MG14 - Talk detail |
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Participant |
Morsella, Gerardo | |||||||
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Institution |
Università Tor Vergata - via della Ricerca Scientifica 1 - Roma - RM - Italy | |||||||
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Session |
QF1 |
Accepted |
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Time |
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Talk |
Oral abstract |
Title |
Spherically Symmetric Quantum Spacetime and the Horizon Problem | |||||
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Abstract |
The analysis of the limitations to spacetime localization of events dictated by the concurrence of general relativity and quantum mechanics, performed by Doplicher-Fredenhagen-Roberts in a flat background, are extended to spherically symmetric spacetimes. The results support the heuristic expectation that in a curved background the effective Planck length depends on the underlying geometry. This also leads to a natural ansatz for the expectation value, in a thermal state, of the energy-momentum tensor of a free scalar field propagating on the corresponding curved Quantum Spacetime. When such a field is coupled semi-classically to the metric, the resulting cosmological evolution is free from the horizon problem. (Based on joint work with Sergio Doplicher and Nicola Pinamonti.) |
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Pdf file |
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Session |
QF3 |
Accepted |
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Order |
Time |
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Talk |
Oral abstract |
Title |
A Quantum Distance between von Neumann Algebras and Applications to Quantum Field Theory | |||||
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Abstract |
I will present a notion of distance between von Neumann algebras endowed with suitable Lipschitz (semi-)norms, i.e., norms inducing the sigma-weak topology on bounded subsets. This can be seen as a dual version of the distance between C*-algebras introduced by M. Rieffel as a quantum analogue of the Gromov-Hausdorff distance between metric spaces. As an example, I will discuss the convergence of the local von Neumann algebras of the free scalar quantum field of mass m, as m tends to 0. |
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Pdf file |
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