Outcome of a Noncooperative Game

Jeudi nov 13, 2008
Speaker(s):

Many statistics problems involve predicting the joint strategy that will be chosen by the players in a noncooperative game. Conventional game theory predicts that the joint strategy will satisfy an equilibrium concept\'\'. The relative probabilities of the joint strategies satisfying the equilibrium concept are not given, and all joint strategies that do not satisfy it are given probability zero. As an alternative, I view the prediction problem as one of statistical inference, where the data\'\' includes the details of the noncooperative game.

Collection/Series:
Scientific Areas:

Physical Limits of Inference

Mardi nov 11, 2008
Speaker(s):

I show that physical devices that perform observation, prediction, or recollection share an underlying mathematical structure. I call devices with that structure inference devices\'\'. I present a set of existence and impossibility results concerning inference devices. These results hold independent of the precise physical laws governing our universe. In a limited sense, the impossibility results establish that Laplace was wrong to claim that even in a classical, non-chaotic universe the future can be unerringly predicted, given sufficient knowledge of the present.

Collection/Series:
Scientific Areas:

From Information Geometry to Quantum Theory

Mardi nov 04, 2008
Speaker(s):

The unparalleled empirical success of quantum theory strongly suggests that it accurately captures fundamental aspects of the workings of the physical world. The clear articulation of these aspects is of inestimable value --- not only for the deeper understanding of quantum theory in itself, but for its further development, particularly for the development of a theory of quantum gravity.

Collection/Series:
Scientific Areas:

The Open Universe: Toward a Post-Reductionist Science

Mardi oct 28, 2008
Speaker(s):

TBA

Collection/Series:
Scientific Areas:

Hawking Boxes and Invariant Sets - A New Look at the Foundations of Quantum Theory and the Associated Role of Gravity

Mardi oct 21, 2008
Speaker(s):

We start by studying the non-computational geometry of fractionally-dimensioned measure-zero dynamically-invariant subsets of phase space, associated with certain deterministic nonlinear dissipative dynamical systems. Then, by studying the asymptotic states of the Hawking Box, the existence of such invariant subsets is conjectured for gravitationally-bound systems. The argument hinges around the phase-space properties of black holes. Like Penrose, it is assumed that phase-space volumes shrink when the contents of the Hawking Box contain black holes.

Collection/Series:
Scientific Areas:

Dirac\'s penumbra: constraints and gauge transformations in reparametrization invariant theories

Mardi oct 07, 2008
Speaker(s):

A simple theorem of Dirac identifies primary first-class constraints as generators of transformations, \'that do not affect the physical state\'. This result has profound implications for the definition of physical states and observables in the quantization of constrained systems, and leads to one aspect of the infamous \'problem of time\' in quantum gravity. As I will discuss, a close look at the theorem reveals that it depends crucially on the assumption of an absolute time.

Collection/Series:
Scientific Areas:

Wiggling Hilbert Space

Mardi sep 23, 2008
Speaker(s):

After using the complex Hilbert space formalism for quantum theory for so long, it is very easy to begin to take for granted features like projection operators and the projection postulate, the algebra of observables, symmetric transition probabilities, linear evolution, etc.... Over the past 50 years there have been many attempts to gain a better understanding of this formalism by reconstructing it from different kinds of (sometimes) physically motivated assumptions.

Collection/Series:
Scientific Areas:

Entanglement and nonlocality in microscopic - macroscopic systems

Mardi aoû 26, 2008

Theoretical and experimental results on the Quantum Injected Optical Parametric Amplification (QI-OPA) of optical qubits in the high gain regime (g > 6) are reported. The entanglement of the related Schroedinger Cat-State (SCS) is demonstrated as well as the establishment of Phase-Covariant quantum cloning for a Macrostate consisting of about 106 particles. In addition, the violation of the CHSH inequality is has been realized experimentally.

Collection/Series:
Scientific Areas:

Local quantum physics versus (relativistic) quantum mechanics: thermal- versus information theoretic- entanglement and the origin of the area law for \"localization entropy\".

Mardi aoû 19, 2008
Speaker(s):

The fundamentally different localization concepts of QT, i.e. the
Born-(Newton-Wigner) localization of (relativistic) QM as compared with the causal localization (modular localization) of QFT, lead to significant differences in the nature of local observables and affiliated states.

Collection/Series:
Scientific Areas:

The intersection of general relativity and quantum mechanics

Mardi aoû 12, 2008
Speaker(s):

Domains were introduced in computer science in the late 1960\'s by Dana Scott to provide a semantics for the lambda calculus (the lambda calculus is the basic prototype for a functional programming language i.e. ML). The study of domains with measurements was initiated in the speaker\'s thesis: a domain provides a qualitative view of information expressed in part by an \'information order\' and a measurement on a domain expresses a quantitative view of information with respect to the underlying qualitative aspect.

Collection/Series:
Scientific Areas:

Speaker: